Spectrophotometric determination of traces of nickel as dithio-oxalate complex

Abstract

The reaction between nickel and potassium dithio-oxalate has been developed into a simple, quick, and precise method for the spectrophotometric determination of traces of nickel and has been applied to the analysis of this element in our studies on its electrodeposition on thin metallized plastic a m s . On making absorption measurements of the colored compound formed by the reaction in various bases and acids at different concentrations, it was found that a dilute sulfuric acid solution is a good medium for preparation of samples and making the measurements. Maximum absorption of the compounds occurs at 500 mp and obeys the Beer-Lambert law over a suitable range. The effect of various ions on the determination of nickel by the method has been measured along with the absorption curves of the compounds formed by the reaction of potassium dithio-oxalate with cobalt and copper. The relative merits of the method are discussed with reference to other methods of analysis of traces of nickel.Une methode spectrophotomktrique d'analyse de traces de nickel, baske sur la reaction de cet dement avec le dithio-oxalate de potassium, a kt6 mise au point. Au cours d'essais avec differents acides et bases, il a kt6 trouvk que dans une solution diluQ d'acide sulfurique le compose color6 issu de cette rkaction se forme rapidement et posshde la stabilitk requise pour faire des mesures d'absorption. L'absorption est maximale A 500 m p et obeit A la loi de Beer-Larnbert. En plus de mesurer les spectres d'absorption des composks formks par la reaction du dithio-oxalate de nickel avec le cobalt et le cuivre, nous avons dktermine les concentrations tolkrables pour plusieurs autres klkments qui contribuent A l'absorption A 500 mp. Cette mkthode a kt6 utilisk avec succbs pour I'analyse de nickel dans plus de quarante khantilIons, obtenus au cows d'ktudes sur l'klectrodkposition de cet klkment sur des films plastiques minces. La mkthode se caracthise par sa simplicitk et prksente plusieurs avantages sur celles dkjA dkrites pour l'analyse de traces de nickel.Canadian Journal of Chemistry, 46,1233Chemistry, 46, (1968 IntroductionThe reaction of nickel with potassium dithiooxalate, K2C202S2, first observed by Jones and Tasker (1) has been used by Fairhall (2) and Yoe and Wirsing (3) for the colorimetric determination of nickel. These investigations indicated that the reagent is extremely sensitive and permits the determination of very small amounts of nickel. The reaction has been further studied in order to establish if it could be developed into a simple, quick, and precise method for the spectrophotometric determination of microgram amounts of nickel in our work on the electrodeposition of the element on thin metallized plastic films (4). Thus, the absorption spectrum of the complex, the application of the BeerLambert law, and the effect of various ions and different experimental conditions have been determined. These studies showed that the reaction meets the requirements set above for our specific application and could also be applicab...

Solubility of NiO in Molten Li2 CO 3, Na2 CO 3, K 2 CO 3, and Rb2 CO 3 at 910°C

“…However, no independent evidence was found in the literature for a compound such as KNiO. Similarly, one could also suggest a reaction such as K20 + 2NiO = K2Ni2020 [20] where the formal oxidation state of the nickel is + 1 and the 022. may be considered a peroxide ion and the 02. is an oxide ion. Other stoichiometries involving peroxide or superoxide ions could be suggested to account for the observed solubility data.…”

“…The method described below was based on one pioneered by Yoe and Wirsing (19) and later refined by Ujihira and Roy (20). The method described below was based on one pioneered by Yoe and Wirsing (19) and later refined by Ujihira and Roy (20).…”

“…The melt samples were analyzed with visible spectrophotometry, using a Beckman Model 35 or a Varian DMS 80 spectrophotometer. The method described below was based on one pioneered by Yoe and Wirsing (19) and later refined by Ujihira and Roy (20).…”

Transport Considerations in the Hot Corrosion of Ni by Molten Alkali Carbonates

“…After equilibrium between the melt and NiO had been reached, (a few hundred hours) the melt was sampled by freezing small portions on a cold AI~O~ rod and extracting them from the setup. The salt samples were analyzed for Ni by a spectrophotometric method which has been described previously (17,18).…”