Amines contain a basic nitrogen atom with a non-bonding electron pair shown (the electron-dense elongated balloon) in the figure below. Amines are classified according to the number of substituents (R Groups) that are attached to the nitrogen atom-numbering up to 3.  In primary amines, there is one substituent, named an R1 group, while disubstituted or secondary amines are designated with an R2 group.  Following this logic  an R3 group is a called a Tertiary Amine and designated a 3o group. CP Lab Chemicals has one of the most chemically diverse collection of  primary, secondary and tertiary amines, and ready to order by Chemical name, CAS Number or Ask a Chemist to help navigate the chemically diverse amines at CP Lab Chemicals.

Ammonia  Examples Primary  Secondary  Tertiary 
  Ethylamine Diethylamine Triethylamine
  Isopropylamine Diisobutylamine   Tris(2-aminoethyl)amines
  Benzylamines Phenylethylamines