羟丙基四氢吡喃三醇（HT）是抗衰老化妆品原料玻色因的主要有效成分。HT的两种非对映异构体（β，S）和（β，R）由于空间构型不同，在生物活性、安全性和功效方面均呈现出差异，其中（β，S）为功能优势构型。该研究建立了高效液相色谱-蒸发光散射检测器（HPLC-ELSD）测定化妆品中HT总量及两种构型比例的方法。液相色谱流动相为0.05%甲酸-水（V∶V）溶液，样品经Agilent Polaris 5 Amide-C18色谱柱分离。结果显示，HT的两种构型完全分离，用外标法定量（β，S）构型，在10.0~300.0 mg/L质量浓度范围内线性关系良好，相关系数（r）大于0.999，检出限与定量限分别为0.15 mg/g、0.5 mg/g。在2.5，5.0和10.0 mg/g加标水平下，加标回收率为94.4%~100.1%。应用该方法对18批化妆品进行检测，有10批被检出含有HT，含量范围为0.1%~11.5%，其中4批仅含有（β，S）构型，6批同时含有（β，S）和（β，R）构型，两者的比例在（51%~53%）∶（49%~47%）之间分布。
Hydroxypropyl tetrahydropyrantriol （HT） is a xyloside derivative and the main active ingredient of pro-xylane, an anti-aging cosmetic raw material. HT has two diastereomeric configurations, （β, S） and （β, R）. The steric configuration of （β, S） and （β, R） is different, and so are their bioactivity, in vivo degradation and safety. （β, S） is the dominant configuration and its biological activity is significantly higher than that of the mixture of （β, S） and （β, R）. In this study, a method for the determination of （β, S） in cosmetics by high performance liquid chromatography with evaporative light-scattering detector （HPLC-ELSD） was established. Samples were separated by an Agilent Polaris 5 Amide-C18 （250 mm×4.6 mm, 5 μm） column with 0.05% formic acid aqueous solution as the mobile phase. The results show that （β, S） and （β, R） can be separated with a resolution （R）>1.5. （β, S） is quantified by the external standard method, and the linear relationship of the compound is good in the range of 10.0 mg/L to 300.0 mg/L. The correlation coefficient （r） is greater than 0.999. The limit of detection （LOD） and quantification （LOQ） were 0.15 mg/g and 0.5 mg/g, respectively. The recoveries of （β, S） are investigated in water-in-oil, oil-in-water, and aqueous solution cosmetic samples at three spiked levels （2.5, 5.0, and 10.0 mg/g）. The recoveries range from 94.4% to 100.1%. The practicability of the method was examined by using 18 batches of commercially available cosmetics with HT on the ingredient label. Ten batches are found to contain （β, S） at the concentrations ranging from 0.1% to 10.6%, and both （β, S） and （β, R） are found in 6 batches. The method has the advantages of simple operation, accurate quantification, and effective separation of isomers. It is suitable for the determination of （β, S） content and diastereomer distribution of （β, S） and （β, R） in HT cosmetics. It can also provide effective technical references for market supervision and product quality control.
