Determination of small amount of lactone by a supercritical fluid FIA with chemiluminescent detection

• Published in: BUNSEKI KAGAKU Vol. 42; no. 3; pp. 173 - 181
• Main Authors: ISHII, Mikita, KOIKE, Mitsuru
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society for Analytical Chemistry 05.03.1993
• Subjects: chemiluminescent determination of small amount of lactone; supercritical fluid FIA
• ISSN: 0525-1931
• DOI: 10.2116/bunsekikagaku.42.3_173

By using a CO2 supercritical fluid (SCF) as FIA carrier and chemiluminescent (CL) reaction medium, a SCF-FIA/CL system was developed in order to determine small amount of lactone. The system was comprised of a single flow line; and a cylinder for CO2 SCF, high pressure pump, two injectors (Rheodyne 7125 : 100μl for reagents; 20 μl for sample), detector and recorder which were set up on the line, in order. A CL is produced as follows. Lactone reacts with sodium hydroxide and sodium hydroxide/ethanol, and changes to oxycarboxylic acid and glycolic acid ester, respectively. These two compounds react with each other, and the diester is finally produced. The diester reacts with dissolved oxygen, and a hypercompound, such as peroxide of oxalic acid diester is produced. The exited compound being a CL emitter produces the CL and the CL is enhanced in SCF. Analytical characteristics for γ-butyrolactone (γ-BuLac) as a representative were as follows. Lower detection limit: 1.0 ×10-10 M (20 μl injection method: S/N=2). Lineality of the calibration: 1.0×10-91.0×10-7M. Selectivity: excellent to lactone. Reproducibility: 5.5% in terms of relative standard deviation (5 repeated runs for 1×10-8 M γ-BuLac in 20 μl injection volume). Analytical time required: ca. 3 s. Recovery test for γ-BuLac in coffee essence was successfully achieved.