CHEMILUMINESCENCE DETERMINATION OF HYDROQUINONE IN ITS MEDICINAL CREAM BY THE REACTION SYSTEM OF Ce(IV)-HYDROQUINONE-TWEEN 40

It was found that the intensity of chemiluminescence (CL) emitted by the CL reaction between Ce(Ⅳ) and hydroquinone is remarkably enhanced by the presence of nonionic surfactant Tween 40. Based on this phenomenon, and by the hyphenation with the flow-injection technique, a new method for the CL-determination of hydroquinone in its medicinal cream was proposed. The linearity of the determination was found in the range of 8.0×10~(-7)～5.0×10~(-5)mol·L~(-1) of hydroquinone with a detection limit of 5.0×10~(-7)mol·L~(-1). RSD′s (n=11) found at the concentration level of 5.0×10~(-6)mol·L~(-1) was 2.5%. Satisfactory results were obtained in the analysis of some cream sample, and recoveries obtained by the standard addition method were in the range of 92.5%～104.5%.