Abstract
A new and sensitive method for the determination of norepinephrine (NE), synephrine, and isoproterenol was developed by CE separation and indirect electrochemiluminescence detection (ECL) based on their quenching effects on the tris(2,2β²βbipyridyl)βruthenium(II)/tripropylamine (TPA) system. The conditions for CE separation and ECL detection were investigated in detail. Under the optimum conditions, the three analytes were well separated within 9 min. The LODs (S/N = 3) in standard solution are 2.6Γ10^β8^ mol/L for NE, 6.6Γ10^β9^ mol/L for synephrine and 8.4Γ10^β8^ mol/L for isoproterenol, respectively. The precisions of intraday and interday are less than 4.4 and 6.1%, respectively. The LOQs (S/N = 10) in real human urine samples are 2.6Γ10^β7^ mol/L for NE, 8.8Γ10^β8^ mol/L for synephrine, and 8.8Γ10^β7^ mol/L for isoproterenol, respectively. The applicability of the proposed method was illustrated in the determination of 20 human urine samples from diabetic patients and healthy persons. The results obtained indicated that the level of NE in patients (mean value 0.41 ΞΌmol/L) was higher than that in healthy persons (mean value 0.24 ΞΌmol/L).