Quantitative Analysis Of Cosmetic Ingredients Using Second-order Calibration Coupled With Three-dimensional Fluorescence

Chemometrics is an interdisciplinary field, which combines the methods ofmathematics, statistics and computer sciences with chemistry. It can provide a newmeans to optimize the experimental design and the methods of measurement as well asanalyze the data and then extract as much as possible useful information from thecomplex multi-component chemical system. It is a very useful tool for qualitative andquantitative analysis. In particular, the second-order calibration methods can offer theso-called “second-order advantage”, namely they can allow for the rapid, directquantitative analysis of the analytes of interest in complex chemical systems even inthe presence of unknown interferences. The research work in this thesis focuses onquantitative analysis of banned and restricted substances in complicated cosmeticsystems using multi-way calibration methodologies.In Chapter2, a sensitive fluorescence method was proposed for thedetermination of estradiol （E2）, in two kinds of cosmetic samples. E2is a naturalestrogen, which has been illegally added in some cosmetics to make skin white andbreast plump, eliminate wrinkles as well as prevent skin from aging. However, thelong-term use of these cosmetics can cause metabolism disorders of the human bodyand occurrence of breast cancer and endometrial hyperplasia. Hence, for qualitycontrol of cosmetic products and protection of consumers’ health, it is extremelyimportant to develop simple, effective routine methods for determination of estradiolin cosmetic products. The fluorescence property of estradiol itself is strong,Satisfactory results have been achieved for estradiol in cosmetic matrices, whencombining the second-order calibration method with excitation-emission matrixfluorescence.In Chapter3, a novel method for simultaneously measuring estriol （E3） andestrone （E1） in liquid cosmetics using three-dimensional fluorescence based on regionselection coupled with parallel factor analysis method is successfully established.Such a chemometrics-based protocol shows several advantages over the traditionalmethods: simple, rapid, accurate and effective. Besides, it is capable of acquiringclean spectra and accurate concentration prediction even in cases with overlappedprofiles of background or interferences. Accordingly, due to its advantages of easysample pretreatment and non-destructive, it will achieve greater development in cosmetic quality control and gradually become a more routine approach.Methylparaben （MP） has been widely used as an antimicrobial preservative incosmetics, but recently some researches have shown its estrogenic activity, whichmakes it not so safe as before. China Standards has announced the use of MP incosmetic products with a maximum concentration of0.4%（4mg g1）. It is thereforeimportant to establish an effective routine method for quantifying MP in cosmeticproducts. In this work, a fast and sensitive three-dimensional fluorescence methodwas proposed to determine methylparaben （MP） in an actual cosmetic sample with theaid of a second-order calibration method based on the self-weighted alternatingtrilinear decomposition （SWATLD） algorithm （Chapter4）. High overlapping of thesignals and influence of matrix effects were observed, we could still obtainsatisfactory results, fully exploiting the “second-order advantage”. In addition, thenormal chromatography method was used to demonstrate the accuracy of our newstrategy.In Chapter5, we focused on the UV filters in cosmetics. Octyl salicylate （OS） isone of the most effective UV filters that can absorb deleterious UV light, therebydecreasing the amount of solar radiation reaching the skin. However, excessive use ofOS will cause skin damage, the maximum concentration of it was5%(50mg g^-1) incosmetic products by China Standards. So we developed a new and effectiveapproach for the quantitative determination of the UV filter octyl salicylate （OS）in sunsreen formulations using excitation-emission matrix fluorescence coupled witha second-order calibration method based on the SWATLD algorithm. Meanwhile, theresults of the normal chromatography method were the same as that of our newmethod.