POSITIVE AND NEGATIVE-ION CHEMICAL IONIZATION MASS-SPECTRA OF AMINO-ACID CARBOXY-N-BUTYL ESTER N-PENTAFLUOROPROPIONATE DERIVATIVES
POSITIVE AND NEGATIVE-ION CHEMICAL IONIZATION MASS-SPECTRA OF AMINO-ACID CARBOXY-N-BUTYL ESTER N-PENTAFLUOROPROPIONATE DERIVATIVES
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DOI：
10.1002/bms.1200110506
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发表时间：
1984-01-01
期刊：
影响因子：
--
通讯作者：
DUFFIELD, AM
中科院分区：
文献类型：
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作者：
LOW, GKC;DUFFIELD, AM
测定了29个氨基酸N-(O，S)-五氟丙酸羧丁酯衍生物的正负化学电离质谱图。正离子(PI)谱符合该氨基酸衍生物的预期裂解模式，但其甲烷负离子化学电离(NICI)谱显示不同氨基酸类别之间以及同一类别内位置异构体之间的显著差异。同分异构体丁酸(α，β和γ)和酪氨酸(o，MAMDP-羟基化)衍生物都有明显不同的NiCI质谱图。脂肪族氨基酸Co2-n-丁基-N-PFP衍生物(甘氨酸除外)可以通过与[M-H-C4CO2H]−相对应的特征裂解过程很容易被识别。虽然PICI质谱图都给出了类似的检测响应，但在NICI模式下操作时，观察到不同氨基酸的差异。6种具有代表性的氨基酸-羧基-正丁基-N-PFP衍生物的检测灵敏度顺序为：羟脯氨酸和GT；赖氨酸和GT；半胱氨酸和GT；甘氨酸=亮氨酸：蛋氨酸；在PICI质谱学中，衍生亮氨酸的响应值比其NICI质谱值低25倍。
The positive and negative chemical ionization mass spectra of 29 amino acid carboxy‐n‐butyl ester N‐(O,S)‐Pentafluoropropionate derivatives hae been determined. The positive ion (PI) mass spectra conform to the expected fragmentation patterns for this amino acid derivative but their methane negative ion chemical ionization (NICI) mass spectra displayed marked differences between various amino acid classes and bvetween positional isomers within the same class. Isomeric butyric acid (α, β and γ) and tyrosine (o,mamdp‐hydroxylation) derivatives all had remarkably difterent NICI mass spectra. Aliphatic amino acid CO2‐n‐butyl‐N‐PFP derivatives (except glycine) can be readily recognized by a characteristic fragmentation process corresponding to [M–H–C4CO2H]−.Deuterium labellung studies were used to delineate some of the major NICI fragmentation processes. While the PICI mass spectra all gave comparable detection responses differences were observed with various amino acids when operating in the NICI mode. The order of sensitivity of detection for six representative amino acid‐carboxy‐n‐butyl‐N‐PFP derivatives were: hydroxyproline > lysine > cysteine > glycine=leucine=methionine in the ratio of 100:20:7:1. In PICI mass spectrometry derivatized leucine yielded a response 25 times less than its NICI mass spectrometric value.