The use of a new silylating agent for analysis of catecholamines by gas chromatography-mass spectrometry.
作者:HIROSHI MIYAZAKI、MASATAKA ISHIBASHI、KOUWA YAMASHITA、MAKOTO YAKUSHIJI
DOI:10.1248/cpb.29.796
日期:——
3-Methoxytyramine, dopamine, norepinephrine, epinephrine and 6-hydroxydopamine were derivatized to their N-trifluoroacetyl-O-dimethyl-n-propylsilyl ether or 2'-O-methyl-N-trifluoroacetyl-O-dimethyl-n-propylsilyl ether derivatives by treatment with trifluoroacetic anhydride, methanol and then dimethyl-n-propylsilyl imidazole. These derivatives could be separated completely by gas chromatography (GC) on a non-polar liquid stationary phase such as OV-101. In addition, these derivatives were very stable in benzene and ethyl acetate, and showed excellent stability during silica gel column chromatography in comparison with the corresponding trimethylsilyl ether derivatives. In GC-mass spectrometry (MS) of these derivatives, ammonia chemical ionization (CI)-MS provided the ion [M+NH4]+ as the base peak or an intense peak. The detection limit of the dopamine derivative in the CI mode with ammonia was 2 pg with S/N at 2 : 1.
将 3-甲氧基酪胺、多巴胺、去甲肾上腺素、肾上腺素和 6-羟基多巴胺用三氟乙酸酐、甲醇和二甲基-正丙基硅醚衍生为 N-三氟乙酰基-O-二甲基-正丙基硅醚或 2'-O- 甲基-N-三氟乙酰基-O-二甲基-正丙基硅醚衍生物。这些衍生物可在 OV-101 等非极性液体固定相上通过气相色谱法(GC)完全分离。此外,这些衍生物在苯和乙酸乙酯中非常稳定,与相应的三甲基硅醚衍生物相比,它们在硅胶柱层析过程中表现出极佳的稳定性。在对这些衍生物进行气相色谱-质谱(MS)分析时,氨化学电离(CI)-MS可提供离子[M+NH4]+作为基峰或强峰。在氨化学电离模式下,多巴胺衍生物的检出限为 2 pg,信噪比为 2:1。