Infrared spectra ot acetone in the C O stretching region have been studied as a function of the composition of a range of mixed protic-aprotic solvents. For methanolic systems, equilibria between hydrogen-bonded and non hydrogen-bonded acetone dominate the spectral changes, but for aqueous systems...
Polarity and ability to form hydrogen bonds of short chain alcohols (polar protic solvents) were crucial in order to observe these changes in the presence of acetone (polar aprotic solvent). Parameters related with the HS-SDME procedure were studied, namely headspace volume, composition, volume ...
Detection of a large range of low molecular polar molecules as well as peptides and proteins, deposited on various supports, was successfully achieved using aqueous protic solvents (e.g. methanol/water) and even, aprotic solvent as acetonitrile. Solvent choice is important in the resultant signal...