I would like to begin SPPS. The purity of DMF could cause issues while coupling if there is any purity. Although we have purchased DMF for peptide Synthesis. However, I would like to check the purity as determined by the UV-Vis. May I know a protocol or standardized procedure for the same.
What are your specifications for the DMF as a solvent? What are you looking to avoid? Use GC or HPLC, GC would be fast to do. A moisture check in older stored DMF would also be required!
Since we will be doing SPPS. We are not only looking for moisture free but low very low amine content.
Get doing with GC first and standardize your solvent contents! The manufacturers also provide contents % listing, check that out, carefully, that may be of much help. Based on more info on contents from GC and manufacturer's list (the amine and other contents) try to get HPLC profile and have a definite status of your solvent. You can use the moisture-free solvent to run all GC etc. The UV/UV-VIS is useless here.
Basically, all pros-cons and specifications should come with the question for the first time itself.
At the later stage, you can try to transput the GC and HPLC results for opting one single way (preferably GC) analysis to make sure the desired specifications for your solvent are being achieved with random checks occasionally!
If needed in small quantity, nearly up to 5 liters, purify, distill and dry the solvent with moisture-free storage. Check the Vogel's and other resources on the net on solvent purification-drying and storage tech, especially-DMF. Keep informed, if you wish, and endorse the queries replies!
Dimethylformamide (DMF) may possibly contain dimethylamine and dissolved carbon monoxide as impurities if boiled, due to possible decomposition. If taken from the original flask without being previously used, It seems that you could possibly accept the purity assessment of the supplier, which should be somehow available; except, possibly, for the water content, as it can be higher for a flask taken off-the-shelf after being stored for some time, particularly if it was opened before for a first use. You can detect free amine in DMF by the colour reaction with 1-fluoro-2,4-dinitrobenzene. Further information on DMF purity assessment is available from: J. Juillard, Pure & Appl. Chem., Vol. 49, 1977, pp. 885-892 (cf. link below). DMF can be dried with type 4A molecular sieves, silica gel, K2CO3, CaSO4, BaO, or Al2O3. Higher amounts of water can be removed by azeotropic distillation with benzene (10% v/v) at the atmospheric pressure by 69―80 ºC, leaving purified DMF at the distillation flask.
Article Dimethylformamide: Purification, Tests for Purity and Physic...
- Badges
- Science topic
- Similar topics
- Chemistry
- Organic Chemistry