Journal of Chromatography & Separation Techniques
Open Access

Abstract

LC-MS Analysis of Low Molecular Weight Carbonyl Compounds as 2,4-Dinitrophenylhydrazones Using Negative Ion Mode Electronspray Ionization Mass Spectrometry

Akio Yasuhara, Yuuka Tanaka, Miyuki Makishima, Shigeru Suzuki and Takayuki Shibamoto

Organic compounds in the environment, such as pesticides, degrade into inorganics via transformation into carbonyl compounds, such as formaldehyde, acetaldehyde, and acetone. 2, 4-Dinitrophenylhydrazones of 37 carbonyl compounds were prepared with 2, 4-dinitrophenyl hydrazine (DNPH). Their ESI negative spectra and EI positive spectra were obtained using an HPLC-mass spectrograph. EI positive spectra showed more ions than ESI negative spectra except in the case of two hydrazones. Molecular ions (M+) of carbonyl-DNPHs appeared as a base peak in the EI positive spectra in the case of all but 8 hydrazones. Many significant ions for the identification of a specific carbonyl compound are obtained by ESI negative spectra. Analysis of acetone in various waste waters was successfully conducted using a newly developed ESI negative spectroscopy method-levels found in the samples ranged from 2.1 mg/L to135.0 mg/L. Results of similar tests of the rate of acetone degradation in various water samples showed that acetone in moat water degraded completely after 18 days, whereas 70% of the acetone remained in pure water after 65 days, suggesting that microorganisms may play an important role in the degradation of carbonyl compounds in the environment.