Detection of paracetamol by capillary electrophoresi

Indirect detection of paracetamol was accomplished using a capillary electrophoresischemiluminescence (CECL) detection system, which was based on its inhibitory effect on a luminol-potassium hexacyanoferrate(III) (K3[Fe(CN)6]) CL reaction. Paracetamol migrated in the separation capillary, where it mixed with luminol included in the running buffer. The separation capillary outlet was inserted into the reaction capillary to reach the detection window.Afour-way plexiglass joint held the separation capillary and the reaction capillary in place.K3[Fe(CN)6] solutionwas siphoned into a tee and flowed down to the detection window. CL was observed at the tip of the separation capillary outlet. The CL reaction of K3[Fe(CN)6] oxidized luminol was employed to provide the high and constant background. Since paracetamol inhibits the CL reaction, an inverted paracetamol peak can be detected, and the degree of CL suppression is proportional to the paracetamol concentration. Maximum CL signal was observed with an electrophoretic buffer of 30mMsodium borate (pH 9.4) containing 0.5mMluminol and an oxidizer solution of 0.8mMK3[Fe(CN)6] in 100mM NaOH solution. Under the optimal conditions, a linear range from 6.6×10−10 to 6.6×10−8 M (r = 0.9999), and a detection limit of 5.6×10−10M (signal-to-noise ratio = 3) for paracetamol were achieved. The relative standard deviation (R.S.D.) of the peak area for 5.0×10−9Mof paracetamol (n = 11) was 2.9%. The applicability of the method for the analysis of pharmaceutical and biological samples was examined. GX毛细管电泳仪(紫外检测)CL1020