Trace analysis of chlorofluorocarbons/partially halogenated chlorofluorohydrocarbons (CFC/HCFC) in polymeric foams by headspace capillary gas chromatography with electron-capture detection or ion trap detection combined with preconcentration on a cold trap

Two headspace-methods were developed for the detection and determination of traces of CFC/HCFC in polymeric foams. These methods consist of capillary gas chromatography using an electron-capture detector (ECD method) or an ion trap detector combined with preconcentration on a cold trap (ITD method). Different CFC/HCFC such as R115, R22, R12, R142b, R114, R11, R141b and R113 were investigated in polyethylene and flexible polyurethane foams. Conditions for sample preparation (e.g. thermostating time and temperature) were optimized. Determination of the detection limits and quantitation of the amount of CFC/HCFC released from the foam were performed with gas standards prepared with the help of mass flow controllers. Quantitative analyses of the total amount of CFC/HCFC present in the foam were performed using multiple headspace extraction. Longterm studies were performed on the rate of release of some CFC/HCFC from the foams. Additionally a method for distinguishing a CFC/HCFC-contaminated foam from an old CFC/HCFC-blown foam is presented. Both methods can be used individually; however, best results are achieved by using the ECD method for screening and the ITD method for confirmation. This combination was used for routine analysis enforcing legal restrictions on the use of CFC/HCFC in foams.Abbreviations CFC chlorofluorocarbon - HCFC partially halogenated chlorofluorohydrocarbon - PUR polyurethane - PS polystyrene - PE polyethylene - MHE multiple headspace extraction - ECD electron capture detector - ITD ion trap detector - FID flame ionization detector - TCD thermal conductivity detector - MS mass spectrometry - WCOT wall coated, open tubular (column) - ppm parts per million (1:10⁶ v/v) - ppb parts per billion (1:10⁹ v/v) - ppt parts per trillion (1:10¹² v/v) - DL detection limit - RSD relative standard deviation - CO₂ carbon dioxide - R115 C₂ClF₅ - R22 CHClF₂ - R12 CCl₂F₂ - R142b C₂H₃ClF₂ - R114 C₂Cl₂F₄ - R11 CCl₃F - R141b C₂H₃ClF - R113 C₂Cl₃F₃