Simultaneous determination of antioxidants and ultraviolet stabilizers in polypropylene food packaging and food simulants by high-performance liquid chromatography

Abstract

The use of polypropylene materials in industry for food packaging is increasing. The presence of additives in the polymer matrix enables the modification or improvement of the properties and performance of the polymer, but these additives are potential risk for human health. In this context, an efficient analytical method for the quantitative determination of three antioxidants (2, 6-di-tert-butyl-4-methylphenol (BHT), dibutylhydroxyphenylpropionic acid stearyl ester (Irganox 1076), and tns-(2.4-ditert- butyl)-phosphite (Irgafos 168)) and five ultraviolet stabilizers (2-(2′-hydroxy-5′- methylphenyl) (UV-P), (2′-hydroxy-3′-tert-5′-methylphenyl)-5-chloroben zotriazole (UV-326), 2-(2′-hydroxy-3′, 5′-di-tert-butylphenyl)-5-chlorobenzotriazole (UV-327), 2-(2Hbenzotriazol- 2-yl)-4-(1, 1, 3, 3-tetramethylbutyl)phenol(UV-329), and 2-hydroxy-4(octyloxy) benzophenone (UV-531)) in polypropylene food packaging and food simulants by high-performance liquid chromatography (HPLC) has been developed. Parameters affecting the efficiency in the process such as extraction and chromatographic condition were studied in order to determine operating conditions. The analytical method showed good linearity, presenting correlation coefficients (R ≥ 0.9977) for all additives. The limits of detection and quantification were between 0.03 and 0.30 μg mL-1 and between 0.10 and 1.00 μg mL-1 for eight analytes, respectively. Average spiked recoveries in blank polypropylene packaging and food simulants were in the range of 80.4-99.5% and 75.2-106.7%, with relative standard deviations in the range of 0.9-9.1% and 0.2-9.8%. Dissolving the polypropylene food packaging with toluene and precipitating by methanol was demonstrated more effective than ultrasonic extract with acetonitrile or dichloromethane for extracting the additives. The method was successfully applied to commercial polypropylene packaging determination, Irgafos 168 and UV-P were frequently found in six commercial polypropylene films, and the content ranged from 166.47 ± 5.11 to 845.27 ± 29.31 μg g-1 and 2.10 ± 0.29 to 19.23 ± 1.26 μg g-1, respectively.