Issue 39, 2018

Rapid qualitative and quantitative analysis of aflatoxin B1 in Pu-erh tea by liquid chromatography-isotope dilution tandem mass spectrometry coupled with the QuEChERS purification method

Abstract

The unique quality of Pu-erh tea is due to the process of pile fermentation that the tea leaves undergo, but this process can lead to the risk of producing aflatoxin B1 (AFB1), the most toxic of aflatoxins. The commonly used methods for the determination of AFB1 in foods are complex and time-consuming. In this paper, an accurate and rapid method for the determination of aflatoxin B1 in Pu-erh tea was developed by isotope dilution mass spectrometry. After extraction of AFB1 in Pu-erh tea using acidified acetonitrile (1% formic acid), a purification step was performed by the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method with primary secondary amine (PSA) and octadecylsilyl silica (C18) as the absorbents. The quantification of AFB1 was performed by liquid chromatography tandem mass spectrometry (LC-MS/MS) in positive mode (ESI+) and selective reaction monitoring (SRM) with 13C-labeled aflatoxin B1 (13C17-AFB1) as the internal standard in less than 5 min. A complete validation study was carried out after method optimization to ensure adequate performance of the developed method. The results showed good linear correlation in the range from 0.10 to 10.00 μg L−1 with a correlation coefficient (R2) > 0.99. The average recoveries of AFB1 from blank samples fortified at three levels (0.50, 5.00, and 20.00 μg kg−1) ranged from 81.4 to 100.8% with the relative standard deviations (RSDs, n = 6) between 1.7 and 4.8%. The limit of detection (LOD) was 0.50 μg kg−1. The validation method was applied to an analysis of AFB1 in 50 raw Pu-erh teas and 50 ripened teas. None of the investigated Pu-erh samples showed an AFB1 content above the LOD. The results indicate that people who are keen on drinking Pu-erh tea are not at risk from AFB1 exposure. The proposed method was demonstrably simple, rapid, highly sensitive and accurate, and was effective in the rapid qualitative and quantitative analysis of AFB1 in Pu-erh tea.

Graphical abstract: Rapid qualitative and quantitative analysis of aflatoxin B1 in Pu-erh tea by liquid chromatography-isotope dilution tandem mass spectrometry coupled with the QuEChERS purification method

Article information

Article type
Paper
Submitted
03 Aug 2018
Accepted
12 Sep 2018
First published
13 Sep 2018

Anal. Methods, 2018,10, 4776-4783

Rapid qualitative and quantitative analysis of aflatoxin B1 in Pu-erh tea by liquid chromatography-isotope dilution tandem mass spectrometry coupled with the QuEChERS purification method

X. Dong, B. Zou, X. Zhao, S. Liu, W. Xu, T. Huang, Q. Zong and S. Wang, Anal. Methods, 2018, 10, 4776 DOI: 10.1039/C8AY01730A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements