在线衍生高效液相色谱法测定酱油中Pb~(2+)和Ni~(2+)的含量

建立了湿法消解处理样品,反相高效液相色谱在线衍生同时测定酱油中Pb~(2+)和Ni~(2+)含量的方法。以二乙基二硫代氨基甲酸钠(Na DDTC)为衍生试剂,Hypersil ODS2 C-18反相色谱柱(5μm,250 mm×4.6mm)为固定相,甲醇-水-衍生剂(体积比63.5∶35∶1.5)为流动相进行检测。结果显示,Pb~(2+)与Ni~(2+)的线性范围为0.5~50μg/m L,相关系数(r~2)分别为0.998 2和0.999 0,检出限分别为0.3μg/m L和0.2μg/m L,样品加标回收率为88.1%~91.8%。该方法操作简单,准确度和精密度较好,可作为酱油样品中重金属离子测定的替代方法。

Determination of Pb2+ and Ni2+ in Soy Sauce by Online Derivation with High Performance Liquid Chromatography

Contents of Pb2+ and Ni2+ in soy sauce were determined by the online derivation and HPLC method with wet digestion.Sodium diethyldithiocarbamate (NaDDTC) was used as the derivtire agent for heavy metal ions.The experimental conditions were as follows:chromatography column:a HypersilODS2C-18(5 μm,250mm×4.6 mm)column,mobile phase:MeOH-H2O-sodium diethyldithiocarbamate(63.5 ∶ 35 ∶ 1.5).The calibration curves for Pb2+ and Ni2+ were linear in the range of 0.5-50 μg/mL with correlation coefficients of 0.998 2 and 0.999 0,respectively.The limits of detection were 0.3 μg/mL and 0.2 μg/mL,respectively,with recoveries of 88.1％-91.8％.The method has the advantages of simplicity,good accuracy and precision,and could be used as an alternative method for the determination of heavy metal ions in real soy sauce samples.