气相色谱和原子荧光联用测定生物和沉积物样品中甲基汞

Determination of Methylmercury in Biological and Sediment Samples by Capillary Gas Chromatography On-Line Coupled with Atomic Fluorescence Spectrometry

提出了一种气相色谱和原子荧光在线联用测定甲基汞的方法。对气相色谱和原子荧光的在线联用进行了设计,优化了进样口温度、载气流速、尾吹气流量及氩气流量等实验条件。在最佳仪器条件下,甲基汞(MMC)和乙基汞(EMC)的绝对检出限(3σ)可达0.005 ng。对于10 ng.mL-1MMC和EMC标准溶液,连续5次进样测得精密度(RSD)分别为2.5%和1.3%。对标准参考物(DORM-2)的分析结果与标准值一致。两个沉积物中甲基汞的加标回收率分别为70%和77%。方法准确、灵敏,可应用于生物和沉积物样品中甲基汞的分析。

A comprehensive method for the determination of methylmercury by capillary gas chromatography(GC) on-line coupled with atomic fluorescence spectrometry(AFS) was developed.The hyphenation system was carefully designed and the operation (conditions) such as injector temperature,carrier gas flow rate,make-up gas flow rate and argon flow rate were optimized in detail.The absolute detection limits(3σ) were 0.005 ng of Hg for both methylmercury(MMC) and ethylmercury(EMC).The relative standard deviations(RSD,n=5) for MMC and EMC at 10 ng·mL^(-1) of Hg levels were 2.5% and 1.3%,respectively.The method was evaluated by analyzing a certified reference material(DORM-2),and the MMC concentration determined was in good agreement with the certified value.In addition, the recoveries of MMC in two sediment samples were 70% and 77%,respectively.The proposed method was accurate,sensitive and suitable for the determination of MMC in biological and sediment samples.