用快速分离柱高效液相色谱法测定食品中的重金属元素的研究

Study on Determination of Heavy Metal Ions in Food by Solid Phase Extraction Followed by High Performance Liquid Chromatography

研究了用固相萃取富集,快速分离柱高效液相色谱法测定食品中6种重金属元素:镍、铜、锡、铅、镉、汞的方法。食品样品用微波消化,样品消化液中的镍、铜、锡、铅、镉、汞用四-(邻氯苯基)-卟啉(T2CPP)柱前衍生,然后用ZORBAXRP1固相萃取小柱萃取富集镍、铜、锡、铅、镉、汞的T2-CPP络合物,富集8倍数为50倍;经富集后的络合物用甲醇-四氢呋喃(92/8)为流动相,ZORBAXStableBound(4.6×50mm,1.8μm)快速分离柱为固定相分离,用二极管矩阵检测器检测。镍、铜、锡、铅、镉、汞的检测限分别为:3、4、4、3、2、2ng/L,分离6种重金属元素络合物的时间只需2.0min。方法相对标准偏差为2.3%～2.8%,标准回收率为95%～105%。该方法用于测定食品中的痕量镍、铜、锡、铅、镉、汞,结果令人满意。

A new method for the determination of copper, nickel, tin, lead, cadmium and mercury by solid phase extraction and high performance liquid chromatography was studied. The copper, nickel, tin, lead, cadmium and mercury ions were pre- column derived by tera-(2-chlorophenyl)-porphine (T 2 CPP). These chelates were enriched by solid phase extraction with C 18 cartridge and the enrichment factor of 50 was achieved. The chelates were separated on a ZORBAX Stable Bound (4.6×50 mm, 1.8 μm) by gradient elution with methanol and THF as mobile phase at a flow rate of 2.0ml/min and detected with photodiode array detector from 350～600 nm. The detection limits of nickel, copper, tin, lead, cadmium and mercury are 3,4,4,3, 2 and 2ng/L, respectively. This method had been applied to the determination of nickel, copper, tin, lead, cadmium and mercury in food with good results.