Just found this old thread by accident, and had an easy test up my sleave. The Hinsberg test can distinguish primary and secondary amines easily.
The test uses benzenesulfonyl chloride in an alkaline aqeous environment. Make a slurry of the benzenesulfonyl chloride in the aquous base (it's insoluble). Add the amine(amphetamine / methamphetamine) and stirr. The salt of the amine is ok to use, if enough base is present to deprotonate it. Because of the insoluble nature of benzenesulfonyl chloride, the reaction will proceed slowly.
If a primary amine is added, everything will dissolve, because an acidic hydrogen is present on the nitrogen (which has reacted with the benzenesulfonyl chloride). The acidic hydrogen makes everything soluble in the alkaline environment. A secondary amine will give a precipitate, as no acidic hydrogen is present.
Thus it's possible to distinguish primary and secondary amines quite easily.
Read more here (http://www.cem.msu.edu/~reusch/VirtualText/amine1.htm)
(http://www.cem.msu.edu/~reusch/VirtualText/amine1.htm)
Regards
Bandil