Applicaiton Of Ionic Liquid-based Liquid Phase Microextraction In Analysis Of Cosmetics

Cosmetics have become necessary products in modern life and play an important role inskin care or making up. However, the safety of cosmetics has attracted increasing attention byconsumers in recent years. The hormones and preservatives which were added in thecosmetics have become a potential or direct threat to the human health. It was essential toestablish a quick, inexpensive sample preparation with accessible devices because cosmeticsare samples with complex matrix, which contains a variety of hormones and preservatives.Ionic liquid-based liquid phase microextraction (IL-LPME) integrates extraction andpreconcentration and has promising application due to the properties of IL, such ashigh-selectivity, environmental friendliness and wide varieties.In the thesis, the sex hormones，glucocorticoids and preservatives in water-solublecosmetics were determined by ionic liquid-based homogeneous liquid liquid microextraction(IL-HLLME) coupled with high performance liquid chromatography (HPLC). The sexhormones in cosmetic products were determined by magnetically stirring extraction barliquid–phase microextraction (MSEBLPME) coupled with HPLC.IL-HLLME was one new method. In the thesis, the hydrophilic ionic liquid was addedin the sample solution first, ion-pairing agent was added successively and the formed dropletsof hydrophobic ionic liquid were homogeneously dispersed. Meanwhile the target compoundswere extracted and concentrated into the formed droplets of hydrophobic ionic liquid.In the thesis, MSEBLPME was developed. In this method, the extraction bar wasprepared by impregnating the ionic liquid into the pores of the fiber wall and the targetanalytes were extracted and concentrated when the extraction bar was immersed into thesample solution with the help of magnetic stirrer.IL-HLLME-HPLC was applied to the determination of the eight estrogen hormones,including17α-estradiol，17α-ethinylestradiol， estrone，17α-hydroxyprogesterone， medroxyprogesterone，megestrol-17-acetate，norethisterone acetate and progesterone. Whenthe sample solution was20.00mL, the optimized experiment conditions were that70μL[C6MIM][BF4] was as extraction solvent, NH4PF6was used as ion-pairing agent, the molarratio of [C6MIM][BF4] to NH4PF6was1:6, the extraction time was2min, the centrifugationtime was8min, the pH value was10.0and the concentration of NaCl was3%. Under theoptimal conditions, the limits of detection(LODs) of the eight estrogen hormones were0.03～0.24ng/mL and the limits of quantitation (LOQs) were0.10～0.79ng/mL. Six samples wereanalyzed. The recovery range of the analytes was91.9～114.2%and the relative standarddeviations (RSDs) were1.1～5.2%by analyzing the spiked samples.IL-HLLME was applied to the extraction and concentration of three glucocorticoids andsix sex hormones in cosmetic products and the analytes were determined by HPLC. Theconditions of IL-HLLME and HPLC were examined by experiments of recoveries in certainconcentration. In optimal conditions, the LODs of three glucocorticoids and six sex hormones,fluocinolone，D(-)-norgestrel，17α-hydroxyprogesteron17-acetate，clobetasol propionate，chlormadinone acetate，medroxyprogesterone17-acetate，medroxyprogesterone17-acetate，beclomethasone dipropionate，nandrolone17-propionate and testosterone propionate, were0.54～1.66ng/mL and the LOQs were1.80～4.82ng/mL. The recoveries and the RSDs werebetween80.3%and116.8%, and1.4%and4.8%, respectively，by the analysis of fourspiked samples.1-Hexyl-3-methylimidazolium tetrafluoroborate was used as extraction solvent andammonium hexafluorophosphate was used as ion-pairing agent. IL-HLLME-HPLC wasapplied to the determination of eight preservatives in cosmetics. The optimal experimentalconditions were as follows:70μL[C6MIM][BF4] was used as extraction solvent, the molarratio of [C6MIM][BF4] to NH4PF6was1:6, the concentration of NaCl was3.0%, the pHvalue was7.0, the extraction time and the centrifugation time was2min and8min,respectively. The LODs were0.16～2.84ng/mL and the LOQs were0.55～8.51ng/mL forthe analytes. Six samples were analyzed and recovery range was76.5～115.9%and RSDsrange was1.0～5.7%. One positive sample was found which contained86.5ng/gtriclocarban and113.0ng/g heptyl4-hydroxybenzoate.MSEBLPME-HPLC was developed to determine five sexual hormones，including19-nortestosterone， estrone， testosterone，17-α-hydroxyprogesterone and medroxyprogesterone, in cosmetic products. The analytes in the sample solution wereextracted，separated and concentrated by MSEB which was made with hollow fiber andhydrophobic ionic liquid [C8MIM][PF6]. The immersion way and time, pH value,concentration of NaCl, extraction time were examined by analyzing spiked sample. Therecovery was highest when the immersion time was20min, pH value was10.0, concentrationof NaCl was15%, and extraction time was40min. Under these optimal conditions, theLODs were12.8～16.2ng/mL and the LOQs were42.6～54.1ng/mL for the five sexualhormones. The recovery range was87.1～98.9%and RSD range was0.9～5.2%foranalyzing the three real samples, including essence, eye gel and aloe vera gel.