液相色谱-串联三重四极杆质谱法测定船舶防腐涂料中三丁基氧化锡的含量

Determination of Tributyltin Oxide in Marine Anticorrosive Coatings by Liquid Chromatography-Tandem Triple Quadrupole Mass Spectrometry

取混合均匀的样品1.00 g于比色管中,加入15 mL提取剂(水基型涂料采用甲醇;溶剂型涂料采用乙酸乙酯),于35℃超声提取15 min,将提取液离心5 min,取10 mL上层清液,氮吹至近干,用甲醇复溶并定容至2 mL,过0.45μm滤膜(水基型涂料采用尼龙滤膜;溶剂型涂料采用有机滤膜),采用液相色谱-串联三重四极杆质谱法测定滤液中三丁基氧化锡的含量。以EC-C_(18)色谱柱为固定相,以不同体积比的0.1%(体积分数)甲酸溶液和甲醇的混合液为流动相进行梯度洗脱。质谱分析中采用电喷雾正离子源和多反应监测模式,外标法定量。结果表明,三丁基氧化锡的质量浓度在0.1~2.0 mg·L^(-1)内与对应的峰面积呈线性关系,检出限为0.031 mg·kg^(-1)。按标准加入法进行回收试验,回收率为86.9%~92.9%,测定值的相对标准偏差(n=6)均小于4.0%。方法用于分析溶剂型涂料和水基型涂料各10个样品,其中溶剂型涂料中有2个样品检出三丁基氧化锡,检出量为1.18,0.82 mg·kg^(-1);水基型涂料中有1个样品检出三丁基氧化锡,检出量为0.48 mg·kg^(-1)。

The uniformly mixed sample(1.00 g)was taken and placed in a colorimetric tube.15 mL of extractant(methanol for water based coatings,and ethyl acetate for solvent based coatings)was added,and the solution was extracted by ultrasound at 35℃for 15 min.The extraction solution was centrifuged for 5 min,and 10 mL of the upper clear liquid was taken and blown to near dryness by nitrogen.The residue was redissolved and made its volume up to 2 mL by methanol,and passed through 0.45μm filter membrane(nylon filter membrane for water based coatings,and organic filter membrane for solvent based coatings).Tributyltin oxide in the filtrate was determined by liquid chromatography-tandem triple quadrupole mass spectrometry,with EC-C_(18) chromatographic column as the stationary phase,and a mixed solution of 0.1%(volume fraction)formic acid solution and methanol at different volume ratios as the mobile phase for gradient elution.The electrospray positive ion source and multiple reaction monitoring mode were adopted into mass spectrometry analysis,and external standard method was used for quantification.As shown by the results,linear relationship between the corresponding peak areas and mass concentrations of tributyltin oxide was found in the range of 0.1-2.0 mg·L^(-1),with detection limit of 0.031 mg·kg^(-1).Test for recovery was made by the standard addition method,giving results in the range of 86.9%-92.9%,with RSDs(n=6)of the determined values less than 4.0%.This method was used to analyze 10 samples of solvent based coatings and 10 samples of water based coatings.Among them,tributyltin oxide was detected in 2 samples of solvent based coatings with detection amounts of 1.18 and 0.82 mg·kg^(-1),and in one sample of water based coating with detection amount of 0.48 mg·kg^(-1).