burgess and d g jones (eds ) spectrophotometry

oo Vll PREFACE The first joint meeting of the UV Spectrometry Group of the UK (UVSG) and the Council for Optical Radiation Measurements of the USA (CORM) was held in Oxford in the summer of 1986 The papers from that conference, the 1st Oxford Conference, were published by Elsevier in 1987 as Volume of the Analytical Spectroscopy Library At that time, both groups felt the need to provide the forum for an interdisciplinary conference on spectrophotometry reviving a tradition from the 1960s and 1970s The purpose was to allow the exchange of information and ideas between the diverse disciplines & groups involved in spectrophotometry; optical physics, analytical chemistry, electronic engineering, the life sciences, national laboratories, manufacturers, academia, industry etc The first conference proceedings provided a watershed whereby the knowledge on standards and standardisation gained over the previous 30 years or so was revised and reviewed A major part of the conference was given to papers from the major national standardising laboratories, NPL of the UK, NBS (now NIST) of the USA, NRC of Canada and PTB of Germany These contributions together with those from industry and academia helped to crystallise our thinking about accuracy and precision of measurements of transmittance, reflectance, luminescence, colour and others In April 1992, the UVSG suggested to the CORM board of directors that the time was right for the 2nd Oxford Conference and that it be held in the USA Much had changed in the intervening years and it was agreed that that it was appropriate to give compliance issues a more prominent role as well as luminescence and the near infra red In addition the scope of the conference was broadened to include applied papers and to provide more time for discussion The conference took place on the delightful campus of Franklin Pierce College set in a lovely part of the New Hampshire countryside near the town of Rindge The atmosphere was relaxed and informal with opportunity for discussions between lecture and poster paper sessions We were well supported by the instrument manufacturers who provided an excellent exhibition Special thanks are due to Varian Associates and Perkin Elmer for sponsoring 'pub nights' during the conference and to Labsphere for sponsoring a relaxing cruise on Lake Sunapee The quality of the presentations was again excellent and 29 of them appear here in written form The balance of the conference has shifted from the 1986 mix towards more applications but once again the National Laboratories have provided an excellent update on the state of the art in many areas The first proceedings were produced from author provided camera ready copy to get as rapid a publication as possible One disadvantage of this approach was the visual diversity of the contributions which perhaps detracted from the overall technical excellence of the book viii As PC based word processing software has improved, we decided to a t t e m p t a house style for authors and produce all the camera ready copy using Microsoft's Word for Windows 6.0a and a Hewlett Packard Laserjet Plus printer Contributors submitted their manuscripts on 3.5" disks in a plethora of formats which were a challenge to say the least!! Line drawings were scanned using a Hewlett Packard Scanjet IIcx and imbedded, usually, as TIF files The use of such techniques with the wide range of submitted hard copy images and electronic images proved to be the most difficult problem of all The editorial process was facilitated by file transfer using CompuServe Email between B a r n a r d Castle and Orlando File compression using PKZIP utilities kept costs to a minimum We hope that a degree of uniformity has been achieved without stifling individual preferences and that the end result is more aesthetically pleasing t h a n before The Email link was vital in terms of time As transfer time was approximately hour, this was much faster than courier (3 days) or airmail (9 days) and rendered the editors' lives bearable if not entirely stress free Our t h a n k s are due also to our indexer, Paul Nash, for his efforts which we feel have greatly enhanced the usefulness of the book No preface is complete without the very necessary task of thanking those people without whom the conference would never have happened In the USA, Art Springsteen of Labsphere was a major factor in our success and the local organisation by conference co-ordinator Kathy Springsteen was par excellence A special mention of Anne Springsteen, Art and Kathy's daughter, for her untiring efforts especially in safely bringing back all those delegates who climbed Mount Monadnock Val Schedin and her team at Franklin Pierce College provided good food and comfortable accommodation In the UK, the local organising committee of Mary Barnard, Wendy Matthews and George Freeman worked on the scientific programme and gave valuable advice gleaned from the first conference Finally our t h a n k s are due to Phil Wychorski, President of CORM, and Mary Barnard, C h a i r m a n of the UVSG, for their support and enthusiasm Thanks are due also to the Association of British Spectroscopist's Trust for financial support for one of us (CB) Even now as we complete these proceedings for the press, our thoughts have turned to the next conference This will, hopefully, be in June of 1998 which coincides with the 50th Anniversary of the founding of the UVSG We hope t h a t m a n y of our colleagues will be there to celebrate it with us Chris Burgess Dianna Jones J a n u a r y 1995 Spectrophotometry, Luminescence and Coulour; Science and Compliance C Burgess and D.G Jones (eds.) 1995 Elsevier Science B.V All rights reserved Robert Boyle and the birth of analytical spectroscopy D u n c a n Thorburn Burns Department of Analytical Chemistry, The Queen's University of Belfast, Belfast BT9 5AG, Northern Ireland, UK Abstract Outlines of Robert Boyle's life, work relating to the birth of spectroscopy and connections with America are followed by an account of his contributions to the early study of luminescence phenomena Key Words R Boyle, American correspondence, Luminescence, Fluorescent indicator, Phosphorus, A.G Hanckwitz, "The Golden Phoenix" I N T R O D U C T I O N The title is not intended to imply that Robert Boyle [1-6] was the world's first spectroscopist p e r s e He did however make studies which led to the conception of many aspects of spectroscopy as we know it today These were (i) a prismatic study of the solar spectrum as noted in the account of the development of instrumentation for measurements in the ultraviolet-visible region at the first Oxford Conference (1986) [7], (ii) examination of colour formation reactions including acid-base indicators [2], (iii) quantitative visual colorimetry [4] and (iv) study of luminous phenomena [6], many of which have since been the subject of detailed spectroscopic study Before discussing the main theme, namely Robert Boyle's contributions to the early study of luminescence [6], it is appropriate to give an outline of his life [1] and connections with America [3] Robert Boyle (From an engraving by R Woodman of a picture formerly in the possession of Lord Dover and now in the National Portrait Gallery London) R O B E R T BOYLE (1627-1691) Robert Boyle was born on J a n u a r y 27th, 1627 in Lismore Castle, Co Waterford, Ireland His early education was at Eton He was on mainland Europe from 16381644 completing his education on the "Grand Tour" He then lived in England, apart from a short return to Ireland from 1652-54, and a brief trip to Holland in 1648 [3] The visit to Ireland is important in that it was, in a letter written in April 1654 to Frederick Clodius, from Ireland that Boyle was the first to use the term "chemical analysis" in the sense in which it has since been used by chemists [2] The latter part of his life was spent in London at his sister's house in Pall Mall, next door but one to Nell Gwyn's residence He died in 1691 and was interred in St Martin-in-the Fields This was not on the site of the present church which was built 1722-1724 The earlier church was pulled down in 1720 and sadly no record of Boyle's grave remains R O B E R T BOYLE'S AMERICAN CONNECTIONS Robert Boyle was deeply religious and was appointed by the King in 1649 to be a Governor of the "Corporation for the Propagation of the Gospel in New England" [11a] He took these duties seriously during his life and arranged for their continuance as part of the balance of his estate left to "pious and other good works." These included "propagating the gospel among the Heathen Nations of New England and other parts ofAmerica." [11b] Dealing with the estate was complex [12] and was arranged by the executors to be effected via the Company for Propagating the Gospel in New England, the president and fellows of Harvard College, and the president and masters of the College of William and Mary, Virginia Boyle achieved a great reputation and influence among the American colonists and they kept him informed of their affairs and sent him news of scientific wonders and strange events Much of this correspondence, indexed by Maddison [13], is readily available in "Works " [10] John Winthrop [14a], (one of the original Fellows of the Royal Society), Governor of Connecticut, wrote from Boston on October 27, 1670 about a mysterious slaughter of fish in a pond which the Indians attributed to its having been struck by lightning He also gave him news of Mr Eliot, a missionary supported by Boyle William Penn [14b] (Philadelphia, August 5, 1683) described the character of the Indians and their dealings with them and commented "Of plants here are excellent for medicine and cure of wounds Some chemists intend an observation upon them." John Clayton [14c] (Virginia, James City, June 23, 1684) referred to Boyle's work on Noctiluca and described the firefly Dr William Avery [14d] wrote (Boston, November 9, 1682) concerning alchemical experiments and also on smallpox A letter from Boyle crossed in the post because in Avery's letter, May 1st, 1684 [14e], he thanks Boyle for his letter of October 16, 1682 "for the letter with the useful book" The nature of the book was not stated but it was important for he says "coming into my hands have laid me under a deep obligation" There are again reports of alchemical experiments and medical matters The alchemical experiments and medical sections refer to items in Starkey's Pyrotech It is probable that the book Boyle sent to Avery was Receipts sent to a Friend in America (1688) although Fulton [15] has not identified the "friend" nor has the original been seen [15a] Birch states [11c] t h a t Medical Experiments 1692 was a second edition of "Receipts "; he also gives the Preface to the 1688 book omitted from subsequent ones The Preface [16] also refers to "the inquisitive Dr W.A ", hence it is thus reasonable to deduce the book in question was Receipts or its manuscript version The choice of the president and fellows of Harvard to deal with the execution of some of the items in Boyle's will was most appropriate since a one-time president, Leonard Hoar, was a friend of Boyle, as was the first Harvard graduate to achieve a reputation in chemistry, George Stirk or Starkey Hoar deserves a special place in the history of chemistry in America [17] since in a letter to Boyle, December 13, 1672 [14f] he outlined his plans for the development of Harvard to include "a chemical laboratory for those philosophers, that by their senses would culture their understandings, are in our design to spend their time of recreation in them; for readings or notions only are but husky provender " However, the laboratory was not built and throughout the greater part of the seventeenth century there appears to be no formal instruction in chemistry, although the Harvard Commencement (i.e Degree Day) Theses and Quaestiones [18,19] prior to 1687 contain chemical topics, as part of natural philosophy Starkey in Pyrotechny asserted and Illustrated, (1658) [20] asserted t h a t "in the year of our Lord 1644 first began the studie of Chemical Philosophie." If true, his studies must have been individual and private Another documentary connection of Robert Boyle with Harvard is the letter, undated but 1663, [21] from his proteg6 Caleb Cheeshahteaumacuk who was the earliest Indian graduate of Harvard in 1665 The largest amount of correspondence from America with a single person was t h a t with John Eliot, [22] a devoted and extraordinary missionary to the Indians Boyle was his main support in his efforts to convert them to Christianity, to translate their dialects and to make the Bible accessible to them Eliot wrote describing his work and the heartbreaking difficulties, addressing Boyle in terms such as "Right honourable, right charitable, and indefatigable, nursing father" Another extensive correspondence was with the Commissioners of the United Colonies of New England [23] Two of the Governors and General Court of New England wrote to t h a n k Boyle for his services to the Nations and in speaking on their behalf to the King- John Edecott [lld] in 1664 and John Leverett [lle] and others in 1676 The charitable objects of Boyle's will concerned with propagating the gospel among the H e a t h e n Nations of New England were deemed to have failed Following a suit in Chancery, the funds were devoted to a topic as near the original idea as possible, namely "the conversion and religious instruction, and education of the Negro slaves in the British West India Islands." To enhance funds a selection from Boyle's Occasionall Reflections was published, together with memoirs of the author [24] ROBERT BOYLE'S CONTRIBUTIONS TO THE EARLY STUDY OF LUMINESCENCE Luminous p h e n o m e n a were of great interest in the early days of the Royal Society [25] Robert Boyle was one of the most outstanding experimentalists in this field in the seventeenth century Although he never wrote a general account of luminescence, there is much on luminescence throughout his works [9,10] Boyle was probably the first to describe phosphorescence, thermoluminescence, electroluminescence and triboluminescence in a single substance, a diamond He also studied phosphorescence, chemiluminescence, bioluminescence and fluorescence Boyle's contributions have been put in perspective within a "History of Luminescence, from the earliest times until 1900" [26] and earlier works [27,28] by E Newton Harvey The account is brought up to date by O'Haver's discussion "The Development of Luminescence Spectrophotometry as an Analytical Tool" [29] with its useful concise account of instrumentation For convenience Boyle's contributions to the study of luminescence are outlined in four sections: examination of solutions - the first fluorescent acid-base indicator, luminescence studies of solids - diamonds, shining wood, fish and flesh and glow worms, phosphorus - manufacture and properties; and the Golden Phoenix, at one time assumed to be Boyle's laboratory 4.1 A n a l y s i s of solutions - the first fluorescent acid-base indicator Boyle made considerable contributions to the examination of solutions developing m a n y selective reactions for iron, copper, salt etc giving their detection limits [2,4] He also made advances in the examination of acids, bases and distinguished neutral salts as such Much of this work is described in his texts Experiments and Contributions Touching Colours [30,31] and Mineral Waters [32,33] Boyle was the first to describe a fluorescent acid-base indicator, extract of lignum nephriticum This extract had been used since pre-Columbian days in the t r e a t m e n t of kidney and bladder infections and as a diuretic The manuscript history of the wood has been reviewed in detail by Partington [34] In the sixteenth and seventeenth centuries the wood was imported into Europe from the New World and attracted attention on account of its apparent medical virtues and for the u n u s u a l yellow colour and pronounced blue fluorescence shown by its infusion with water The section in Boyle's Colours [30,31] experiments 10 and 11 in P a r t III, is quite detailed and comprises 20 pages [31a] The effect of concentration, acidity and angle of viewing are described The earliest account known to Boyle was t h a t of Monardes [35], he also cited the work of the great Jesuit encyclopaedist, Kircher [36] Boyle was particularly fond of using extract of lignum nephriticum and refers to it in Sceptical Chemist [37,38] Experimel~ta Observationes Physicae [39,40c], An Essay on the Porousness of Solid Bodies [41,42a], Icy Noctiluca [43,44e], and in Mineral Waters [32,33a] Robert Boyle's examination of mineral waters was more detailed and a considerable advance on those of earlier workers, contemporaries and most later workers up to the time of Kirwan [45] His account is brief and fragmentary yet it gives a clear insight into Boyle's experimental approach and his knowledge of the limitations of the various experiments A set of suggested geographical and mineralogical observations (heads or titles 1-17) are followed by the physico-chemical part (titles 1-30) This later section is amplified in sections on "Experimental Remarks" by "Marginal Notes".The book concludes with consideration of mineral water as a medicine In general few details are given, it being assumed t h a t the reader was fully familiar with Boyle's earlier works For example, title 16 of the physicochemical part reads "How to examinee, without evaporation, whether the Mineral Water have any acidity, tho' it be but very little" The marginal notes concerning the sixteenth title extend to two pages where he states "The circumstances, that made this way of examining so critical, will cost me too many words to set down here, and I have done it in another Paper expressly written, of the way of discovering the Qualities of divers Bodies, by changes of colour made in or with them: And therefore I shall here but briefly tell you, that I discover the Acidity of Liquors by their operations upon the colours of an Infusion of Lignum Nephriticum made in Lympid Water, (and order'd after a certain manner) " He then discusses his results with selected mineral waters including imported German Spaw Water By the mid-eighteenth century the wood had become rare in Europe and its botanical origin was lost Safford [46] positively identified the material used by Boyle as Eysenhardtia Polystachya The principal fluorescent acid-base indicator component of the heart wood has been established as hydroxy-2',4',-5',trimethoxyisoflavone [47] 4.2 L u m i n e s c e n c e s t u d i e s of solids Boyle's principal luminescence studies of solids began with diamonds extended to shining wood, fish and flesh and ended with the element phosphorous 4.2.1 Luminous Diamonds Belief in luminous stones seems to have been widespread in medieval times Gesner in the first text, Lunariae [48] on luminescence, reported on a stone in a ring owned by Catherine of Aragon (1485-1536) which luminesced at night As noted by Boyle, Cellini, the celebrated Italian jeweller, told of a diamond which shone after exposure to light [49] Boyle's experiments show the t r u t h of the matter, the account is annexed to Colours [30] They were carried out on 27th October 1663 using Mr Clayton's diamond The account was well referenced including de Boot's G e m m a r i u m [50], the latest account known to Boyle was t h a t of Olaus Worimus' Musaeum [51] The diamond had to be gently rubbed before it shone in the dark, it also shone if gently warmed Boyle examined a series of precious stones - rubies, sapphires, emeralds etc but only some, but not all, diamonds shone in the dark 4.2.2 Bioluminescence - Shining wood, fish and flesh and glow worms Boyle made numerous studies of shining wood, fish and flesh with his air pump aided by his laboratory assistant Robert Hooke [52] The experiments were made on October 29, on the following nights and on December 6, 1667 [53] From the later series we note Boyle worked a seven-day week 10 " so that I caused the Receiver to be exhausted once more, but that it being a S u n d a y night, I was u n w i l l i n g to scandalize any, by p u t t i n g my servants upon a laborious, a n d not necessary work." Both the shining wood and fish lost their light when air was removed which was restored w h e n air was readmitted He then published observations and trials about the resemblances and differences between a burning coal and shining wood [54] Boyle noted five resemblances, both were luminaries, the light resided in them, both need air to continue shining and recovered after lack of air, could be quenched by w a t e r and air t e m p e r a t u r e was not important Six differences were noted, a live coal was extinguished by compression not so for shining wood, once a coal was totally extinguished, it did not recover on admitting air unlike shining wood, shining wood needed air, gave no smoke, did not waste so fast and was not even lukewarm F u r t h e r experiments were February 15, 1671/72, on the flesh of a pullet and of veal [55] Boyle noted t h a t spirit of wine quenched the light after fifteen minutes but w a t e r did not at least within one hour Although Boyle did not know t h a t luminous bacteria were responsible for the shining fish and flesh or t h a t mycelium of a luminous fungus caused the wood to shine, we must credit him with recognising the f u n d a m e n t a l similarity of the two phenomena and with demonstrating the necessity of some latent property of air (oxygen) to maintain the luminescence These are the first i m p o r t a n t experiments on luminescence At the time Boyle had studied the effects of air on shining wood and flesh he h a d wished to examine glow worms, but none were available A few years later an experiment was carried out and the results appeard in Tracts touching the relation betwixt F l a m e a n d A i r [56,57] Boyle's motive was to learn more about the 'vital flame' of animals in relation to air He introduced the experiments as follows [57a] "For the sake of those learned men, that have thought the light of glow w o r m s a n d other s h i n i n g insects to be a k i n d of effulsion of the biolychnium, or vital flame, that nature has m a d e more l u m i n o u s in these little a n i m a l s than in others we took two glow w o r m s these we laid on a little plate, which we included in a s m a l l receiver of finer glass t h a n ordinary a n d as we expected, upon the first exsuction there began to be very m a n i f e s t d i m i n u t i o n of the light, which grew d i m m e r a n d d i m m e r , as the air was more a n d more w i t h d r a w n until at le~gth it disappeared, though there were y o u n g eyes a m o n g the assistants This darkness h,aving suffered to continue a long while in the receiver we let the air in agail~, whose presence as we look for, restored at least as m u c h light as its absence deprived us of." 421 The major technical goals to be achieved in the next phase of the development are: A) finalise the mechanical design and address various ever-present weatherproofing issues, B) build and deploy a group of instruments to verify the long-term stability of the filters, C) conduct exhaustive environmental testing of the enclosure and D) develop and perform instrument calibrations both in the laboratory and in the field using the Langley method [3] This final step of providing Langley analysis provides the user with a means of checking the instrument's interference filter calibration drift due to the effects of solarization in the field R e f e r e n c e s Beaubien, M.C., "A Platform for Evaluating Various Detector Technologies", Poster paper presented at the Second National Institute of Standards and Technology UV-B Workshop, May 1994 in Gaithersburg, MD Harrison, L., Michalsky, J., and Berndt, J "The Automated Multi-Filter Rotating Shadowband Radiometer: An Instrument for Optical Depth and Radiation Measurements." To be published Fall 1994 in Applied Optics Harrison, L and Michalsky, J "Objective Algorithms for the Retrieval of Optical Depths from Ground-Based Measurements." To be published Fall 1994 in Applied Optics 425 I N D E X OF C O N T R I B U T O R S Arthurs, E.G., 399 Barnes, P.Y., 65 Battle, D., 137 Beaubien, A.F., 415 Beaubien, M.C., 415 BShme, W., 185 Burgess, C., 21 Casciero, J., 175 Cruz, L., 385 Drummond, I., 399 Fateley, W.G., 315 Fox, N.P., 337 Freeman, G.H.C., 71 Frenkel, A., 129 Gentile, T.R., 129 Gignac, D.S., 97 Glenny, R.W., 255 Goodman, T., 155 Hammaker, R.M., 315 Hammond, J.P., 205 Hanssen, L.M., 115 Hemmendinger, H., 159 Himel, C.M., 281 Hsia, J.J., 65 Huckins, S.R., 225 Malkin, F., 137 Mayer, R.T., 281 Migdall, A.L., 129 Miller, J.N., 247 Monti, J., 175 Mortensen, A.N., 315 Naundorf, G., 185 Nettleton, D.H., 337 Obremski, R.J., 235 Oldenburg, K., 385 Orr, E.A., 315 Paukstelis, J.V., 315 Porter, D.J., 35 Ralph, V.E., 337 Rich, D.C., 137 Shippy, S., 385 Silzel, J., 235 Sobczynski, R., 315 Sweedler, J.V., 385 Taylor, J.L., 225, 281 Thorburn Burns, D., Thorne, A.P., 355 Timperman, A., 385 Tsay, T., 235 Verrill, J.F., 49, 111 Ingleson, A., 137 Jankowski, J.A., 385 Klink, T., 195 Kremer, A., 399 Lambe, R., 155 Larason, T.C., 65 Liekmeier, W., 185 Williams, D.C., 111 Williamson, C., 137 Workman, J., Jr., 369 Zhang, Z.M., 129 Zwinkels, J.C., 97 427 SUBJECT INDEX N o t e : A l p h a b e t i z a t i o n is l e t t e r - b y - l e t t e r ( i g n o r i n g spaces) F i g u r e s a n d T a b l e s a r e i n d i c a t e d by italic p a g e n u m b e r s Absolute colour measurements future collaboration required, 170-171 requirements, 159 Absolute harmonization, 38, 42 Absolute Virtual Instrument concept, 372, 377, 378 Absorbance transfer standards, 50-53 inter-reflection effects, 53 temperature effects, 52, 203 uniformity of, 50-51 See also Transmission standards Acceptance testing, 216, 217, 218 Accreditation, meaning of term, 210 Accreditation schemes, 47, 210 Acetylcholine, 283 AChE (acetylcholinesterase), 283-288 acyl AChE allosteric site, 303-305 fluorescence quenching of ligands by, 303-304 ligand binding to, 288 allosteric control of, 285-286 allosteric site on, 297-299 anionic centre in free form, 292-297 casual anionic centers, 305-306 casual hydrophobic areas, 306-307 crystal structure of, 291-292 hydrolysis of acetylcholine catalysed by, 283 inhibitor probe binding effect of probe hydrophobicity, 292, 294 kinetic considerations, 291-299 steric hindrance effects, 294-295, 295 thermodynamic considerations, 299-305 ligand binding to free form, 287-288 fluorescence quenching resulting, 287288, 299-303 mechanism of action, 284-285 peripheral allosteric site, existence questioned, 305-309 physiological background, 283 rate control mechanism investigation, 281-309 methodology, 286 probe synthesis, 288-290 steady-state kinetic analysis of inhibitorenzyme interactions, 286-287 AC power supplies, sideband problems caused by, 364, 365 1,2-Acridine araphane probe, 290 interactions with ACHE, 293 Acridine-based compounds, 289 interactions with ACHE, 293, 295-296, 299, 300, 302 Acrylic plastic, thermochromism of, 138 Allosteric sites on ACHE, 297-299 peripheral allosteric sites, 305-309 on acyl ACHE, 303-305 American correspondence [to/from Robert Boyle], 5-7 Amino acids, electrophoretograms, 389, 392 9-Aminoacridine compounds, 289 interactions with ACHE, 293, 296-297, 299, 300, 301, 302 Ammonium cobalt sulfate, as photometric accuracy standard, 188 AOTFs (acousto-optic tunable filters), 318, 324 in four-dimensional spectrometry, 324329 multi-wavelength AOTF, 329-330 ASTM standards colour measurement of fluorescent materials, 104 gasoline analysis, 383 stray-light quantification, 401 ATP (adenosine triphosphate), determination using bioluminescence, 225233 Attenuation definition, 130 measurements, 129-130 at infrared wavelengths, 131-134 at visible/near-infrared wavelengths, 130-131 Avery, William, Bandpass filters, 412, 413 Bandwidth standards, 55-56 428 Barium sulphate as integrating-sphere coating, 153, 339 as spectrofluorimetric reference standard, 107 specular port, 78, 84, 163-164 BCRA-NPL Ceramic Colour Standards, 60 effect of dual correction, 165, 169 spectral variation of reflectance, 145, 149, 169 thermochromism, 138-140, 138, 139, 140, 143, 144 variation over time, 142, 144, 147-152 Benzene vapor, wavelength resolution assessed using, 181, 186 BESSY electron storage ring, 156 Beta light [tritium-activated phosphor], 79, 91 BG36 filter, reproducibility of trasmission spectrum, 362, 363 Biological fluids, NIR fluors as probes in assays, 235-246 Bioluminescence ATP determination using, 225-233 instrument parameters, 232 methodology, 232 reagents, 231-232 results, 232-233 standard addition method, 229, 230, 231 Boyle's observations, 9-11 effect of removal of air, 10-11 'fast-burn' chemistries, 226 'slow-burn' chemistries, 226 Black Perspex [in light trap], 88 Blood flow measurements, 255 Boehringer-Mannheim ATP bioluminescence kit, 226, 231 Boyle, Robert [1627-1691] American connections, 5-7 life history, luminescence studies, 7-13 portrait, various studies listed, will and estate, 5, 6, BRDF (bidirectional reflectance distribution function), relative BRDF for integratingsphere coating, 123, 124 British Standards, 92, 210 Broadband infrared filters, 134-135 BSA (bovine serum albumin), cyanine dyes bound to, 242, 252 Burning coal, effect of lack of air, 10 Cadmium lamps, effect of AC power supplies, 365 Calibration, 181, 186-187, 197-201, 218219, 356 See also Wavelength calibration Calibration automation, 215 errors possible, 53 Calibration frequency, 46, 47, 183 Calibration services NIST, 65-66 NPL, 50, 53, 55, 72, 93, 95, 156-157 quality system covering, 65-68 Capillary electrophoresis, 386 fluorescence detection in, 386-387, 390, 396 CCD (charge coupled device) detectors, 387389, 403 in fluorescence instruments, 236, 238, 387-389, 390 methods of reading, 388, 389, 403 quantum efficiency of, 387, 402 size of, 390, 406, 412 Cell sampling schemes, 385, 386 Ceramic colour standards See Colour standards, ceramic Ceramic tiles, 55 CERAM Ltd diffuse reflectance long-term repeatability experiment, 141-142 results, 142-152 Change procedure, 27-28 Chelsea Instruments spectrometer, 355 Chemiluminescence, 225 Cholinergic synapses, 283 See also AChE (acetylcholinesterase) CIE (Commission Internationale de l'Eclairage), publication 15.2, 170 CIELAB metric chroma difference temperature dependence for BCRA tiles, 139, 143 variation with time for BCRA tiles, 142, 144 Cobalt/nickel perchlorate solutions, as absorbance standard, 186, 202, 203 Colorimetry, 138 effect of thermochromism, 145-146 fluorescent materials, 99-100, 104 material standards for, 60, 138-140 metameric standards for, 60-61 specular correction applied, 162-163 Colour separation, in fluorescence, 262-265 429 Colour standards, 60-61 ceramic, 60 factors affecting measurement errors, 138 thermochromism of, 60, 138-139, 140, 143 See also BCRA-NPL Ceramic Colour Standards metameric colour standards, 60-61 uniformity of, 60 Commissioning Certificate, 216 Compatibility of measurement systems, 37, 38 requirements, 40 Compliance, 22, 24-28, 65-68 manufacturers' approaches, 175-221 Compound hyperbolic concentrators, 121, 122 Compound parabolic concentrators, 118-119 Computer hardware, acceptance testing of, 217 Computer software acceptance testing of, 216, 218 design considerations, 216 documentation of, 67 for fluorescence measurements, 258 for instrument validation, 189, 193 module and integration testing of, 216 Connes advantage, 356 Control charts, 41, 44 Cost/benefit analysis, 25 Crystal wavelength standards, 53, 62 See also McCrone wavelength standard Cubic spline interpolation, 46, 198, 199, 200 Cuvettes, matching in fluorescence measurements, 272, 279 Cyanine dyes, 236, 249, 251 spectral properties, 244 See also DOTC; DTTC; HDITCP; ICG Czerny-Turner type instruments, 105, 250, 356, 399, 403, 405 Dark current [of photomultipliers], 236, 237 Dark error [in diffuse reflectance measurements], 80 Datacolor International Spectraflash spectrometers, 60, 141, 153, 166 spectral correction factors, 166, 167 Data display, too much emphasis on, 22-23 Data integrity, factors affecting, 22, 23, 2428, 176, 177, 209 Data manipulation, too much emphasis on, 22-23 Deconvolution, 264 Depth profiling, 319, 324 Derivatisation, of peptides, 393-396 Design, meaning of term, 207 Design Qualification, 25, 211-212 requirements summarized, 25 Detection limits capillary electrophoresis/laser-induced fluorescence system, 386, 390-391, 396 near-infrared fluorescence, 241, 242, 243 Detectors characteristics validated, 179-180 charge coupled device, 236, 238, 387-389, 399, 402, 403, 408-410, 412-413 diode array, 112, 197, 369-370, 399, 402, 403, 408-411, 412-413 infrared-wavelength, 131 mercury-cadmium-telluride, 122, 132, 133 multichannel, 250 photoconductive, 74 photodiode, 74, 74, 75, 83, 87, 92, 106, 179, 250, 345, 346, 418 photomultiplier, 74, 74, 78, 179, 236, 387 pyroelectric, 118 quantum efficiency of, 351, 387, 402 trap, 345-346, 346, 350-351 See also CCD ; PDA ; PMTs Deuterium lamps, 156, 157, 181 calibration facility, 156-157 reproducibility test, 363 in wavelength accuracy validation, 181, 187 Diamonds, luminescence of, Dichromate See Potassium dichromate Diffuse reflectance measurements CERAM long-term repeatability experiment, 141-142 results, 142-152 dark error, 80 gap error, 82 gloss trap error, 80 NIST instrumentation, 115-128 hemi-ellipsoidal mirror system, 116-120 integrating sphere system, 120-127 NPL Spectrometer, 77-85 sample recess error, 82, 83 specular beam screening error, 81 Diffuse reflectance standards, 57-59 glossy standards, 59 matt standards, 59 translucency effects, 57, 58 white reflectance standards, 57, 62 Diffuse transmittance measurements, 57 430 Diffusively reflected/transmitted flux, measurement as function of flux, 90 Diffusively reflecting wavelength standards, 55 Diode-array detectors See PDA detectors Diode-array spectrofluorimeter, 112 Diode-array spectrometers, 195-204, 369384 advantages, 370, 384, 397 design features, 372-378 filter wheel component characteristics, 374, 374, 376 implementation strategy, 372 instrument standardization, 377-378 sample cell, 375 sample cell correction methodology, 375, 377 effects of major component replacements, 382 performance results, 379-382 detector linearity, 382 for gasoline analysis, 383 instrument functions, 379 noise, 379, 380 signal-to-noise ratios, 380, 381 stray-light errors, 380-381 wavelength drift, 382 photometric accuracy standards, 30-33, 202-203, 375 wavelength calibration, 197, 200, 375, 377 Diode lasers, 236, 248, 249 See also Laser diodes DNA sequencing, 392 DNA spectra, 307 DOTC (3,3'-diethyloxatricarbocyanine iodide), 251 Double aperture [linearity] system, 75, 91, 93 DTTC/DTTCI (3,3'diethylthiatricarbocyanine iodide), 244, 251,252 Edisbury Square, 30 EN 45000 series standards, 185, 210 Enzymic interactions inhibition]control mechanisms, 285-286, 291 inhibitor probe binding kinetic considerations, 291-299 thermodynamic considerations, 299-305 with neurotransmitters, 283 See also AChE Equipment records, 28, 66 2-(2-Ethoxyethoxy) ethyl acetate, 257, 271 European Pharmacopoeia absorbance/transmission standard, 30, 32, 202 stray-light standards, 197 wavelength accuracy standards, 187 Eysenhardtia polystachya extract, 8-9 FDA (Food and Drug Administration, USA), 206 Fellgett advantage, 356 Fibre optics, 248, 339-340, 372 Filter radiometers, 348, 349 spectral responsivity of, 352, 353 spectrometric measurements, 348-353 Fitness for purpose, 24, 25, 27 See also Design ; Installation ; Operational Qualification Flicker noise, 46 Fluorescamine, derivatisation using, 395, 396 Fluorescein [dye], 249, 388, 396 Fluorescence emission wavelengths, 258, 259 excitation wavelengths, 258, 259 meaning of term, 258 multichannel detection using CCDs, 387393 Fluorescence quenching, 260 acetylcholinesterase-ligand interaction, 287-288, 299-303 factors affecting, 273, 277, 278, 279 way to confirm presence, 279 Fluorescence spectrometry, 260-262 compared with UV-VIS spectrometry, 247, 258, 260-262 long wavelength, 247-254 NPL reference instrument, 111-114 NRCC reference instrument, 99-109 peak intensity method, 262 sensitivity, 261 synchronous scanning method, 264, 265 wavelength resolution assessment, 108, 181 Fluorescence techniques, advances in, 225309 Fluorescent acid-base indicator, Robert Boyle's observations, 8-9 Fluorescent dyes/phosphors/pigments, 98, 114, 244, 248-250, 262 Fluorescent labels, 247 Fluorescent lamps, 157, 359 Fluorescent Microsphere Resource Center, 277 431 Fluorescent microspheres, 256 colours available, 256 in organ perfusion studies, 265-280 calculation of number of microspheres for injection, 265-266 comparison with radio-labeled microspheres, 275-276 estimate of number of microspheres per ml of suspension, 266 fluorescence measurement, 272-274 fluorescent dye extraction, 271 future directions, 276-277 injection procedures, 266-267 isolation of microspheres from tissue, 269-271 potential sources of error, 277-279 reference blood sampling procedures, 267-269 solvents for, 256, 257-258, 271 impurity effects, 258, 278, 280 spectrometer used, 258, 272 Fluorescent probes, 235, 247, 288-290 binding to AChE kinetic considerations, 291-299 thermodynamic considerations, 299-305 Fluorescent whitening agents, 98, 114 Fluorophores long-wavelength/near-infrared, 244, 248250 See also Cyanines; Phenoxazines; Xanthenes Four-dimensional spectrometry, Hadamard techniques used, 318, 319, 324-328 Fourier transform spectrometry, 119, 126, 130, 134, 355-365 See also FT Fraunhofer lines, 39 FTIR (Fourier transform infrared) spectrometers, 119, 126, 130, 134 FTS (Fourier transform spectrometry), 355 compared with grating spectrometry, 356357, 366 practical measurements using, 357-365 Gallium phosphide detectors, 418 Gasoline analysis, 370, 383 Gemstones, luminescence of, General Electric-Hardy spectrometer, 162, 163 correction facors, 167, 168 Germanium, temperature coefficient of refractive index, 133 Germanium photodiode detectors, 74, 75 Glan-Taylor polarizer, 105 Glass filters multivariate harmonization using, 42 NPL transfer standards, 29, 50, 52 photometric performance measured using, 28-29, 83, 91, 94, 186, 188, 190 stability of, 189 temperature coefficients, 52 Glass lens, transmittance results, 347 Global economy, 35-36, 47 Global harmonization of standards, 38, 47 Gloss measurements, 92 Glossy colour standards, 59, 60 Glossy reflectance standards, 59, 92, 161 Glow worms, 10-11 GLP (Good Laboratory Practice), 185, 209 Gold coatings on broadband filters, 135 in integrating spheres, 122-124 on ruled disk for integrating-sphere characterization, 125, 126 Golden Phoenix laboratory, 13 Gonioreflectometer See Reflectometer Grating, effects of replacement on diodearray spectrometers, 382 Grating spectrometry, compared with Fourier transform spectrometry, 356-365, 366 Ground-based UV-B monitoring, 415, 416 Hadamard encoding masks liquid crystal optical shutter array, 317 polymer dispersed liquid crystal, 317 two-dimensional masks, 318 Hadamard masking, application for multidimensional studies, 315-333 Hadamard transform photoacoustic spectrometry, 318, 319, 324-325 Hadamard transform Raman spectrometry, 317, 319 Hadamard transform spectrometry, 316 advantages, 317 four-dimensional spectrometry, 318, 319, 324-328 one-dimensional spectrometry, 317, 319 three-dimensional spectrometry, 318, 319324, 319 two-dimensional spectrometry, 318, 319 Halon as specular-port material, 162, 163-164 effect of dual correction, 165 See also PTFE Hanckwitz, Ambrose Godfrey, 11, 13 Hardy spectrometer See General ElectricHardy spectrometer 432 Harmonization of standards, 37-48 key step in process, 37 multivariate approaches, 42-47 types of harmonization, 37-38 Harmony between measurement systems, 36 multivariate harmony, 41 spectroscopic harmony, 38-41 Harvard College, and Robert Boyle, 5, Haze measurements, at NPL, 57, 93-95 HDITCP (1,1', 3,3,3', 3'-hexamethyl-4,4', 5,5'dibe nzo- 2,2'- in d otricar bocy anine perchlorate) detection limits, 241, 242, 243 dose-response fluorescence curves, 241, 242 spectral properties, 244 Health and safety issues, 25 Hemi-ellipsoidal mirror system, 116-120 advantages/disadvantages, 118, 127 measurement geometries, 117 Hemispherical reflectance/transmittance, 116, 117, 120 Hemmendinger Color Lab, 162 Herschel region, 248 Heterodyne detection methods, 132-134 Hewlett Packard spectrometers, 28-29, 29, 32, 195-204 High-intensity UV sources, 157 Hoar, Leonard, Holmium oxide HT-PA spectra, 320, 321, 323, 329 PA spectra from AOTF, 326 Holmium wavelength standards, 55, 62, 186, 189, 197-201 stability of, 189, 198 Hotelling's tS2s statistic, 44 Human colour-difference/matching perceptibility, 138, 159 Human serum background spectrum, 240, 242 detection limits for NIR fluors, 242, 242, 243 dose-response curves for NIR fluors, 242, 243 7-Hydroxy-2',4', 5'-trimethoxyisoflavone, ICG (Indocyanine Green) detection limits, 241, 243 dose-response fluorescence curves, 237, 241 fluorescence lifetime data, 244, 245 spectral properties, 244 Incandescent sources disadvantages, 337-338 See also Tungsten lamps Information rates, effect of, 46, 47 Infrared See Near-infrared Infrared attenuators, 131 Installation Qualification, 26, 176, 213, 214, 216 requirements summarized, 26 Instrument, definition of, 206-207 Instrument response linearity, 180-181 Instrument stability, 137-153 Instrument standardization advantages of, 379 for diode-array spectrometers, 377-378 Instrument system validation, 24-28, 211218 Integrating spheres advantages/disadvantages, 120 coatings used, 122-124, 153, 339 errors encountered, 80-83, 160 in laser-based spectrometry, 339-343, 344, 345, 350 polarization properties, 343 radiance stability, 343 uniformity of irradiance, 341, 342 maintenance requirements, 153 in NIST/NRL system for diffuse reflectance measurements, 120-124 test results, 125-128 in NPL system for diffuse reflectance measurements, 77, 78 in NRCC spectrofluorimeter, 103 ruled gold-coated brass disk for sphere characterization, 125, 126 test results, 127 uniformity of, 83-85, 341, 342 Intensity calibration [of lamps], 359 Intensity standards, 358 Interchangeable parts, historical background, 36 Interdisciplinary approaches, 282-309 Interference filters, in UV-B radiometer, 416-417 Interferometers, 366-367 Inter-reflection effects/errors, 50, 53, 75 ISO 9000 series standards, 36, 38, 46, 47, 185, 209 ISO/IEC Guide 25, 210 quality system at NIST based on, 65-68 See also Quality assurance system 433 Jacquinot advantage, 356 Lambertian coating, 124 Lamps, 104, 150 characteristics of, 179, 180 effects of replacement on diode-array spectrometers, 382 indications when to renew, 150, 180, 273 intensity calibration of, 358, 362 sidebands caused by AC power supply, 364, 365 spectral transmittance affected by type, 100 standard lamps, 156, 157, 362 See also Cadmium ; Deuterium ; Mercury ; Tungsten ; Xenon lamps Langley analysis, 421 Laser-based measurements, 131, 132, 133 Laser-based spectrometry, 337-354 filter radiometer measurements, 348-353 lens transmittance measurements, 344348 Laser diodes, 236, 248, 249 emission spectrum of typical device, 238 log intensity spectrum of typical device, 240 stability of, 238, 239 Laser-induced fluorescence, 318, 319, 386 fluorescamine used for peptides, 395, 396 Lasers tunable dye lasers, 338-354 wavelength calibration using, 356, 375, 377 LEDs (light-emitting diodes), 236, 248, 250, 330 in high-throughput near-infrared spectrometers, 330, 331-332 Lens transmittance measurement, laserbased spectrometry used, 344-348 Lexan [polycarbonate] substrates [for filters], 135 Lifetime measurements, fluorescent dyes, 243, 244, 245, 246 Light sources tritium-activated phosphor, 79, 91 See also Lamps; Laser diodes; Lasers; LEDs; Radiation sources Lignum nephriticum extract, 8-9 Line shape, standardization of, 374, 378 Linewidth standards, 358 Long-term repeatability, reflectance spectrometers, 137-153 Long-wavelength fluorescence spectroscopy, 247-254 See also LWF spectroscopy Luciferase, ATP determination using, 225233 Luminescence Robert Boyle's contributions to early study, 7-13 fluorescent acid-base indicator, 8-9 luminescence studies of solids, 9-11 phosphorus, 11-12 See also Bioluminescence; Chemiluminescence; Fluorescence Luminous diamonds, LVIFs (linear variable interference filters), 318, 319, 324 LWF (long-wavelength fluorescence) spectroscopy, 247-254 advantages, 248 applications, 252 fluorphores, 248-250 instrumentation, 250-251 typical results, 251-252 McCrone wavelength standards, 53, 54, 55, 56, 62, 357, 360-361 Mahalanobis distance, 44 Maintenance requirements, 153, 219, 379 MANOVA, 46, 47 Manufacturers approaches to compliance, 175-221 exchange of information with users, 171, 184 Maretin [normality reagent], 286, 288 Matt colour standards, 59, 60 Matt reflectance standards, 59 Mean square errors, 46 Measurement assurance programs, 42, 47 Measurement errors ceramic colour standards, 138 diffuse reflectance measurements, 118 diode-array spectrometers, 381 grating spectrometry, 357 reflectance measurements, 91 transmittance measurements, 75 Mercury lamps, 157, 179 wavelength accuracy validation using, 108, 181, 187, 218, 219, 411 Metal-on-silica filters, 50, 62, 202 inter-reflection effects/errors, 50, 53, 75, 182, 202 uniformity, 51 Metameric colour standards, 60-61 Method validation, 211 434 Michelson interferometer, 356, 366 Microspheres in organ perfusion studies, 255-280 quantification methods, 255 See also Fluorescent microspheres Mineral waters, Robert Boyle's examination, 8-9 Mirrors, reflectance measurements, 86, 93, 160 Mixed reflectance, 160 See also Diffuse reflectance; Reflectance Model transfer, 372, 377 Monitoring programmes, 22, 27 Multichannel detectors, 400, 403 See also Detectors, charge-coupled device; diode-array Multichannel fluorescence detection system, 387-393 detection limits, 390, 391 fluorescamine used for peptides, 395 Multichannel spectroradiometers, stray-light problems, 399 Multidimensional spectrometry, Hadamard masking used, 315-333 Multivariate adjustment, 45, 379 Multivariate analysis of variance, 46, 47 Multivariate approaches [to harmonization], 42-47 past approaches, 42 proposed approach, 43-47 Multivariate control chart, 44 Multivariate difference, 43 classification of, 44-45 significance, 44 Multivariate harmony, 41 Multivariate normal distribution, 43 Multivariate statistical control, 43 Mutual active compatibility, 42 Mutual active harmonization, 37 Mutual passive compatibility, 42 Mutual passive harmonization, 37 NAMAS (National Measurement Accreditation Service, UK), 26, 210 Naphthalene dialdehyde, peptides derivatised by, 393-394, 395 Narrow-band global atmospheric UV-B spectrodadiometer, 415-421 environmental isolation design, 417 future development goals, 421 mechanical and optical design, 417-418 performance tests, 419, 420 thermal design, 419 National reference instruments See Reference National standardizing laboratories absolute compatibility between, 42 glass filters, 28 and global harmonization, 47 need to consider specular-port reflectance correction, 170 See also NIST; NPL; NRCC; PTB Near-infrared fluorescence, 235-246 Near-infrared Hadamard transform Raman spectrometry, 317 Near-infrared spectrometers, 74, 330-333, 370, 372-384 Near-infrared transfer standards, 62 Negative pressure filtration, fluorescent microspheres separated from digested tissue by, 270-271 Neodymium:YAG filter, 376, 378 Neodymium oxide HT-PA spectra, 320, 321, 322, 329 PA spectra from AOTF, 326 Neuroactive compounds, analyzing small amounts, 385-386 Neurotransmitters, 283 See also ACh (acetylcholine) Neutral density filters, 29, 50, 52, 83, 91, 94 NIST, 129-136, 186, 202 See also Glass filters Nile Blue, 249 Nile Red, 249, 251, 252, 252 NIR See Near-infrared NIR fluorophores microenvironment effects, 243 reasons for use as probes, 235-236 spectral properties, 244 NIST (National Institute of Standards and Technology, USA) diffuse reflectance/transmittance measurement instrumentation, 115-128 hemi-ellipsoidal mirror system, 116-120 integrating sphere system, 120-124 integrating sphere test results, 125-128 neutral density filter measurements, 129136 photometric accuracy standards, 186 quality assurance of spectrometric measurements, 65-68 SRMs See Standard reference materials wavelength standards, 181 Noise performance/specifications, 183, 379, 380 435 NPL (National Physical Laboratory, UK) calibration services, 50, 53, 55, 72, 93, 95, 156-157 Primary Standard radiometer, 352 Reference Spectrofluorimeter, 111-114 reference spectrometric instruments, 7196 Reference Spectroradiometer, 156 transfer standards, 49-63, 114, 186 NRCC (National Research Council Canada) reference spectrofluorimeter, 99-109 reflectance scale, 77, 92, 98 transmittance scale, 98 NRL (Naval Research Laboratory, USA), diffuse reflectance measurement instrumentation, 116-128 Nyquist sampling criterion, 366 Operability factors, 25 Operational Qualification, 26-27, 176, 213, 214, 217 requirements summarized, 27 Optical density, definition, 130 Optical radiation sources See Lamps; Lasers; Radiation sources Organ perfusion measurements [using microspheres], 255, 265 calculation of number of microspheres for injection, 265-266, 277 calculation of regional perfusion, 274-276 comparison between fluorescent and radio-labeled microspheres, 275-276 estimation of number of microspheres per ml of suspension, 266 injection of microspheres, 266-267 isolation of microspheres from tissue, 269271 alkaline digestion, 269 enzymatic digestion, 269 negative pressure filtration, 270-271 sedimentation, 271 potential sources of error, 277-279 reference blood sampling procedure, 267269 sample dilution, 274-275 Oxazine 750, 249 Ozone atmospheric measurements, 415, 416 reduction of, 157, 179 Paper fluorescence spectrum, 99, 113 fluorescent materials used, 98, 114 PDA (photodiode array) detectors exposure time required, 403 in NIR instruments, 369-370 quantum efficiency plot, 402 sampling interval of, 197 size of, 406, 412 spectral responsivity, 402, 403 in spectrofluorimeter, 112 in stray-light studies, 403, 408-411, 412413 PDA spectrometers See Diode-array spectrometers Peak intensities [of fluorescent colours], 262 Peer review, 27 Peptides, derivatisation of, 393-396 Performance Qualification, 27-28, 176, 213, 214, 217, 218-219 requirements summarized, 28 Performance validation, 175-184 Perkin-Elmer spectrometers bioluminescence measurements, 225-233 fluorescence measurements, 258, 272, 273, 274, 288 Luminometer accessory, 226, 229, 232 validation procedures, 189-193 Perspex, 88 Pharmaceutical industry, compliance in, 22, 186, 205-206 Phenanthridium moiety, binding characteristics of, 307 Phenoxazines, 249-250 advantages, 249 See also Nile Blue; Nile Red; Oxazine Phosphorus Boyle's preparation of, 12 commercial manufacture of, 13 first discovered, 11 Photoacoustic spectrometry, combined with Hadamard transform spectrometry, 318, 319, 324, 325 Photodiode array See Diode-array ; PDA Photodiode detectors, 74, 74, 75, 83, 87, 92, 106, 179, 250, 345, 346, 418 Photometric accuracy assessment technique, 182-183 standards, 28-32, 182, 187-188, 202-203 for diode-array spectrometers, 30-33, 202-203 problems with liquid standards, 203, 204 See also Absorbance ; Transmisssion standards 436 Photometric linearity, 180-181, 273 Photometric repeatability/reproducibility, 182-183, 203-204, 379 Photomultiplier tubes See PMTs Photon transfer, 238 Physikalisch-Technische Bundesanstalt [Germany], 77, 92, 156, 186 PICSVF (Pharmaceutical Industry Computer Systems Validation Forum), 205, 218 PMTs (photomultiplier tubes), 74, 74, 78, 179, 387 limitations, 236, 237 responsivity as function of angle in diffuse reflectance measurements, 79 Political agreements [on measurement harmony], 47 Polyacene molecules, 288 interaction with ACHE, 296, 297 Porcelain, thermochromism of, 138 Poretics filtration device, 270 Potassium chloride, 188, 197 Potassium dichromate concentration effects, 31 laboratory variance illustrated, 32 as photometric accuracy standard, 30-33, 187, 202 disadvantages, 202 temperature coefficients, 52 tolerance limits, 30, 32, 33, 187 trial results listed, 30, 31 Preconcentrator reactors, 393-394, 396 Primary standards, 155-156, 186, 188 Principal component(s) analysis/regression, 44-45, 377 Prism spectrograph, 403, 406, 411, 413 Process diode-array spectrometers, 370, 373 Process integrity, 22, 23 Propidium cation, 307 binding characteristics of, 306, 308 PTB (Physikalisch-Technische Bundesanstalt, Germany), 77, 92, 156, 186 PTFE (polytetrafluoroethylene), 138 See also Halon Pulmonary perfusion measurements, 275 Pyridine-based compounds, 289 interactions with ACHE, 293 Quaesitum, 40 Quality assurance system [ISO/IEC Guide 25], 65-68 calibration and test methods, 67 complaint handling procedures, 67 computer software documentation, 67 equipment records, 66 quality manual, 66 test report format, 67 Quality systems, 209 Quantum efficiency definition, 260 of detectors, 351, 387, 402 of fluorescent microspheres, 256 Quantum yield, calculation of, 182 Quenching [in fluorescence], 260 acetylcholinesterase-ligand interaction, 287-288 factors affecting, 273, 277, 278, 279 way to confirm presence, 279 Quinoline-based compounds, 289 interactions with ACHE, 293 Radiation sources characteristics validated, 179 differences in fluorescence measurements, 98, 100 intensity calibration of, 358 stability of, 180 transfer standards, 155-156 See also Lamps; Lasers; LEDs Raman spectral bands of methanol, 241 of water, 183, 241, 391, 392 Rare-earth-containing tiles, 55, 62 Reference Hazemeter [NPL], 57, 93-95 description, 94, 95, 96 errors, 94 Reference instruments, spectrophotometry, 71-114 Reference Radiometer [NPL], 351 Reference Reflectometer [NPL], 57, 86-93 future developments, 92-93 light-trapping arrangements, 87-89 measurement errors, 91 measurement procedure, 89-90 mechanical description, 86-87 optical system, 87 Reference Spectrofluorimeter [NPL], 111114 instrumentation, 112-113 measurements, 113-114 Reference Spectrofluorimeter [NRCC], 99109 beam geometry/uniformity, 108, 109 conceptual design, 103 design considerations, 99-104 instrument design, 104-106 instrument operation, 106-107 performance tests, 107-109 437 wavelength scale calibration and checking, 108 Reference Spectrophotometer [NPL], 72-85 diffuse reflectance measurements, 77-85 description, 77, 78 detector linearity, 83 measurement philosophy, 78-79 scales used, 77 sphere errors, 80-83 sphere integration uniformity, 83-85 traceability to, 50, 53, 55 transmittance measurements, 72-76 measurement errors, 75 wavelength and bandwidth measurements, 76 Reference Spectroradiometer [NPL], 156 Reflectance spectrophotometry balancing of diffuse and specular components, 159-171 correction factors application, 161-162 definition, 161 long-term repeatability of instruments, 137-153 standards, 56-57 See also Diffuse reflectance measurements Reflectometer, NPL reference instrument, 57, 86-93 Regulatory compliance, 185, 204 early [1970s] requirements, 22 4Qs approach, 24-28 instrument design affected by, 205-221 Regulatory environment, 207, 208 Repeatability, 138, 182-183 Reproducibility lamps, 362, 363 spectrophotometers, 138, 182-183, 201202 Rhodamine 800, 249 Russian opal, 57, 58 Safety clothing/signs, dyes/pigments in, 114 Sample integrity, 22, 23 Sap Green [food dye], as transfer standard, 33 Scatchard plots, 288, 301, 302 Secondary standards, 189 See also Transfer standards Sedimentation, fluorescent microspheres separated from digested tissue by, 271 Self-diagnostic tests, 178, 180 effect on validation frequency, 196 Servicing, 219 effect on reflectance measurements, 147 Shining wood, 10 Sideband problems, 364, 365 Signal-to-noise ratios diode-array spectrometers, 380, 381 Fourier transform spectrometers, 357, 366 Silica, reflectance of, 92 Silica/aluminium-coated mirrors, 56, 62, 105 Silica lens, transmittance results, 347 Silicon photodiode detectors, 74, 75, 83, 87, 179, 345, 348 Solar radiation as calibration reference source, 416 measurement of UV-B, 415-421 SOPs (Standard Operating Procedures), 27, 176, 2O9 Sources See Lamps; Laser diodes; Lasers; Light-emitting diodes; Radiation sources Spatial heterodyne spectrometer, 366-367 Specification Qualification, 211 Speckle patterns causes, 339, 340 removal of effects, 340 Spectralon, 57, 58, 62, 157, 225 Spectral reflectance effect of thermochromism, 145-146 long-term repeatability of measurements, 141-153 standards, 60, 141 Spectral responsivity, of filter radiometers, 352, 353 Spectral total flux measurements, 157 Spectrofluorimeters commercial instruments for liquids, 98 NPL reference instrument, 111-114 NRCC reference instrument, 97-109 required characteristics listed, 177 sources in, 100, 104, 179 two-monochromator reference system, 102, 106 validation of, 175-184 signal-to-noise specifications, 183 Spectrographs in stray-light studies, 403, 404-406 SW-NIR, 373 Spectrophotometers instrument variation listed, 371 NPL reference instrument, 72-85 required characteristics listed, 177 specular ports, 77, 78 measurements with new instruments, 166-169 measurements with variety of specular ports, 163-166 replacement with Halon, 162 438 validation of, 21-34, 175-221 detector response, 179-180 noise specifications, 183 photometric accuracy and repeatability, 182-183 photometric linearity, 180-181 source characteristics, 179 source stability, 180 wavelength accuracy, 181 wavelength linearity, 183 wavelength resolution, 181-182 Spectrophotometric measurements advances in, 69-172 quality assurance of, 65-68 Spectrophotometric standards harmonization of, 35-48 See also Transfer standards Spectrophotometric transfer standards, 3033, 49-63 Spectrophotometry advances in, 315-421 reflectance spectrophotometry, 137-171 See also Reflectance spectrophotometry Spectroradiometers costs, 416 narrow-band global UV-B radiometer, 415-421 source measurement scales for, 155-157 stray-light performance studies, 399-413 Spectroscopic harmony, 38-41 Specular-excluded reflectance measurements colour change variation with time, 148 geometries used, 77 reflectance factor variation with time, 149, 150 wavelength scale variation with time, 151 Specular-included reflectance measurements colour change variation with time, 148 correction factor application in colorimetry, 162-163 calculation, 161 errors introduced, 162 errors, 81 geometries used, 77 reflectance factor variation with time, 149, 150 wavelength scale variation with time, 151 Spillover matrix [for fluorescent colours], 262-263, 262 Standard reference materials SRM 930, 186, 202 SRM 931, 186, 202, 203 SRM 935, 186 SRM 2O26, 170 SRM 2031, 186 SRM 2O34, 197 Standards customers' views, 196 harmonization of, 35-48 See also Transfer ; Transmission ; Wavelength standards Starkey, George, Stokes shift, 258, 259 Stratospheric chemistry studies, 415, 416 Stray light components of, 400 meaning of term, 400-401 measurements for various spectrographs, 407-413 quantification of, 401 Stray-light characterization and correction methodology, 372, 377, 381 Stray-light errors, 345, 380 Stray-light standards, 188, 197 Student's t statistic, 40-41 Sulforhodamine 101, 390-391 Sulforhodamine 101 chloride, 249 SW-NIR (short-wavelength near-infrared) measurements, 369, 370 TDI (time delay integration) method, 388 advantages, 388 charge-coupled devices read using, 388, 389 electrophoretogram using, 389 Testing procedures, 178 components, 179-183 Test report format, ISO/IEC Guide 25, 67 Texas Red, 249, 390 Thermochromism colorimetry affected by, 145-146 colour standards affected by, 60, 138-140, 143, 144 Three-dimensional spectrometry, Hadamard techniques used, 318, 319-324, 319 Time resolved studies, fluorescent dyes, 243, 244, 245, 246 Trace analysis, 386, 393 Training, 177, 220 Transfer instruments, 153, 378 Transfer standards absorbance standards, 30-33, 50-53 advances at NPL, 49-63 bandwidth standards, 55-56 colour standards, 60-61 diffuse reflectance standards, 57, 59 factors affecting stability, 189 fluorescent standards, 114 439 near-infrared, 62 radiation source scales, 155-156 reflectance standards, 56-57 wavelength standards, 53-55 See also Absorbance ; Bandwidth ; Reflectance ; Wavelength standards Translucency, in reflectance standards, 57, 58-59 Transmission standards ammonium cobalt sulphate, 188 cobalt/nickel solution, 186, 202, 203 glass filters, 28-29, 83, 91, 94, 186, 188, 202 metal-on-silica/quartz filters, 50, 53, 62, 75, 182, 186, 202 potassium dichromate, 30-33, 52, 187, 202 Sap Green, 33 See also Absorbance standards Transmittance, definitions, 39, 73 Transmittance measurements NIST instrumentation, 116-128 NPL Spectrometer, 72-76 Transmittance transfer standards, 50-53 See also Absorbance transfer standards Transmitting wavelength standards, 53, 54 Trap detectors, 345-346, 346 Trend analysis, 29, 217 Tristimulus values, 141 Tungsten halogen lamps, 157, 319, 372, 401, 402 Tungsten lamps, 100, 180, 359, 362 Turbidity measurements, 93 Tween-80, 256, 269, 279 Two-dimensional spectrometry, Hadamard techniques used, 318, 319 Uncertainty ellipses, 42 Unity transmittance, 39 User manuals, 218, 219 Users' responsibility, 171 UV-B irradiance measurements, 415-421 UV Spectrometry Group, monographs, 22 UV-VIS spectrometers, 74 validation of, 175-221 UV-VIS spectrometry, compared with fluorimetry, 247, 258, 260 Validation components of, 24, 176, 212 definitions, 24, 196 of fluorimeters, 175-184 frequency of, 196 reasons for need, 22, 196 of spectrometers, 21-34 manufacturers' approaches, 175-221 Varian spectrometers, 51, 52 Wavelength calibration, 181, 186-187, 197201, 218-219, 356 automated calibration procedure, 215 errors possible, 53 for diode-array spectrometers, 197, 200, 375, 377 standardization of, 376, 378 for spectrofluorimeters, 108, 181 Wavelength linearity, assessment of, 183 Wavelength reproducibility, 201-202, 379 Wavelength resolution, 181-182, 188, 340 Wavelength-resolved electrophoretogram, 392 Wavelength standards, 53-55, 181 diffusively reflecting wavelength standards, 55 Fe(I)/Fe(II) standards, 356 holmium filter/solution/tile, 55, 62, 186, 189, 197-201, 204 lamp emission lines, 181, 187, 219 McCrone crystal, 53, 54, 55, 56, 62, 357, 360-361 near-infrared, 62 transmitting wavelength standards, 53, 54 WELAC (Western European Laboratory Accreditation Co-operation), 210 Wellplate reader, 272-273, 277 White reflectance standards, 57 Xanthenes, 249 See also Fluorescein; Rhodamine 800; Texas Red Xenon lamps, 104, 150, 157, 179, 180, 325 in spectrofluorimeters, 100, 104, 112, 179, 237, 258 variation of characteristics with time, 150, 180 YAG crystals, 357, 376, 378 Zeiss spectrometers, 101 Zero transmittance, 39 ... arranged for their continuance as part of the balance of his estate left to "pious and other good works." These included "propagating the gospel among the Heathen Nations of New England and other parts... Regulatory Compliance, National Laboratories OVERVIEW The robustness and reliability of spectroscopic data has been the subject of great interest and heated debate for over 50 years In the late 1940s and. .. be there to celebrate it with us Chris Burgess Dianna Jones J a n u a r y 1995 Spectrophotometry, Luminescence and Coulour; Science and Compliance C Burgess and D.G Jones (eds.) 1995 Elsevier Science