Spectrofluorimetric determination of N-Nitroso-N-methylurea with sodium sulphide, taurine and o-phthalaldehyde
Abstract
N-Nitroso-N-methylurea (NMU) was determined fluorimetrically (λex. 350 nm, λem. 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.