液液萃取-高效液相色谱-电感耦合等离子体质谱同时测定海水中的多种有机锡

利用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP/MS)联用技术对海水中的五种有机锡三甲基氯化锡(TMT)、二丁基氯化锡(DBT)、三丁基氯化锡(TBT)、二苯基氯化锡(DPhT)和三苯基氯化锡(TPhT)]进行了分离，采用Agilent TC-C18色谱柱，流动相为乙腈/水/乙酸(65∶23∶12, φ)，0.05%三乙胺，pH 3.0，流速为0.6 mL·min-1, 测定了0.5～100 μg·L-1范围内五种有机锡化合物的混合标准工作曲线，其相关系数R2优于0.998，方法的检出限均小于3 ng·L-1。100 mL海水样品用10 mL含有0.2% Tropolone的CH₂Cl₂萃取两次后，有机相合并氮吹浓缩至最后一滴，加入1 mL的乙腈，用0.2 2 μm的有机滤膜过滤后分析。结果表明，海水中只检测到TPhT，含量为53.2 ng·L-1。样品的加标证明DBT, DPhT, TBT和TPhT的加标回收率均优于80%。TMT可能存在吸附或降解问题，回收率仅为50%。

Simultaneous Determination of Multi-Organotin Compounds in Seawater by Liquid-Liquid Extraction-High Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry

The hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was applied to the simultaneous determination of five organotin compounds (trimethyltin, dibutyltin, tributyltin, diphenyltin and triphenyltin) in seawater samples. Agilent TC-C18 column was used for the separation, the mobile phase of HPLC was CH3CN:H2O:CH3COOH=65:23:12 (φ),0.05% TEA, and pH value was adjusted to 3.0 by diluent ammonia. The flow rate was 0. 6 mL · min^-1. Five mixed organotin compounds in a mix standard solution from 100 to 0. 5 μg · L^-1 were applied for the method assessment. The experimental results indicate that the correlation coefficient of calibration curves (Rz ) for each organotin compound was over 0. 998 and the detection limits of the five organotin compounds were lower than 3 μg · L^-1. Different mixed organic solvents including dichloromethane or toluene were used for extraction of organotin and the extraction condition of organotin from seawater was optimized. The 100 mL seawater acidized by hydrochloric acid was extracted by 10 mL carbon dichloride (CH2 Cl2 ) with 2 % tropolone for 10 min twice. Extracted organic solvents were mixed and blown to one drop by nitrogen with the rate of 1.7 mL · min^-1, then 1 mL acetonitrile was added to the drop for redissolving theorganotin compounds. Finally, the mixed redissolution was filtered by 0. 22 btm organic filter membrane before analysis. It was found that the only organotin compound in seawater was triphenyltin (TPHT) and the content was 53.2 ng · L^-1. The recoveries test from the standard addition for diphenyltin (DPHT), dibutyltin (DBT), tributyltin (TBT) and triphenyltin (TPHT) were over 80%. However, the recovery for trimethyltin (TMT) was relatively low and the value was 50%. The reason might be attributed to the decomposition or adsorption of those compounds during the extraction procedure. Further study on this subject is in progress.