AFS Determination of Mercury in Halobionts with Microwave Assisted Sample Digestion

AFS was applied to the determination of mercury in halobionts. The sample was digested in a microwave sample digestor under the optimized conditions of: ① using power of 1 600 W for digestion; ② raising the digestion temperature to 120 ℃ in 5 min and keeping at this temperature for 5 min; ③ raising the temperature to 160 ℃ in 5 min and keeping for 10 min. In AFS analysis, negative high-voltage of 260 V, lamp current of 40 mA and flow-rate for carrier gas of 800 mL·min-1 were taken. Linear relationship between values of fluorescence intensity and mass concentration of mercury was obtained in the range within 0.80 μg·L-1, with detection limit (3s/k) of 0.002 mg·kg-1. The proposed method was applied to the determination of mercury in samples of halobionts, giving values of RSD (n=6) and recovery in the ranges of 2.7%-6.0% and 90%-104% respectively.