Development of cereulide HPLC-ELSD method based on MT-PDMS bonded silica hydrophobic stationary phase

Cereulide, an emetic toxin produced by Bacillus cereus , exhibits high crypticity, remarkable stability and rapid toxic effects, posing a serious threat to food safety and public health. Existing detection methods for cereulide are limited by poor selectivity, narrow applicability and insufficient robustness. To address these challenges, a high- performance liquid chromatography-evaporative light scattering detection (HPLC- ELSD) method based on a novel methoxy-terminated polydimethylsiloxane- bonded silica (MT-PDMS-Sil) hydrophobic stationary phase was developed. The MT-PDMS- Sil stationary phase, featuring a high bonding density of 2.26 mmol/g, was systematically characterized and demonstrated exceptional thermal stability and robust mechanical properties. Compared to the conventional ODS column, the proposed stationary phase facilitated a more rapid analysis of cereulide with significantly improved separation efficiency and sensitivity. Under the optimized conditions, the established HPLC-ELSD method presented good linearity in the range of 0.1 µg/mL − 20 µg/mL (r = 0.99964), with detection and quantification limits of 5 ng/mL and 16.3 ng/mL, respectively. The average recoveries in rice and milk samples ranged from 82.5% to 102.6%, with relative standard deviations all below 3.5%. Overall, the HPLC-ELSD method developed in this study demonstrates high sensitivity and matrix interference removal efficiency, providing a reliable analytical platform for the specific, rapid and accurate detection of cereulide in foods. Additionally, it affords a solid technical foundation for the effective supervision and regulation of food safety.