光甘草定的光化学反应动力学及干预研究

Photochemical Reaction Kinetics and Intervention of Glabridin

研究了常用美白剂——光甘草定的光降解过程.首先研究了光源种类对光甘草定光降解的影响,结果发现紫外线更容易使光甘草定发生降解.为了研究其光降解动力学,将不同初始浓度的光甘草定置于紫外线下照射.结果显示,它的光降解速率随着浓度的减小而增大,且降解过程符合一级反应动力学.研究发现光甘草定在甲醇中表现出最高的稳定性.为了干预光甘草定的光降解,过氧化氢、盐酸(氢氧化钠)、金属离子、聚合物、紫外吸收剂、表面活性剂、还原剂和络合剂等被加入到光甘草定的溶液中.结果证明某些紫外吸收剂和表面活性剂能够有效地保护光甘草定,而诸如过氧化氢、盐酸(氢氧化钠)和金属离子等则会加快光甘草定的光降解.这些研究结果将有利于光甘草定的处方设计,以及加速它作为一种环境污染物时的降解过程.

The photochemical reaction of glabridin, a common used skin whitening agent, by irradiations was investigated. The effects of light sources on the photodegradation of glabridin were studied. The results demonstrated that the UV irradiation resulted in the fastest degradation rate. To study the photodegradation kinetics of glabridin, various initial concentrations of glabridin were irradiated by UV. It was found that the photodegradation rate increased with the decreasing of initial glabridin concentrations,and the degradation of glabridin followed pseudo first-order reaction. The study showed that glabridin in pure methanol exhibited the highest stability. For intervention study, H2 02, HCI（NaOH）, metal ions, polymers, UV absorbents, surfactants, reductants and complexant were added to the solution of glabridin. The results demonstrated that some UV absorbents and surfactants could protect the glabridin against from UV irradiation,whereas some substances, such as H202, HCI（NaOH） and metal ions, would accelerate the photodegradation of glahridin. These results would be helpful to design the formulations of glabridin and accelerate the degradation of glabridin as a pollutant in environment.