Chromatography Forum

Hi everybody,
Wich type of capilary column could I use to separate small amounts of alcohols (0,1% v/v) aprox. (methanol, ethanol and isopropyl) into another solvent as methylene clorhyde or isopropyl alcohol.
We used a packed column DC550 type but we want now switch to capilary.
Any help would be very appreciate.

Hello jmsalcines,

As reference, you can use the columns indicated in ASTM D5501 or EN 15721.
The ASTM D5501 uses a non-polar methyl-silicone column with dimensions of 100 m x 0.25 mm x 0.5 um or 150 x 0.25 x 1.0 m.
The EN 15721 uses a CPWax 57 CB (25 m x 0.25 mm x 0.2 um) or a DB 1701 (60 m x 0.25 mm x 1.0 um).

All columns can make the separation of methanol, ethanol and iso-propanol, the only difference is the analysis time and method configuration.

Regards.

thank you so much, lynoguchi

Residual solvents everyone has a column optimized for it Restek, Agilent, Zebron, Macherey Nagel, Supelco etc. It is a very popular GC method.

btw when looking at small very volatiles you are better off picking a high boiling solvent that will elute after the analytes like dimethyl acetamide DMSO DMF or limonene. Otherwise most columns seem to be cyanopropyl based like 624. I use a wax anf ethanol and isopropanol can be tough to separate.