A novel water-soluble fluorescent probe for the determination of methylamine

A novel water-soluble fluorescent probe, monosodium 7-(4,6-dichloro- 1,3,5-triazinylamino)-1,3-naphthalenedisulfonic acid (DTND), was synthesized by reacting cyanuric chloride with 7-amino-1,3-naphthalenedisulfonic acid monopotassium salt at 0-5 degreesC. This new reagent was used for the determination of methylamine. The linear range is 3x10(-6)-2x10(-4) mol L-1 with a detection limit (S/N=3) of 7.2x10(-8) mol L-1, and the relative S.D. is 1.3% for ten replicate determinations of 1x10(-5) mol L-1 CH3NH2. Common species in the aqueous environment have no or only slight influence on the determination. The method can be used to determine methylamine in real water samples.