Dimerization reaction of protonated and deprotonated amino acids in atmospheric pressure chemical ionization

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• 作者：Sung-Seen Choi ; ^{sschoi@sejong.ac.kr} ; Ok-Bae Kim
• 关键词：Dimerized amino acid ion ; Protonated amino acid ; Deprotonated amino acid ; APCI
• 刊名：International Journal of Mass Spectrometry
• 出版年：2013
• 出版时间：1 April, 2013
• 年：2013
• 卷：339-340
• 期：Complete
• 页码：34-38
• 全文大小：444 K

文摘

Twenty protein amino acids (AAs) were ionized by atmospheric pressure chemical ionization, and dimerized product ions of protonated and deprotonated AAs ([2M+H]⁺ and [2M?H]^?, respectively) were analyzed. It was found that formation of the [2M?H]^? ions was much more favorable than that of the [2M+H]⁺ ions. In the positive ion mode, the relative abundances of the [2M+H]⁺ ions of proline and tryptophan were greater than those of the other AAs. In the negative ion mode, the relative abundances of the [2M?H]^? ions of glycine, histidine, methionine, and tryptophan were greater than those of the other AAs. Compared to the formation of [2M+H]⁺ ions, superior formation of the [2M?H]^? ions could be due to the structural stability. The relative abundances of dimerized AAs increased with increase in the concentration, whereas they decreased with increase in the cone voltage.