Development of a Zeolite H-ZSM-5-Based D-μSPE Method for the Determination of Organophosphorus Pesticides in Tea Beverages

Abstract

In this study, a novel dispersive micro-solid phase extraction (D-μSPE) technique with H-ZSM-5 zeolite as an adsorbent was developed for the determination of 21 trace pesticides in tea beverages. The adsorption and desorption of H-ZSM-5 zeolites were investigated based on structural characteristics and adsorption properties similar to those of H-beta zeolites. In combination with the properties of the adsorbates, it was explained that the adsorption reaction occurred on the microporous surface and mesopores of H-ZSM-5. Based on optimal parameters, the beverage samples were extracted by 50 mg of zeolite within 1 min. The zeolite was eluted with 2 mL of an acetonitrile-water mixture after separation, and the eluent was filtered prior to HPLC-MS/MS analysis. The D-μSPE protocol demonstrated acceptable accuracy and precision, with recoveries between 62.1% and 106.6% and relative standard deviations of 1.4% to 12.6%, as validated by analytical reliability. The correlation coefficient in the linear range of 0.2–50 ng·mL−1 was greater than 0.98, with limits of detection of 0.05–0.1 ng·mL−1 and limits of quantification of 0.1–0.2 ng·mL−1. The matrix effects ranged from 76.2% to 112.7%. The results indicate that the novel D-μSPE technique based on H-ZSM-5 is a rapid, simple, green and economical method for the determination of pesticide residues in tea beverages. The proposed method achieved simultaneously low adsorbent dosage, 20-fold enrichment factor, rapid pre-concentration in 12 min, minimal organic wastes, and effective reduction of matrix interference.