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Determination of Concentration and Stability of Hydroquinone in Skin Whitening Creams sold in Sudan

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dc.contributor.author Mohamd, Tsabih Mahgoub Abdelhalim
dc.date.accessioned 2018-12-03T08:14:09Z
dc.date.available 2018-12-03T08:14:09Z
dc.date.issued 2018-06-21
dc.identifier.uri http://repo.uofg.edu.sd/handle/123456789/3121
dc.description Submitted to the University of Gezira in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science,in,,Chemistry, Department of Chemical Engineering and Chemical Technology, Faculty of Engineering and Technology, June 2018 en_US
dc.description.abstract Nowadays, the use of skin whitening creams among Sudanese ladies is popular without awareness about the potential dangers that can threaten their health while using these products. Several skin lightening creams available in Sudanese markets are unsafe. The aim of this study is the determination of hydroquinone (HQ) contents in some skin whitening creams product sold on the market. Five types of this cream from different sources were collected from local market, samples (A, B and E) Italian samples and (C and D) Egyptian samples. About 1g of each sample (A, B, C, D and E) was dissolved in (0.05)M sulfuric acid and the absorbance was measured at wave length (288.6)nm in a UV-VIS spectrophotometer. The concentration of hydroquinone was determined from a calibration curve constructed by a series of (HQ) concentrations. Also the stability of (HQ) at different conditions of temperature, pH and light was examined. 40% of the skin whitening creams samples analyzed for hydroquinone had concentrations more than the US Food and Drug Administration’s (USFDA) acceptable limit of (2%),the detected percentage was 4.44% in sample (A) followed by 3.13% in sample (E) Italian samples. The third Italian sample (B) contained only 0.2%. The Egyptian samples (D) containing hydroquinone 0.072% and (C) containing 0.0299%, they are within the recommended limit of hydroquinone according to the USFDA. The absorbance of all samples increase due to the increasing temperature in the range from (30 to 60)°C as followed: standard solution (6 ppm) (0.127 and 0.146), (C) sample (0.306 and0.378) and (D) sample (0.660 and 0.770)respectively, even though ⅄max of hydroquinone did not significantly change with temperature (288.6) nm at room temperature, (288.31) nm at 60°C. The absorbance of hydroquinone standard solution (6 ppm) exposed to light was (0.130), and (0.131) in the dark. So hydroquinone is stable when exposed to light at constant temperature. The⅄maxof HQ standard solution when dissolve in(0.05) M Sulfuric acid (pH=1) was (288.6) nm, and indistilled water (pH= 7) ⅄max slightly differ (289.3) nm. But when dissolved HQ in Sodium hydroxide solution (0.05) M (pH= 12.8) ⅄max significantly changes (261.81) nmbecause hydroquinone is converted to Quinone. That means hydroquinone is stable when exposed to light and heat, and influenced by pH.It is recommended that awareness of user should be raised about the hazards of topical skin whitening creams containing hydroquinone, purchased by Sudanese ladies without prescription, it is also studies and explanation why the absorbance of hydroquinone increase with elevated temperature, analyzed of hydroquinone may be carry out in neutral solution. en_US
dc.description.sponsorship Fathalrhman Abbass Elshikh (Main supervisor) Mustafa Ohag Mohamed (Co-supervisor) en_US
dc.language.iso en en_US
dc.publisher University of Gezira en_US
dc.subject Chemistry en_US
dc.subject Chemical Engineering en_US
dc.subject Chemical Technology en_US
dc.title Determination of Concentration and Stability of Hydroquinone in Skin Whitening Creams sold in Sudan en_US
dc.type Thesis en_US

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