应用流动注射技术,用D412螯合树脂微柱富集海水中的铅(Ⅱ),并与火焰原子吸收光谱法相结合测定海水中铅(Ⅱ)。20 mL海水样品以3 mL·min-1流量进柱,被树脂螯合吸附富集,以0.2 mol·L-1乙酸铵溶液5 mL淋洗柱体去除干扰物,以4 mol·L-1硝酸溶液4 mL为洗脱剂(流量为7 mL·min-1),洗脱液直接引入火焰原子吸收光谱仪雾化器,在线检测。当海水样进样20 mL时,铅(Ⅱ)测定灵敏度可提高约35倍;检出限(3s)为1.3 μg·L-1。实际应用于海水样品分析,加标回收率为94.5%,测定值的相对标准偏差(n=6)为2.2%。

Trace amount of lead(Ⅱ) in sea water was pre-enriched on a micro-column packed with D412 chelate resin in a FI-system. Twenty mL of sea water sample was injected into the micro-column by wriggling pump at a rate of 3 mL·min-1, and Pb(Ⅱ) in the sample solution was adsorbed on the chelate resin. The micro-column was washed with 5 mL of 0.2 mol·L-1 NH4OAc solution to remove residual seawater. Pb(Ⅱ) was stripped from the micro-column with 4 mL of 4 mol·L-1 HNO3 solution at the rate of 7 mL·min-1. The eluate was transferred directly to the atomizer of the instrument. Peak-shaped absorption signal was recorded and the value of peak height was taken as parameter for quantification. By the enrichment procedure mentioned above, sensitivity for determination of the Pb(Ⅱ) was raised 35 times as compared with the procedure without pre-enrichment. Detection limit (3s) of the method was 1.3 μg·L-1. Test for recovery was made by standard addition method, giving value of recovery of 94.5% with RSD (n=6) of 2.2%.