In situ hydrothermal growth of ZnO/g-C3N4 nanoflowers coated solid-phase microextraction fibers coupled with GC-MS for determination of pesticides residues.

In this paper, Zinc oxide (ZnO) hybridized with graphite-like C3N4 (ZnO/g-C3N4) nanoflowers based solid phase microextraction (SPME) coating was prepared on fiber using in situ hydrothermal growth method for gas chromatographic -mass spectrum (GC- MS) separation and analysis target analytes in complex matrixes for the first time. The proposed hybrid ZnO/g-C3N4 fiber exhibited wide linearity for the pesticide residues in range of 0.003-5.0 ng mL(-1). The limits of detection (LOD) were 0.001-0.0025 ng mL(-1). The relative standard deviation (RSD) for three replicate extractions using one fiber was ranged from 2.3% to 7.6%. The fiber to fiber RSD was 5.3-11.3% (n = 3). This method was successfully used for simultaneous determination of nine pesticide residues in cucumber, pear, Green tea and Minjiang water with satisfactory recoveries of 79.1-103.5%. These results indicated that the ZnO/g-C3N4 composite provided a promising alternative in sample pretreatment and analysis.