Method development

From Chiral-separations.com

You submit your compound and we return a ready-to-use chiral GC method!

We develop and optimise enantioseparation methods based on chiral GC. With custom method development you can be sure to buy the right column which perfectly solves your chiral separation requirements. Waste no time in your laboratory optimising chiral separation conditions, but rely on our vast experience in gas chromatography and enantiomer separation. Save time, costs and efforts!

Flat-rate offer

We will test your compound on at least five different stationary phases (10 m column) and optimise the most promising chiral separation on a 10 m, 25 m or 30 m column with at least three injections. You will receive full documentation of the best method including the exact chiral GC column type and temperature program along with all relevant chromatograms and experimental conditions.

After succesful method development we will offer you a chiral GC column for purchase which is individually tested to separate your target compound with at least equal performance. Naturally, there is no obligation to purchase any column.

If you have got any special requirements not covered by our flat-rate offer, please feel free to discuss your ideas with us.

Conditions for sample submission

• We need approx. 0.8 ml of a 1% solution of your pure compound in hexane (preferred) or dichloromethane. The solution has to be absolutely clear and free of any solids (e.g. salts, catalysts, metals, active carbon, emulsions). We recommend filtering the solution through a PTFE syringe filter or at least through a cotton wool plug.
• Further, you need to supply an achiral GC chromatogram including chromatographic conditions (temperature program, column length, column diameter, carrier gas pressure, type of carrier gas).
• We need the structural formula and molecular weight. If the structure is confidential, a complete summary of functional groups and the approximate molecular weight is sufficient.
Amino acids have to be provided as TFA amide and methyl aster. We do not accept any zwitterionic compounds or organic salts.

Recommendations

Derivatisations

We recommend to derivatise free acids as methyl ester with diazomethane. Generally, the less free hydroxy and carboxy groups are present, the more likely are excellent and rapid resolutions. So if it is possible for you to derivatise protic functional groups to less polar groups, we recommend to do it.

Volatility, retention and temperature

Modified cyclodextrin phases have an upper temperature limit of approximately 180 °C (isothermal) or 200%nbsp;°C in short-term exposures. Usually lower temperatures achieve better separations than higher temperatures. Thus, method development aims at determining the best balance between short retention times (favoring higher temperature) and best enantioseparations (favoring lower temperature).

Compounds with a molecular weight larger than 450 g/mol are unlikely to be eluted in reasonable time under applicable chromatographic conditions and maximum temperature. Compounds up to 300 g/mol are usually eluted and resolved at suitable temperatures, depending on their volatility, polarity and functional groups.