# Simultaneous Determination of Aristoloxazines, Aristolochic Acids, and Aristolactams Using HPLC–Fluorescence Detection with a Post-column Microreactor: Application in Identifying New Aristoloxazines

## TL;DR

A new HPLC method detects genotoxic compounds in herbs and soil, revealing high levels in commonly used plants.

## Contribution

A novel HPLC-fluorescence detection method with a post-column microreactor enables simultaneous determination of AXs, AAs, and ALs.

## Key findings

- AXs were detected at concentrations up to hundreds of μg/g in some Asarum samples.
- The method was validated against LC–MS/MS and applied to herbal and soil samples.
- The findings highlight previously unrecognized human exposure to genotoxins from herbal medicine.

## Abstract

Aristoloxazines (AXs), aristolochic acids (AAs), and
aristolactams
(ALs) are potent genotoxins found in Asarum and Aristolochia plants, many of
which are commonly used as herbal medicines. Emerging evidence indicates
that these compounds contaminate arable soil during the cultivation
of Aristolochiaceae herbs. Currently,
no method exists for their simultaneous detection. In this study,
we developed a high-performance liquid chromatography (HPLC)-based
method for their determination. This method employs an iron powder-packed
microreactor to convert non-fluorescent AXs and AAs into naturally
fluorescent ALs, enabling fluorescence detection after HPLC separation.
After being validated against LC–MS/MS analysis, the method
was applied to quantify these genotoxins in herbal and soil samples,
detecting AXs at concentrations as high as hundreds of μg/g
in some Asarum samples. Given that Asarum plants are widely used in herbal medicine,
these results reveal previously unrecognized human exposure to genotoxins
that warrants the attention of both the general public and regulatory
agencies.