Determination of UV Absorbing Polyolefin Additives by Gradient and Isocratic Normal-Phase High Performance Liquid Chromatography

Abstract
A method previously developed for the rapid extraction of BHT, Irganox 1076, and Irganox 1010 from polyethylene pellets was extended to include other ultraviolet absorbing additives in polyethylene and polypropylene matrices. These were Santonox R, Ethyl 330, Goodrite 3114, and Topanol CA. Polyolefin pellets were dissolved in decalin at 110$C followed by cooling to precipitate the polymer. The concentrations of the additives present were determined by normal-phase high-performance liquid chromatography of a portion of filtered extract. The HPLC stationary phase was μ-Porasil and the mobile phase was a heptane to methylene chloride gradient. The separation of some additives strongly retained with the gradient system was studied also using an isocratic methylene chloride mobile phase.