The Content Detection And Analysis Of Whitening Agents And Preservatives In Aqueous Cosmetics By DAD-HPLC

Some highly toxic phenols such as hydroquinone,phenol,resorcinol are prohibited from being added to whitening cosmetics in Safety Technical Specifications for cosmetics.And because toxic mechanism and side effects are not fully understood,many whitening agents have not strictly stipulated the maximum allowable dosage.Some commonly used cosmetic preservatives induce inhibitory strongly effect on microorganisms.The addition of high concentration lead to the maladjustment of human skin.Through the optimization of instrument conditions and pretreatment of HPLC,a simple and efficient detection and analysis method was established for 11 whitening components and 11 preservative components.So that some whitening ingredients in aqueous cosmetics can obtain operable and optimized instrument detection methods.The research contents and results are as follows:1.Under the experimental conditions,the contents of 11 whitening components in aqueous cosmetics were determined by HPLC with SPDM20 A.The chromatographic conditions of the instrument were optimized,such as selecting the ZORBAXEB-C18 column(Agilent,4.6 * 250 mm,5μm)as the chromatographic column,setting 270 nm as experimental wavelength and choosing 0.8 ml/min as optimum flow rate.Also,the mobile phase system consisted of ammonium acetate buffer with methanol.Effect of different solvents,ultrasound and vortex on the extraction rates in the target fractions were investigated by ultrasonic direct extraction method.The results showed that the best recovery could be achieved when the blank matrix spiked sample was ultrasonic for 10 minutes,vortex for10 minute and centrifugation for 20 minutes in methanol and water solvent.Finally,the methodology was investigated: It has a good linear relationship in the concentration range of 0.5～100 μg/ml,the correlation coefficient is0.9999.detection limit is in the range of 0.16 μg/ml ～1.07 μg/ml,the limit of quantification is 0.48 μg/ml～3.26 μg/ml.Under the concentration gradient of adding 100 μg/g(low),200 μg/g(medium),500 μg/g(high).The recoveries of eleven whitening agents are between 89.8% and 100.6%,the precision is 0.11%～1.22%,and they have good stability within 24 hours.The results show that the method has high accuracy,good sensitivity.The test detected 250 kinds of aqueous cosmetics in the samples sent by enterprises,and among them,107 kinds of aqueous cosmetics of target substances were detected.2.Good separation effect could be obtained by choosing CNW Athena C18 column(4.6*250 mm,5 μm)after the analysis of the 11 target components in HPLC with SPD-M20 A.Separation of 11 preservatives could be made better through acidified ammonium acetate buffer with methanol as mobile phase system.Wavelength 270 nm and flow rate of 0.8ml/min made better sensitivity on instrument conditions.Through ultrasonic extraction and Qu ECh ERS purification,the interference of impurities in cosmetic can be reduced.Finally,the methodology was investigated: It has a good linear relationship in the concentration range of5.0～500 μg/ml,the correlation coefficient is 0.9996;detection limit is in the range of 0.1～1.0 μg/ml,the limit of quantification is 0.31～1.02 μg/ml,Under the concentration gradient of adding 450 μg/g(low),1000 μg/g(medium),2000 μg/g(high),the recoveries of eleven preservative agents are between 84.0% and 110.8%,the precision is 0.10%～0.98%.The results show that the method is simple and feasible,and various preservatives can meet the detection requirements in daily aqueous cosmetics.The test detected 192 kinds of aqueous cosmetics in the samples sent by enterprises,and among them,117 kinds of aqueous cosmetics of target substances were detected.