RESUMO
A novel chemiluminescence method for the determination of uric acid based on its inhibitory effect on the catalysis of Co2+ for the oxidation of luminol by H2O2 is described. The proposed method is simple, very sensitive and inexpensive. The decrease of cheniluminescence intensity is linearly correlated with uric acid concentration. The calibration graph is linear over the range of 1.0 x 10(-10) - 7.0 x 10(-6) mol x L(-1) and the detection limit is 1.1 x 10(-11) mol x L(-1). The relative standard deviation (RSD) for 5.0 x 10(-8) is 1.9% (n=4). The method has been successfully applied to the determination of uric acid in human urine and serum samples.
Assuntos
Luminescência , Ácido Úrico/sangue , Ácido Úrico/urina , Catálise , Cobalto/química , Humanos , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Luminol/química , Oxirredução , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Ácido Úrico/análiseRESUMO
Based on the chemiluminescence reaction of KMnO4-HNO3-2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside sensitized by HCHO, an analytical method for 2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside by RP-HPLC with chemiluminescence detector was developed. The chromatographic conditions were optimized. AN ODS hypersil column(25 mm x 4.0 mm, 125 x 4.0 mm i.d. 5 microm) was used with acetonitrile--0.3% H3PO4 [25:75, (phi)] as mobile phase, and the flow rate was 0.8 mL x min(-1) at the column temperature of 40 degrees C. The linear range of calibration curve was from 15.75 to 136.5 microg x mL(-1), the detection limit was 11.83 microg x mL(-1) with a concentration of 21 microg x mL(-1) of 2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside, and the recovery was 102%-108%. The relative standard deviation was 3.45% (Cs = 21.0 microg x mL(-1), n = 3). The method has been applied to the determination of 2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside in a few Chinese medicines, and the results were satisfactory. The method was simple, rapid and highly selective.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Glucosídeos/análise , Luminescência , Estilbenos/análise , Cápsulas , Cromatografia Líquida de Alta Pressão/instrumentação , Formaldeído/química , Glucosídeos/química , Cinética , Medições Luminescentes/instrumentação , Medições Luminescentes/métodos , Estrutura Molecular , Ácido Nítrico/química , Reprodutibilidade dos Testes , Estilbenos/química , ComprimidosRESUMO
A novel chemiluminescence method for the determination of Levofloxacin is based on its enhancement effect on thereaction of luminol with H2O2. The calibration graph is linear over the range of 5.53 x 10(-11)-2.21 x 10(-8) mol x L(-1) and the detection limit is 1.38 x 10(-11) mol x L(-1). The relative standard deviation (RSD) is 2.56% (n = 9). The method has been successfully applied to the determination of Levofloxacin in capsule samples.
