SOLID-PHASE EXTRACTION IN CONJUNCTION WITH SOLUTION OR SOLID-STATE VOLTAMMETRY AS A STRATEGY FOR THE DETERMINATION OF NEUTRAL ORGANIC-COMPOUNDS

Solid phase extraction by a perfluorosulfonate, Nafion, of various aromatic amines and dipeptides, phenylalanine, and selected N-nitrosamines was found to occur by both ion-exchange and nonspecific interactions. The latter was not observed at an ionomer based on sulfonated styrene, A polymeric ruthenium oxide film retained its electrocatalytic activity in the presence of a Nation overlayer, The combination of solid phase extraction and electrocatalysis provided a new stripping voltammetric method by which such compounds as 4-nitroso-N,N-diethylaniline, 1-amino-2-phenylethane, cysteine-glycine, and N-nitrosodiphenylamine (NNDPhA) were determined at the submicromolar level by linear calibration curves, Both the extraction and catalysis chemistry operated for gas phase analytes, thereby allowing the design of an amperometric sensor for gases without a solution phase. Linear calibration curves at the micromole level for methanol and the nanomole level for NNDPhA in a 15-mL chamber were obtained.