JMSSJ On-line

JMSSJ On-line, Vol. 52 (2004) No. 3, pp. 142-148

Mass Spectrometric Analysis of Synthetic Polymers Using Desorption/Ionization on Porous Silicon (DIOS):Optimal Etching Conditions for DIOS Chips		>> Full Text PDF >> References
*Shoji OKUNO, ^a) Yukiyasu SHIMOMAE, ^b) Kazuma OHARA, ^b) Hiroki FUJIWARA, ^b) Jun OHYAMA, ^b) Masayoshi OHMOTO, ^b) Yoshinao WADA, ^{a), c)} and Ryuichi ARAKAWA ^{a), b)}** ^a) Japan Science and Technology Agency, Wada Proteomics Project (3-1-10 Technostage, Izumi, Osaka 594-1144, Japan)^*b) Department of Applied Chemistry, Kansai University (3-3-35 Yamatecho, Suita, Osaka 564-8680, Japan)^c) Osaka Medical Center and Research Institute for Material and Child Health (840 Murodo-cho, Izumi, Osaka 594-1101, Japan)

Desorption/ionization on porous silicon (DIOS) is a novel matrix-free variant of laser desorption/ionization (LDI) techniques for mass spectrometry. The DIOS chips are produced by electrochemical etching of silicon wafers under light exposure. In the present report, the optimal conditions, regarding resistivity of silicon wafer, etching current density and etching time, for making DIOS chip with better ionization performance are described. In addition, the DIOS mass spectra of various synthetic polymers including polyethyleneglycol, nonylphenolpolyethoxylate, nonylphenolpolyethoxylatesulfate, polymethylmethacrylate are compared with the matrix-assisted LDI mass spectra.

Key words: DIOS (desorption/ionization on porous silicon), Laser desorption mass spectrometry, Synthetic polymer