title: Adsorptive preconcentration for voltammetric measurements of trace levels of zirconium.
abstract: This paper describes an electrochemical stripping procedure for ultratrace measurements of zirconium, in which preconcentration is achieved by the adsorption of a zirconium-Solochrome Violet RS complex onto a hanging mercury drop electrode. Cyclic voltammetry was used to characterize the interfacial and redox behaviour. For a 10-min preconcentration time, the detection limit found was 2.3 x 10(-10)M. Optimal experimental conditions were found to be use of a stirred acetate buffer (pH 4.6) solution with Solochrome Violet RS concentration 1.5 x 10(-6)M, a preconcentration potential of -0.3 V and linear scan mode. A 60-fold enhancement of the response is obtained following 5-min preconcentration. With preconcentration for 60 sec, calibration plots for zirconium are linear for the 1.1 x 10(-8)-1.1 x 10(-7)M range. The relative standard deviation at 5.5 x 10(-8)M is 1.7%. Possible interferences by surface-active organic materials and other trace metals have been investigated. Zirconium added to a sea-water sample at the 10 ng/ml level was readily determined.
authors.affiliation: Department of Chemistry, New Mexico State University, Las Cruces, New Mexico 88003, USA.
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: P
authors.initials: P
authors.lastname: Tuzhi
authors.forename: K
authors.initials: K
authors.lastname: Varughese