Capillary GC determination of amines in aqueous samples using sorptive preconcentration on polydimethylsiloxane and polyacrylate phases

The use of sorptive extraction/thermal desorption (SE/TD) for the enrichmen t of amines from aqueous samples was investigated. The amines were derivati zed in situ in the water sample by pentafluorobenzoyl chloride and subseque ntly enriched onto the SE cartridge, Two SE/TD cartridges were used, a comm ercially available polydimethylsiloxane (PDMS) packed cartridge and a simil ar cartridge prepared with newly synthesized poly(butyl acrylate) (PBA), Bl ank profiles of PEA were not as good as those obtained from the PDMS phase. A complex chromatogram was obtained using mass spectrometric detection. Fo rtunately, the use of a nitrogen-phosphorus detector (NPD) resulted in clea n blanks. The PEA phase showed superior performance for the enrichment of t he polar amine derivatives from water samples compared to the PDMS material . Using a CGC-NPD set-up and only 1 mL samples, detection limits are in the sub-ppb range.