Effect of Ultrasonic Microdroplet Generation in the Low-Temperature Plasma Ionization-Mass Spectrometry

• Published in: Mass spectrometry letters Vol. 10; no. 4; pp. 103 - 107
• Main Authors: Hyoung Jun Lee, Yong-Hyeon Yim
• Format: Journal Article
• Language: English
• Published: 한국질량분석학회 01.12.2019; 사단법인 한국질량분석학회
• Subjects: 화학; ultrasonic microdroplet generation; low-temperature plasma ionization
• ISSN: 2233-4203; 2093-8950
• DOI: 10.5478/MSL.2019.10.4.103

Low-temperature plasma (LTP) ionization is one of the ambient ionization methods typically used in mass spectrom- etry (MS) for fast screening of chemicals with minimal or no sample preparation. In spite of various advantages of LTP ioniza- tion method, including simple instrumentation and in-situ analysis, more general applications of the method are limited due to poor desorption of analytes with low volatilities and low ionization efficiencies in the negative ion mode. In order to overcome these limitations, an ultrasonic vibrator of a commercial hand-held humidifier was interfaced with an LTP ionization source, which generated microdroplets from sample solutions and assisted with LTP ionization. Ionization behaviors of various chemi- cals in microdroplet-assisted LTP (MA LTP) were tested and compared with typical LTP ionization from dried samples applied on a surface. MA LTP efficiently ionized small organic, amino, and fatty acids with low volatilities and high polarities, which were hardly ionized using the standard LTP method. Facile interaction of LTP with ultrafine droplets generated by ultrasonic res- onator allows efficient ionization of relatively non-volatile and polar analytes both in the positive and negative ion modes. KCI Citation Count: 0