微小电极测定植物油过氧化值准确度评价

Accuracy Evaluation of Determining Peroxide Value in Vegetable Oils by Microelectrode

研究设计了一种检测过氧化值的新方法,即采用壳聚糖修饰丝网印刷电极经微分脉冲溶出伏安法扫描,来取代碘量法中人工滴定确定碘离子浓度变化的步骤.采用该方法对40种市售植物油的过氧化值进行测定,并与国标法（GB/T 5538-2005）的测定结果进行比对,综合偏离度与En数2项指标进行评价,结果表明：2种方法在定性判定方面结果一致,而在定量判断方面有37个结果满意,整体满意率为92.5％,其中0.016 ～0.075 mmol/kg区间内的结果更为准确,满意率为91.6％.研究表明,与国标法相比,新方法在操作性、安全性等方面存在一定优势,在一定过氧化值范围内,结果准确性能够得到认可.

A New method in the determination of peroxide value has been developed, namely by differential pulse anodic stripping voltammetry; adopted chitosan modified screen printing electrode scan vegetable oil samples to instead of titration to determine changes of the iodine ion concentration. In the research described in the paper, the proposed method determine peroxide value of 40 saled vegetable oil samples, and compare with the national standard method （GB/T 5538--2005 ）. Through evaluate comprehensive deviation degree and En value, it was determined that the results were all satisfied in the qualitative evaluation, and had 37 satisfied ones in respect of quantitative judg- ment, the overall satisfaction rate was 92.5%. Especially in the range of 0. 016 ～0. 075 mmol/kg the result is more accurate and satisfaction rate can reach 91.6%. This research showed that compared with the national standard meth- od, the new method in operational, security, etc. has a certain advantage, and the result accuracy could be recog- nized within the limits of certain peroxide value range.