A Rapid Extractive Spectrophotometric Method for the Determination of Tin with 6-Chloro-3-hydroxy-2-(2′-thienyl)‎-4-oxo-4H-1-benzopyran

Abstract EN

An extractive spectrophotometric method for the determination of the trace amounts of tin has been carried out by employing 6-chloro-3-hydroxy-2-(2′-thienyl)-4-oxo-4H-1-benzopyran (in acetone) (CHTB) for the complexation of the metal ion in HCl medium.

The colored species thus produced is quantitatively extracted into dichloromethane and shows the maximum absorbance at 432–437 nm.

The method obeys Beer’s law in the range 0.0–1.3 μg mL−1 of tin with molar absorptivity and Sandell’s sensitivity of 5.81×104 L mol−1 cm−1 and 0.0020 μg Sn cm−2, respectively, at 435 nm.

The method is highly selective and free from the interference of a large number of elements including platinum metals.

The ratio of metal to ligand in the extracted species is 1 : 2.

Utilizing this method, the analysis of various synthetic and technical samples including gun metal and tin can have been carried out satisfactorily.