| The analysis of tin in both oxidation states has been studied by various methods. In the present work, the EDTA method of Dubsky has been modified and applied to the determination of tin in tin(II) chloride solution. The results obtained are satisfactory in comparison with those obtained from the standard iodometric method and the extent of interference by various ions has been studied. A modified Kinnunen and Wennerstrand EDTA back titration has been devised for the determination of tin(IV). The results obtained from this method differ from those obtained by the iodometric method only within experimental error. The determination of tin(IV) in the presence of some interfering anions and cations has been investigated. The separation of tin(IV) from certain interfering ions namely, antimony(V), copper(II), iron(II), nickel(II), cobalt(II), manganese(II), aluminium, arsenic(V), bismuth(III) and zinc, using an anion-exchange column technique has been studied. After elution, EDTA titration methods have been employed for the determination of these elements in the eluates, except in the case of arsenic(V) and antimony(V) where the iodometric method has been used. Results obtained show that tin can be separated completely from the above mentioned elements. The EDTA titration method for tin(IV) described above can then be used for the determination of tin in the eluate. Procedures for the determination of tin in its alloys and concentrates based on the foregoing observations are described. |
