A Flow Injection Chemiluminescence Method for Determination of Hydrocortisone in Human Serum by Trivalent Silver Complex / 分析化学

ABSTRACT

A flow-injection chemiluminescence ( FI-CL ) reaction system with diperiodatoargentateⅢ was developed for the determination of hydrocortisone in human serum. The weak chemiluminescence signal from the reaction between DPA and sulfuric acid system can be greatly enhanced in the presence of hydrocortisone. The optimal conditions of the CL system were 1. 0 mol/L H2SO4, 2. 5×10-4 mol/L diperiodatoargentateⅢ, and flow rate of 4. 20 mL/min. Under the optimal conditions, the CL intensity was linearly to the concentration of hydrocortisone from 3 . 0 × 10-10 g/mL to 1 . 0 × 10-7 g/mL and the detection limit was 2 . 2 × 10-10 g/mL ( 3σ) . The relative standard deviation ( RSD ) was 0 . 6% ( n =11 ) for 5 . 0 × 10-8 g/mL hydrocortisone solution. The proposed method was successfully applied to the direct determination of hydrocortisone in serum samples with the recoveries of 93 . 0%-110 . 0%, and the relative standard deviations were 0 . 3%-3 . 2%. The possible chemiluminescence mechanism was investigated by measuring fluorescence spectra and UV-vis absorption spectra of the system.