Fluorometric Determination of Cyanate in Plasma by Conversion to 2,4(1H,3H)-Quinazolinedione and Separation by High-Performance Liquid Chromatography

✍ Scribed by P. Lundquist; B. Backmangullers; B. Kagedal; L. Nilsson; H. Rosling

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 420 KB
• Volume: 211
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.1993.1226

✦ Synopsis

A fluorometric high-performance liquid-chromatographic method is described for the determination of cyanate in human plasma. The method is based on the derivatization of cyanate with 2 -aminobenzoic acid (anthranilic acid), leading to a stable cyclic fluorescent product, (2,4(1 \mathrm{H}, 3 \mathrm{H}))-quinazolinedione. The fluorescent product was extracted with ethyl acetate, passed through a cation-exchange resin to eliminate the excess of derivatization reagent, and then concentrated on a Sep-Pak C-18 cartridge before reversed-phase chromatography and fluorometric detection. The precision of the method was satisfactory (coefficient of variation (2.3 %) ) and the analytical recovery was quantitative (103%). Detection limit was found to be (8 \mathrm{nmol} /) liter from a 1-ml plasma sample. Cyanate in plasma was stable for 3 months when stored in liquid nitrogen. The mean and SD cyanate level in human plasma from 17 healthy nonsmoking subjects was (45 \pm 21 \mathrm{nmol} /) liter. (c) 1993 Academic Press, Inc.