Molecularly imprinted polymer-based solid phase clean-up for analysis of ochratoxin A in ginger and LC-MS/MS confirmation

Abstract Ginger, one of the most commonly used spices and additives, is also widely used to prevent and treat human disease as a traditional medicine. However, ginger is prone to contamination by ochratoxin A (OTA), which is toxic, carcinogenic and thermostable. Here, a simple, reliable and low-cost method based on molecularly imprinted polymer (MIP) as selective sorbent of solid-phase extraction (SPE) was proposed for the determination of OTA in ginger by ultra-performance liquid chromatography coupled with fluorescence detection (UPLC-FLR). The samples were firstly extracted and then cleaned up with an AFFINIMIP ® SPE OTA column for UPLC-FLR analysis. Under the optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) for OTA were 0.09 and 0.30 ng mL −1 , respectively. The recoveries of OTA from ginger spiked at 5, 15 and 25 μg kg −1 ranged from 87.6 to 94.5%. In addition, after a simple regenerated procedure, the MIP-based SPE column could be reused at least forty-one times to obtain more than 80% recoveries of OTA for ginger samples. The developed method was applied to the detection of twenty batches of ginger and six samples were contaminated by OTA with levels below the newest legal limits.