Abstract:Three kinds of pesticides, organic phosphorus, organosulfur and neonicotinoids were used widely in the cultivation and production of leaf vegetables. The chromatographic methods are difficult to realize in situ detection. In this work, a surface-enhanced Raman scattering (SERS) approach for qualitative and quantitative detection pesticide residues in leaf vegetables was developed. The characteristic Raman peaks of pesticides were selected as correction peaks. The linear calibration equations were established with pesticide residues concentration and correction peak intensity. The limit of quantitation (LOQ) was calculated by substituting the correction peak intensity of SERS spectrum corresponding to the limit of detection (LOD) into the linear calibration equation. The results showed that the LOD for phosmet residues in pakchoi reached below 0.5 mg/kg with the correction Raman peak of 604 cm-1, and the correlation coefficient R2 was 0.95273, and the standard deviation (SD) was 2.89%~13.63%, the recovery rate was 96.00%~121.33%. The LOD for thiram residues in Chinese cabbage reached below 0.5 mg/kg with the correction Raman peak of 1385 cm-1, and R2 was 0.8905, and SD was 3.90%~8.39%, the recovery rate was 88.80%~112.44%. The LOD for acetamiprid residues in swamp cabbage reached below 1 mg/kg with the correction Raman peak of 1111 cm-1, and R2 was 0.93858, and SD was 2.12%~9.29%, the recovery rate was 87.67%~107.17%. These showed that the SERS method might be an effective method for the rapid and reliable detection of pesticide residues in leaf vegetables.
