化妆品中致病菌检测能力验证样品制备技术研究

Research of the technology of proficiency testing sample preparation for pathogenic bacteria in cosmetics

目的研制化妆品中致病菌检测能力验证样品，建立有效的样品制备流程和制定科学合理的评估依据。方法通过试验筛选确定能力验证样品中的化妆品介质成分，将选定的介质成分配成化妆品溶液，灭菌后与检测对象（化妆品检测指标菌及相关干扰菌）混合，分装至玻璃冻干管中，通过冷冻、干燥技术使样品升华结晶，抽真空后封装制成能力验证样品；通过均一性和稳定性试验确定样品符合能力验证样品要求后，组织实验室间比对试验，评价实验室检测能力以及验证样品预期结果。结果通过试验选定了6种（脱脂奶粉、海藻糖、甘油、凡士林、吐温-80、甲氧基肉桂酸乙基乙酯）化妆品组分作为化妆品能力验证样品的介质成分，将这6种成分和检测对象混合制成能力验证样品按10％比例抽检36份样品进行验证鉴定，确认能力验证样品具有良好的均一性；通过冷藏、室温、升温保存开展稳定性实验，结果显示能力验证样品在4℃和室温（25—28℃）条件下，35d内菌量变化差异没有统计学意义（均P〉0．05），在37℃和42℃条件下，菌量快速减少，但37℃条件下样品可以稳定保存≤16d，42℃条件下样品可以稳定保存≤12d。21家实验室参加室间比对实验室检测能力验证，结果显示，满意占90．5％，基本满意占9．5％。结论本研究制备的冻干能力验证样品适合用于化妆品致病菌能力验证。

Objective To develop proficiency testing samples for pathogenic bacteria in cosmet- ics, then to set up an effective sample preparation process, and establish a scientific and reasonable evalua- tion basis. Methods The medium ingredients for proficiency testing samples of cosmetics were determined by screening experiment, and then prepared as cosmetic solution. After sterilization, the medium solution was mixed with testing objects （testing indicator bacteria and related interference bacteria in cosmetics）, and dispensed into freeze-dried glass tubes. Next, the mixture was sublimated and crystallized by freezing and drying technology, then testing samples were vacuumed and encapsulated. Finally, inter-laboratory comparisons were conducted after uniformity and stability tests of the proficiency testing samples to evaluate the laboratory testing capabilities and validate expected results. Results Six cosmetics （Skim milk pow- der, Trehalose, Glycerol, Vaseline, Tween-80, and Methoxy ethyl einnamate ethyl ester） were determined as medium ingredients for proficiency testing samples, then mixed with testing objects. The sampling re- suits of 36 samples to be identified by sampling ratio 10% showed that the proficiency testing sample hadgood uniformity. The stability tests were proceeded at refrigerated storage temperature, room temperature （25 to 28 ℃ ） , and raising temperature. The data showed that the significant change was not observed in the bacteria amounts in proficiency testing sample within 35 days at 4 ℃ and room temperature （ all P 〉 0. 05）. At 37 ℃and 42 ℃ , the amount of bacteria decreased quickly. However, the samples would be stable for 16 days or less at 37 ℃ , and 12 days or less at 42 ℃. The inter-laboratory comparisons by 21 comparison labs showed that the satisfaction was 90. 5% and basic satisfaction was 9.5%. Conclusion The preparation of freeze-drying proficiency testing samples in this study is suitable for proficiency testing of pathogenic bacteria in cosmetics.