University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Alloy -> brass

Citations 3

"An Online Solid Phase Extraction System Using Polyurethane Foam For The Spectrophotometric Determination Of Nickel In Silicates And Alloys"
Anal. Chim. Acta 1999 Volume 378, Issue 1-3 Pages 287-292
Sérgio Luis Costa Ferreira, Djane Santiago de Jesus, Ricardo Jorgensen Cassella, Antonio Celso Spinola Costa, Marcelo Souza de Carvalho and Ricardo Erthal Santelli

Abstract: The present paper describes the use of a solid phase extraction system using a polyurethane foam (PUF) minicolumn, in order to separate nickel from interferences due to other elements and determine it by flow injection analysis with spectrophotometric detection. Separation is based on the retention of thiocyanate complexes of interferent ions in the PUF minicolumn. Nickel does not form complex with thiocyanate and pass through the minicolumn and then it can be determined by using 4-(2-pyridylazo)-resorcinol (PAR) as chromogenic reagent. So, parameters such as thiocyanate concentration and pH effects on the separation efficiency, sorption capacity of the polyurethane foam minicolumn, influence of the flow rates, PAR concentration, pH effect on the chromogenic reaction, minicolumn regeneration, analytical features and others were investigated. The results demonstrated that nickel (at concentration of 0.5 mg/ml) can be quantitatively separated from iron and copper (200 mg/ml), zinc and cobalt (100 mg/ml) by using a minicolumn containing 0.125 g of polyurethane foam. Nickel can be determined with great selectivity and sensitivity and the procedure was applied for nickel determination in brass, bronze, steel and rock certified reference materials. The results showed satisfactory accuracy and precision. The limit of detection was 77 ng/ml and the RSD was 2.63%. A dynamic range from 0.25 up to 5.00 µg/ml and a sample throughput of 24 samples per hour were achieved.
Nickel Spectrophotometry Solid phase extraction Column Preconcentration Reference material Optimization

"Automated Determination Of Tin And Nickel In Brass By Online Anodic Electrodissolution And Electrothermal Atomic Absorption Spectrometry"
Talanta 1998 Volume 47, Issue 5 Pages 1191-1198
José Bento Borba da Silva*, Maria Bertília Oss Giacomelli, Ivan Gonçalves de Souza and Adilson José Curtius

Abstract: The application of an online metallic alloy dissolution system using anodic electrodissolution in a flow injection system for the determination of Sn and Ni in Cu alloys is described. After the electrolyzed material was collected in the autosampler cup, determination was carried out using electrothermal atomic absorption spectrometry (ETAAS). Using specific software developed in Turbo Pascal 7.0, it is possible to control electrolysis time, intensity of the applied current, and triggering of the three-way solenoid valves that push the fluids. Through manipulation of these variables, it is possible to adjust the anal. signal to within the working range of the spectrometer. Calibration of the spectrometer was accomplished by processing reference material. For Sn, relative standard deviations for measurements (n = 5) performed on the same point and on different points of the sample were smaller than 2 and 4%, respectively.; for Ni, 2 and 5%, respectively. The results for Sn and Ni were in good agreement with those obtained through application of the classical methodology, as well as with data obtained by optical emission spectrometry. The detection limit for Sn was 0.001% (wt./wt.), whereas for Ni it was 0.003% (wt./wt.). The anal. throughput is 30 samples h-1.
Tin Nickel Spectrophotometry Electrochemical dissolution Method comparison Computer

"Rapid Determination Of Copper In Various Copper Base Alloys By Flow Injection Analysis"
Bunseki Kagaku 1980 Volume 29, Issue 10 Pages T73-T78

Abstract: A flow injection method is described for the spectrophotometric determination of copper in various types of copper-base alloys. The system utilizes either the light absorption of aquacopper(II) ion at 805 nm or the light absorption of colored complex of copper(II) with EDTA (730 nm). Simple dissolution of alloys in nitric acid in the presence of tartaric acid suffices for sample preparation. The procedures have been applied to standard samples of copper-base alloys including several types of brasses, beryllium copper, deoxidized copper, German silver and aluminum bronze. The results obtained agree very satisfactorily with the certified values for these alloys. The precision is better than 0.5 % for the aquacopper(II) ion method. The sampling rate is 1 7 samples per hour.
Copper Spectrophotometry Method comparison Reference material