High-performance liquid chromatography tandem mass spectrometry for simultaneous detection of aflatoxins B_1, B_2, G_1 and G_2 in Indian medicinal herbs using QuEChERS-based extraction procedure

摘要

Since the discovery of aflatoxins (AFs) in the 1960s, much research has focused on detecting the toxins in contaminated food and feedstuffs. But the quality determination in medicinal plant matrices with respect to AFs is scare. Hence, a simple, accurate and sensitive high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of AFs AFB(1), AFB(2), AFG(1) and AFG(2) in two Indian popular medicinal herbs i.e. senna (Cassia angustifolia) and kalmegh (Andrographis paniculata). AFs have been extracted from herb matrix using a QuEChERS (quick, easy, cheap, effective, rugged and safe)-based extraction procedure followed by applying primary secondary amine and C18 for further clean-up step and then were quantified under the multiple reaction monitoring together with positive ionisation modes. Matrix-matched calibration was used for quantification in order to reduce the matrix effect. Validation of the method was carried out in herbs by recovery experiments. Recoveries of the spiked samples were in the range of 61.9-111.5% with an inter-day and intraday relative standard deviation lower than 20.0%. Limits of detection and quantification ranged from 0.41 to 0.95ngmL(-1) and 1.2 to 3.8gkg(-1), respectively. The expanded uncertainty of the method was 21% for all the toxins in both the herbs. Finally, the proposed method was successfully applied to determine AF residues in real field samples of senna and kalmegh obtained from different locations in India.