A new method for sensitive and rapid indirect electrochemiluminescence(IECL)detection of norepinephrine(NE),synephrine,and isoproterenol with capillary electrophoresis(CE)was developed.IECL detection is based on their quenching effects on Ru(bpy)2+3/tripropylamine(TPA)system.Under the optimum conditions,the detection limits(S/N=3)were 2.6×10-8 mol/L for NE,6.6×10-9 mol/L for synephrine,and 8.4×10-8 mol/L for isoproterenol.The RSD of migration time and peak area were less than 1.3% and 4.4%,respectively.The proposed method was successfully applied to the analysis of NE in the urine samples of 10 healthy people and 10 diabetic nephropathy patients.The results indicate that the content of NE in diabetic nephropathy patients is much higher than that in healthy people.
A new approach for the determination of methylephedrine hydrochloride(ME),thebaine,codeine phosphate(CP),and acetylcodeine(AC) was established by CE-ECL with ionic liquid(1-butyl-3-methylimidazolium tetrafluoroborate,BMIMBF4). The conditions for the CE separation,ECL detection and the effect of ionic liquid(IL) were systematically investigated. Under the optimal conditions,the four analytes were well separated within 8 min using BMIMBF4 as additive in the electrophoretic buffer. The concentration detection limits of ME,thebaine,CP,and AC were 2.1×10-8,1.4×10-7,6.3×10-8,and 3.6×10-8 mol/L(S/N=3),respectively. The limits of quantitation(LOQ,S/N=10) in real human urine samples were 7.6×10-7 mol/L for ME,3.6 ×10-6 mol/L for thebaine,6.5×10-7 mol/L for CP,and 4.6×10-7 mol/L for AC,respectively. The recoveries of four alkaloids at different levels in human urine samples were between 90.0% and 103.5%. The developed method was successfully applied to the determination of four drug alkaloids in human urine samples.
