Improvenmet and applications of nano-electrospray LC/MS for the microscale structural analysis of glycolipids.

Research Project

Project/Area Number	09680583
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Structural biochemistry
Research Institution	Tokyo medical and dental university
Principal Investigator	KASAMA Takeshi Tokyo Medical and Dental University Instrumental Analysis Research Center for Life Science Associate Professor, 機器分析センター, 助教授 (80124668)
Project Period (FY)	1997 – 1998
Project Status	Completed (Fiscal Year 1998)
Budget Amount *help	¥2,900,000 (Direct Cost: ¥2,900,000) Fiscal Year 1998: ¥1,300,000 (Direct Cost: ¥1,300,000) Fiscal Year 1997: ¥1,600,000 (Direct Cost: ¥1,600,000)
Keywords	Electrospray Ionization / Mass Spectrometry / LC / MS / Liquid Chromatography / Glycosphingolipid / Ganglioside
Research Abstract	I tried improvement of nano-electrospray LC/MS with the aim of simplification of the carbohydrate structure analysis of glycoipid. Glycolipid sugar chain analysis by FABMS or SIMS becomes the common method to obtain quickly sugar-chain information without MS/MS.However, we have being able to use low-cost MS/MS equipment by the appearance of ion trap MS, etc. recently. With using the microscale LC/MS/MS combining with nano-electrospray which is the high-sensitive ionization method, the carbohydrate structure analysis will become easy with limited amount and low purified glycolipid. Negative electrospray was suitable for the high sensitive analysis of glycolipid, because only the deprotonated molecule appeared in the spectrum. In the positive mode, the molecular related ions have been divided into protonated molecule and sodium adducted ion. Halide solvent-containing solvent system which removes the electrons in the spray droplet was effective for stable electrospray in the negative mode. Especially, the chloroform was convenient solvent, because it is often used as a chromatography solvent for glycolipids. The addition of the basic compounds such as ammonia and monomethylamine to the solvent was also effective in order to the efficient formation of negative ions. In this study, the precise LC flow control was difficult to attach with the nano-electrospray. There was also difficult to avoid the plugging of the spray nozzle in diameter of few micrometers. The spray nozzle about 50 micrometers in diameter was suitable for micro LC/MS in practice. It was also proven that the micro litter-delivering pump was required for the micro HPLC.In present circumstances, however, the conventional pump would be used concerning the cost. The spray chip was placed close to the column exit for reducing the spread of elution band. But the reproducible formation of column end frit using potassium silicate was not easy. At present time, I am trying to overcome this problem.