ORIGINAL PAPER Automated method for the determination of total arsenic and selenium in natural and drinking water by HG-AAS Mariela Pisto ´n • Javier Silva • Ramiro Pe ´rez-Zambra • Isabel Dol • Moise ´s Knochen Received: 10 February 2010 / Accepted: 11 April 2011 Ó Springer Science+Business Media B.V. 2011 Abstract A multicommutated flow system was designed and evaluated for the determination of total arsenic and selenium by Hydride Generation Atomic Absorption Spectrometry (HG-AAS). It was applied to the determination of arsenic and selenium in samples of natural and drinking water. Detection limits were 0.46 and 0.08 lgl -1 for arsenic and selenium, respec- tively; sampling frequency was 120 samples h -1 for arsenic and 160 samples h -1 for selenium. Linear ranges found were 1.54–10 lgl -1 (R = 0.999) for arsenic and 0.27–27 lgl -1 (R = 0.999) for selenium. Accuracy was evaluated by spiking various water samples and using a reference material. Recoveries were in the range 95–116%. Analytical precision (s r (%), n = 10) was 6% for both elements. Compared with the Standard Methods, APHA, 3114B manual method, the system consumes at least 10 times less sample per determination, and the quantities of acid and reducing agent used are significantly lower with a reduction in the generation of pollutants and waste. As an additional advantage, the system is very fast, efficient and environmentally friendly for monitoring total arsenic and selenium levels in waters. Keywords Flow analysis Á Selenium Á Arsenic Á Water Á Trace element monitoring Introduction Arsenic and selenium are two widely distributed semimetals which for different reasons have attracted interest in connection with public health issues. Arsenic has been known for centuries as a toxic element: in popular imagination, it has become a synonymous of poison. Besides the obvious behavior of some of its compounds in acute exposure, there is an increasing concern about the risk associated with long- term exposure. There exists considerable evidence suggesting that consumption of arsenic-containing water can cause skin, bladder and lung cancer (Goyer 1996). One of the main problems in some geographical areas arises from groundwater contamination of either mineral or anthropogenic origin. A number of chronic intoxication episodes have occurred that have drawn attention to the risk to which the population of certain areas is exposed due to consumption of water from contaminated wells. Thus, it has been classified as a high-priority substance for screening in drinking water sources. Maximum acceptable levels of total arsenic in drinking water have been the object of some contro- versy, although there is a trend toward the establish- ment of lower values. WHO, in its Guidelines for M. Pisto ´n (&) Á J. Silva Á R. Pe ´rez-Zambra Á I. Dol Á M. Knochen Facultad de Quı ´mica, Universidad de la Repu ´blica, Ca ´tedra de Quı ´mica Analı ´tica. Av. Gral. Flores 2124, P.O. Box 1157, 11800 Montevideo, Uruguay e-mail: [email protected]123 Environ Geochem Health DOI 10.1007/s10653-011-9436-9
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ORIGINAL PAPER
Automated method for the determination of total arsenicand selenium in natural and drinking water by HG-AAS
Mariela Piston • Javier Silva •
Ramiro Perez-Zambra •
Isabel Dol • Moises Knochen
Received: 10 February 2010 / Accepted: 11 April 2011
� Springer Science+Business Media B.V. 2011
Abstract A multicommutated flow system was
designed and evaluated for the determination of total
arsenic and selenium by Hydride Generation Atomic
Absorption Spectrometry (HG-AAS). It was applied to
the determination of arsenic and selenium in samples
of natural and drinking water. Detection limits were
0.46 and 0.08 lg l-1 for arsenic and selenium, respec-
tively; sampling frequency was 120 samples h-1 for
arsenic and 160 samples h-1 for selenium. Linear
ranges found were 1.54–10 lg l-1 (R = 0.999) for
arsenic and 0.27–27 lg l-1 (R = 0.999) for selenium.
Accuracy was evaluated by spiking various water
samples and using a reference material. Recoveries
were in the range 95–116%. Analytical precision
(sr (%), n = 10) was 6% for both elements. Compared
with the Standard Methods, APHA, 3114B manual
method, the system consumes at least 10 times less
sample per determination, and the quantities of acid
and reducing agent used are significantly lower with
a reduction in the generation of pollutants and waste.
As an additional advantage, the system is very fast,
efficient and environmentally friendly for monitoring
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