Analytical application of a new thiazolylazo reagent, 2-(2-benzothiazolylazo)-5-dimethylamino-4-tolylarsonic acid Spectrophotometric determination of palladium

A new thiazolylazo reagent, 2-(2-benzothiazolylazo)-5-dimethylamino-4-tolylarsonic acid, has been synthesized and found to be a good chromogenic reagent for palladium. A 1:1 blue chelate (lambda(max) = 718 nm) is formed in a sulphuric or nitric acid medium. The molar absorptivity is 6.65 x 10(4) l. mole(-1).cm(-1). Beer's law is obeyed in the range 0-1.6 mug/ml Pd. Relatively large amounts of co-existing elements, including noble metals, can be tolerated.