外来盐的存在对电喷雾和激光喷雾中气态离子形成的影响。

The effect of the presence of foreign salts on the formation of gaseous ions for electrospray and laser spray.

作者信息

Hiraoka Kenzo, Asakawa Yoshiki, Kawashima Yoko, Okazaki Shigemitsu, Nakamura Masana, Yamamoto Yasuteru, Takamizawa Atsushi

机构信息

Clean Energy Research Center, University of Yamanashi, Takeda-4, Kofu 400-8511, Japan.

出版信息

Rapid Commun Mass Spectrom. 2004;18(20):2437-42. doi: 10.1002/rcm.1644.

DOI:10.1002/rcm.1644

PMID:15378710

Abstract

The effect of the presence of foreign salts (NaCl, aerosol OT, tetra-n-hexylammonium bromide, and CH3COONH4) on the formation of gaseous ions for electrospray (ES) and laser spray (LS) was studied in the positive and negative modes of operations. The ion signals for amino acids show sudden decrease with the concentration of foreign salts greater than 10(-5) M for both ES and LS. When the surface-active counter ions were added, the signal intensities showed a marked decrease for both ES and LS. This may be due to the enrichment of the surface-active counter ions on the surface of the charged droplets. When CH3COONH4 was added to an aqueous solution of 10(-6) M lysozyme chloride, an increase of the signal intensities for (lysozyme+nH)n+ and a decrease in the values of n were observed. The decrease in n may be due to the salt formation of (lysozyme+nH)n+ with the negative acetate ion leading to the reduction of positive charges.

摘要

研究了在正、负操作模式下，外来盐（氯化钠、气溶胶OT、四正己基溴化铵和醋酸铵）的存在对电喷雾（ES）和激光喷雾（LS）气态离子形成的影响。对于ES和LS，当外来盐浓度大于10⁻⁵ M时，氨基酸的离子信号会突然下降。当添加表面活性抗衡离子时，ES和LS的信号强度均显著降低。这可能是由于表面活性抗衡离子在带电液滴表面富集所致。当向10⁻⁶ M溶菌酶氯化物水溶液中添加醋酸铵时，观察到(溶菌酶 + nH)ⁿ⁺的信号强度增加，n值减小。n值的减小可能是由于(溶菌酶 + nH)ⁿ⁺与醋酸根负离子形成盐，导致正电荷减少。