Development of Flow Injection-Spectrophotometry Method for Hydroquinone Determination Based on The Formation of Blue Starch-Iodine Complex

9th Annual Basic Science International Conference 2019

自然科学（总论）

Trenggamayunelgi, Fahrana Salas^1^2 ; Sulistyarti, Hermin^1^2 ; Retnowati, Rurini^1^2

Department of Chemistry, Faculty of Science, Brawijaya University, Indonesia^1

LCAMIA (Low Cost and Automated Method and Instrumentation Analysis) Research Group, Brawijaya University, Indonesia^2

关键词: Flow injection method;    Flow injection spectrophotometry;    Flow-injection system;    Low concentrations;    Optimum conditions;    Phenolic compounds;    Spectrophotometric detection;    Visible spectrophotometries;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/546/3/032031/pdf
DOI  :  10.1088/1757-899X/546/3/032031

学科分类：自然科学（综合）

来源: IOP

【 摘 要 】

Hydroquinone (1,4-dihydroxybenzene) is an aromatic organic phenolic compound used in drug and should not be used as cosmetic products. Although the use of hydroquinone has been banned in cosmetics, it is still found at low concentration for skin whitening. The effect for excess use of hydroquinone can cause irritation and changes in skin color become blackish permanently. The determination of hydroquinone can be performed by a flow injection system with spectrophotometric detection based on the redox reaction between hydroquinone and iodine. Under this method, hydroquinone can be determined based on the decreasing intensity of the blue color of the starch-iodine complex when hydroquinone was added to the solution. Hydroquinone will react with the excess iodine, thus iodine is reduced to iodide. The rest of iodine which does not react with hydroquinone, will form a blue complex with starch in an acidic condition (pH = 1). The blue color of the starch-iodine complex was analyzed by visible spectrophotometry at a wavelength of 628 nm. The optimum conditions for determination of hydroquinone using the flow injection system provide at 0.05 % starch and 40 mg/L iodine by the length of mixing coil of 50 cm on the flow rate of 5.8 mL/min, and a sample volume of 100 L. Under these optimum conditions, the flow injection method showed the linearity from 0 to 15 mg/L with a correlation (R2) of 0.9941.