Graphene oxide adsorbent based dispersive solid phase extraction coupled with multi-pretreatment clean-up for analysis of trace aflatoxins in traditional proprietary Chinese medicines

- Development of a new GO-based DSPE method combined with multi-step preparation for determination of AFs in PCM.
- The BBD was used to optimize factors affecting adsorption procedure.
- The proposed method was successfully applied for the analysis of trace AFs in PCM.

Graphene oxide (GO)-based dispersive solid phase extraction (D-SPE) method combined with multi-step preparation has been proposed for the evaluation of trace aflatoxins in proprietary Chinese medicines (PCM). After being extracted by methanol, the sample was purified based on multi-step preparation, including dehydration with MgSO4/NaCl and cleanup with neutral alumina. Then GO was used as an adsorbent in D-SPE method for further preconcentration of aflatoxins prior to high performance liquid chromatography-fluorescence detection. The selected conditions were investigated. The Box-Behnken design (BBD) was used to optimize factors affecting adsorption procedure. Under the optimized conditions, good linear relationships had been achieved with the correlation coefficient (R2) varying from 0.9904 to 0.9990. The LODs and LOQs were ranging from 0.020 to 0.041 ng/mL and 0.061 to 0.125 ng/mL, respectively. The results of the recoveries were 74.0-102.7% for the four aflatoxins, while the precisions from 1.8% to 7.2% were obtained, which indicated that the method was suitable for the analysis of aflatoxins in PCM.