Reduced graphene oxide-zinc oxide nanocomposite as dispersive solid-phase extraction sorbent for simultaneous enrichment and purification of multiple mycotoxins in Coptidis rhizoma (Huanglian) and analysis by liquid chromatography tandem mass spectrometry

Zafar Iqbal Tanveer; Qingwen Huang; Li Liu; Keqiu Jiang; Dongxia Nie; Hongye Pan; Yong Chen; Xuesong Liu; Lianjun Luan; Zheng Han; Yongjiang Wu

doi:10.1016/j.chroma.2020.461515

Reduced graphene oxide-zinc oxide nanocomposite as dispersive solid-phase extraction sorbent for simultaneous enrichment and purification of multiple mycotoxins in Coptidis rhizoma (Huanglian) and analysis by liquid chromatography tandem mass spectrometry

J Chromatogr A. 2020 Sep 1:1630:461515. doi: 10.1016/j.chroma.2020.461515. Online ahead of print.

Authors

Affiliations

¹ College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
² College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China; Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.
³ Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.
⁴ Institute for Agro-food Standards and Testing Technology, Shanghai Key Laboratory of Protected Horticultural Technology, Laboratory of Quality and Safety Risk Assessment for Agro-products (Shanghai), Ministry of Agriculture, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China. Electronic address: hanzheng@saas.sh.cn.
⁵ College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China. Electronic address: yjwu@zju.edu.cn.

PMID: 32911177
DOI: 10.1016/j.chroma.2020.461515

Abstract

In the current study, a robust dispersive solid-phase extraction (dSPE) strategy using reduced graphene oxide-zinc oxide (rGO-ZnO) nanocomposite as the sorbent was proposed for separation, purification and enrichment of 12 mycotoxins in Coptidis rhizoma (Huanglian). The targeted mycotoxins included aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, aflatoxin M1, alternariol-methylether, mycophenolic acid, ochratoxin A, penitrem A, nivalenol, zearalenone and zearalanone. The rGO-ZnO nanocomposite was successfully synthesized through hydrothermal process by a modified Hummers method, and further characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FTIR spectroscopy, ultraviolet-visible spectroscopy and X-ray diffraction (XRD). Several key parameters affecting the performance of the dSPE approach were extensively investigated, and after optimization, acetonitrile/water/formic acid (80/19/1, v/v/v) as the extraction solution, 2% acetonitrile as the adsorption solution, 15 mg rGO-ZnO as the sorbent, n-hexane as the washing solution, and methanol/formic acid (99/1, v/v) as the desorption solution presented an excellent purification and enrichment efficiency. Under the optimal dSPE procedure followed by analysis with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), adequate linearity (R² ≥ 0.991), high sensitivity (limit of quantification in the range of 0.09-0.41 µg kg^-1), acceptable recovery (70.3-105.7%) and satisfactory precision (RSD 1.4-15.0%) were obtained. The analysis of 12 selected mycotoxins was also carried out in real Coptidis rhizoma (Huanglian) samples for applicability evaluation of the established method.

Keywords: Coptidis rhizoma (Huanglian); Dispersive solid-phase extraction; Mycotoxins; Reduced graphene oxide-zinc oxide; Ultra-high performance liquid chromatography-tandem mass spectrometry.