Abstract
The cyclic voltammetric behavior of acetaldehyde and the derivatized product with 2,4-dinitrophenylhydrazine (DNPHi) has been studied at a glassy carbon electrode. This study was used to optimize the best experimental conditions for its determination by high-performance liquid chromatographic (HPLC) separation coupled with electrochemical detection. The acetaldehyde-2,4-dinitrophenylhydrazone (ADNPH) was eluted and separated by a reversed-phase column, C18, under isocratic conditions with the mobile phase containing a binary mixture of methanol/LiCl(aq) at a concentration of 1.0 × 10-3 M (80:20 v/v) and a flow rate of 1.0 mL min-1. The optimum condition for the electrochemical detection of ADNPH was +1.0 V vs. Ag/AgCl as a reference electrode. The proposed method was simple, rapid (analysis time 7 min) and sensitive (detection limit 3.80 µg L-1) at a signal-to-noise ratio of 3:1. It was also highly selective and reproducible [standard deviation 8.2% ± 0.36 (n = 5)]. The analytical curve of ADNPH was linear over the range of 3 - 300 mg L-1 per injection (20 µL), and the analytical recovery was > 99%.
