This titration will probably not be useful to you, however for those with aqueous solutions of methylamine; here is a titration that may help. I have never run this personally, however if I have time I will and report the results.
This is taken from the current USP:
USP27-NF22
Methylamine, 40 Percent in Water, CH 5N— 31.06 —
Assay — Using a syringe, transfer about 0.5 mL of a well-shaken specimen to 100 mL of water, at a point below the surface of the water. Determine the weight of the specimen by weighing the syringe before and after the transfer. Mix, and titrate with 0.5 N hydrochloric acid VS,determining the endpoint potentiometrically, using a silver-silver chloride pH electrode and a calomel reference electrode. Perform a blank determination, and make any necessary correction. Each mL of 0.5 N hydrochloric acid is equivalent to 15.53 mg of CH 5N: between 39.0% and 41.0% is found.
m_e