Palladium has often been dcterminccl with dimcthylglyoxime, not only gravimetricallyr but also by an extraction procedure". Several other dioximes have been used for the dcterminatian of palladium3~". These facts suggested that it mi&t bc possible to determine palladium with the simplest of the dioximcs, namely, glyoxime, (HCN.OH)z. Preliminary tests of solutions of the platinum-group clcmcnts indicated that palladium(II), ruthenium(III), and osmium(V1) reacted with glyoxime. Palladium(I1) gave a yellow precipitate which was soluble in chloroform. 13ecause of the intensity of color and the stability of the palladium(I1) glyoximate chloroform solution, glyoximc was investigated as a reagent for the determination of palladium.
44 ppamt1cs
Absorbance mcasurcmcnts wcrc' made with a Beckman Model DU spectrophotometer, using matched silica cells of I.oo-cm optical path. Measurements of PH wcrc made with a 13eckmnn Zeromatic PH meter, using glass and calomel electrodes. A Mcttlcr microbalance, Type M-5, was used for making wci@ings requiring a high dcgrce of accuracy.
Rcagcnts
Stanrlard y5alladiuw sohttion.
Pure l~alladium(I1) chloride was obtained from -9. D. Mackay, Inc., New York. A sample was weighed out and dissolved in the stoichiometric amount of standard hydrochloric acid to form the tetracl~loropallaclate(II), and then diluted to known volume. The solution was also standardized gravimetrically by the procedure given by KOLTHOFF AND ELVINC~, and was found to be 0.2238 M.
Glyoxime.
This reagent was purchased from Frinton Laboratories, South Vineland, New Jersey. The following solutions were prepared :
(I) 0. I M glyoxime in 25% aqueous alcohol (reagent).
(3) 1.000 ' 10-a M aqueous glyoxime solution.
(3) Saturated solution of glyoxime in chloroform. (4) 9.94 . x0-4 M solution of glyoximc in chloroform. (5) 0.1022 M solution of glyoxime in I : I dioxane-water. l Condensed from a dissertation submittcd by JACK B. MARTIN to tbc grclcluntc school of The University of TCXZIS in pnrtinl fulfilmcnt of the rcquircmcnts for the Ph.D. dcgrcc, May 1965.