The tea specific pretreatment methods for rapid detection of aflatoxin B1 and ochratoxin A on dark tea samples

Matrix interference of dark tea was effectively eliminated by tea-specific clean-up. • Tea-specific pretreatment enabled rapid detections of AFB1 and OTA on tea sample. • A simple and cost-effective strategy was validated for rapid detection in dark tea. • Tea-specific pretreatment compatible with rapid test strips and instrumental analysis. Rapid test strips have been widely used for mycotoxins detection in foods; however, their application in tea is strictly limited by pronounced matrix interference. In this study, tea-specific cleaning methods were developed to enable rapid detection of aflatoxin B1 (AFB 1 ) and ochratoxin A (OTA) in dark tea and tea infusions. The proposed methods achieved recoveries ranging from 81.5% to 128.07% for AFB 1 and ranging from 80.05% to 131.48% for OTA. Method validation demonstrated robust accuracy and precision, with AFB 1 recoveries of 83.82%–110.00% (RSDs: 0.46%–12.74%) and OTA recoveries of 82.83%–118.47% (RSDs: 0.69%–11.74%). The limits of detection (LODs) were 1.14–2.52 μg/L for AFB 1 and were 1.13–3.04 μg/L for OTA in tea samples. The tea-specific clean-up effectively minimized matrix interference, yielding extracts compatible with rapid test strips for qualitative and quantitative testing. Overall, this study provides a simple, efficient and cost-effective strategy for improving the reliability of rapid mycotoxins detection in complex tea matrices.