Infrared Spectroscopic Determination of Acetamiprid Pesticide in Apple

Abstract

ABSTRACT This study aimed to test the ability of a nondestructive and fast method of Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy quantifying acetamiprid levels in apple and to compare with a universal chemical method. Non-pesticide applied apple were entirely homogenized with 0.00, 0.156, 0.31, 0.625, 1.25, 2.50, 5.00, 10.00, 20.00, 40.00, 80.00 and 160.00 ppm acetamiprid. Universal chemical method produced acceptable performance: accuracy of 90% and precision of 22% in acetamiprid quantification. In contrast, partial least square regression (PLSR) model 1 using raw spectra data and PLSR model 2 using its second derivate have higher accuracy of 108% and 101% and precision of 9.33% and 3.67%, respectively, and the model 2 being more powerful. Moreover, ATR-FTIR combined PLSR models produced lower root mean square error (RMSE) of quantification (0.41–0.87) than that of universal method (3.46). In conclusion, acetamiprid levels up to 80-folds of legally permitted level (2 ppm) in fresh apple can accurately be detectable by ATR-FTIR spectroscopic method.