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

Phenyl content is a crucial quality indicator for phenyl silicone oils, but the current ¹H NMR method for determining it is still unreliable because of the possibility of interference from methylphenylcyclosiloxane or solvents such as toluene and xylene. Here, a novel method for the determination of the phenyl content in phenyl silicone oils for has been developed using 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⁻¹ with a squared correlation coefficient of more than 0.999, and a quantification limit of 0.972 μg mL⁻¹ has been obtained. Potential interference-causing substances, such as methylphenylcyclosiloxane, toluene or xylene, and various silicone oils can be readily ruled out using the GPC-UV method. The phenyl content in 9 samples of phenyl silicone oil that were readily available was determined with a recovery in the range of 84.63–106.74%. The amount (0.613 mg g⁻¹) of phenyl in sample H1 by GPC-UV was in good agreement with that (0.603 mg g⁻¹) by the ¹H NMR analysis. [ABSTRACT FROM AUTHOR]