固相萃取-电感耦合等离子质谱测定酱油中铅和镉

摘要

建立酱油中铅和镉的固相萃取-电感耦合等离子质谱同时测定方法,样品经微波消解赶酸后用缓冲溶液控制pH值,然后用固相萃取仪将样品溶液泵入多合一的重金属固相萃取柱,以达到铅镉从高盐基体中的分离.对缓冲液pH值的控制效果及固相萃取柱的基体分离效果、柱容量、重复性进行验证试验.试验表明,该柱对铅回收率91.8%~99.7%,变异系数3.7%,镉回收率90.5%~98.4%,变异系数3.5%.该重金属固相萃取柱能够解决酱油中铅和镉ICP-MS测定的基体干扰问题.%A method for simultaneous determination of lead and cadmium in soy sauce by ICP-MS with solid phase extraction was established.Soy sauce sample was microwave digested,and then adjusted the pH of the digest with buffer after removing most of the acid. The solution were pumped into the solid phase extraction column by using SPE instrument. Lead and cadmium were chelated in solid phase extraction column and separated from high salty matrixes.A series of verification test were implemented including buffering capacity of buffer,separation effect of the solid phase extraction column and the capacity and repeatability.The repetitive experimental results showed that the recoveries of the column for lead were between 91.8 % to 99.7 % with RSD of 3.7 %,and the recoveries for cadmium were between 90.5 % to 98.4 % with RSD of 3.5 %.The solid phase extraction column can solve the problem of soy sauce matrix interference effect for ICP-MS anaysis of Pb and Cd in soy sauce.