Determination of soluble arsenic(III) and arsenic(V) in Niuhuang Jiedu tablets by AFS

A method for the determination of soluble As(91) and As(V) in niuhuang jiedu tablets by AFS was established. The basic effects of soluble As(III) and As(V) in niuhuang jiedu tablets were inspected, and the effects of HCl acidity and concentration of reducer NABH(4) on the determination of As(III) and As(V) were discussed. In a hydrochloric acid medium of between 3.6 and 5.8 mol.L-1 and when 2.0 %-2.5 % of NaBH4 was used as a reductive agent, As(III) may be detected by AFS. After As(V) was reduced into As(III) by difference reducing method, the total quantity of arsenic in niuhuang jiedu tablets may be determined in the same way. Through calculation the contents of As(III) and As(V) were obtained, respectively. During six times of analyses of niuhuang jiedu tablets produced in the same factory, the relative stardard deviation was 0.8 % and 2.9 %, and the addition standard recovery was 96.7%-116.3% and 109.0%-116.8% for As(III) and As(V).