Automated method for the determination of total arsenic and selenium in natural and drinking water by HG-AAS

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 μg l(-1) for arsenic and selenium, respectively; sampling frequency was 120 samples h(-1) for arsenic and 160 samples h(-1) for selenium. Linear ranges found were 1.54-10 μg l(-1) (R = 0.999) for arsenic and 0.27-27 μg 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 (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.

Bacteriological and physicochemical parameters of some selected borehole water sources in Abakaliki metropolis, Nigeria

“…The washed items were dried and stored in zip locked polyethylene bags. 15 Water samples were filtered and collected into these precleaned wide mouthed containers (ca. 1 litre) with cap.…”

Influence of mining and agricultural activities on the quality of groundwater from some rural areas of South-eastern Nigeria

“…All items for collecting and storing samples and reagents were first washed with distilled deionised water (DDW), soaked overnight in 10% (v/v) nitric acid and then rinsed exhaustively with DDW. The washed items were dried and stored in zip locked polyethylene bags (Pistόn et al 2012). Twelve groundwater samples (six samples per area) were collected twice per month between March and July 2013.…”

“…Several methods have been optimised for the determination of total and speciated forms of arsenic in water (Pistόn et al 2012;Villa-Lojo et al 2002;Bednara et al 2004). This study adopted the method of Nyamah and Torgbor (1986).…”

A new separation and preconcentration method for selenium in some foods using modified silica gel with 2,6-diamino-4-phenil-1,3,5-triazine

“…However, high selenium levels in our body can cause toxicity, losing hair, nails and irritation of skin and eye (Stoica, Babaua, Iorgulescu, Marinescu, & Baiulescu, 2002). It has narrowest toxic ranges so control in the intake of Se by living organisms is imperative (Fordyce, 2005;Pistón, Silva, Pérez-Zambra, Dol, & Knochen, 2011). The selenium level in humans is 0.01-1 mg/g and high dose indicates toxic effects (Masson, Orignac, & Prunet, 2005;Stoica et al, 2002).…”