The use of L-ascorbic acid in speciation of arsenic compounds in drinking water

Abstract

Arsenic speciation, besides total arsenic content determination, is very important in analysis of water, foodstuffs, and environmental samples, because of varying degrees of toxicity of different species. For such purpose hydride generation atomic absorption spectrometry can be used based on the generation of certain types of hydride, depending on the pH value and pretreatment in different reaction media. In this study, we have investigated the effect of L-ascorbic acid as the reaction medium as well as the pre-reducing agent in speciation of arsenic by hydride generation-atomic absorption spectrometry in order to determine monomethyl arsonic acid (MMA) in the presence of inorganic forms of arsenic.Prilikom analize razlicitih vrsta uzoraka voda, zivotnih namirnica i uzoraka iz zivotne sredine, ukazuje se potreba da se osim odredjivanja sadrzaja ukupnog arsena izvede i odredjivanje razlicitih oblika arsena. Atomska apsorpciona spektrometrija sa gradjenjem hidrida je metoda kojom je moguce odrediti razlicite oblike arsena primenom razlicitih uslova stvaranja hidrida. L-askorbinska kiselina se moze upotrebiti kao reakcioni medijum, odnosno kao preredukcioni agens u stvaranju hidrida arsena tokom specijacije. Cilj ovog rada je da se ispita mogucnost koriscenja L-askorbinske kiseline pri odredjivanju organskog oblika arsena, monometil arsonske kiseline (MMA), u vodi za pice u prisustvu neorganskog arsena (As(III) i As(V)).