Simultaneous determination of aminothiols, ascorbic acid and uric acid in biological samples by capillary electrophoresis with electrochemical detection.
A method based on capillary electrophoresis with electrochemical detection has been employed for the separation and determination of homocysteine, cysteine, reduced glutathione, ascorbic acid and uric acid. Effects of several important factors such as the acidity and concentration of the running buffer, separation voltage, injection time and detection potential were investigated to acquire the optimum conditions. The detection electrode was a 500 microm diameter platinum disk electrode at a working potential of +1.05 V (vs saturated calomel electrode). The five analytes were well separated within 10 min in a 50 cm long fused silica capillary at a separation voltage of 18 kV in a 100 mm phosphate buffer (pH 7.8). The relation between peak current and analyte concentration was linear over about 3 orders of magnitude with the detection limits (S/N = 3) ranging from 0.83 to 2.58 microm. The proposed method was successfully applied to determine cysteine, reduced glutathione, ascorbic acid and uric acid in human whole blood and rat brain tissues with satisfactory assay results and should find a wide range of bioanalytical applications.
Yao
Xiao
X
Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China.
Wang
Yuting
Y
Chen
Gang
G
D000818:Animals; D001205:Ascorbic Acid / Q000097:blood*; D002021:Buffers; D004563:Electrochemistry / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D013438:Sulfhydryl Compounds / Q000097:blood*; D014527:Uric Acid / Q000097:blood*
D002021:Buffers; D013438:Sulfhydryl Compounds; D014527:Uric Acid; D001205:Ascorbic Acid