腐乳中苯甲酸、山梨酸残留量的液相色谱测定

Determination of benzoic acid and sorbic acid in furu by HPLC

建立了腐乳中苯甲酸、山梨酸残留量的检验方法。研究了腐乳样品的净化方法,选择合适的沉淀剂使腐乳凝结,再调节清液的pH值,在碱性条件下用乙醚萃取去除杂质,在酸性条件下,用乙醚提取苯甲酸、山梨酸残留。苯甲酸和山梨酸在1.0～20μg/mL范围内,相关系数分别为γ=0.999 1和γ=0.999 3(n=6)。最低定量限(LOQ)均为2.0mg/kg。标准添加回收率均大于85％,相对标准偏差均小于4.64％。

Furu sample is different from any other samples.It is more difficulty to puritified than others. This article studied the method to extract and purify the Furu sample. Selected NH4CL and phosphoric acid solution to precipitate sample solution.The upper layer was purified by adjusting the pH value of the solution and extracting with ether.In the basic condition the organic layer was discarded and in the acid condition the organic layer was collected and then concentrated . Add 2.0 mL buffer solution to dissolve the residue and filter it for HPLC. The linear ranges of benzoic acid and sorbic acid were 1.0-20 μg/mL, the limit of detection were 0.7 mg/kg and the limit of quantification were 2.0 mg/kg. The recoveries were 86.0-89.0% .Spiked samples with the concentration of2.0,5.0,10 mg/kg were determined, and the recoveries were 86.0-89.0% .The RSDs( n = 10) were from 3.73% to 4.64% .