高效液相色谱法测定花椒中的苯甲酸

Determination of Bezonic Acid in Zanthoxylum Using HPLC

本文研究了花椒中苯甲酸的高效液相色谱检测方法,并首次确定了花椒中苯甲酸的含量。因花椒样品基质复杂,在前处理中增加了混合阴离子固相萃取小柱以净化样品,以磷酸盐缓冲溶液-甲醇(97:3)为流动相,选用Waters sunfire C18色谱柱在230 nm下进行高效液相色谱分析。本方法在线性范围1.0~20.0 mg/kg内线性关系好,R^2为0.999,方法的检出限为2.0 mg/kg,低于国标GB5009.28-2016的检出限5.0 mg/kg,在2.0、5.0和20.0 mg/kg三个添加水平的加标回收率为73.1%~94.3%,RSD为2.8%~7.4%。该方法可为其他复杂基质中苯甲酸的测定提供参考。进而对四川抽取的40批次花椒样品进行分析,39批花椒样品中检出苯甲酸,含量为2.08~12.20 mg/kg,平均含量6.02 mg/kg。本研究初步明确了花椒中天然苯甲酸的本底值范围,为制订或修订食品行业相关标准提供了重要依据。

In this paper, the high performance liquid chromatography（HPLC） method was studied for benzoic acid content in zanthoxylum. Based on the complex chemical compositions of zanthoxylum, mixed anion solid phase extraction column was used to purify the sample in the pretreatment. The separation was performed at 230 nm with Waters sunfire C18 column and with phosphate buffer solution-methanol（95：5） as mobile phase. This method had good linear relationship in the range of 1.0-1.0 mg/kg with R^2 0.999 and LOD was 2.0 mg/kg, which was lower than the national standard GB 5009.28-2016 detection limit of 5.0 mg/kg. The recovery ratio at 2.0, 5.0, and 20.0 mg/kg levels was 73.1%-73.1%, while RSD was 2.8%-7.4%. This method also provided reference for the determination of benzoic acid in other complex matrix. Then 40 samples of zanthoxylum in Sichuan province were analyzed, and benzoic acid was detected in 39 samples with the content of 2.08-12.20 mg/kg, and the average content was 6.02 mg/kg. This study preliminarily determined the background level of natural benzoic acid in Sichuan peppercorns, which provided an important basis for the formulation or revision of relevant standards in the food industry.