Determination of (Ultra)trace Amounts of Arsenic(III) and Arsenic(V) in Water by Inductively Coupled Plasma Mass Spectrometry Coupled with Flow Injection On-Line Sorption Preconcentration and Separati
详细信息 查看全文
- 作者：Xiu-Ping Yan ; Robert Kerrich ; and M. Jim Hendry
- 刊名：Analytical Chemistry
- 出版年：1998
- 出版时间：November 15, 1998
- 年：1998
- 卷：70
- 期：22
- 页码：4736 - 4742
- 全文大小：83K
- 年卷期：v.70,no.22(November 15, 1998)
- ISSN：1520-6882
文摘
A method has been developed for determination of (ultra)trace amounts of As(III) and As(V) in water by flowinjection on-line sorption preconcentration and separationcoupled with inductively coupled plasma mass spectrometry (ICPMS) using a knotted reactor (KR). The determination of As(III) was achieved by selective formationof the As(III)-pyrrolidine dithiocarbamate complex overa sample acidity range of 0.01-0.7 mol L-1 HNO3, itsadsorption onto the inner walls of the KR made from 150-cm-long, 0.5-mm-i.d. PTFE tubing, elution with 1 mol L-1HNO3, and detection by ICPMS. Total inorganic arsenicwas determined after prereduction of As(V) to As(III) ina 1% (m/v) L-cysteine-0.03 mol L-1 HNO3 media. Theconcentration of As(V) was calculated by difference (thetotal inorganic arsenic and As(III)). Owing to the group-specific character of the chelating agent, and the use ofan efficient rinsing step before elution, the interferencesencountered in conventional ICPMS from common majormatrix, alkali and alkaline earth metals, and chlorideswere eliminated. The presence of organoarsenic speciessuch as monomethylarsonate and dimethylarsinate inwater samples had no effect on the results of As(III) andAs(V). Thus, the method can be applied to the speciationanalysis of inorganic arsenic at submicrogram per literlevels in aqueous solutions with high total content ofdissolved solids and/or high content of chlorides. Usinga preconcentration time of 60 s and a sample flow rate of5 mL min-1, an enhancement factor of 22 was achievedin comparison with conventional ICPMS. The time required for a single determination was 200 s. The detection limits (3s) was evaluated to be 0.021 
g L-1 forAs(III) and 0.029 g L-1 for total inorganic arsenic. Theprecision for 14 replicate determinations of 1 g L-1 As(III) was 2.8% (RSD) with drift correction and 3.9% (RSD)without drift correction. The concentrations of As(III) andAs(V) in synthetic mixtures obtained by the presentmethod were in good agreement with expected values.Results obtained by the proposed method for total arsenicin a river water reference material agreed well withcertified and recently reevaluated values. The method wasalso applied to the speciation analysis of inorganic arsenicin porewaters.
g L-1 forAs(III) and 0.029 g L-1 for total inorganic arsenic. Theprecision for 14 replicate determinations of 1 g L-1 As(III) was 2.8% (RSD) with drift correction and 3.9% (RSD)without drift correction. The concentrations of As(III) andAs(V) in synthetic mixtures obtained by the presentmethod were in good agreement with expected values.Results obtained by the proposed method for total arsenicin a river water reference material agreed well withcertified and recently reevaluated values. The method wasalso applied to the speciation analysis of inorganic arsenicin porewaters.