Intente links en:Similares en:
Next, having established the chromatographic conditions for each analyte, the behavior of the ILs was studied by analyzing methanolic solutions (1% v/v) of each IL. It most be noted that the 1% concentration level used in this experiments was chosen keeping in mind that almost always samples from microextraction must be diluted with an adequate solvent before injection due to the immiscibility and/or viscosity of the extraction solvents. In our case, most of the ILs showed wide signals that eluted at same time as the model drugs included in the study. For instance, Fig. 1. shows the chromatogram obtained for EMIM-ntf under the conditions established for caffeine. As it can be observed, a poor signal shape was attained and this was attributed to the high content of methanol in the sample. Nevertheless, the use of solvents with higher aqueous content, compatible with the mobile phase use was not possible due to the immiscibility of the ILs.