Identify tertiary amine from following.

Tertiary amines are characterized by a nitrogen atom bonded to three alkyl or aryl groups, with no hydrogen substituents.

Cyclohexanamine ($\text{C}_6\text{H}_{11}\text{NH}_2$) contains nitrogen bonded to one cyclohexyl group and two hydrogen atoms, making it a primary amine.

Ethane 1,2-diamine ($\text{H}_2\text{N}-\text{CH}_2-\text{CH}_2-\text{NH}_2$) contains two nitrogen atoms, each bonded to an alkyl fragment and two hydrogens, classifying it as a primary diamine.

N-Phenylbenzeneamine ($(\text{C}_6\text{H}_5)_2\text{NH}$) contains nitrogen bonded to two phenyl groups and one hydrogen, designating it as a secondary amine.

N-Ethyl-N-Methylpropan-2-amine ($(\text{CH}_3)_2\text{CH}-\text{N}(\text{C}_2\text{H}_5)(\text{CH}_3)$) contains nitrogen bonded to an isopropyl group, an ethyl group, and a methyl group. With three alkyl substituents and no hydrogen atoms, this is a tertiary amine.