液相色谱-串联质谱法测定水环境中的十氯酮

Determination of kepone in water byliquid chromatographytandem mass spectrometry

建立了分析测定水环境中十氯酮的液相色谱-串联质谱法。水样经液液萃取、净化后，采用 Eclipse plus C18柱（100 mm×2.1 mm，3.5μm）分离，乙腈和水为流动相进行梯度洗脱，在电喷雾负离子多反应监测模式下进行检测，同位素内标法定量。结果表明：采用液相色谱-质谱联用技术，证实了十氯酮在甲醇中以半缩醛的形式存在，而在丙酮/乙腈中以偕二醇的形式存在。由于十氯酮极性较强，在净化时难以洗脱，并且不耐酸，所以不能与其他有机氯农药一起分析。十氯酮在5～100μg / L 范围有良好的线性关系，相关系数 r2=0.999，检出限及定量限分别为0.70 ng / L 和2.8 ng / L；在5、40和100 ng / L 3个浓度添加水平的平均回收率为95.1％～98.9％，相对标准偏差为3.85％～4.72％。本方法具有良好的灵敏度、回收率和重现性，适用于水环境中十氯酮的测定。

An analytical procedure for the determination of kepone in water was described. Water samples were extracted by liquid-liquid extraction,and then cleaned-up. Chromatograph-ic separation was performed on an Eclipse plus C18 column（100 mm＆#215;2. 1 mm,3. 5 μm）with gradient elution using acetonitrile and water at a flow rate of 0. 3 mL / min. The target com-pounds were determined in multiple reaction monitoring（MRM）mode via negative electrospray ionization（ ESI - ）and quantified by isotopic-dilution technique. Results showed that kepone existed as diol form and hemiacetal in acetone / acetonitrile and methanol respectively,the structures of which were confirmed by liquid chromatography-tandem mass spectrometry（ LC-MS / MS）. Due to the polar nature of kepone,it was difficult to be eluted during clean-up proce-dure and it may be decomposed during sulfuric acid washing. Therefore,it could not be ana-lyzed together with the other organochlorine pesticides. The calibration curve showed good line-arity in the range of 5-100 μg / L with correlation coefficient（r 2 ）of 0. 999. The limit of detec-tion was 0. 70 ng / L and the limit of quantification was 2. 8 ng / L in water. The average recover-ies when spiked at 5,40 and 100 ng / L in water were 95. 1% -98. 9% ,and the relative standard deviations（RSDs）were 3. 85% -4. 72% . The method can be used to the determination of kepone in water due to its high sensitivity,good recovery and reproducibility.