采用固相萃取-高效液相色谱-原子荧光光谱法联用技术测定了水样中无机汞及有机汞.水样流经以DDTC溶液改性的C18固相萃取小柱.用含有10%(体积分数)乙腈的混合洗脱液4 mL,分4次,以1~2 mL·min-1流量从小柱上将3种形态的汞洗脱.收集洗脱液,混匀,过滤后通过Venusil MP C18色谱柱,用乙腈、145 mmol·L-1乙酸铵溶液和20 mmol·L-1半胱氨酸溶液(5+45+50)混合液作为流动相进行色谱分离.根据选定的形态分析条件,用原子荧光光谱法进行测定.汞质量浓度在0.5~20 μg·L-1范围内与其峰面积呈线性关系,汞(Ⅱ)、甲基汞、乙基汞的检出限(3S/N)依次为1.6,0.5,1.2 ng·L-1.加标回收率在71.2%~95.2%之间,测定值的相对标准偏差(n=6)在4.9%~10%之间.

HPLC and AFS in hyphenation were applied to the determination of inorganic and organic mercury in water.The water sample was passed through DDTC modified C18 SPE microcolumn.The column was eluted with 4×1 mL of a mixture containing 10% (φ) of acetonitrile at a flow-rate of 1-2 mL·min-1.The eluates were collected,mixed and filtered.Chromatographic separation was made with the filtrate obtained,by using venusil MP C18 column as stationary phase and a mixture containing CH3CN,145 mmol·L-1 NH4OAC solution and 20 mmol·L-1 L-cysteine solution (mixed in the volumic ratio of 5+45+50) as mobile phase.Contents of Hg in the 3 species were determined by AFS under the prescribed condition.Linear relationship between values of peak area and concentration of mercury were found in the range of 0.5-20 μg·L-1.Detection limits (3S/N) were 1.6 ng·L-1 (for Hg2+),0.5 ng·L-1 (for MeHg) and 1.2 ng·L-1 (for EtHg).Values of recovery found by standard addition method were in the range of 71.2% to 95.2%,and values of RSD′s (n=6) in the range of 4.9%-10%.