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 aro matic amines and dipeptides, phenylalanine, and selected N-nitrosamine s was found to occur by both ion-exchange and nonspecific interactions . The latter was not observed at an ionomer based on sulfonated styren e, A polymeric ruthenium oxide film retained its electrocatalytic acti vity in the presence of a Nation overlayer, The combination of solid p hase extraction and electrocatalysis provided a new stripping voltamme tric method by which such compounds as 4-nitroso-N,N-diethylaniline, 1 -amino-2-phenylethane, cysteine-glycine, and N-nitrosodiphenylamine (N NDPhA) were determined at the submicromolar level by linear calibratio n 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.