title: An indirect method for the spectrofluorimetric determination of trace amounts of germanium after extraction as an ion association complex with rhodamine B in the presence of chromotropic acid.
abstract: A highly sensitive and selective spectrofluorimetric method for the determination of 0.05-2.00 mug germanium is described. Germanium is treated with chromotropic acid at pH 2.5 and the resultant anionic complex is extracted as an ion pair with rhodamine into toluene. Addition of butanol to the organic extract releases the fluorescent dye and facilitates its measurement at 570 nm after exciting at 540 nm. The method provides a detection limit of 0.003 mug ml(-1) and is virtually free from interference from extraneous ions. The relative standard deviaiton is 2.9% for ten determinations of 1.0 mug germanium. The method has been applied to the determination of germanium in various ores, minerals and rock samples.
authors.forename: S
authors.initials: S
authors.lastname: Nalini
authors.forename: T V
authors.initials: TV
authors.lastname: Ramakrishna