Quantitative determination of cyfluthrin in n-hexane by terahertz time-domain spectroscopy with chemometrics methods

Terahertz time-domain spectroscopy (THz-TDS) was used for the detection of cyfluthrin content in N-hexane solvent with the concentration range of 0.5-10 μg/mL. The absorbance of the solution form cyfluthrin was obtained in the frequency range between 0.5-1.5 THz. Two kinds of multivariate linear regression models were then built between the absorbance and the concentration of 15 samples, using partial least squares (PLS) and principle component regression (PCR) methods. The number of factors leading to the least root-mean-square error of cross validation (RMSECV) was 2 for PCR and 9 for PLS respectively. Compared to the PCR model, the PLS model proves to be more effective, with the RMSECV as low as 0.565 μg/mL. Results show that the THz-TDS plus PLS method is very promising for the further pesticide residue detection in food safety control, with the characteristics of being nondestructive and laborsaving compared to other analytical tools.