ABSTRACT
An MEKC method combining field-amplified sample injection (FASI) has been developed for the analysis of albumin (Alb) and transferrin (TRF) in human urines. Various parameters affecting FASI preconcentration were optimized systematically. Under the optimum conditions, using electrokinetic sample injection for 90 s, the sensitivity was improved 77.6- and 45.3-fold for TRF and Alb, respectively, without loss of separation efficiency when compared with hydrodynamical sample injection for 5 s (0.5 psi). The detection limits of TRF and Alb were found to be 0.31 and 0.14 mg/L, respectively. The proposed method has been successfully applied to the determination of TRF and Alb in desalted urines from patients with kidney diseases, and the recoveries of TRF and Alb were 91.1-101.7%.
Subject(s)
Albumins/isolation & purification , Albuminuria , Chromatography, Micellar Electrokinetic Capillary/methods , Transferrin/urine , Acetonitriles/chemistry , Humans , Kidney Diseases/metabolism , Sensitivity and Specificity , Sodium Chloride/chemistry , Solvents/chemistry , Transferrin/isolation & purification , Trifluoroacetic Acid/chemistry , Water/chemistryABSTRACT
A method has been developed for the determination of triptonide in the traditional Chinese herb Tripterygium wilfordii Hook F. by micellar electrokinetic capillary chromatography combined with cloud point extraction. The analyte was extracted at pH 3.0 by micelles of the nonionic surfactant polyoxyethylene 7,5-octylphenyl ether (Triton X-114). A 250-muL aliquot from the extracted surfactant-rich phase was diluted to 400 muL with ethanol to reduce its viscosity before separation by MEKC. Under optimum conditions, an enrichment factor of 25 is obtained and the determination limit of triptonide is found to be 3.15 x 10(-7) mol/L. The proposed method has been successfully applied to the determination of triptonide in T. wilfordii tablet and spiked urine matrix, demonstrating the feasibility and reliability of the proposed method.