文摘
A method of self-enhanced absorption spectrum was proposed for the quantitative determination of thiamethoxam in tea infusion. Based on wavelet transform of original absorption spectra and self-enhanced spectra by wavelet function Gau8, the ratio of wavelet coefficients at analysis point was used to acquire thiamethoxam’s concentration. The analysis point of original spectra is at 251 nm by observation which may result in artificial error. However, the analysis point of self-enhanced spectra is at zero point which is fixed, reducing artificial impact. Certain parameters such as limit of detection(LOD), limit of quantitation(LOQ), root mean of standard error of calibration(RMSEC), and relative standard deviation (RSD) were applied which illustrated that wavelet transform of both the two kinds of spectrum could determine thiamethoxam’s concentration. There was no significant difference between the two kinds of spectrum by one-way ANOVA test. Besides, prediction of actual samples indicated that the method of wavelet transform of self-enhanced absorption spectrum is an effective method for quantitative determination of thiamethoxam residue in tea infusion.
