Spectrophotometric determination of tin(II) using 3-hydroxy-2-phenyl-4-oxo-4H- 1-benzopyran as a complexing agent

Department of Chemistry, Kurukshetra University, Kurukshetra-136 119, Haryana, India E-mail : Chem_hks@rediffmail.com Manuscript received 7 May 2007, accepted 21 May 2007 Tin(II) forms a 1 : 2 (M : L) yellow complex with 3-hydroxy-2-phenyl-4-oxo-4H-1-benzopyran in HCI medium which is extracted into dichloromethane and used for spectrophotometric determination of tin. The method obeys Beer's law in the range 0-2.0 µg Sn ml-1 with molar absorptivity and Sandell's sensitivity of 5.46 x 104 L mol-1 cm-1 and 0.0022 Sn µg cm-2 respectively at 405 nm. A large number of cations and anions do not interfere with the determination Ti, Zr, V, Nb, Mo, Wand Fe can be masked with suitable masking agents. The method is simple, rapid, sensitive and selective; its applicability has been tested by the analysis of various synthetic and technical samples including gun metal. In order to authenticate the method, the complex has been synthesised and characterized by spectral methods (IR, 1H NMR) and TGA studies