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Published on: November 27, 2017
[Isolation of polyethylene microbeads in cosmetics by double-density separation]
Shasha Qu1, Huijuan Zhu1, Fengping Liu1
1National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China.
Objective:
To develop a stable method for isolation and quantitation of polyethylene microbeads in cosmetics and to observe its morphology and size.
Methods:
Polyethylene microbeads were isolated by using the difference of relative density between polyethylene and two kinds of separation solutions( sodium chloride solution and acetonitrile). The contents of polyethylene microbeads in cosmetics were determined by gravimetric method. The morphology and particle size were observed by microscope.
Results:
A stable method was developed by optimizing experimental method. The recoveries were from 93. 2% to 98. 2%, and the relative standard deviations varied in the range from 0. 16% to 2. 81%. Samples labeled containing microbeads could be isolated polyethylene microbeads, and the contents were from 0. 11% to 7. 76%, and size ranged from 100 μm to 200 μm. The morphology of isolated polyethylene microbeads were mostly regular, and color were mainly blue and white.
Conclusion:
The developed method is simple, repeatable and reliable that can be used for isolation and quantitation of polyethylene microbeads with a density lower than 1 g/cm in cosmetics.
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