# Metal element fingerprints combined with chemometrics deciphering the discrimination of different Calculus bovis and a novel risk–benefit assessment

## TL;DR

This study uses metal element analysis and chemometrics to distinguish real from fake Calculus bovis and assess health risks and benefits.

## Contribution

A novel risk-benefit assessment model and chemometric method for differentiating Calculus bovis products using metal element fingerprints.

## Key findings

- Calculus bovis samples were effectively separated using multi-element fingerprints with Sr, Ca, K, V, Ti, and Al as key variables.
- Non-carcinogenic risk from heavy metals like Pb was acceptable, but Pb's hazard index exceeded 1 in Calculus bovis.
- Combined risk-benefit evaluation showed HI exceeding 1 for K, Ca, and Mg across all products, regardless of gender.

## Abstract

In recent years, the phenomenon of adulterated Calculus bovis being sold as cheap Calculus bovis has been continuously observed in the market. To effectively differentiate among the three products, original Calculus bovis, Bovis calculus sativus, and Bovis calculus artifactus, our group analyzed and evaluated the elements present in these products that are relevant to the therapeutic efficacy of traditional Chinese medicines (TCMs). The elements were evaluated using inductively coupled plasma mass spectrometry (ICP-MS) combined with chemometric analysis to differentiate among the abovementioned three marketed products. Chemometric analysis showed that Calculus bovis samples could be well separated based on established multi-element fingerprints, with Sr, Ca, K, V, Ti, and Al identified as the most important variables for discrimination. When Calculus bovis is medicinally used or consumed, non-carcinogenic risk assessment results indicate that the risks associated with exposure to heavy metals such as Pb, Cd, As, and Hg were acceptable for both genders. However, the hazard index (HI) of Pb in Calculus bovis exceeded 1. The results of the carcinogenicity risk assessment indicated that the carcinogenicity risk (CR) of Pb and As in all Calculus bovis samples was less than 1, indicating that the risks were acceptable. For the nutrients K, Ca, and Mg, the combined risk–benefit evaluation of the three Calculus bovis products indicated that the HI exceeded 1 across all three products, regardless of the gender of the individual consuming the medication. The benefit index (BI) for K, Mg, Cr, Se, and Mo was less than 1, indicating that risks need further consideration. The identification model developed in this study can effectively differentiate between the three marketed Calculus bovis products, aiming to address quality issues such as adulteration, forgery, under-injection, and other such concerns.