Spectrofluorimetric determination of N-Nitroso-N-methylurea with sodium sulphide, taurine and o-phthalaldehyde

Abstract

N-Nitroso-N-methylurea (NMU) was determined fluorimetrically (λ_ex. 350 nm, λ_em. 450 nm) by an alkylation reaction with sodium sulphide reagent (pH 8.5) in aqueous acetonitrile at room temperature followed by successive condensation reactions with o-phthalaldehyde and taurine at pH 8.0. A linear calibration graph was obtained in the concentration range 0.03–5 nmol of NMU in 200 µl of acetonitrile with a relative standard deviation of 1.4–2.4%. The method was applied to the determination of NMU in mixtures which simulated those found in the stomach.