多功能针式过滤器-高效液相色谱法快速检测豆芽中的吲哚乙酸

A Multifunctional Needle Filter-HPLC Method for the Rapid Determination of Indole Acetic Acid in Bean Sprouts

摘要:

基于QuEChERS原理，该研究建立了多功能针式过滤器-高效液相色谱法快速检测豆芽中的吲哚乙酸。样品经1%乙酸乙腈和1 g氯化钠、2 g硫酸镁提取，多功能针式过滤器快速净化后，采用ZORBAX SB-C18（4.6×250 mm，5 μm）为色谱柱，以乙腈和0.1%甲酸溶液为流动相，梯度洗脱，流速1.0 mL/min，柱温：35 ℃，检测波长：267 nm，对提取净化液中吲哚乙酸含量进行高效液相色谱检测。吲哚乙酸在豆芽基质中基质效应较小，故使用纯溶剂配制的标准曲线进行定量。结果显示，吲哚乙酸在0.05~10.0 mg/L范围内线性关系良好，相关系数为0.9999。在0.1~5.0 mg/kg的加标水平范围内得到的平均回收率为80.6%~105.3%，相对标准偏差（RSD）是2.3%~4.6%。检出限为0.03 μg/kg，定量下限为0.1 μg/kg。该方法操作简单、准确可靠，适用于豆芽中吲哚乙酸残留量的快速检测。

Abstract:

To rapidly determine indole acetic acid (IAA) in bean sprouts, a multifunctional needle filter–high-performance liquid chromatography (HPLC) method was established based on the quick, easy, inexpensive, effective, robust, and safe (QuEChERS) method. Samples were subjected to extraction with 1.0% acetonitrile acetate with the addition of 1 g sodium chloride and 2 g magnesium sulfate. This was followed by rapid purification using a multifunctional needle filter. The IAA content of the purified extract was then measured by HPLC on a Zorbax SB-C18 column (4.6×250 mm, 5 μm) with acetonitrile and 0.1% formic acid as the mobile phase. Gradient elution was performed under the following conditions: flow rate: 1.0 mL/min, column temperature: 35 ℃, detection wave length: 267 nm. Considering the low matrix effect of IAA in the bean sprout matrix, quantification was performed using standard curves obtained with the pure solvent. IAA exhibited a good linear relationship within the range of 0.05~10.0 mg/L, with a correlation coefficient of 0.9999. Within the spike level range of 0.1~5.0 mg/kg, the average recovery rate and relative standard deviation (RSD) were in the ranges of 80.6%~105.3% and 2.3%~4.6%, respectively. The limits of detection and quantification were 0.03 μg/kg and 0.1 μg/kg, respectively. The considerable ease of operation, accuracy, and reliability of this method make it suitable for the rapid detection of residual IAA in bean sprouts.