基于胆固醇和冰乙酸的反应物与硫酸铁铵生成的紫色化合物能有效抑制双[2,4,6-三氯苯基]草酸酯(Bis(2,4,6-trichlorophenyl) oxalate,TCPO)-H2O2-咪唑化学发光反应,建立了流动注射-化学发光联用检测胆固醇的方法.对流动注射、化学发光等实验参数进行了优化.当咪唑浓度为0.001 mol/L,H2O2浓度为0.3 mol/L,TCPO浓度为1.0×10-3 mol/L,主副蠕动泵转数分别为20和15 r/min时,体系具有最强的化学发光.在优化的实验条件下,测定胆固醇的线性范围为8.6×10-6～ 2.2×10-4 mol/L；检出限(S/N=3)为2.5×10-6 mol/L；相对标准偏差(RSD,n=11,c=6.5×10-5 mol/L)为1.5％.不同加标水平下的加标回收率为95.0％ ～ 105.0％；相对标准偏差(n=6)小于3.6％.本方法已应用于地沟油中胆固醇的测定,结果令人满意.%Based on the inhibiting effect of product of cholesterol-glacial acetic acid-ammonium ferric sulfate on the bis (2,4,6-trichlorophenyl) oxalate ( TCPO)-H2O2-imidazole chemiluminescence (CL) reaction, a flow-injection coupling with indirect CL detection method for the determination of cholesterol was developed. The key experimental parameters for flow injection and CL were respectively optimized. The optimal conditions of CL system were 0. 001 mol/L imidazole, 0. 3 mol/L H2O2 and 1.0×l0-3 mol/L TCPO, and peristaltic pump was 20 r/min and that of sub-peristaltic pump was 15 r/min. Under the optimum conditions, the rela tive CL intensity is linearly proportional to the concentration of cholesterol from 8. 6x10 -2. 2×10 mol/L (R = 0.9988) , the detection limit (S/N = 3) turned out to be 2.5×10-6 mol/L. For the analysis (n=11) of 6.5×l0-5 mol/L cholesterol, a relative standard deviation was 1.5%. For the determinations of real sample, the addition standard recoveries were 95. 0% -105. 0% , and the relative standard deviations were below 3.6%. The method has been applied to determine cholesterol in hogwash oil with satisfactory results.
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