U.S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Silver Spring, MD 20993, USA.
J Sep Sci. 2012 Mar;35(5-6):661-5. doi: 10.1002/jssc.201100920. Epub 2012 Feb 14.
This paper presents sample stacking with in-column silylation (SIS) for quantitative analysis of less volatile polar compounds using gas chromatography-mass spectrometry (GC-MS). This was achieved by the combination of sandwiched in-column silylation and multiple injections (up to 100 times or 100 μL in total). N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) was used as a silylating reagent. For the SIS technique, samples were introduced multiple N times (N = 2~100) into a capillary column in between BSTFA injections. The quantitative characteristic of SIS technique was studied using bisphenol A (BPA) as a model compound. The sandwiched in-column silylation for the less volatile polar compounds effectively replaced polar hydrogen with trimethylsilyl group to reduce sample adsorption and band broadening. Meanwhile, multiple injections at the SIS technique contributed to increase the sensitivity quantitatively. The capability and limitation of this analytical approach were further investigated with various types of compounds such as hydroxyls, carboxylic acids, and amine.
本文提出了柱内硅烷化（SIS）与进样内浓缩联用的方法，结合了夹心柱内硅烷化和多次进样（多达 100 次或总共 100 μL），使用气相色谱-质谱（GC-MS）对较少挥发性的极性化合物进行定量分析。采用 N,O-双（三甲基硅基）三氟乙酰胺（BSTFA）作为硅烷化试剂。对于 SIS 技术，在 BSTFA 进样之间将样品多次（N = 2~100）引入毛细管柱中。使用双酚 A（BPA）作为模型化合物研究了 SIS 技术的定量特征。对于较少挥发性的极性化合物，夹心柱内硅烷化有效地用三甲基硅基取代极性氢，从而减少样品吸附和谱带展宽。同时，SIS 技术的多次进样有助于定量增加灵敏度。进一步用各种类型的化合物，如羟基、羧酸和胺，研究了这种分析方法的能力和局限性。
