Detection of Ni2+ by a dimethylglyoxime probe using attenuated total-reflection infrared spectroscopy.
A new analytical approach for the detection of Ni2+ utilizing an attenuated total reflection (ATR) technique is discussed in this paper. Nickel detection was accomplished on a silicon ATR parallelogram crystal uniformly coated by a ca. 1.5-microm Nafion film embedded with dimethylglyoxime (DMG) probe molecules. The detection of Ni2+ is based on the appearance of a unique infrared absorption peak at 1572 cm(-1) that corresponds to the C=N stretching mode in the nickel dimethylglyoximate, Ni(DMG)2, complex. The suitable operational pH range for the nickel infrared sensor is between 6 - 8. High alkalinity in the sample solution causes a leaching of Ni(DMG)2. The detection limit of the nickel infrared sensor is 1 ppm in a sample solution of pH = 8. Interference studies revealed that Cu2+ could compete with Ni2+ for the DMG sites in the Nafion matrix. The new nickel detection methodology can be potentially utilized, after further improvement, in field analysis to locate hot spots contaminated with a high ppm of Ni2+.
Ponnuswamy
Thomas
T
University of North Texas, Department of Chemistry, Denton 76203, USA.
Chyan
Oliver
O
D002412:Cations / Q000032:analysis; D005465:Fluorocarbon Polymers / Q000737:chemistry; D005618:Fresh Water / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D009532:Nickel / Q000032:analysis*; D010091:Oximes / Q000032:analysis*; D012825:Silicon / Q000032:analysis; D013055:Spectrophotometry, Infrared / Q000379:methods; D013997:Time Factors
D002412:Cations; D005465:Fluorocarbon Polymers; D010091:Oximes; C013501:dimethylglyoxime; C040402:perfluorosulfonic acid; D009532:Nickel; D012825:Silicon