Analytical Control of the Mass Fraction of the Basic Substance in Antioxidants 2,4,6-Tri-tert-butylphenol and Pentaerythritol Tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) by High-Performance Liquid Chromatography

A technique for high-performance liquid chromatographic determination of the mass fraction of the basic substance in antioxidants 2,4,6-tri-tert-butylphenol (antioxidant P-23) and pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (antioxidant Agidol-110) was developed. The technique consists in dissolution of the antioxidant in acetonitrile, followed by adding ethanol, separation of the basic substance and impurities by column chromatography, and recording the chromatogram, whereupon the mass fraction of the basic substance is calculated by the normalization method. Use of this technique allows determining the mass fraction of the basic substance in the 98.0-100% range for P-23 antioxidant and in the 95.0-100% range for Agidol-110 antioxidant. The technique developed can be recommended for analytical monitoring of the mass fraction of the basic substance in antioxidants for the purpose of incoming inspection of the raw materials and of the control after expiration of the warranty storage period.