固相萃取富集高效液相色谱法测定烟草及烟草添加剂中的重金属元素

Solid Phase Extraction Followed by High Performance Liquid Chromatography for the Determination of Heavy Metal Ions in Tobacco and Tobacco Additive

报道用固相萃取富集,高效液相色谱法测定烟草及烟草添加剂中镍、铜、锡、铅、镉、汞的方法。样品用微波消化,消化液中的镍、铜、锡、铅、镉、汞用四-(对甲氧基苯基)-卟啉(T_4MPP)柱前衍生,用C_(18)固相萃取小柱萃取富集镍、铜、锡、铅、镉、汞的T_4-MPP络合物,然后用甲醇和四氢呋喃为流动相梯度洗脱,Waters Xterra^(TM) RP_(18)色谱柱分离二极管阵列检测器检测。镍、铜、锡、铅、隔、汞的检出限在2～4 ng/L之间,方法相对标准偏差为1.8％～2.4％,加标回收率为96％～103％。

A new method for the solid phase extraction followed by high performance liquid chromatographic determination of copper, nickel, tin, lead, cadmium and mercury was studied. The copper, nickel, tin, lead, cadmium and mercury ions were pre-column derivatized by Tera-(4-methoxyphenyl)-porphine(T_4 MPP). These chelates were enriched by solid phase extraction with C_(18) cartridge and the enrichment factor of 50 was achieved. In further analysis, the chelates were separated on a Waters Xterra^(TM) RP_(18) column(3.9×150mm, 5μm)by gradient elution with methanol and THF as mobile phase at a flow rate of 1.0 mL/min and detected with photodiode array detector from 350～600 nm. The detection limits of nickel, copper, tin, lead, cadmium and mercury are 3 ng/L, 2 ng/L, 4 ng/ L, 3 ng/L, 2 ng/L and 3 ng/L, respectively. This method had been applied to the determination of nickel, copper, tin, lead, cadmium and mercury in tobacco and tobacco additive with satisfied results.