DETERMINATION OF HIGH-MOLECULAR-MASS AND LOW-MOLECULAR-MASS PLASTICIZERS IN STRETCH-TYPE PACKAGING FILMS

A single analytical procedure is presented for determination of so-cal led monomeric plasticisers such as di(2-ethylhexyl) adipate, polymeric plasticisers such as poly(butylene adipate), and secondary plasticise rs such as epoxidised soybean oil. The plasticisers are extracted from the film with concurrent derivatisation. Ester linkages are cleaved b y treatment with potassium hydroxide in ethanol, epoxide moieties are opened using hydrochloric acid generated in situ by addition of acetyl chloride and, lastly, hydroxy groups are converted to silyl ethers us ing bis(trimethylsilyl)trifluoroacetamide. This reaction sequence is c onveniently performed sequentially on a single sample leading to produ cts that can be measured in a single GC analysis. The method has been applied to samples of known provenance and in a large survey of retail stretch-type films. The combined method offers significant savings in time compared with the separate analytical methods published earlier for monomeric and polymeric poly(vinyl chloride) plasticisers. The met hod is quantitative and gives results in good agreement with these ear lier procedures.