Fluorometric determination of cyanate in plasma by conversion to 2,4(1H,3H)-quinazolinedione and separation by high-performance liquid chromatography.
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(1H,3H)-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 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 +/- 21 nmol/liter.
Lundquist
P
P
Department of Clinical Chemistry, University Hospital, Linköping, Sweden.
Backman-Gullers
B
B
Kågedal
B
B
Nilsson
L
L
Rosling
H
H
D000328:Adult; D016477:Artifacts; D002851:Chromatography, High Pressure Liquid; D003485:Cyanates / Q000097:blood* / Q000737:chemistry; D005260:Female; D005470:Fluorometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D011799:Quinazolines / Q000032:analysis*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012907:Smoking / Q000097:blood; D014508:Urea / Q000737:chemistry
D003485:Cyanates; D011799:Quinazolines; C081989:2,4(1H,3H)-quinazolinedione; D014508:Urea; C024835:potassium cyanate