AbstractAn approach to quantitative nephelometric measurements using a spectrofluorometer is presented. The measurements are performed with the aid of a monochromatic filter, which is transparent for the line 546 nm and by adjusting the monochromator for the same wavelength. The method was applied for the determination of micro amounts of: (1) sulphate as barium sulphate in colorless or colored aqueous solutions, in phosphoric acid, in the presence of large amounts of iron and in ores; is also suitable for determination of total inorganic sulfur after oxidation to sulphate and in organics after combustion; (2) calcium as calcium naphthalhydroxamate in aqueous and phosphoric acid solutions; and (3) calcium in the presence of large amounts of magnesium. The proposed technique has proved useful for quantitative nephelometric determinations in colored solutions. The high sensitivity also permits the use of micro samples.