Head space gas chromatography determination of acetaldehyde in PET preforms and bottles used in Czech Republic
1995
Voldrich, M. | Dobias, J. | Curda, D. (Vysoka Skola Chemickotechnologicka, Prague (Czech Republic). Ustav Konzervace Potravin a Technologie Masa)
The acetaldehyde contents in 22 PET preforms and bottles used by Czech producers of soft drinks were analysed. Bottle was cut (0.5 x 0.3 cm pieces), preform was cooled with liquid nitrogen and ground to power. Polymer was placed into head space vial, closed by septum and heated for one hour at 130 degrees C. After at least 30 min of equilibration at 90 degrees C 0.5 to 1 ml of head space volume was analysed by GC. The capillary columns (HP1 50 m, 0.22 mm i.d., DB23 30, 0.33 mm i.d.) operated in low flow rate at 60 degrees C were used. Detection limit of the procedure was 0.5 ppM, relative standard deviation (n=5) was lower than 5 degrees C. The content of 22 analysed preforms varied from 1.8 to 10.2 ppM of acetaldehyde, the levels in bottles were slightly lower (about 78 % of the average content of preforms).
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