title: Extraction-spectrophotometric determination of zinc(ii) with 4-(2-pyridylazo)-resorcinol and a quaternary ammonium salt.
abstract: A simple and sélective extraction spectrophotometric determination of zinc is described. The complex [Zn(PAR)(2)](CDBA)(2), where PAR is the 4-(2-pyridylazo)resorcinol anion and CDBA is cetyldimethylbenzylammonium ion, is extracted from a solution buffered at pH 9.7 with carbonate/bicarbonate. Beer's law is obeyed over the range 0.2-1.2 ppm zinc, the molar absorptivity being 9.2 x 10(4) 1 .mole(-1).cm(-1). The precision in this range is 0.0056 ppm. Cadmium in up to a 50-fold w w ratio may be masked with diethyldithiocarbamate.
authors.affiliation: Department of Analytical Chemistry, University of Sofia, 1 Anton Ivanov Avenue, Sofia 26, Bulgaria.
authors.forename: D
authors.initials: D
authors.lastname: Nonova
authors.forename: V
authors.initials: V
authors.lastname: Nenov
authors.forename: N
authors.initials: N
authors.lastname: Lihareva