Likely contaminants of 2,6-Lutidine (CAS NO. ) include 3- and 4-picoline (similar boiling points). However, they are removed by using BF₃, with which they react preferentially, by adding 4mL of BF₃ to 100mL of dry fractionally distd 2,6-lutidine and redistilling. Distn of commercial material from AlCl₃ (14g per 100mL) can also be used to remove picolines (and water). Alternatively, lutidine (100mL) can be refluxed with ethyl benzenesulfonate (20g) or ethyl p-toluenesulfonate (20g) for 1h, then the upper layer is cooled, separated and distd. The distillate is refluxed with BaO or CaH₂, then fractionally distd, through a glass helices-packed column.

2,6-Lutidine can be dried with KOH or sodium, or by refluxing with (and distilling from) BaO, prior to distn. For purification via its picrate, 2,6-lutidine, dissolved in abs EtOH, is treated with an excess of warm ethanolic picric acid. The ppte is filtered off, recrystd from acetone (to give m 163-164.5 °C), and partitioned between ammonia and CHCl₃/diethyl ether. The organic soln, after washing with dilute aqueous KOH, is dried with Na₂SO₄ and fractionally distd. 

Alternatively, 2,6-lutidine can be purified via its urea complex, as described under 2,3-lutidine. Other purification procedures include azeotropic distn with phenol, fractional crystn by partial freezing, and vapour-phase chromatography using a 180-cm column of polyethylene glycol-400 (Shell, 5%) on Embacel (May and Baker) at 100 °C, with argon as carrier gas.