Simultaneous determination of molybdenum and tungsten by first-derivative synchronous spectrofluorimetry

Abstract

A method for the simultaneous determination of molybdenum and tungsten in mixtures by first-derivative synchronous spectrofluorimetry is described. The method is based on the formation of fluorescent complexes with carminic acid at pH 5.1. The constant wavelength difference chosen to optimise the determination was Δλ=λ_em.-λ_ex.= 50 nm. Molybdenum was measured at λ_ex./λ_em.= 550/600 nm and tungsten at λ_ex./λ_em.= 561/611 nm. The range of application is between 1 and 12 µM molybdenum and between 1 and 6 µM tungsten. The accuracy and precision of the method are reported.