摘要
目的用石油醚代替乙醚测定食用油脂酸价。方法用石油醚-异丙醇（1：1）混合溶剂50ml，振荡溶解样品，加入酚酞指示剂溶液5滴，用0.1moL／L氢氧化钾标准滴定溶液滴定至淡红色1min内不褪色为终点。结果精密度RSD值在0.98％-1.3％、回收率在95％-101％,与国标法比较结果基本一致。结论用石油醚代替乙醚做混合溶剂具有无毒、滴定终点易判断、测定结果稳定、准确度和精密度高等优点。
Objective to determine the price of edible oleic acid by substituting petroleum ether for ethyl ether. Methods 5Oral petroleum ether- isopropanol （1：1） mixed solvent was used to oscillate the sample. 5 drops of phenolphthalein indicator solution were added. The standard titration solution of 1moL/L potassium hydroxide was titrated to a reddish color for 1min. Results the RSD value of precision was between 0.98% and 1.3%, and the recovery rate was between 95% and 101%. Conclusion using petroleum ether instead of ethyl ether as the mixed solvent has the advantages of nontoxic, easy to determine titration end point, stable measurement result, high accuracy and precision.
出处
《中国食品工业》
2018年第7期71-74,共4页
China Food Industry
关键词
混合溶剂
测定
酸价
mixed solvent
determination
acid value
