A flow-injection analytical (FIA) system was developed for the determination of cholesterol concentrations based on enzymatic reactions that occurred in a cholesterol oxidase (CHO_x)-immobilized, fused-silica capillary followed by electrochemical detection. The production of hydrogen peroxide from cholesterol in an enzymatic reaction catalyzed by CHO_x was subsequently oxidized electrochemically at an electrode. Our FlA system demonstrated its cost-effectiveness and utility at an applied potential of 0.6 V (vs. Ag/AgCl), a flow rate of 100 μL/min and, under optimal conditions, the resulting signal demonstrated a linear dynamic range from 50 μM to 1.0 mM with a limit of detection (LOD) of 12.4 μM, limit of quantification (LOQ) of 44.9 μM, and the coefficient of variation of 5.17%. In addition, validation of our proposed system using a reference HDL-cholesterol kit used for clinical diagnosis suggested our FIA system was comparable to commercial kits for the determination of the cholesterol incorporation amount in various aqueous liposomal suspensions. These good analytical features achieved by FIA could make the implementation of this methodology possible for on-line monitoring of cholesterol in various types of samples.

开发了一种流动注射分析 (FIA) 系统，用于根据胆固醇氧化酶 (CHO x ) 固定的熔融石英毛细管中发生的酶反应确定胆固醇浓度，_然后进行电化学检测。_{在 CHO x}催化的酶促反应中，胆固醇产生过氧化氢，随后在电极上被电化学氧化。我们的 FlA 系统在 0.6 V 的施加电压（相对于Ag/AgCl）、100 μL/min 的流速下展示了其成本效益和实用性，并且在最佳条件下，所得信号表现出 50 μM 的线性动态范围至 1.0 mM，检测限 (LOD) 为 12.4 μM，定量限 (LOQ) 为 44.9 μM，变异系数为 5.17%。此外，使用用于临床诊断的参考 HDL-胆固醇试剂盒对我们提出的系统进行验证表明，我们的 FIA 系统与用于测定各种水性脂质体悬浮液中胆固醇掺入量的商业试剂盒相当。FIA 实现的这些良好的分析功能可以使该方法的实施成为可能，用于在线监测各种类型的样品中的胆固醇。