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.
