HG-AFS Determination of Arsenic and Selenium in Garlic

HG-AFS was applied to the determination of arsenic and selenium in garlic. Hydrides of As and Se ions were generated from HCl (5+95) solution by reacting with 20 g·L-1 KBH4 solution (dissolved in 50 g·L-1 NaOH solution). Flow-rates of carrier gas of 800 mL·min-1 for As and 600 mL·min-1 for Se, and flow-rate of shielding gas of 1 000 mL·min-1 were taken in the analysis. Mixed solution of thiourea and ascorbic acid was added to the sample solution as reductant. An aliquot of 0.5 mL of sample solution was introduced and operated under the prescribed working condition of the instrument. Linear relationships between the fluorescence intensity and mass concentration of As and Se were found in the ranges of 0.04-0.40 and 1.00-10.0 μg·L-1, with detection limits (3s/k) of 0.017 μg·L-1 and 0.314 μg·L-1 respectively. Recovery was tested by addition of standard solutions, giving values of recovery in the ranges of 95.3%-104.4% for As and 94.7%-105.2% for Se.