胶束电动毛细管色谱法分析玫瑰纯露中的苯乙醇

玫瑰纯露是玫瑰提取精油后的重要副产物，是玫瑰精油的饱和水溶液，不仅含有植物水溶活性成分，同时也保留了精油的芳香成分，含有矿物养分，具有抗衰老、清除自由基，抗过敏、抗菌、消炎、防紫外线损伤等功效，是继玫瑰精油之后护肤领域重要的优势产品之一，但目前尚无关于其质量控制的标准，市售产品质量参差不齐。为此，该研究发展了一种胶束电动毛细管色谱法用于快速检测玫瑰纯露中的指标成分苯乙醇。在实验过程中分析物的定性通过标准物质加标及紫外吸收可见光谱图比对确认。实验对缓冲溶液中硼砂浓度、十二烷基硫酸钠（SDS）浓度、分离电压、进样条件、检测条件等影响检测的关键因素进行了考察。在优化条件（分离缓冲溶液10 mmol/L Na₂ B₂ O₇ +15 mmol/L SDS，分离电压+20 kV，检测波长208 nm，进样5 kPa，5 s）下，玫瑰纯露样品在7 min内可以完成检测。本方法对苯乙醇检测的线性范围为0.50~1000 mg/L，线性相关系数（r ² ）为0.9990，检出限（LOD，S/N =3）为0.091 mg/L，定量限（LOQ，S/N =10）为0.35 mg/L，实际样品加标回收率为98.1%~102.7%（加标水平10、100、500 g/L），相对标准偏差（RSD）≤2.8%。结果表明，该方法为玫瑰纯露及其制品的质量控制提供了一种简便、快速、灵敏、稳定的分析方法。

Determination of phenylethyl alcohol in rose dew by micellar capillary electrochromatography

Rose dew has emerged as one of the superior products in the field of skin care after rose essential oil. However, at present, there is no quality control standard for rose dew. To this end, a micellar capillary electrochromatography (MEKC) method was developed to determine the amount of phenylethyl alcohol, one of the characteristic components of rose dew. The factors affecting the MEKC performance, including the concentrations of borax and sodium dodecyl sulfate (SDS), separation voltage, injection conditions, and detection conditions, were optimized. The capillary length was selected as 48.5 cm, and the effective capillary length was 40 cm. The new capillary was treated successively with methanol, sodium hydroxide (NaOH) solution, and deionized water for 10 min, 60 min, and 30 min when it was used for the first time. Under the running process, the capillary was flushed with 0.5 mol/L NaOH, deionized water, and running buffer solution (10 mmol/L Na₂ B₂ O₇ +15 mmol/L SDS) for 2 min, 2 min, and 3 min each. Between two runs, the capillary was balanced with the running buffer solution for 5 min. Sample injection was performed under a pressure of 5 kPa for 5 s. The separation voltage was set at a positive value of 20 kV. The capillary was maintained at a constant temperature of 20 ℃ using an air refrigeration system. A photo-diode array (PDA) detector with a detection wavelength range of 190-600 nm was coupled to the capillary for monitoring the target molecule, and the optimum wavelength was fixed at 208 nm. Under the optimized conditions, the rose dew samples could be separated and detected within 7 min. The linearity for phenylethyl alcohol detection was found to be 0.50 to 1000 mg/L, with a correlation coefficient (r ² ) of 0.9990. The limit of detection (LOD, S/N =3) and limit of quantification (LOQ, S/N =10) of the method were calculated to be 0.091 mg/L and 0.35 mg/L, respectively. The accuracy was tested by spiking phenylethyl alcohol into the rose dew samples at mass concentrations of 10, 100, and 500 g/L. The recoveries ranged from 98.1% to 102.7%, and the relative standard deviations (RSD; n =3) were less than 2.8%. This MEKC method is fast, sensitive, inexpensive, and highly effective for the determination of phenylethyl alcohol in rose dew. With the advantages of good stability, anti-matrix interference ability, and high sensitivity, this method represents a simple, sensitive, accurate, and robust strategy for the quality control of rose dew and related products.