Determination of chromium, copper and lead in river water by graphite‑furnace atomic
absorption spectrometry after coprecipitation with terbium hydroxide
著者 Minami Tomoharu, Sohrin Yoshiki, Ueda Joichi journal or
publication title
Analytical Sciences
volume 21
number 12
page range 1519‑1521
year 2005‑01‑01
URL http://hdl.handle.net/2297/3907
1５１９ ＡＮＡＬＹＴＩＣＡＬＳＣｍＮＣＥＳＤＥＣＥＭＢＥＲ２００５,VOL21
2005oTheJapanSocietyfOrAnalyticalChemistry
Determinationo症ＣｈｒＯｍｉｕｍ,CopperandLeadinRiverWater byGraphite-FumaceAtomicAbsorptionSpectrometryafter CoprecipitationwithhrbiumHydroxide
nmoharuMINAMI,＊YOshikiSoHRIN,＊andJoichiUEDA*＊
＊I)Ｍ〃e/brChe〃cαノルｓｅａＪ℃/z,KOﾉoroU7zjvemZMﾉ【/j6II-00〃,"pα〃
**ＲＪＭＤﾉq/EdMcaZjo",KZJ"αｚａｗａＵ７ｍﾉＣＭ〕ＵＭｕ"mamachj,肋"αＺａｗａ９２０〃92,"pα〃
Coprecipitationwithterbiumhydroxidequantitativelyrecoveredtraceamountsofchromium(Ⅲ),copper(Ⅱ)ａｎｄlead(Ⅱ）
atｐＨ８．４－１０．８，８０－１１．５ａｎｄ８．７－１１．５，respectively・Theprecipitatewasdissolvedin0.85moldm-3nitricacid,and
theanalytesweredeterminedbygraphite-fUrnaceatomicabsolptionspectrometry(ＧＦ－ＡＡＳ)．Thepresenceofterbium(ｕｐｔｏ７ｇｄｍ－３)didnotinterferewiththedetenninationThedetectionlimitswereO3Ugdm-3fOrchromium,０．４Ug
dm-3fOrcopperandO5Ugdm-3fOrlead,whentheanalytesin200cm3ofthesamplesolutionwereconcentratedinｔｏｌＯ ｃｍ３・TheionsaddedtoriverorseawaterwerequantitativelyrecoveredChromiumandcopperinacontaminatedriver waterweresuccessfUllydetennined(ReceivedJune3,2005;AcceptedSeptemberl2,2005）
CoprecipitationwithmetalhydroxideshasbeenwidelyusedfOr theconcentrationoftracemetalionsinwater,associatedwitha numberofdeterminationtechniques・'’２variouscoprecipitants havebeenusedfOrthepreconcentrationofchromium,3-5 copper4,d8andlead7innaturalwaterpriortｏｄｅterminationby graphite-fUrnaceatomicabsolptionspectrometry（GF-AAS)．
Theyincludehydroxidesofgallium,３indium,４ortin,7,8andiron hexamethylenedithiocarbamate､5,6 Sincemostofthese
coprecipitantscausesenousspectralinterference,theseparation ofanalytesfromthecoprecipitantsisnecessary・
Wehavebeenstudyingthesystematicsofcoprecipitationwith rareearthhydroxides・Inpreviousstudies,gJowefOundthat
scandiumhydroxidehasagoodcollectingabilityfOrmanytrace metals,ａｎｄhardlycoprecipitatesmatrixions,suchasalkaliand alkalineearthmetalsSincescandiumdoesnotcausesenous interference,theanalytesweredeterminedbyGF-AASafterthe precipitatewassimplydissolvedindilutednitricacid
WefOcusedonterbiumasamiddleraleearthelement・Terbium
hydroxidehasbeenusedfOrthecoprecipitationofselenitelIand indium12Recently，wefOundthatterbiumhydroxidehasa goodcollectingabilityfOrchromium(Ⅲ)，copper(Ⅱ）ａｎｄ lead(11)，andhardlycoprecipitatesthematrixions Additionally，terbiumdoesnotintelferewiththedetennination ofthemetalsbyGF-AＡＳ,andislessexpensivethanscandium
lnthispaper,wedescribetheconditionsfOrthecoprecipitation oftraceamountsofchromiumcopperandleadwithterbium hydroxideandfOrthedetenninationoftheseｅｌｅｍｅｎｔｓｂｙＧＦ‐
ＡＡＳ,andtheapplicationofthepresentmethodtoriverwater．
studiedusingaO85moldm-3nitricacidsolutioncontaining２．５ ｇｄｍ－３ｏｆｔｅｒｂｉｕｍａｎｄＯ１ｍｇｄｍ－３ｏｆｃｈｒomium，copperand lead,aresummarizedinTablel・AHitachi-HoribaModelM-5 pHmeterwithaglass-electrodewasusedfbrpHmeasurements．
RecJge"応
Nitricacidandsodiumhydroxideofguaranteedreagentgrade (NacalaiTesquelnc.）wereusedReagentsofguaranteed reａｇｅｎｔｇｒａｄｅｗｅｒｅｕｓｅｄａｓｌｏｎｇａｓｔｈｅｙwereavailable DeionizedwaterwithaMilli-Qsystem(Elix-5-Guradient-A10，
Millipore)wasusedtoprepareofallsolutions．
。）わ〃l"?z(〃,CQ〃e汀")α"d化αd(")so伽o"８.Astocksolution containinglgdm-3ofchromium(Ⅲ),copper(Ⅱ)ｏｒlead(11)was preparedbydissolvingtheirnitratesinasmallamountof concentratednitricacidanddilutingwithdeionizedwater・The concentrationofchromiumandleadwasdeterminedby complexometrictitrationusingXylenolOrange(Dotite）asan indicatorandthatofcopperusiｎｇＭurexide(Dotite)．
ＴＭﾌﾉ""zsoﾉ"rjo〃Aterbiumstocksolution（8.5ｇＴｂ３+dm-3）
の
TnblelOperatingconditionsfOｒＧＦ－ＡＡＳ
Ｃｒ Ｃｕ Ｐｂ
Samplevolume/mm3 Analyticalwavelength/nm LampculTent/mA Slitwidth/nm Argongasflowrate
Innergas/dm3min-1 Outergas/dm3min-l Drying(Ramp）
Ashing(Step）
Atomizing(Step)a C1eaning(Step）
２０ ３５７９
１０ ０．５０
20 324.7
１０ ０．５０
２０ ２８３３
１０ １．０
1.5 15 150°Ｃ,４０ｓ 700°Ｃ,２０ｓ 2500°Ｃ,４ｓ 2800°Ｃ,２ｓ
１．５ 1.5 150℃,４０ｓ 500°Ｃ,２０ｓ 2300°Ｃ,４ｓ 2800°Ｃ,２ｓ
1.5 Ｌ５ １５０°Ｃ,４５ｓ 250°Ｃ,２０ｓ 1400°Ｃ,３ｓ 2800℃,２ｓ
Experimental
A〃αｍｍｓ
ＡＳｈｉｍａｄｚｕＡＡ－６６０Ｇａｔｏｍｉcabsorptionspectrometerwitha GFA-4AgraIphitefUrnaceatomizerwasusedfOrGF-AAS
measurements、Theoptimumoperatingconditions,whichｗｅｒｅ alnnergaswasstopped．
1５２０ ＡＮＡＬＹＴＩＣＡＬＳＣＩＥＮＣＥＳＤＥＣＥＭＢＥＲ２００５,ＶＯＬ２１
Iable2Tbleranceratioofdiverseionsfbrthedetermination ofCr3+,Ｃｕ2+ａｎｄＰｂ２＋
宗へ百①シ８Ｑ函 100
Tbleranceratioa
lon[mgyrb[ｍg］ IC、
5０ 1０
０．０４ Ｎａ+,Ｋ十,Mg2+,Ｃａ2＋
Li+,Ｂａ2+,Ａ13+,La3+,Th4+,Ｚｒ4+,Cr3+,ｂ ＭｏＯ４２－,ＷＯ４２~,Ｍｎ2+,CO2+,Ｎｉ2+,Ｃｕ2+,c Zn2+,Cd2十,1,2+,Sn4+,Ｐｂ2+,dSb3＋
Fe3＋
0
0．０２ １０
pＨ
1112 ９
a・ErrorsindeterminationofCr3+,Ｃｕ2＋ａｎｄＰｂ２＋werewithin±５％，
ｗｈｅｎtheratioofthediverseionwaslessthanthevalue blnfluenceonCu2+ａｎｄＰｂ２+wasexamined・
clnHuenceonCr3+ａｎｄＰｂ２+wasexamined dInHuenceonCr3+ａｎｄＣｕ２+wasexamined Fig.１EffectofthepHontherecoveryofCr3+(●),Ｃｕ2+(ﾛ)orPb2＋
(○)．
waspreparedbydissolvingterbiumchloride（NacalaiTesque Inc.，extrapurereagentgrade)，andtheconcentrationwas detenninedbycomplexometrictitrationusingXylenolOrange
asanindicator．
fivemilligramsofterbiumwasusedinfUrtherexpenments・
TherecovenesoftheanalytesreachedlOO96withinseveral mnutesafterthefOnnationofterbiumhydroxide,andremained unchangedwhilestandingfOr3h
Theprecipitateofterbiumhydroxidewasreadilydissolved withnitricorhydrochloriｃacid．
Recomme"dCdpmcedm花
Asamplesolution(200ｃｍ3)placedinaPyrexglassbeaker wasaddedto3cm3oftheterbiumstocksolution，which contained25mgofterbium,andthepHwasadjustedto9with a０．１moldm-3sodiumhydroxidesolutionAfterthesolution wasallowedtostandfOrseveralminutes，theprecipitatewas collectedona3G4sintered-glassfilter（ｐｏｒｅｓｉｚｅ５－１０ｕｍ，
diameter30nm),washedwithasmallamountofdeionized water，anddissolvedwithO6cm3ofconcentratednitricacid、
ＴｈｅｓｏｌｕｔｉｏｎｗａｓｍａｄｅｕｐｔｏｌＯｃｍ３ｗｉｔhdeionizedwater・The atoncabsorbanceofchromium,copperorleadinthissolution wasmeasuredundertheoperatingconditionsgivｅｎｉｎＴａｂｌｅＬ
Ｉｔｔｏｏｋｓｏｍｅｌ５ｍｉｎｆＯrfiltrationwithaglassfilter、Thefilter waseasilycleanedwithnitricacidandusedrepeatedly．
ルノe剛"αrjo"qﾉﾉﾊeα"αlyreshyGF-AAS
TheconditionsfOrthedetenninationoftheanalytesbｙＧＦ－
ＡＡＳｗｅｒｅｎｏｒｍａｌｌｙｅｘａｍｉｎｅｄｉｎthepresenceofZ5gdm-3of terbium・Theatomicabsorbanceoftheanalytesdidnotdepend ontheconcentratiｏｎｏｆｎｉｔｒｉｃａｃｉｄｉｎａｒａｎｇｅｏｆ０．５－２.Ｏｍｏｌ ｄｍ－３・However,theabsorbanceofchromiumandleadgradually decreasedwithanincreaseinthehydrochloricacid concentration・Theabsorbanceofleadｗａｓａｂｏｕｔ４５９Ｉ６１ｏｗｅｒｉｎ
Ｏ９ｍｏｌｄｍ－３hydrocmoricacidthanthatin0.85moldm-3nitlic acidThus,nitricacidwasusedinfUrtherexpenments、
Theabsorbancesandconcentrationｓｓhowedlinear
relationships,passingthroughtheorigin,ｕｐｔｏ２００Ｕｇｄｍ－３ｆＯｒ ｃｈｒｏｍｉｕｍａｎｄｃｏｐｐｅｒａｎｄｌ５０ｕｇｄｍ－３ｆＯｒｌｅａｄ、The absorbancesoftheanalytesdidnotchangewiththepresenceof terbｉｕｍｕｐｔｏ７ｇｄＩＩＴ３・
TherelativestandarddeviationsfOrtheabsorbancesobtained fromfiverepeateddetenninationsfOrlOO1Lgdm-3of chromium(Ⅲ)，copper(11）ａｎｄlead(II）ｗｅｒｅ3.2％，3.7％ａｎｄ 4.6％,respectively・Thedetectionlimits,whichwerecalculated as3-timesthestandarddeviation，ｗｅｒｅＯ３ｕｇｄｍ－３ｆＯｒ ｃｈｒｏｎｕｍ,Ｏ４１ＬＬｇｄｎｒ３ｆＯｒｃｏｐｐｅｒａｎｄＯ・ＳＵｇｄｍ－３ｆＯｒｌｅａｄ，
whena20-timesconcentrationwasapplied．
ResultsandDiscussion
。P伽mmco"d伽"s/brcOP”cjP伽jo〃
Inapreliminaryexperiment,wefOundthatterbiumhydroxide HocculatedatpHabove7，givingafilterableprecipitate・The effectofthepHonthecoprecipitationofmetalionswith terbiumhydroxidewasstudiedwithasolutioncontaining5ug dm-3ofchromium(Ⅲ),copper(11)ａｎｄlead(11)．Theresultsare showninFig・LQuantitativerecoveneswereobtainedoverpH rangesof８．４－１０．８fOrchromium(Ⅲ),８．０－１１．５fOrcopper(11）
ａｎｄ８７－１Ｌ５ｆＯｒｌｅａｄ(11)．ApHof9wasusedfOrthe coprecipitationoftheseionsinfUrtherexperiments
Amonglanthanoide(Ⅲ）hydroxides，lanthanuml3-I5and samariuml6hydroxideshavebeenusedfOrthecoprecipitationof chromium，copperandlead，ａｓｆａｒａｓｗｅｋｎｏｗ・Whenusing thesehydroxides，ｉｔｉｓｎｅｃｅｓｓａｒｙｔｈａｔｔｈｅｐＨｏｆｔｈｅｓａｍｐｌｅ solutionisadjustedtohigherthan9.8．Thus,thepHfOrthe coprecipitationoftheseanalyteswithterbiumhydroxideis lowerthanthatwithhydroxideoflanthanumorsamanumThis isprobablyduetothelowersolubilityproductofterbium hydroxide・'７ＴｈｅlowerpHfOrcoprecipitationwithterbium hydroxideisadvantageousfOrtheseparationoftheanalytes
fromalkaliandalkalineearthmetals・
ThenecessaryamountofterbiumfOrthecoprecipitationwas examinedwith200cm3ofthesamplesolutionspikedwith5Ug dllr3ofchromium(ⅡI),copper(11)ａｎｄlead(11)．Morethanl4 mgofterbiumwasrequiredfOrquantitativerecoveries・Ｔｗｅｎｔｙ
mre旅”"cesq/dive応ezo"ｓ
Ｔｈｅｅｆｆｅｃｔｏｆ２３ｄｉｖｅｒｓｅｉｏｎｓｏｎｔｈｅdeternnnationsof chromium(Ⅲ),copper(11）ａｎｄlead(11）wasexaminedthrough thereconⅡnendedprocedureusing40cm3ofsamplesolution Theinitialconcentrationswere25Ugdm-3fOrtheanalyteｓａｎｄ 0.625gdm-3fOrterbiumTable2showsthatlargeamountsof sodium，potassium，magnesiumandcalciumdidnotinterfere withthedeterminationOtherionstesteddidnotproduceany seriousinterferenceeffectuptolZ5-25mgdm-3.
此coverjesqハp脱ｄｃＡｍ〃""z(〃，cOpper("）α"ｄノead("）
βomwarersampJes
Therecovenesofspikedchromium(Ⅲ)，copper(Ⅱ）ａｎｄ lead(Ⅲ）fromnverandseawaterwereexaminedThewater sampleswerecollectedfromtheupperreachesoftheAsano RiverandtheKanaiwaHarbor，IshikawaPrefecture，and acidifiedto7､５×１０－３molｄｍＦ３ｎｉｔｒｉｃａｃｉｄＡｓｓｈｏｗｎｉｎＴａｂｌｅ ３，theobtainedrecovenesaresatisfactory・BIankrunswere
1５２１ ＡＮＡＬＹＴＩＣＡＬＳＣⅢＮＣＥＳＤＥＣＥＭＢＥＲ２００５,ＶＯＬ２１
Table3RecoveryofspikedCIQ+,Ｃｕ2+ａｎｄＰｂ２+fromwatersamples
Pb2十 Cr3＋ Ｃｕ2十
Sampla sampling
date
Found／
Uｇｄｍ－３
Addedソ
uｇｄｍ－３ Recovery,ａ
９６ ＦｏｕｎＷ
ｕｇｄｍ－３
AddeCy
lLgdm-3 Recovery,ａ
９１６ FOund／
uｇｄｍ－３
ＡｄｄｅＷ
ｕｇｄｍ－３ Recovery,ａ
％ Ｒｉｖｅｒｗａｔｅｒ
Ｐｅｈ８ Ｄｅｃｌ７ Ｆｅｈｌ２ Ｓｅａｗａtｅｒ Ｆｅｂｌ９ Ｄｅｃｌ４ Ｆｅｂ２０
0.5 ５ ７．５
１０１±１０ ９５．７±3.3 96.0±２．３ １０１±２．６
１００±６．０ １０３±3.0
0.51 0.41 0.47
０．５ ５ １０
96.4±４．７ １０２±6.8 95.0±３．２
ＤＤＤ ＮＮＮ
０．５ ５ １０ 0.35
ＮＤ 0.44
１０１±８．９ １０１±2.1 96.7±１．５ 0.47
0.73 Ｎ，
０．５ ５ １０
１０５±１１ ９６．１±3.3 99.1±４．２
0.95 058 Ｎ，
0.5 ５ ７．５ ０．４１
ＮＤ ＮＤ
０．５ ５ １０
99.0±２．６ １００±1.9 99.8±１．１
aTherecoveryistheaverageandSDofthreereplicatedetenninations､ＮＤ:Notdetected．
Tnble4Resultsofthedetenninationofchromium,copperand
leadinwaterofatributalyoftheGohtaniRiver additionmethodTheresultsofcoppｅｒｗｅｒｅｉｎｇｏｏｄａｇｒｅｅｍｅｎｔ ｗｉｔｈｔｈｅｔｗｏｍｅｔｈｏｄｓＴｈｅｄａｔａｏｆｃｈｒｏｍｉｕｍｂｙｔｈｅstandard additionmethodgave，however，slightlyhighervaluesand variationsthanthosebythecalibrationcurvemethodLeadwas notdetected，sincethefOundvalueswerenotsignificantly higherthantheblankvalues．
Cr/Uｇｄｍ－３Ｃｕ/lＬｇｄｍ－３Ｐｂ/ｕｇｄｍ－３ Method
Calibrationcurve method Standardaddition
method
0.72±０．０９206a±１６ ０．９８±０．１７222a±１２
ＮＤ
References
LA・Mizuike,“Emc伽e"t71ecﾉ！"ｊ９"es/ｂｒｍｏ咽α"ｉｃｍｃｅ Ａ"αJysjs",1983,Springer-Verlag,Berlin,５６－６６．
２．Ｙｕ・ＡＺｏｌｏｔｏｖａｎｄＮＭＫｕｚ，min,“Preco"Ce"tmrjo〃ｑ／
ＴｍｃｅＥﾉeme"L,",ｉｎ``ＣＤ叩”/ze"sjveA"αbﾉticaﾉＣ/te〃srry"，
ｅd､Ｇ・Svehla,19,0,ＶＯＬ25,Elsevier,Amsterdam,７９－９４．
３．Ａ・Boughriet，ＬＤｅｒａｍ，andMWartel，ＬＡ"αﾉ．Ａｒ，
Specjrom.,1994,9,1135.
4．MHiraide，Ｚ．ＳChen，ａｎｄＨ・Kawaguchi，Ａ"αＬＳｃｊ.，
１９９１，７，６５．
５．Ｔ､Stafilov,GPavlovska,ａｎｄＫ・Cundeva,Ｍｃ'ＲＯＣ/ｚｅｍＪ.，
1998,60,32.
6.Ｋ.Cundeva,Ｔ､Stafilov,ａｎｄＧ､Pavlovska,Microchem.Ｊ・’
2000,65,165.
7．MHiraide,Ｚ．ＳChen，Ｋ・Sugimoto，ａｎｄＨ・Kawaguchi，
Ａ"αﾉ.Ｃ/z伽Ａｃｒａ,1995,302,103.
8.Ａ.Mizuike,Ｈ・Kawaguchi，KFukuda,Ｙ､Ochiai，ａｎｄＹ・
Nakayama,Ｍｊｃｍｃｈ伽.ＡＣ、,１９７４，９１５．
９．Ｊ・ＵｅｄａａｎｄＴ・Minami,Ｃ/zem.Ｌｅ".,1997,681.
10.Ｔ・Minami,Ｋ・Atsumi,ａｎｄＪ､Ueda,Ａ"αＬＳＣｉ.,2003,19,313.
11.Ｖ・IPlotnikov,Ｖ､Ｌ､Kochetkov,ａｎｄＶ・Ｐ､Chinaeva,ﾉ２１ﾉ．
ＡﾉhJd・ＭＪ"ﾉＭ(αz・SSR,Ｓｃ灰Ｆｊｚ.-ＭZr.,1967,5,71.
12.Ｖ・LPlotnikowandEG・Gibova,１２Ｖ・AAEadhMzzMFKZzZ、
SSR,Ｓｃ凪Ｋ/z〃.,1968,ノ８，９．
１３．Ｋ．Himeno，Ｋ・Yanagisawa，TYuki，ａｎｄＹ・Nakamura，
Ｂ""sekjKagalcm,1984,33,Ｔ43.
14.0．KUjirai,Ｋ､Yamada,andRHasegawa,ＪＡ"αＬＡｔ，
SPecrrom.,1193,8,481.
15.Ｙ・Toyota，SOkabe，SKanamori，ａｎｄＹ・Kitano，Ｊ・
ＯＣＣα"０８尻ＳＯＣ.Ｊ､，1982,38,357.
16.s・Saracoglu,MSoylak,ａｎｄＬＥｌｃｉ,ＺＭＺＪ"、,2003,59,287.
17.Ｗ､FeitknechtandP・Schindler,P"reAppLChem.,1963,6,
126.
TheresultsaretheaverageandSDfOrthleereplicatedeterminations．
、):Notdetected -:Notdetennined
a,Thefinalsolutionwasdiluted30tiｍｅｓｗｉｔｈＯ８５ｍｏｌｄｍ－３ｎｉｔｒｉｃ ａｃｉｄｐｒｉortothedetennination．
caniedoutusing200cm3ofdeionizeｄｗａｔｅｒａｓａｓａｍｐｌｅ・The blankvalueswereO3ugdm-3fOrchromium,0.41Lgdm-3fOr copperandO5Ugdm-3fOrlead,whichwerealmostthesameas thedetectionlimitsdiscussedaboveThus，itseemsthatthe proposedmethodisapplicabletotheanalysisofthesewater samplescontainingaboveO､３－０．５トＩｇｄｍ－３ｏｆｃｈｒｏｍｉｕｍ(Ⅲ)，
copper(Ⅱ)andlead(Ⅱ)．
A〃/jca"o〃ｍｒｈＭａｅ伽"αrjo"sqfc/"Ｄ"zj""０，cOPPerα"ｄﾉｅａｄ
ｍｒ〃erWarer
Thepresentmethodwasapｐｌｉｅｄｔｏａｎｖｅｒｗａｔｅｒｓａｍｐｌｅｔｈａｔ ｗａｓcollectedfromatributaryoftheGohtaniRiverflowingin KomatsuCity,IshikawaPrefecture，Thereisacoppermine,the OgoyaMine，ｉｎthedrainageareaofthetributary．Themine hadbeenworkedfOrsome300yearsandshutdowninl962・
ThissamplewasfilteredthroughAdvantecquantitativefilter paper(No.５C,diameter300mm),andacidifiedtoO12mol dm-3hydrochloricacidPriortocoprecipitation,２００cm3ofthe samplewasspikedwith０．５gofhydroxylanmoniumchloride，
andleftstandingfbr3hinordertoreducechromium(VI）to chromium(Ⅲ)．Thedeternnnedconcentrationis,therefOre,fOr thesumofchronum(111)andchromum(Ⅵ)．
ＴｈｅｒｅｓｕｌｔｓａｒｅｇｉｖｅｎｉｎＴａｂｌｅ４ＴｈｅｄatafOrchromiumand copperwerecolTectedfOrtheblankvalues・Theconcentrations ofchromiumandcopperinthesamplesolutionwere deternnnedbyacalibrationcurvemethodandastandard
