| 摘要 |
PURPOSE:To enable quick and exact measurement of an L-amino acid at a low cost by bringing a measuring probe attached with oxidase for an L-amino acid into contact with a liquid to be examined, introducing a gas contg. oxygen into said liquid and measuring the concn. of the liquid and the decreased value of the output current from a quadrupole type mass spectrometer corresponding to the oxygen consumed near the measuring probe. CONSTITUTION:The soln. 2 prepd. by dissolving L-glutamic axid oxidase, L-tyrosine oxidase, etc. or oxidase which oxidizes an L-amino acid in water is coated on a carrier 3 consisting of nylon mesh, etc. Said carrier is coated thereon with a film 4 having fine pores such as a cellophane film or the like which prohibits permeation of enzyme. Such carrier is attached on a diaphragm 1. Measurement is accomplished by passing a sample in a flow cell 9 through a buffer feed port 11 while blowing a gas contg. oxygen through a blow port 10. The L-amino acid in the sample is oxidized by the oxidase in the flow cell 9 and oxygen is consumed. The change in the concn. of oxygen results in a decrease in the current output from mass number 32 corresponding to the oxygen in a quadrupole mass spectrometer through the diaphragm 1 and is recorded in a recorder 14. |
