Abstract

ARIAS-BARRANTES, Betzabel; URBINA-CAMPOS, Azucena  and  ALVARADO-GAMEZ, Ana Lorena. VALIDATION OF A METHODOLOGY TO DETERMINE As(III) AND As(V) IN DRINKING WATER BY ANION EXCHANGE CHROMATOGRAPHY AND INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY. Rev. Int. Contam. Ambient [online]. 2020, vol.36, n.1, pp.45-53.  Epub Dec 22, 2020. ISSN 0188-4999.  https://doi.org/10.20937/rica.2020.36.53391.

A methodology was optimized and validated for the determination of soluble and particulate arsenic (As[III] and As[V]) in drinking water using anion exchange chromatography (AEC) and inductively coupled plasma mass spectrometry (ICP-MS). The AEC optimization consisted in a laboratory simulation of the procedure to be followed in the field to evaluate the recovery of 10 mixtures of As(III) and As(V) in synthetic water. The following figures of merit were obtained in the total arsenic analysis: detection limit (LOD) of 0.1 μg/L, quantification limit (LOQ) of 0.2 μg/L, linear range between 0.1 μg/L and 300 μg/L, and coefficients of determination ≤ 0.9996. Repeatability and intermediate repeatability were evaluated with a total arsenic standard solution of 12.5 μg/L, obtaining an average repeatability of 12.6 μg/L with a standard deviation of 0.2 % and a coefficient variation of 0.2 % for n = 7, while the intermediate precision had an average of 12.6 µg/L with a standard deviation of 0.4 % and a coefficient variation of 0.3 % for n = 7.. The average recoveries in the mixtures were: total arsenic ≤ 99 %, soluble arsenic ≤ 99 % and for arsenite and arsenate ≤ 97 %.

Keywords : arsenic; arsenite; arsenate; soluble arsenic; particulate arsenic; ICP-MS; oxidation states.