title: Determination of photoinitiator 4-methylbenzophenone in milk by cloud point extraction.
abstract: An efficient and easy sample pretreatment methodology was proposed for the detection of photoinitiator 4-methylbenzophenone from milk before high-performance liquid chromatography. Appropriate conditions for demulsification were studied. The parameters affecting cloud point extraction, such as concentration of Tween-20, electrolyte salt, equilibration temperature, and time, have been investigated. When the spiked level was 200-1000 μg/kg, the average addition standard recovery was 99.14-105.98% with the optimum cloud point extraction conditions (concentration of Tween-20, 138 g/L; mass of anhydrous sodium sulfate, 0.75 g; equilibration temperature, 65°C; equilibration time, 30 min). To decrease the detection limits, further work about the organic solvent, shaking time, and ultrasonic parameters was carried. When the spiked level was 10-100 μg/kg, the average addition standard recovery was 70.40-106.91% with the optimum cloud point extraction and enrichment conditions (optimum cloud point extraction conditions; volume of cyclohexane, 30 mL; shaking time, 20 min; time of ultrasonic, 20 min; temperature of ultrasonic bath, 45°C).
authors: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, P. R. China.
authors: Shengli
authors: S
authors: Ding
authors: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, P. R. China. yqcaohx@163.com.
authors: Yanqiu
authors: Y
authors: Cao
authors: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, P. R. China.
authors: Aijun
authors: A
authors: Gong
authors: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, P. R. China.
authors: Yujiao
authors: Y
authors: Wang
mesh_terms: D000818:Animals; D001577:Benzophenones / Q000032:analysis*; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid; D008892:Milk / Q000737:chemistry*; D014465:Ultrasonics
chemical_list: D001577:Benzophenones; C549177:4-methylbenzophenone
keywords: Cloud point extraction; Food contact packaging; Photoinitiators