Investigation of the usefulness of NTA, EDTA and DTPA in separation of some platinum metals on cellulose exchangers.
The possibility of using NTA, EDTA and DTPA as complexing agents for separation of some platinum group ions on cellulose ion-exchangers has been investigated. The greatest differences in the affinities of Pd(II) and Pt(IV) toward the cellulose ion-exchangers are obtained in the presence of DPTA, Cellex D (as ion-exchanger) in hydroxide form. The column separation of Pd(II) from Pt(IV), Rh(III) from Pd(II) and of a Rh(III)Pd(II)Pt(IV) mixture can be achieved with DPTA and chloride solutions. The method can be for determination of the components of RhPdPt alloys.
Komplexone XLVI. EDTA‐Komplexe des Pt(II)‐Ions mit und ohne einzähnige Fremdliganden
The formation of complexes between Pt(II)EDTA2− and H+, OH−, Cl−, Br−, SCN−, CN− and NH3 was investigated using pH and UV.-spectrophotometric measurements at ionic strength 1.0 and 25°. The existence of the following species could be proved (charges are omitted): HpPt(EDTA) (0 ≤ p ≤ 3), Pt(EDTA)X (X = OH, NH3, Cl, Br, I, SCN), HpPt(EDTA)X (1 ≤ p ≤ 3; X = Cl, Br) and H4Pt(EDTA)Cl2. They have been characterised by spectral data as well as with equilibrium constants. The different modes of attachment of EDTA are discussed.
THE IRON-ACETOCARMINE METHOD OF FIXING AND STAINING CHROMOSOMES
A short description of this procedure was given in Vol. 55 of the American Naturalist, pp. 573â€”574. The method has now been used almost daily for five years, and certain improvements have suggested themselves. The solution can be prepared by mixing about equal volumes of glacial acetic acid and water. To this is added powdered carmine in excess. The liquid is then â€ ? just brought to boil, cooled, and decanted. To the red solution there are then added a few drops of a solution of ferric hydrate in 50 per cent. acetic acid, to act as a mordant. The amount of iron varies with different objects. Too much produces a precipitate in a short time. The more