Abstract: Determinate the multi-component samples, the absorption curve offen overlaps in varying degrees , It is difficult to quantitate each component using spectrophotometry generally, but the wavelet transforrrmtion (WT) in the field of chemical application which particularly in the field of nonlinear applications are very wide and have achieved good results. In this paper,Using a standard low-frequency coefficient C1 for the original absorbance data to structure analysis matrix to PLS regression analysis, forecasting results is better than the original entire spectrum model.In this paper using WT-PLS spectrophotometry to simultaneously determinate the Cough Syrup which has four components: acetaminophen, guuaifenesin, caffeine, p-aminophenol.the recovery ranged from 100.36% to 118.50% ,the result is basically satisfied. Using wavelet coefficients to build PLS model, not only can eliminate some of noise in the original signal , but also can greatly reduce the volume of data,the forecast accuracy can be improved,.In conclusion,the WT-PLS spectrophotometry provides a simple, reliable method for the simultaneous determination of multi-component.
Keywords: wavelet transforrrmtion;PLS;UV spectrophotometry;simultaneous determination of multiple components;Cough Syrup