title: Flow injection visible diffuse reflectance quantitative analysis of nickel.
abstract: Flow injection (FI) methodology, using diffuse reflectance in the visible region of the spectrum, for the analysis of nickel, precipitated in the form of dimethylglyoximate, is presented. A reflectance cell, constructed in polytetrafluoroethylene, using a LED (light emitting diode) as light source and a LDR (light dependent resistor) as detector, is described. The analytical signal (S) correlates with nickel concentration (C) between 1.6 x 10(-4) and 6.6 x 10(-4)molL(-1). This correlation is described by the equation S=-1.108+3.314 x 10(4)C-2.081 x 10(7)C(2) (r=0.9996). The experimentally observed limit of detection is about 1.3 x 10(-4) molL(-1), as in lower concentrations the formation of precipitate is not observed. The experimental quantitation limit is about 1.6 x 10(-4) molL(-1). The mean R.S.D. (relative standard deviation) is about 2.7%. Samples containing nickel were analyzed and the results obtained in this method were compared with those of other methods using the statistical Student's t-test.
authors: Instituto de Química, Universidade Estadual de Campinas, CP 6154, CEP 13083-970 Campinas, SP, Brazil.
authors: Matthieu
authors: M
authors: Tubino
authors: Carlos A R
authors: CA
authors: Queiroz