detection and identification of gases and volatile organic compounds

... fraction of non-exempted volatile organic compounds in the non-propellant portion n = number of non-exempted volatile organic compounds in the non-propellant portion WL = weight (gm) of the non-propellant ... DETERMINATION OF VOLATILE ORGANIC COMPOUNDS (VOC) IN CONSUMER PRODUCTS AND REACTIVE ORGANIC COMPOUNDS IN AEROSOL COATING PRODUCTS APPLICABILITY 1.1 This method (Method 310) applies to the determination of ... commencing with section 94500, and (2) low vapor pressure -volatile organic compounds (LVP-VOC) as that term is defined in section 94508(a), and (3) the reactive organic compounds (ROC) contained in...

Ngày tải lên: 14/03/2014, 20:20

... molecular configuration and composition of some of the compounds discussed in this report The Quality of Our Nation’s Waters Volatile Organic Compounds in the Nation’s Ground Water and Drinking-Water ... solvent and an extractant, and as an intermediate product in organic synthesis Also, chloroform and other THMs are by-products of the chlorination of drinking waters and wastewaters, and the ... and use of manmade organic compounds, many of which are classified as VOCs, increased by an order of magnitude between 1945 and 1985.(5) Some VOCs have had, and continue to have, very large and...

Ngày tải lên: 14/03/2014, 19:20

... where di and si are the values of wind direction and wind speed of sample i The ranges of wind direction and wind speed are divided into a series of subranges having similar numbers of samples ... concentration of compound j in the emission of source p, and the strength of source p on sample i (16, 19) In this section, wind direction and wind speed will be used to illustrate the construction of the ... (the number of sources) elements T(ti,p) represents the action of temperature ti for source p The task of solving this expanded PMF model is to determine the values of F, G, D, S, W, and T to fit...

Ngày tải lên: 22/03/2014, 14:20

... biomarkers of inflammatory and oxidative lung processes, and different volatile organic compounds (VOCs) of endogenous or exogenous origin have been analyzed to study lung diseases [1] and characterize ... time with that of pure standard and charac- The method was validated by studying the linear range, and the limits of detection and precision Linearity was established over four orders of magnitude ... Diagnostic potential of breath analysis – focus on volatile organic compounds Clin Chim Acta 2004, 347:25-39 Imbriani M, Ghittori S: Gases and organic solvents in urine as biomarkers of occupational...

Ngày tải lên: 12/08/2014, 18:21

... burning oil, gas, and coal, and from discharges of ethylbenzene from factories Ethylbenzene gets into the soil by spills of gasoline or other fuels and poor disposal of industrial and household wastes ... part of crude oil, gasoline, and cigarette smoke Benzene is one of the major components of JP-8 fuel Industry is the main source of benzene in the environment Emissions from burning coal and oil, ... as a solvent and in the printing, rubber, and leather industries It is used as a cleaning agent and a thinner for paint and varnishes Xylene is a major component of JP-8 fuel Route of exposure...

Ngày tải lên: 14/02/2014, 03:20

... 3 Introduction Volatile organic compounds are important precursors to ozone and secondary particulate matter, which affect both human health and global climate (Seinfeld and Pandis, 1997; IPCC, ... speciation profiles based on summer 1996 and later data only for use with the summer 2000 Central California Ozone Study Of the profiles reported here, the summer 1999 and 2001 fuel and tunnel profiles ... end of 2003, blending of MTBE and other ethers in California gasoline had been banned, and refiners switched to ethanol as a fuel oxygenate where one was needed A summary of the evolution of Bay...

Ngày tải lên: 05/03/2014, 20:20

... on the characterization of volatile organic compounds (VOCs) in the MCMA, both on the ground and aloft and on the emission, transport, and transformation of VOCs downwind of the metropolitan area ... individual and classes of VOC species This will be used to help understand the chemical transformation of air parcels as they are exported out of and downwind of the MCMA For organic compounds ... evolution of volatile organic compounds Fig The top 20 compounds measured at T0 (top panel) and T1 (lower panel) in terms of mixing ratios between 09:00 and 18:00 local time averaged over the month of...

Ngày tải lên: 28/03/2014, 20:20

... mixture of volatile organic compounds Neurotoxicol Teratol 12,649-652 Rothweiler H., Wager P.A and Schlatter C., 1992 Volatile organic compounds and some very volatile organic compounds in new and ... usage of indicators for assessing the effects of volatile organic compounds (VOCs) in indoor air on comfort and health is reviewed Advantages and disadvantages of a TVOC (Iota1 Volatile Organic Compounds) ... of volatile organic compounds in indoor air - A review Indoor Air, 4, 123-134 Cometto-Muniz, J.E., Cain, W.S., 1995 Mixtures of volatile organic compounds: Detection of odour, nasal pungency, and...

Ngày tải lên: 28/03/2014, 19:20

Ngày tải lên: 12/04/2015, 14:24

... spring of 2002, with the primary goal of better quantifying the transport of pollution, in particular CO, ozone and its precursors, fine particles, and other chemically and radiatively active compounds, ... C3-C6 alkanes, alkenes, and alkynes, and the MSD channel for analysis of a range of other VOCs, including aromatic, oxygenated and halogenated compounds For 36 minutes out of every hour, two subsample ... determining the coherence of slnX-t trends for different types of compounds We note, however, that the falloff in variability for compounds with t < day, and the higher degree of scatter in the slnX-t...

Ngày tải lên: 05/03/2014, 20:20

... identified and measured the mixing ratios of major volatile organic compounds emitted by pigs and sheep in Germany The diurnal variations of carbon dioxide, nitrous oxide, methane, and ammonia ... Quellgruppe Landwirtschaft Braunschweig : FAL, 279 p, Landbauforsch Völkenrode SH 260 Filipy J, Rumburg B, Mount G, Westberg H, Lamb B (2006) Identification and quantification of volatile organic compounds ... Characterization and quantification of odorous and non-odorous volatile organic compounds near a commercial dairy in California Atmos Environ 37(7):933-940 Schade GW, Crutzen PJ (1995) Emissions of aliphatic...

Ngày tải lên: 05/03/2014, 21:20

... production of secondary organic aerosol (SOA) depends on the chemical state of the atmosphere, both in terms of oxidative capacity, and in term of the quantity and nature of gas phase organic material ... the roles of primary and secondary OC production is an important step toward an improved understanding and modeling of the sources, morphology and effects of aerosol OC The technique of minimizing ... Schlapfer, and S Wunderli (1998), Emission factors from road traffic from a tunnel study (Gubrist tunnel, Switzerland) part III: Results of organic compounds, SO2 and speciation of organic exhaust...

Ngày tải lên: 05/03/2014, 21:20

... with C Potter of NASA Ames, R Atkinson of UC Riverside, and P Harley and A Guenther of NCAR are much appreciated References Andreae, M O., and P Merlet (2001), Emissions of trace gases and aerosols ... C J Popp, and R S Martin (2004), Biogenic emissions and ambient concentratiosn of hydrocarbons, carbonyl compounds and organic acids from Pondorosa pine and Cottonwood trees of rural and forested ... emissions of CH3CHO have been measured with Holzinger et al [1999] reporting a source of 11 Tg yrÀ1 and Andreae and Merlet [2001] recommending only Tg yrÀ1 On the basis of a number of assumptions,...

Ngày tải lên: 14/03/2014, 20:20

... Switzerland) Once suspicious colonies are identified, confirmation of the isolates as E coli O157:H7 is dependent upon biochemical identification and demonstration of the presence of somatic and ... strains), C1-6 (strains of Cornell Univ.) and P1-7 (strains from E coli reference center of Pennsylvania State Univ.) b The presence of Stx1 and Stx2 “-” and “+” indicate negative and positive, respectively ... assessment of the risks difficult, and the options for management and control unclear The objectives of this study are (i) to examine the prevalence of E coli O157:H7 in slaughterhouses and retail...

Ngày tải lên: 07/08/2014, 18:21

... standard methods at SVA, which comprise fermentation of glucose, maltose, lactose, sucrose, starch, mannitol and fructose, and production of lecithinase, tryptophanase, urease and hydrolysis of ... Collection of samples from farms Manure, soil and silage Eleven dairy farms (A-K) from the island of Öland of south-east Sweden were included in this study (Table 1) Blackleg is endemic on this island ... standard method for detection of C chauvoei is based on culture and in most muscle samples from cattle dead from blackleg the amount of C chauvoei is high However, this is not always the case and...

Ngày tải lên: 12/08/2014, 18:22

... applied to analyze the residues of N-methylcarbamate and related compounds (propoxur and its metabolisms as model compounds) in biological materials (goldfish, tortoises and sea lettuce) Orthogonal ... various pH and irradiation sources (sunlight, darkness, indoor incandescent lighting and artificial UV lighting) Hydrolysis was found to be very much 143 pH-dependent irrespective of the type of water ... recoveries of tested compounds in goldfish, tortoises and algal samples under the respective optimum MAE conditions ranged from 85% to 87% with good reproducibility The conjugate of 2-isopropoxyphenol...

Ngày tải lên: 16/09/2015, 17:13

... 30 ml of methanol, an 80 °C extraction temperature, and 6-min microwave heating The differences between the distribution of propoxur and its transformation products in biota and soils, and additionally ... assignment of the main variables (A, B, C and D), two-variable interaction, and the level setting values of the main variables applied to aquatic animals (goldfish and tortoises) and sea lettuce ... of 0.02 s and a mass span of mass unit Quantitation was based on the area under the peak from the mass chromatogram of the above molecular ions at m/z 60, 151, and 210 For the LC separation of...

Ngày tải lên: 16/09/2015, 17:13

... Influence of matrix, moisture, aging of spiked soil on recovery of tested pollutants The effects of matrix, moisture and aged spiked soil on recovery of analytes were investigated and the results ... following was performed: ml of standard solution containing ppm of propoxur, thiuram, propham, methiocarb and chlorpropham was evaporated to dryness and, then 30 ml of the appropriate extractant ... Comparison of extraction efficiencies of carbamates from freshly spiked soil and time-aged soil by MAE and SFE 113 120 Recovery (%) 100 80 MAE 60 SFE 40 20 Analyte Fig 4-10 Comparison of mean MAE and...

Ngày tải lên: 16/09/2015, 17:13

... RESULTS AND DISCUSSION 3.3.1 Identification of TPs of Propoxur and Comparison of ESI and APCI The results showed that under alkaline condition (0.5M NaOH), propoxur was hydrolyzed to two TPs (1, and ... sets of standards of propoxur dissolved individually in methanol and ultrapure water were prepared with the concentrations of 0.025, 0.05, 0.10, 0.25, 0.50 and 1.0 ng/µl, respectively A set of ... application of LC-APCI-MS for the determination of carbamates: carbofuran and 3hydroxy-carbofuran, and the analysis of triazine herbicides in water [8] LC-ESI-MS...

Ngày tải lên: 16/09/2015, 17:13

... air-dried, pulverized and sieved through a 60mesh sieve In order to remove possible traces of PAHs, PCBs, triazines, carbamates and other organic contaminants, 100 g of each of the soil sample was ... fortification standards for recovery and analytical precision, a portion of each fish sample was added an appropriate volume of standard solution, thereby obtaining the required levels of target analytes ... initially tuned based on a mixture of caffeine, L-methionyl-arginyl-phenylananyl-alanine acetate·H2O and a mixture of perfluoroalkoxycyclotriphosphazenes in both positive and negative ionization modes...

Ngày tải lên: 16/09/2015, 17:13