Optimization of a headspace solid‐phase microextraction‐gas chromatography–mass spectrometry procedure for odor compounds from polyolefin resin used in plastic food packaging

Abstract

This research investigated the best headspace solid‐phase microextraction (HS‐SPME) extraction conditions and used the response surface Box–Behnken trial design to optimize the parameters for the analysis of volatile compounds in polyolefin resin, which is made from powdered polyolefin resin and additives by heating processing. The results showed that when the extraction temperature was 64°C, the extraction time was 34 min, the sample weight was 2.0 g, the testing matrix was air, and the fiber type was 50/30 μm DVB/CAR on PDMS, and the number of volatile compounds in the resin pellets was the highest. The performance characteristics of the optimized method were also determined, and they showed excellent linear ranges, recovery, repeatability, detection, and quantification limits. In the resin pellets and powdered polyolefin resin, the alkane content was the highest, at 585.346 and 581.789 mg/kg, respectively. In the additives, the benzene content was the highest at 39.495 mg/kg. Compounds with odor activity values (OAVs, ratio of concentration to odor threshold) above 1.0 are considered key aroma‐active compounds. In total, 135 volatile compounds were identified, and 19 of them had an OAV above 1.0, and 4‐methyl‐octane and o‐xylene were identified as the key odorants in the resin pellets. Only one odorant, 4‐methyl‐octane, was detected in the powdered polyolefin resin. In the additives, 18 volatile compounds were identified as key aroma‐active compounds, such as octanal, nonanal, hexanol, octanol, heptanol, and decanol. The significance of this research was to furnish data to support the further study of odor abatement from food packaging materials.