SFOD-LPME-HPLC法测定白酒中甘草酸、甘草次酸

Determination of glycyrrhizin and glycyrrhetinic acid in Baijiu by SFOD-LPME-HPLC

建立漂浮有机液滴凝固液相微萃取联合高效液相色谱法(SFOD-LPME-HPLC)测定白酒中甘草酸(GA)和甘草次酸(GTA)。取2 mL白酒经95℃热水浴脱醇,20 mL水溶液复溶后进行微萃取,以40μL正十二醇作为萃取剂,50μL四氢呋喃作为分散剂,以酸性体系作为萃取供相,加入1.0 g氯化钠,在40℃条件下萃取15 min。在最优萃取条件下,甘草酸及甘草次酸在2.50~50.0 ng/mL的质量浓度范围内线性关系良好,相关系数R2>0.999,检出限为0.004 mg/L,定量限为0.01 mg/L,样品加标回收率在89.2%~105.0%之间,精密度试验结果相对标准偏差(RSD)在1.59%~5.57%。该方法快速准确,绿色环保,适用于白酒中甘草酸、甘草次酸的检测。

A method for the determination of glycyrrhizin(GA)and glycyrrhetinic acid(GTA)in Baijiu was developed by liquid phase microextraction based on solidification of floating organic drop(SFOD-LPME)combined with HPLC.The Baijiu samples(2 ml)were heated in 95℃water bath to remove ethanol and diluted by 20 ml water for microextraction.Using 40μl N-dodecyl alcohol as extraction solvent,50μl tetrahydrofuran as dispersant,acid system as extraction phase,1.0 g sodium chloride were added,and extracted at 40℃for 15 min.Under the optimum extraction conditions,the corresponding linear range(2.50-50.0 ng/ml)for the glycyrrhizin and glycyrrhetinic acid exhibited a good linear relation(R2>0.999),the detection of limit(LOD)was 0.004 mg/L,the quantitation of limit(LOQ)was 0.01 mg/L,the recoveries of real samples spiked were 89.2%-105.0%,and the relative standard deviations of precision tests results(RSD)were between 1.59%-5.57%.The method was simple and sensitive with environmentally friendly,which was suitable for the extraction of glycyrrhizin and glycyrrhetinic acid in Baijiu.