01946naa a2200193 a 450000100080000000500110000800800410001902400270006010000170008724501080010426000090021252013330022165300120155465300320156670000260159870000280162470000210165277300790167310472872023-03-13       2005    bl uuuu     u00u1 u    #d7 a10.1021/jf049227u2DOI1 aLIN, P. K. T  aNew PVC nitrate-selective electrodebapplication to vegetles and mineral waters.h[electronic resource]  c2005  aThe paper refers the analytical potentialities of the oxa-azamacrocycles as potentiometric ionophores for the construction of electrodes selective to nitrate. Afterward, the membrane selective to nitrate is designed and optimized using a [3.3.3.3]oxazane as an ionophore. The membrane was prepared using dibutylphthalate as a solvent mediator, tetraoctylammonium as a lipophilic membrane additive, and poly(vinyl chloride (PVC) as a polymeric matrix, applied directly onto a conductive graphite/epoxy resin support. The electrodes presented a slope of 60 ± 0.1 mV log-1, a low limit of linear response of 4.2 × 10-6 mol L-1, a useful lifetime of 1 year, and improved selectivity characteristics when compared with other nitrate electrodes. The good working characteristics of this electrode, constructed without inner-reference solution, made possible its application to the determination of nitrate in different types of vegetables and bottled mineral waters without the use of a conditioning solution. The application of a significant F test proved that the results obtained were similar to those attained by application of the brucine spectrophotometric method adopted as a reference technique. Linear regression analysis also showed good agreement between the results obtained by the proposed method and the reference one.  aNew PVC  aNitrate selective electrode1 aNOGUEIRA, A. R. de A.1 aMONTENEGRO, M. C. B. S.1 aPÉREZ-OLMOS, R.  tJournal of Agricultural and Food Chemistrygv. 53, n. 2, p. 211-215, 2005.