防晒霜防晒指数的光谱分析研究

防晒指数SPF是反映防晒用品防晒效果的主要指标，文章采用ASD公司的便携式光谱仪研究了防晒指数与光谱特性之间的关系。选用丁家宜SPF15，SPF20，SPF30三种品种防晒霜共75个样本进行了光谱分析，将样本分为60个试验样本和15个预测样本，用光谱仪获取样本的反射光谱数据。采用主成分分析法对400～960 nm范围内光谱数据进行处理，表明主成分1和主成分2的累计可信度达91%，再用偏最小二乘回归方法建立了校正模型，并用该模型对剩余15个样本进行预测。结果表明，预测相关系数为0.967 7,得到了较好的预测结果。说明文章提出的光谱分析方法具有很好的分类和鉴别作用，为防晒霜SPF值的检测提供了一种新方法。

Spectroscopic Analysis of Sun Protection Factor (SPF) of Sunscreen Cosmetic

Sunscreen index is the primary indicator of the protection effect of sunscreen cosmetics.A handheld spectrometer was used to study the relationship between sunscreen index and reflectance spectra.Three kinds of Dingjiayi brand sunscreen cosmetics,which is SPF15,SPF20 and SPF30,were chosen as experimental material.The sunscreen cosmetics were divided into 75 samples,and 60 of them were used as calibrated samples,while the other 15 samples were used as prediction samples.The reflectance spectra data were collected by the spectrometer.The data from the wavelength range between 400 and 960 nm were processed by principal component analysis method,and the results showed that the cumulate reliabilities of PC1 and PC2(the first two principal components) reached 91%.Then partial least square analysis method was applied to build prediction models,and the remaining 15 prediction samples were disposed by this model.The results show that the prediction correlation coefficient is 0.967 7,and the prediction precision is good.So the spectral analysis method proposed in the present paper has good performance in classification and discrimination of sunscreen cosmetics,and is a new approach to test the SPF of cosmetics.