Analysis and occurrence of matrine in liquorice raw materials - Exclusion of its application as pesticide

ABSTRACT

A quick and selective analytical method was developed employing LC-MS/MS for the quantitation of matrine. This is known to be a natural ingredient of Sophora ssp. and is suggested to be a potential contaminant, e.g. in herbal raw materials from liquorice or confectionery products based on liquorice. To prove that the finding of matrine in liquorice roots does not originate from an active use of pesticides, wild collection areas, as well as geographical, legal and economic aspects have been studied with the help of experienced traders and suppliers in cooperation with local liquorice producers. An LC-MS/MS method was successfully developed and applied for monitoring of raw material and semi-finished products (N = 104) and afterwards a model test was performed to show that findings of matrine in liquorice products originates from a co-harvesting of nearby growing Sophora roots during the manual collection of liquorice roots.

KEYWORDS:

• Matrine
• liquorice
• Sophora spp
• LC-MS/MS

Acknowledgments

The authors thank Mr. Michael Schmanns and Mrs. Esther Gundlach, both from the company Hepner & Eschenbrenner, Hamburg for their productive and constructive consulting.

We also thank the German Tea & Herbal Infusion Association, Hamburg, and the Association of Firms engaged in Wholesale and Foreign Trade in Drugs and Chemicals, Hamburg, for building the bridge to the liquorice raw material industry and organising huge amounts of samples analysed.

Furthermore, we would like to thank Mr. Christian Lange and Mr. Erwin Kriesl from the company Martin Bauer, Vestenbergsgreuth for carrying out the model test, providing reference material and their continuous support regarding technical questions.

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Funding

The author(s) reported that there is no funding associated with the work featured in this article.