Tiêu chuẩn iso 22962 2008

14 0 0
Tiêu chuẩn iso 22962 2008

Đang tải... (xem toàn văn)

Tài liệu hạn chế xem trước, để xem đầy đủ mời bạn chọn Tải xuống

Thông tin tài liệu

Reference number ISO 22962 2008(E) © ISO 2008 INTERNATIONAL STANDARD ISO 22962 First edition 2008 01 1 5 Titanium and titanium alloys — Determination of iron — Inductively coupled plasma atomic emissi[.]

I N TE RN ATI ON AL S TAN D ARD ISO 22962 Fi rst ed i ti on 2008-01 -1 Titanium and titanium alloys — Determination of iron — Inductively coupled plasma atomic emission spectrometry Titane et alliages de titane — Dosage du fer — Spectrométrie d'émission atomique par plasma couplage inductif Referen ce n u mber I SO 22962: 2008(E) © I SO 2008 I SO 22962: 2008(E) PDF d i sclai m er Th i s PDF sh al l n ot fi l e be Ad o b e no is D e ta i l s a of th i s u n l es s fi l e , l i a b i l i ty i n th e th i s th e acce p t th a t a wh i ch th e re i n In a re th e a cco rd a n ce em b e d d e d re s p o n s i b i l i ty wi th a re of Ad o b e ' s l i ce n s e d n ot to l i ce n s i n g an d i n fri n g i n g p o l i cy, i n s ta l l e d Ad o b e ' s on th i s th e l i ce n s i n g fi l e m ay com p u te r p o l i cy be p ri n te d p e rfo rm i n g Th e I SO or vi e we d th e C e n tra l bu t e d i ti n g In S e cre ta ri a t a re a S ys tem s p ro d u cts o p ti m i ze d u n l i ke l y e ve n t typ e fa ces type fa ces o f Ad o b e s o ftwa re we re em b e d d e d p a rti e s tra d em a rk p a m e te rs th e co n ta i n e d i te d d o wn l o a d i n g a cce pts m ay u sed to fo r p ri n ti n g p ro b l em I n co rp o te d cre a te E ve ry re l a ti n g to it th i s ca re is PDF h as fo u n d , fi l e been pl e a s e ca n take n be fo u n d to e n s u re i n fo rm th e in th e th at C e n tra l G e n e l th e fi l e is I n fo re l ati ve s u i ta b l e S ecre ta ri a t a t th e for to use a d d re s s th e by fi l e; I SO g i ve n th e P D F -cre a ti o n m em b e r b o d i es In b e l o w COPYRI G H T PROTECTED DOCU M EN T © I SO Al l ri g h ts 008 res e rve d e l e ctro n i c I S O's U n l e ss m e ch a n i ca l , m em b e r b o d y i n I SO th e o th e rwi s e i n cl u d i n g co u n try s p eci fi e d , no p h o to co p yi n g o f th e p a rt an d of th i s p u b l i ca ti o n m i cro fi l m , wi th o u t m ay be re p ro d u ce d p e rm i s s i o n in wri ti n g or u ti l i ze d from in e i th e r an y I SO fo rm at th e or by an y a d d re s s m ean s, b el ow or re q u e s te r co p yri g h t o ffi ce Ca s e p o s ta l e 56 • CH -1 1 Te l + 41 22 749 01 1 Fax + 41 22 749 09 47 E -m a i l W eb G e n eva 20 co p yri g h t@ i s o o rg www i s o o rg P u bl i sh ed ii or in S wi tze rl a n d © I SO 2008 – Al l ri g h ts res e rve d I SO 22962: 2008(E) Con ten ts Page Foreword i v Scope N ormati ve referen ces Pri n ci pl e Reagen ts Apparatus Sampl e Procedu re Expression of resu l t Precisi on Bi bl i ograph y © ISO 2008 – All rights reserved iii I SO 22962: 2008(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work of preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part The main task of technical committees is to prepare International Standards Draft International Standards adopted by the technical committees are circulated to the member bodies for voting Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights ISO shall not be held responsible for identifying any or all such patent rights ISO 22962 was prepared by Technical Committee ISO/TC 79, Light metals and their alloys, Subcommittee SC 1 , Titanium iv © ISO 2008 – All rights reserved I N TERN ATI ON AL STAN D ARD I SO 22962: 2008(E) Ti tan i u m an d ti tan i u m al l oys — Determi n ati on of i ron — I n d u cti vel y cou pl ed pl asm a atomi c emi ssi on spectrometry Scope This International Standard specifies an inductively coupled plasma atomic emission spectrometric method for the determination of the mass fraction of iron in titanium and titanium alloys The method is applicable to titanium and titanium alloys with a mass fraction of iron in the range from 0,01 % to 3,0 % N orm ati ve referen ces The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies ISO 384:1 978, Laboratory glassware — Principles of design and construction of volumetric glassware ISO 648:—1 ), Laboratory glassware — Single volume pipettes ISO 042:1 998, Laboratory glassware — One-mark volumetric flasks ISO 3696:1 987, Water for analytical laboratory use — Specifications and test methods ISO 4787:1 984, Laboratory glassware — Volumetric glassware — Methods for use and testing of capacity Pri n ci pl e Dissolve the test portion in nitric acid and hydrofluoric acid, or sulfuric acid and hydrofluoric acid Determine the iron concentration in the test portion using an inductively coupled plasma (ICP)-atomic emission spectrometer 4 Reag en ts G en eral During the analysis, use only reagents of recognized analytical grade and water that complies with grade of ISO 3696 ) To be published (Revision of ISO 648:1 977) © ISO 2008 – All rights reserved I SO 22962: 2008(E) H yd roch l ori c aci d (1 +1 ) Add slowly 500 ml of hydrochloric acid (ρ20 ,1 g/ml to ,1 g/ml) to 500 ml of water (4.1 ) ρ20 ,42 g/ml ) N i tri c aci d ( 4 N i tri c aci d (1 +1 ) Add slowly 500 ml of nitric acid (ρ20 ,42 g/ml) to 500 ml of water H yd rofl u ori c aci d (1 +1 ) Add, carefully and slowly, 00 ml of hydrofluoric acid (ρ20 ,1 g/ml) to 00 ml of water Su l fu ri c aci d (1 +1 ) Add slowly 500 ml of sulfuric acid (ρ20 ,84 g/ml) to 500 ml of water, while stirring and cooling Su l fu ri c aci d (1 + 3) Add slowly 00 ml of sulfuric acid (ρ20 ,84 g/ml) to 300 ml of water, while stirring and cooling Ti tan i u m Minimum purity 99 % (mass fraction), the mass fraction of iron is as low as possible and already known If the mass fraction of iron is unknown, it should be determined by the mass fraction of iron in ISO 22960 Cobal t sol u ti on (1 m g Co/m l) Weigh ,00 g of cobalt metal [minimum purity 99,5 % (mass fraction)] into a 300 ml beaker, heat and decompose with 40 ml of nitric acid (4.4) After cooling, transfer to a 000 ml volumetric flask, make up to the mark with water and mix Yttri u m sol uti on (1 m g Y/m l ) Weigh ,27 g of yttrium oxide(III) [minimum purity 99,5 % (mass fraction)] into a 300 ml beaker, heat and decompose with 20 ml of hydrochloric acid (4.2) After cooling, transfer to a 000 ml volumetric flask, make up to the mark with water and mix 1 Lan th an u m sol u ti on (1 m g La/ml ) Weigh ,1 g of lanthanum oxide(III) [minimum purity 99,5 % (mass fraction)] into a 300 ml beaker, heat and decompose with 20 ml of hydrochloric acid (4.2) After cooling, transfer to a 000 ml volumetric flask, make up to the mark with water and mix I ron stan d ard sol u ti on (0, 500 m g Fe/m l ) Weigh, to the nearest 0,1 mg, 0,500 g of iron metal [minimum purity 99,9 % (mass fraction)], into a 300 ml beaker, heat and decompose with 30 ml of hydrochloric acid (4.2) Add ml of nitric acid (4.4) to oxidize iron and heat until nitrogen oxides evaporate After cooling, transfer to a 000 ml volumetric flask, make up to the mark with water and mix © ISO 2008 – All rights reserved I SO 22962: 2008(E) Apparatu s G en eral U se n orm al l aboratory apparatus Vol u metri c g l assware , of cl ass A com pl yi n g wi th I SO 384, I SO 648 an d I SO 042 U se i n accord an ce wi th I SO 4787 Pol yeth yl en e beaker an d watch g l ass Pol ytetraflu oroeth yl en e (PTFE) beaker an d PTFE watch g l ass 5 An al yti cal bal an ce , sen siti ve to 0, m g ICP-atomi c 238, 20 n m , or em i ssi on 259, 94 n m spectrometer capabl e and th e em i ssion line of si m u l taneousl y m easu ri n g of th e i n tern al stan d ard the cobal t i ron em i ssion (228, 62 n m ), line yttri u m (371 , 03 n m ), l an th anu m (398, 85 n m ), ti tan i u m (255, 60 n m ) or ti tan i u m (333, n m ) A h yd roflu ori c-acid -resistan t n ebu l i zer i s recom m end ed for th e d ecom positi on m eth od wi th n i tri c aci d an d h yd rofl u ori c aci d (7 2) Sam pl e Sam pl i n g Th e sam pl i n g proced u re for ti tan i u m and ti tan i u m al l oys sh al l be ag reed u pon u n ti l a correspond i n g stan d ard m ethod h as been pu bl i shed Test porti on Extract a test portion of 0, 50 g from th e test sam pl e an d wei g h to th e n earest 0, m g Proced u re N u m ber of d eterm i n ati on s Carry ou t th e d eterm i n ati on at l east i n d u pl i cate, as far as possibl e u n d er repeatabi l i ty d i ti on s, on each sam pl e Bl an k test Carry ou t a bl an k test i n paral l el wi th th e an al ysis, u si n g th e sam e q u anti ti es of al l reagen ts bu t om i tti n g th e test portion 7 3.1 Preparati on of cal i brati on sol u ti on Gen eral Prepare th e cal i bration solu ti on s i n accordan ce wi th 2, 3 or © I S O 2008 – Al l ri g h ts reserved I SO 22962: 2008(E) I n th e case of d ecomposi ti on wi th n i tri c aci d an d h yd rofl u ori c aci d (Th i s meth od i s u sed for th e procedu re d escri bed i n 4.2) Weig h fou r sam pl es of ti tan i u m (4 8), each of 0, 50 g , an d transfer to pol yeth yl en e beakers (200 m l ) Ad d 50 m l of n i tric aci d (4 4) and m l of h yd rofl u ori c aci d (4 5), cover with a pol yeth yl en e watch g l ass and h eat g en tl y on a water bath to d ecom pose th e ti tan i u m sam pl e Con ti n u e h eati n g u n ti l n i trogen oxi d es evaporate Cool to room tem peratu re Rem ove a watch g l ass, ad d , from a bu rette or pi pette, m l , m l , 20 m l an d 30 m l of i ron stan d ard sol u ti on (4 2) Tran sfer th e sol u ti on i n to a 00 m l vol u m etri c flask Ad d 5, m l of i n tern al stan d ard sol u ti on [cobal t (4 9)] , m ake u p to th e m ark with water an d m i x I m m ed i atel y, tran sfer th e sol u ti on i n to a d ry pol yeth yl en e or PTFE bottl e wi th a stopper an d reserve 3 I n th e case of d ecomposi ti on wi th su l fu ri c aci d an d h yd rofl u ori c aci d (Th i s m eth od i s u sed for th e procedu re d escribed i n 3) Weig h fou r sam pl es of ti tan i u m (4 8), each of 0, 50 g , an d tran sfer to PTFE beakers (200 m l ) Ad d m l of su l fu ri c acid (4 6) an d m l of h yd rofl u ori c aci d (4 5), cover wi th a PTFE watch g l ass an d h eat g entl y to d ecom pose th e ti tani u m I f the d ecom positi on i s i n com pl ete, ad d a sm al l q u anti ty of h yd rofl u oric aci d (4 5) an d h eat ag n Ad d m l of n i tric aci d (4 4), an d h eat for a few m i n u tes Rem ove th e watch g l ass, ti n u e h eati n g u n ti l whi te fu m es appear for about m i n Then cool to room tem peratu re, an d ri n se th e i n si d e of th e beaker with a sm al l q u an ti ty of water H eat ag n u n ti l strong whi te fum es appear for to m i n Th e vol u m e of su l fu ri c aci d rem ain i n g i n th e beaker wil l i n fl u en ce the i n tensi ty of em i ssi on Therefore, i t i s recom m end ed th at care be taken to keep a constan t vol u m e of th e rem n i n g su l fu ri c aci d H owever, th at i n fl u en ce wi l l be can cel l ed by u sin g an i n tern al stan d ard m eth od Cool to room tem peratu re Ad d m l of h yd roch l ori c aci d (4 2) an d a sm al l q u an ti ty of water to d i ssol ve th e sal t Ad d , from a bu rette or pi pette, m l , m l , 20 m l , an d 30 m l of i ron stan d ard sol u ti on (4 2) Tran sfer the solu ti on i n to a 00 m l volu m etric fl ask Ad d 5, m l of i n tern al stan d ard solu ti on [cobal t (4 9), yttri u m (4 0) or l an th an u m (4 1 )], m ake u p to the m ark wi th water an d m i x I n th e case of d ecomposi ti on wi th su l fu ri c aci d (Th i s meth od i s u sed for th e procedu re i n 4) Weig h fou r sam pl es of ti tan i u m (4 8), each of 0, 50 g , an d tran sfer to coni cal beakers (1 00 m l ) Ad d 40 m l of su l fu ri c aci d (4 7), cover with a watch g l ass an d h eat g en tl y to d ecom pose al l of th e ti tan i u m (m n tai n i n g th e vol u m e with d i stil l ed water) After d i ssol u ti on of th e ti tan i u m , ad d n i tri c aci d (4 3) d rop by d rop for ti tan i u m oxi d ati on, an d h eat th e solu ti on u n ti l wh i te fum es appear Cool to room tem peratu re Rem ove a watch gl ass, ad d , from a bu rette or pipette, m l , m l , 20 m l an d 30 m l of i ron stan d ard sol u ti on (4 2) Tran sfer th e sol u ti on i n to a 00 m l vol u m etri c flask with water M ake u p to the m ark with water an d m i x © I S O 2008 – Al l ri g h ts reserved I SO 22962: 2008(E) 7 4.1 Preparati on of a test sol u ti on for presen tati on to th e I CP-atom i c emi ssi on spectrom eter G en eral Prepare th e test sol u ti ons for presentati on to th e I CP-atom i c em i ssion spectrom eter i n accord an ce with 2, or 4 Decomposi ti on wi th n i tri c aci d an d h yd rofl u ori c aci d N OTE Th i s m ethod is appl icabl e for th e d eterm in ation of i ron i n ti tan i u m (in cl u d in g comm erci al l y avai l abl e pu re ti tan i u m ) an d ti tan i u m al l oys Transfer th e test porti on to a pol yeth yl ene beaker (200 m l ) Ad d 50 m l of n i tri c acid (4 4) and m l of h yd rofl u ori c aci d (4 5), cover with a pol yeth yl en e watch g l ass an d h eat g entl y on a water bath to d ecom pose th e test porti on Con ti n u e h eati n g u n ti l n i trogen oxi d es evaporate Cool to room tem peratu re Rem ove th e watch gl ass an d tran sfer th e sol u ti on i n to a 00 m l vol u m etric fl ask Ad d 5, m l of i n ternal stan d ard solu ti on [cobalt (4 9)] , m ake u p to th e m ark with water an d m i x I m m ed i atel y, transfer the sol u ti on i n to a d ry pol yeth yl en e or PTFE bottl e wi th a stopper an d reserve Decomposi ti on with su l fu ri c aci d an d h ydrofl u ori c aci d N OTE Th i s m ethod is appl icabl e for th e d eterm in ation of i ron i n ti tan i u m (in cl u d in g comm erci al l y avai l abl e pu re ti tan i u m ) an d ti tan i u m al l oys Transfer th e test portion to a PTFE beaker (200 m l ) Ad d 20 m l of su l fu ri c aci d (4 6) an d m l of h yd rofl u oric aci d (4 5), cover with a PTFE watch gl ass an d h eat g entl y to d ecom pose th e test portion I f d ecom posi ti on i s i n com pl ete, ad d a sm al l q u an ti ty of h yd rofl u oric acid (4 5) an d h eat ag n Ad d m l of n i tric aci d (4 4) an d h eat for a few m i n u tes Rem ove th e watch g l ass, ti n u e h eatin g u n ti l wh i te fu m es appear for m i n After cool i n g to room tem peratu re, ri n se th e i n sid e of th e beaker wi th a sm al l q u an ti ty of water H eat ag n u n ti l strong wh i te fu m es appear for to m i n Th e volu m e of th e su l fu ri c acid rem n i n g i n th e beaker wi l l i n fl u en ce th e i n ten sity of em i ssion Therefore, i t i s recomm en d ed th at care be taken to keep a stan t vol u m e of th e rem ain i n g su l fu ri c aci d H owever, th at i n fl u en ce wi l l be can cel l ed by u sin g an i n tern al stan d ard m eth od Cool to room tem peratu re Ad d m l of h yd roch l ori c acid (4 2) an d a sm al l q u an ti ty of water to d i ssol ve th e sal t After cool i n g to room tem peratu re, transfer the sol u ti on i n to a 00 m l vol u m etric flask Ad d 5, m l of i n tern al stan d ard sol u ti on [cobal t (4 9), yttri u m (4 0) or l an than u m (4 1 )] , m ake u p to th e m ark wi th water an d m i x 4 N OTE Decompositi on wi th su l fu ri c acid (u si n g ti tan i u m as th e i n tern al stan d ard ) Th i s m ethod u ses titan i u m as th e i n ternal stan d ard , and is appl icabl e to the d eterm i n ati on of i ron in comm erci al l y avai l abl e pu re titan i u m on l y Transfer th e test portion to i cal beakers (1 00 m l ) © I S O 2008 – Al l ri g h ts reserved I SO 22962: 2008(E) Ad d 40 m l of su l fu ri c aci d (4 7), cover wi th a watch g l ass an d h eat gen tl y to d ecom pose th e ti tan i um (m n tai n i n g th e vol u m e with d i stil l ed water) After d i ssol u ti on of th e ti tan i u m , ad d n i tri c aci d (4 3) d rop by d rop for ti tan i u m oxid ati on H eat the sol u ti on u n ti l wh i te fu m es appear After cool i n g to room tem peratu re, tran sfer th e sol u ti on i n to a 00 m l vol u m etri c flask with water M ake u p to the m ark with water an d m i x Determ i n ati on of i ron cen trati on 5.1 Th e G en eral i n stru m ent backgrou n d sh al l correction be set up positi on s in accordan ce an d i g n i te th e wi th th e pl asm a m an u factu rer’s torch for at i n stru ction l east 30 Ch ose before appropriate u se, to al l ow stabi l i zation M easu re th e em i ssion i n ten sity u sin g th e I CP-atomi c em i ssion spectrom eter u sin g th e i n ternal stan d ard m eth od When u sin g d evi ces for a com pu ter system preparation of a workin g cu rve, stan d ard i zati on (d ri ft correction, n orm al i zation , recal i brati on ) an d m easu rem ent of i ron centration sh al l be i n accord ance wi th th e operatin g m an u al for th e d evice’s com pu ter system software Preparation of workin g cu rve Spray a portion of the cal i bration solu ti on s i n to th e arg on pl asm a of an I CP-atom i c em i ssion spectrom eter, m easure the em i ssion i n ten si ty of i ron an d th e i n tern al stan d ard el em en ts (Co, Y, La, or Ti) sim u l taneousl y at th e wavelen g th sh own i n Tabl e Table — El emen t an d m easu remen t wavelen g th Wavel en g th El em en t nm Fe 238, 20 or 259, 94 Co 228, 62 Y 371 , 03 La 398, 85 Ti a For Fe 238, 20 nm 255, 60 or 333, 21 l i n e, th e Ti 255, 59 nm line sh ou l d a used as th e i n tern al stan d ard l i n e an d for th e Fe 259, 94 nm , th e Ti 333, 21 nm l i n e sh ou l d be used th e as i ntern al stan d ard l i n e Cal cu l ate th e i n ten sity rati os of th e em i ssion i n ten si ti es of i ron an d th e i n tern al stan d ard el em en ts u si n g Eq u ati on (1 ) R =I Fe /II S (1 ) wh ere R i s th e i n ten si ty ratio of i ron an d th e i n tern al stan d ard el em en t; IFe i s th e em i ssi on i n ten si ty of i ron ; II S i s th e em i ssi on i n ten si ty of th e i n tern al stan d ard el em en t © I S O 2008 – Al l ri g h ts reserved I SO 22962: 2008(E) Prepare th e rel ati on cu rve between the obtain ed i n ten si ty ratios an d th e i ron cen tration , i n m g /1 00 m l En su re th at th e g raph achi eves better th an 0, 999 correl ation an d i s su i tabl y l i n ear Prepare th e workin g cu rve for a sam pl e b y paral l el sh i ftin g of the rel ati on cu rve, so as to l et th e cu rve pass th rou g h th e ori gi n of th e coordi n ate axes 5.3 M easu remen t of i ron cen tration Spray a porti on of th e test sol u ti on s i n to th e arg on pl asm a of an I CP-atom i c em i ssion spectrom eter M easu re the em i ssion i n ten sity of i ron an d th e i n tern al stan d ard el em en ts (Co, Y, La, or Ti) sim u l taneou sl y at th e wavel eng th sh own i n Tabl e Cal cu l ate th e i n ten sity ratios of th e em i ssion i n ten si ti es of i ron an d th e i n tern al stand ard el em ent u sin g Eq u ati on (1 ) Determ i n e th e i ron centration (m g /1 00 m l ) of the test sol u ti on s from the workin g cu rve Expressi on of resu l t Th e m ass fraction of i ron i n th e test portion , w Fe = ρ1 − ( ρ − ρ ) m w Fe , expressed as a percentag e, i s g i ven b y th e E q u ati on (2) × 00 × −3 (2) wh ere ρ1 i s th e cen trati on of i ron i n th e test sol u tion , expressed i n m g /1 00 m l ; ρ2 i s th e cen tration of i ron i n th e bl an k sol u ti on , expressed i n m g /1 00 m l ; ρ3 i s th e cen trati on of i ron i n th e ti tan i u m (4 8) u sed i n or 3, expressed i n m g /1 00 m l ; m i s th e m ass of test porti on , expressed i n g Cal cu l ate th e m ass fracti on of i ron i n th e test porti on to th e th i rd d eci m al pl ace Th e d i fferen ce i n resu l ts of two paral l el d eterm i n ati on s of th e m ass fracti on of i ron i n th e sam e sam pl e sh al l n ot be g reater th an th e tol eran ce [Eq u ati on (3), (4), (5), (6), (7) or (8)] I f th e d i fferen ce exceed s th e tol eran ce, th e an al ysi s sh al l be repeated © I S O 2008 – Al l ri g h ts reserved ISO 22962:2008(E) Precision 9.1 General The tolerance of this analytical method is expressed by the following equations 9.2 In the case of a mass fraction of iron less than 0,25 % Repeatability limit 2,8 × [0,001 88 × (wFe) + 0,000 3] % (mass fraction) Within-laboratory-reproducibility limit 2,8 × [0,002 75 × (wFe) + 0,000 6] % (mass fraction) Between-laboratory-reproducibility limit 2,8 × [0,096 × ( wFe) + 0,001 0] % (mass fraction) (3) (4) (5) 9.3 In the case of a mass fraction of iron more than 0,25 % Repeatability limit 2,8 × [0,007 75 × (wFe) + 0,001 0] % (mass fraction) Within-laboratory-reproducibility limit 2,8 × [0,01 61 × (wFe) − 0,001 57] % (mass fraction) Between-laboratory-reproducibility limit 2,8 × [0,022 58 × (wFe) − 0,001 7] % (mass fraction) (6) (7) (8) © ISO 2008 – All rights reserved I SO 22962: 2008(E) Bi bl i og raph y [1 ] I S O 2 , Titanium and titanium a lloys — Determination of iron — Molecular absorption spectrometry using , 0-phenanthroline © I S O 0 – Al l ri g h ts res erve d I SO 22962: 2008(E) I CS 77 20 50 Price based on pages © ISO 2008 – All rights reserved

Ngày đăng: 12/04/2023, 21:11

Tài liệu cùng người dùng

  • Đang cập nhật ...

Tài liệu liên quan