HG-AFS Determination of Arsenic in Victoria Medicines with Microwave Assisted Sample Digestion

The sample of Victoria medicines,i.e. chickpeas,pepper or black pepper,was treated by microwave digestion,and the content of arsenic(Ⅲ) in the sample solution was determined by hydride generation-atomic fluorescence spectrometry (HG-AFS). Working parameters of the instrument including lamp current,negative high-voltage,the flow-rates of carrier gas and shielding gas and the chemical reaction conditions,including acidity of medium,concentration of potassium borohydride added,kinds of pre-reductants,conditions of sample digestion,and interferences of coexisting ions were studied and optimized. Linear relationship between values of fluorescence intensity and mass concentration of As(Ⅲ) was kept in the range of 1.0-10.0 μg·L-1,with detection limits (3s/k) of 0.5 μg·L-1. The proposed method was applied to the analysis of Victoria medicines,and values of recovery found were ranged from 90.2%-99.4%.