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

作者：Choi Sung Seen^*; Kim Ok Bae

来源：International Journal of Mass Spectrometry, 2013, 339: 34-38.

DOI：10.1016/j.ijms.2013.02.001

• Dimerized amino acid ion
• Protonated amino acid
• Deprotonated amino acid
• APCI

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 Ms. 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 Ms. 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 Ms increased with increase in the concentration, whereas they decreased with increase in the cone voltage.

• 出版日期2013-4-1