Capillary electrophoresis coupled with electrochemical detection using porous etched joint for determination of antioxidants.

摘要: Abstract Capillary electrophoresis coupled with electrochemical detection (CE–EC) for determination of antioxidants, propyl gallate (PG) and tert-butylhydroquinone (TBHQ), in cosmetic samples was proposed this work. A porous etched joint used to isolate the from electrophoretic high voltage. Compared 25 μm i.d. capillary without a decoupler CE–EC system, 75 μm applied present system gave an improvement both sample injection sensitivity. Moreover, carbon fiber working electrode could be directly touch end separation due elimination effect voltage on EC detection, so alignment became easy dead volume also decreased. Baseline two antioxidants achieved by CE 50 cm long × 75 μm at 20 kV using 5.0 mmol L−1 phosphate buffer (pH 8.00). 0.7 V (versus Ag/AgCl) detection. Under optimal condition, precisions (RSD, n = 4) peak height migration time PG TBHQ were 2.39–3.59% 0.34–0.44%, respectively. The limits 2.51 × 10−6 4.88 × 10−6 mol L−1 standard solution 0.0751 0.0328 mg g−1 real consumption 0.3 g sample. Analysis cosmetics spiked recoveries analytes range 93.6–98.8%.