To process the HPLC ion mobility TOF data of fentanyl analog screening, begin by checking the calibration in the data analysis software. To do so, right-click on the file name under the analysis box and select properties. When the window, labeled File Name_Analysis Properties appears, select calibration status.
From the drop-down box, select instrument calibration for the mass spectrometer and confirm that the error is no greater than 1 ppm. Then, select initial mobility calibration and confirm that the error is no greater than 1%To prepare a chromatogram in the data analysis software, right-click on chromatogram under the file name and select edit chromatogram. In type, click the drop-down box and select extracted ion chromatogram.
Under filter, select all MS, and for scan mode, select all. If using masses to extract an ion, insert the theoretical mass-to-charge ratio of the molecule of interest, set the polarity to positive mode, and add the ion to the list. If using a formula to extract an ion, insert the formula for the molecule as well as the ion forms of interest for the chromatogram.
For the mass spectrum, make sure the chromatogram is selected and right-click at the baseline of one edge of the compound peak and drag to the other edge of the peak. To generate a mobilogram, right-click on the left tab titled mobilogram and select edit mobilogram. When the window titled edit mobilogram traces appears, begin editing the chromatogram.
In the retention time input, add the retention time range of the peak of interest. Once the parameters are selected, click add, followed by okay at the top right. To generate the compound spectra, at the bottom of the spectrum view window, sequentially select profile MS and fragment MS.At spectrum view, right-click and select copy compound spectra.
To process the data, click on find, then select compounds manually, chromatogram, or mobilogram. Left-click and drag to highlight the desired peak to yield important information on the molecule of interest. Screening of the four isomers in a particular fentanyl analog screening kit revealed that the methoxyacetyl fentanyl and fentanyl carbamate separated well in the LC and mobility domains from the paramethoxyacetyl fentanyl and B-hydroxyl fentanyl.
However, a clear separation of the latter two was achieved in their fragmentation patterns. Screening of three isomers in another kit showed that alpha-methyl-thiofentanyl and trans-3-methyl-thiofentanyl separated in the LC domain, but not in the mobility domain. However, trans-3-methyl-thiofentanyl and cis-3-methyl-thiofentanyl separated in the mobility domain and not in the LC domain.
This data indicated the complementarity of the orthogonal LC and mobility domains in improving the identification of the isometric species.
