METHOD FOR DETERMINING MEDICINAL SUBSTANCES IN URINE, SALIVA OR BLOOD PLASMA Russian patent published in 2024 - IPC G01N33/15 G01N33/487 G01N30/90 G01N1/28 

FIELD: medicine; therapy; toxicology.

SUBSTANCE: invention can be used for determination of medicinal substances in urine, saliva or blood plasma. Samples of determined substances in solution and samples of witness substances are chromatographed in a thin layer of sorbent. Test solution is prepared from 10 ml of urine, saliva or blood plasma by isolation with 40 ml of ethyl acetate with successive change of pH: pH=3.0, then pH=10.0 using buffer solutions. Chromatography is carried out on Sorbfil plates in a system of solvents dioxane—chloroform—acetone—25% ammonia solution in a volume ratio of 40:40:6:3 and determination of zones of substances on chromatogram in UV light at wave length 254 nm. Mobility factor R_f is determined. If R_f values are 0.4±0.01, perchlozon is determined, 0.79±0.01—rifabutin, 0.1±0.01—ftivazide, 0.46±0.01—pyrazinamide, 0.37±0.01—linezolid, 0.02±0.01—levofloxacin, 0.56±0.01—prothionamide, 0.24±0.01—abacavir, 0.71±0.01—amitriptyline, 0.3±0.01—phenobarbital, 0.75±0.01—aminazin, 0.35±0.01—metronidazole, 0.85±0.01—cinnarizine, 0.5±0.01—analgin.

EFFECT: method provides higher selectivity, objectivity and sensitivity of analysis in urine, saliva or blood plasma of medicinal substances due to the fact that ethyl acetate is used as a solvent for isolating medicinal substances with successive pH change: pH 3, then pH 10, and chromatography is carried out in the system dioxane—chloroform—acetone—25% ammonia in ratio 40:40:6:3.

1 cl, 1 ex