固相萃取-流动注射分光光度法快速鉴别潲水油的研究

摘要

Solid phase extraction and flow injection spectrophotometry ( FIA ) method was developed to analyze the cholesterol content in oil. Cholesterol and o-phenylenediamine formed polymer with concen-trated sulfuric acid, which had maximum absorption peak at 413 nm, so the FIA automatic analysis meth-od was established for quantitative analysis of cholesterol. When the linearity of this method ranged from 2. 0 mg/L to 100 mg/L,the mass concentration of cholesterol had good linear relationship with the height of peak. The correlation coefficient was 0. 999 2, the relative standard deviation was 1. 81% (20 mg/L of cholesterol, n=12) and the limit of detection was 0. 16 mg/L. The results showed that the solid phase extraction and FIA method had items of simpleness, rapidness, accuracy and few reagents consumption, and the cholesterol content in oil could be determined within 30 min. The instrument was compact and portable,which was suitable for on-site inspection of cholesterol content in oil and rapid identification of swill-cooked dirty oil.%采用固相萃取法快速提取油脂中的胆固醇,与流动注射分光光度法( FIA)联用建立测定油脂中胆固醇含量的自动分析方法。利用胆固醇与邻苯二胺在浓硫酸作用下形成聚合物,在413 nm处有最大吸收峰,以此建立FIA自动分析方法对胆固醇进行定量分析。该方法在2.0~100 mg/L的范围内,胆固醇质量浓度与峰高成良好线性关系,相关系数R2=0.9992,相对标准偏差为1.81%(20 mg/L胆固醇,n=12),方法检出限为0.16 mg/L。实验表明：固相萃取-FIA联用法操作简单、回收率高、耗时短、消耗试剂量少,30 min内可完成油脂中胆固醇含量的测定,仪器小巧、便携、可实现油脂中胆固醇的现场检测,便于快速鉴别潲水油。