Lopes, Teresa I. M. S.Rangel, António O. S. S.Lima, José L. F. C.Montenegro, M. Conceição B. S. M.2011-10-112011-10-111995LOPES, Teresa I. M. S....[et al] - Construction and use of a tubular picrate ion-selective electrode for reducing sugar determination in Port wine by flow-injection analysis. Analytica Chimica Acta. ISSN 0003.2670. Vol. 308 n.º 1-3 (1995), p.122-128http://hdl.handle.net/10400.14/5941A picrate ion-selective electrode without inner reference solution and based on bis(triphenylphosphoranylidene)ammonium picrate dissolved in 2-nitrophenyloctyl ether was constructed and its characteristics assessed. With respect to reducing sugar determination in Port wine, a tubular electrode based on the same sensor system was developed and incorporated into a flow-injection manifold devised for this determination. The methodology involves a reaction between the reducing sugar and picric acid, the decrease in the picrate concentration being monitored with the tubular electrode. A linear dependence between peak width, at a fixed potential and the logarithm of sugar concentration in the range 25–200 g l−1 was obtained. The proposed system allows wine samples to be injected with no previous treatment and allows a sample throughput of 50 determinations per hour, a relative standard deviation less than 4%, and the results are comparable to the reference procedures.engFlow injectionIon selective electrodesPicrateSugarWinejournal article10.1016/0003-2670(94)00598-G0029060315A1995RD48900014