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Determination of Inorganic Arsenic (III) and Arsenic (III Plus V) Using Automated Hydride‐Generation Atomic‐Absorption Spectrometry
Author(s) -
Glaubig Robert A.,
Goldberg Sabine
Publication year - 1988
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1988.03615995005200020044x
Subject(s) - hydride , arsenic , chemistry , atomic absorption spectroscopy , detection limit , oxalate , analytical chemistry (journal) , inorganic arsenic , aqueous solution , nuclear chemistry , metal , inorganic chemistry , chromatography , physics , organic chemistry , quantum mechanics
A simple method was developed to analyze aqueous inorganic arsenic in the µg L −1 range using automated hydride‐generation atomic‐absorption spectrometry. Total inorganic arsenic, As(III plus V), was determined by reducing As(V) to As(III) using KI then generating the hydride in 6 M HCl. Arsenic (III) was determined by generating the hydride at pH 4.0 to 4.5 using an oxalate buffer. Detection limits for the As(III plus V) and As(III) analytical methods were less than 0.4 µg As L −1 . Arsenic(V) was calculated by difference. Spiking of actual sample solutions with As(III) and As(V) showed the procedure to be accurate on solutions with initial pH values ranging from 2.7 to 9.8 and As(III)/As(V) ratios ranging from 1:4 to 4:1. Recoveries of As were within 1.5 µg As L −1 of added amounts ranging from 10.0 to 40.0 µg As L −1 , and standard deviations of triplicate analyses were within 0.4 µg As L −1 . Automated hydride generation allowed analysis at a rate of 53 samples per h, a significant rate increase over traditional batch hydride generators. Spontaneous oxidation of As(III) to As(V) was observed on spiked samples mixed 3 h before analysis.