Head-Space-GC Determination of Volatile Organic Compounds in Plastic Packaging Materials for Foodstuffs with Matrix Matching Calibration

Ten volatile organic compounds (VOC′s), i.e., toluene, ethyl acetate, 2,4-pentanedione, 2-ethyl-1-hexanol, 1-nanaldehyde, decanecarbaldehyde, dodecanacarbaldehyde, decane, octane and dodecane in soft plastic packaging materials were determined by head-space gas chromatography using matrix matching calibration to compensate the matrix interference. A representative portion of the sample (packaging film, ca. 100 cm2) was taken and stoved in a vacuum oven at 90 ℃ for 24 h. This portion of the sample was cut and used as blank matrix for preparation of calibration curve and definita amounts of standard solutions of the 10 VOC′s wer added to it and treated in the same way as the sample. A similar portion of the sample was cut and transferred into the headspace bottle, closed the bottle immediately and equilibrized at 100 ℃ for 30 min. HP-INNOWAX chromatographic column was used for separation at programed temperature elevation from 20 ℃ to 220 ℃. FID was adopted for determination. Detection limits (3S/N) found for the 10 VOC′s were ranged from 0.2 to 2.0 μg·dm-2. Values of recovery and RSD′s (n=6) were in the ranges of 82.5%-97.6% and 1.0%-14.0% respectively.