3-hydroxy-2-(2 '-thienyl)-4H-chromon-4-one as a spectrophotometric reagentfor the trace determination of zirconium in an aqueous phase

A rapid, simple, selective, and sensitive method for the trace determinatio n of zirconium has been developed based on the reaction of 3-hydroxy-2-(2'- thienyl)-4H-chromon-4-one in an hydrochloric acid medium to form a yellow-c olored complex which is rendered water soluble by the micellar action of Tr iton X-100 and measured at 415 urn. Most of the metal ions do not interfere with the determination. Beer's law is obeyed in the concentration range 0- 2.0 mug/mL and the molar absorptivity of the complex is 2.73 X 10(4) L mol( -1) cm(-1); Sandell's sensitivity is found to be 0.0034 mug cm(-2). The met hod has been applied for the determination of zirconium in various samples, and satisfactory results have been obtained.