Accurate Quantitation of the Phenyl Group in Methylphenylsilicone Oils by GPC-UV

Abstract

The phenyl content is an important quality parameter for phenyl silicone oils, yet its current determination method by 1 H NMR is still unsatisfactory due to the potential interference of methylphenylcyclosiloxane or solvents such as toluene and xylene. Herein, a novel method has been developed for the determination of the phenyl content in phenyl silicone oils by gel permeation chromatography-ultraviolet detection (GPC-UV) analysis. Under optimized parameters, the standard curve has been established in the linear range of 5-1000 µg/mL with a squared correlation coe cient of more than 0.999, and a quanti cation limit of 0.972 µg/mL. The GPC-UV method can easily exclude potential interfering substances, such as methylphenyl cyclosiloxane, toluene or xylene, and various silicone oils. The phenyl content in 9 available phenyl silicone oil samples was determined with a recovery in the range of 84.63%-106.74%. The determined phenyl content of sample H1 by GPC-UV was in good agreement with that (0.603 mg/g) by the 1 H-NMR analysis.