消除基质硫酸镁对尿素乳膏微生物限度检测的干扰

Interference Elimination of Matrix Magnesium Sulfate on the Microbial Limit Test for Urea Cream

目的:消除尿素乳膏基质对微生物限度检测的干扰。方法:在供试液中加入一定量硫酸镁,充分搅拌,放置一定时间使乳膏分层,取澄明度高的水层进行微生物限度的检测。结果:尿素乳膏加入硫酸镁后,微生物限度检测不受基质干扰,大肠埃希菌、金黄色葡萄球菌、枯草芽孢杆菌、白色念珠菌和黑曲霉的平均回收率分别为96.00%、97.00%、100.00%、99.00%和101.00%。控制菌铜绿假单胞菌和金黄色葡萄球菌阴性和阳性可靠。结论:在对尿素乳膏进行微生物限度检测时,硫酸镁可作为一种较好的辅助剂,使检测方法更准确可靠。

Objective： To eliminate the interference of matrix in urea cream on the microbial limit test. Methods： A certain a- mount of magnesium sulfate was added to the test solution fallowed by stirring and placing sometime to make the cream layering, and the water layer was used for the microbial limit detection. Results： After magnesium sulfate was added to urea cream, microbial limit test was not affected by the matrix. The average recovery of Escherichia oli, Staphylococcus aureus, Bacillus subtilis, Candida albicans and Aspergillus niger was 96.00%, 97.00%, 100.00%, 99.00% and 101.00%, respectively. The negative and positive results of Psudomonas aeruginosa and Staphylococcus auress were reliable. Conclusion： In the detection of microbial limit for urea cream, mag- nesium sulfate can be used as a good auxiliary agent to make the detection method more convenient and reliable.