title: Modified spectrophotometric method for the determination of selenium in environmental and mineral mixtures using 2,3-diaminonaphthalene.
abstract: Reaction of selenium with 2,3-diaminonaphthalene was reinvestigated with bromide ion as a catalyst. In acid medium, selenium reacts with the above reagent to form a complex extractable with cyclohexane and with an absorption maximum at 378.5 nm. The molar absorptivity of the complex is 17.5 x 10(3) 1 mol(-1) cm(-1). Beer's law is obeyed in the range 0.5-12 mg 1(-1). The method is reproducible and the standard and relative standard deviation for seven replicate analyses of 2 mg 1(-1) of selenium are 0.05 absorbance units and 2.5%, respectively. The limit of detection is 0.012 mg 1(-1). The method was optimized for the determination of selenium in water, soil, cereal and mineral mixtures and cattle feed and was compared with the reported 2,3-diaminonaphthalene method.
authors.affiliation: Shriram Institute for Industrial Research, 14-15 Sadarmangala Industrial Area, Whitefield Road, Bangalore, India.
authors.forename: K N
authors.initials: KN
authors.lastname: Ramachandran
authors.forename: G S
authors.initials: GS
authors.lastname: Kumar