Rosenberg E, Kmetov V, Grasserbauer M
Institute of Analytical Chemistry, Vienna University of Technology.
Fresenius J Anal Chem. 2000 Feb;366(4):400-7. doi: 10.1007/s002160050082.
Liquid chromatography with atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) was applied for the determination of butyl- and phenyltin compounds. Chromatography was performed on a 30 x 2 mm, 3 microm C18 column, enabling the separation of mono-, di- and trisubstituted butyl- and phenyltin compounds in less than 10 min using a water/1% trifluoroacetic acid/methanol gradient. While satisfactory retention and resolution is achieved for the di- and trisubstituted butyl- and phenyltin compounds, monobutyltin and monophenyltin cannot be resolved chromatographically. Depending on the parameter values of the interface, APCI-MS detection allows both specific detection of the molecular ion or cluster ion at low to intermediate fragmentor voltages or quasi-element specific detection of the Sn+ ion released from the organotin compounds at high fragmentor voltages. The sensitivity of MS detection is similar for butyl- and phenyltin compounds, but varies largely from mono- to trisubstituted organotin compounds with tributyl- and triphenyltin being the most sensitively detectable compounds. Detection limits are in the 20-65 pg (abs.) range in SIM mode and in the 750-2000 pg (abs.) range in the scan mode for tributyl- and triphenyltin and for dibutyl- and diphenyltin, respectively. Monobutyl- and monophenyltin can be detected with much lower sensitivity which, together with their unfavorable chromatographic behavior, accounts for the fact that they cannot be analyzed at environmentally relevant concentrations. Although LC-APCI-MS is generally less sensitive than comparable GC methods, it is applicable to the analysis of environmental samples as demonstrated by the analysis of the PACS-2 sediment certified reference material. Although the derivatization of the ionic organotin compounds, which particularly in real samples is a potential source of error, is circumvented when LC-APCI-MS is used, the extraction step is still critical and may lead to underestimation when quantitation is not done by the method of standard addition.
采用液相色谱-大气压化学电离质谱联用技术（LC-APCI-MS）测定丁基锡和苯基锡化合物。色谱分析在一根30×2 mm、3μm的C18柱上进行，使用水/1%三氟乙酸/甲醇梯度，可在不到10分钟内分离单取代、二取代和三取代的丁基锡和苯基锡化合物。虽然二取代和三取代的丁基锡和苯基锡化合物能实现令人满意的保留和分离，但一丁基锡和一苯基锡在色谱上无法分离。根据接口的参数值，APCI-MS检测在低至中等碎裂电压下可对分子离子或簇离子进行特异性检测，在高碎裂电压下可对有机锡化合物释放的Sn+离子进行准元素特异性检测。丁基锡和苯基锡化合物的质谱检测灵敏度相似，但从单取代到三取代的有机锡化合物灵敏度差异很大，其中三丁基锡和三苯基锡是最易检测的化合物。在选择离子监测（SIM）模式下，三丁基锡和三苯基锡以及二丁基锡和二苯基锡的检测限分别在20 - 65 pg（绝对值）范围和750 - 2000 pg（绝对值）范围。一丁基锡和一苯基锡的检测灵敏度要低得多，再加上它们不利的色谱行为，导致无法在环境相关浓度下对其进行分析。尽管LC-APCI-MS通常比同类气相色谱方法灵敏度低，但通过对PACS-2沉积物标准物质的分析表明，它适用于环境样品的分析。虽然使用LC-APCI-MS时可避免离子型有机锡化合物的衍生化（这在实际样品中尤其可能是误差来源），但萃取步骤仍然至关重要，若不采用标准加入法进行定量，可能会导致低估结果。
