Direct determination of a polymeric hindered amine light stabilizer in polypropylene by thermal desorption–gas chromatography assisted by in-line chemical reaction

Abstract

A method to determine a polymeric hindered amine light stabilizer (HALS), Adekastab LA-68LD, in polypropylene (PP) was developed on the basis of reactive thermal desorption–gas chromatography (RTD-GC) in the presence of an organic alkali, tetramethylammonium hydroxide [(CH₃)₄NOH, TMAH]. RTD-GC using 25% TMAH methanol solution allowed the sensitive determination of HALS in PP as methylated fragments on the resulting chromatogram with a 4.8% relative standard deviation without the need for any sample pre-treatment.