摘要
研究比较了油脂过氧化值 (POV)的两种碘量测定法———滴定法和比色法。滴定法是在酸性条件下油脂中的过氧化物同过量的碘化钾作用生成碘后 ,用硫代硫酸钠标准溶液滴定生成的碘。比色法则利用碘与淀粉的显色反应并由标准曲线确定碘的生成量。样品的POV根据硫代硫酸钠消耗量或碘的生成量计算。数据分析表明 ,对所研究的 4个样品 ,两种测定法无显著差异 ,测定结果相同。但比色测定所需样品量较少 (约 0 2g) ,有机溶剂消耗少 ,在 1～ 15meq/kg的油脂样品均可用比色法测定。
Two Determination methods for peroxide value(POV) of oils were studied and compared.These methods were titration method and colorimetric method and both were based on the reaction of potassium iodide with peroxides in oil to form iodine quantitatively at acidic condition.Iodine formed was then titrated by Na 2S 2O 3 solution standard in titration method.In colorimetric method,iodine formed was reacted with starch solution later.Then a blue color was developed and measure by spectrophotometer at 585 nm.The amount of iodine formed could be calculated from the standard curve,which obtained by mixing standard iodine solution with starch solution and measuring by spectrophotometer.The POV of sample was calculated from the Na 2S 2O 3 consumed or iodine formed therefore.From results it was shown that two methods had no significant difference for four samples we selected,Colorimetric method could be used to analyze oil samples satisfactory when POV was about 1～15 meq/kg.Meanwhile less sample(about 0.2g)and less organic solvent was needed in colorimetric method.
出处
《中国油脂》
CAS
CSCD
北大核心
2003年第4期60-62,共3页
China Oils and Fats
