关键词: 流动注射, 火焰原子吸收光谱, 编结反应器, 铅, 皮蛋

Abstract: A new method for the determination of trace lead in preserved eggs was developed using flow injection (FI) coupled with flame atomic absorption spectrometry (FAAS). During the elution procedure, the eluent was pumped into knotted reactor (KR) by the suction of the peristaltic pump. By using this new method, the dispersion of the analyte was decreased significantly, and high absorbance peak value was achieved. Emptying procedure was added in order to ensure the precision and repeatability of each determination. An enrichment factor (EF) of 11.6 was achieve in the determination of 500 μg/L lead through sampling at a flow rate of 6.0 mL/min for 60 s, while the EF obtained using the traditional method was 3.7. The limit of detection (3σ) and determination frequency of this method were 3.91 μg/L and the 41 h-1, respectively. The precision RSD for 11 replicate determinations was 1.8%. Using 0.1‰ triethannolamine as the masking reagent, the recovery rates of lead from preserved egg white and yolk were determined to be 97.0%－99.5%.

Key words: flow injection (FI), flame atomic absorption spectrometry (FAAS), knotted reactor, lead, preserved egg