Microwave-assisted oxidation of phosphite-type antioxidant additives in polyethylene film extracts

  1. Garrido-López, A. 1
  2. Sancet, Idoia. 1
  3. Montaño, P. 1
  4. González, R. 1
  5. Tena, M.T. 1
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

Revista:
Journal of Chromatography A

ISSN: 0021-9673

Año de publicación: 2007

Volumen: 1175

Número: 2

Páginas: 154-161

Tipo: Artículo

DOI: 10.1016/J.CHROMA.2007.10.045 PMID: 17981288 SCOPUS: 2-s2.0-36549079032 WoS: WOS:000251947300002 GOOGLE SCHOLAR

Otras publicaciones en: Journal of Chromatography A

Resumen

Two oxidation methods for reducing the analysis time required to determine Irgafos 126 and Irgafos 168 by pressurised liquid extraction (PLE) and high-performance liquid chromatography (HPLC) were optimised and compared. Analyte oxidation was performed using sodium peroxodisulphate (SPD) as oxidation agent and two different heating methods: with a hotplate and a reflux apparatus; and with a microwave oven. The influence of variables, such as oxidation time, temperature and sodium peroxodisulphate concentration was studied using a central composite design in order to optimise experimental conditions. A temperature of 68 °C for 2.5 h and a SPD concentration of around 6 × 10 -4 M were required for conventional oxidation, while a temperature of 120 °C for 30 min and a SPD concentration of 4 × 10 -4 M were found to be the best for microwave-assisted oxidation. After optimising the methods, their repeatability values were calculated and the two methods were applied to a solution containing other additives in order to check that they were not affected by the oxidation treatment and thus confirm that the methods could be used for oxidation of I126 and I168 in pressurised liquid extracts of polyethylene film samples before their determination by HPLC. Finally, the methods were applied to the analysis of antioxidants in polyethylene film samples. © 2007 Elsevier B.V. All rights reserved.