微波萃取高效液相色谱-冷原子荧光光谱法测定沉积物中甲基汞和无机汞

建立了微波萃取高效液相色谱-冷原子荧光光谱法(MAE-HPLC-CVAFS)测定沉积物中甲基汞(MeHg+)和无机汞(Hg2+)的方法。以0.1%(V/V)2-巯基乙醇为萃取剂,用于沉积物样品中汞形态的萃取,在80℃下萃取8 min,萃取液直接注入HPLC-CVAFS系统分析。在优化条件下,MeHg+和Hg2+的检出限分别为0.58和0.48 ng/g;加标回收率分别为96.2%和95.8%;RSD(n=6)分别为5.7%和4.1%。对标准参考物质(IAEA-405和ERM-CC580)的分析结果与推荐值一致。本方法简单、快速、准确、检出限低,抗干扰能力强,具有很好的实用性和推广价值。

Determination of Methylmercury and Inorganic Mercury in Sediments by High Performance Liquid Chromatography Hyphenated to Cold Vapor Generation Atomic Fluorescence Spectrometry Following a Microwave-Assisted Extraction

A high performance liquid chromatography(HPLC) coupled with cold vapor generation atomic fluorescence spectrometry method(CVAFS) has been developed for the separation and determination of methylmercury(MeHg+) and inorganic mercury(Hg2+) in sediment samples.The previous extraction of samples was carried out at a temperature of 80 ℃ for 8 min by using 0.1%(V/V) 2-mercaptoethanol as the extractant.The separation and determination of mercury species were achieved by direct injecting the extractant to HPLC-CVAFS system.Under the optimized conditions,the limit of detection was 0.58 ng/g for MeHg+ and 0.48 ng/g for Hg2+.The average recoveries were 96.2% and 95.8% for MeHg+ and Hg2+,respectively,by spiking three concentration levels of mercury species into samples.The proposed method was validated for the determination of certified reference material IAEA-405 and ERM-CC580,and the analytical results were in good agreement with the certified values.The proposed method was simple,rapid,accurate,no interference and suitable for the determination of methylmercury and inorganic mercury in sediment samples.