|Figure 1. Full scan total ion count mass chromatogram (upper trace) and Cold EI mass spectrum of Haloperidol (bottom trace).|
|Figure 2. Zoomed full scan TIC trace of Haloperidol (Magnified TIC of Figure 1) with scale at about 0.12% (upper trace), and cold EI mass spectrum of the prominent impurity peak at about 6.9 min elution time (eluting after the Haloperidol peak).|
- The main goal of analyzing drugs impurities was achieved and demonstrated with the 5975-SMB GC-MS with Cold EI for Haloperidol and Ramelteon drugs.
- The uniform response of Cold EI with its fly-through ion source uniquely enables quantitation of the drug impurities levels without compound specific calibration curves. This capability is assumed to be 5975-SMB unique and we believe that such information cannot be obtained by any other type of GC-MS or LC-MS. Thus, the 5975-SMB GC-MS with Cold EI eliminates the need to identify and synthesize trace API impurities for their quantitation.
- Informative Cold EI mass spectra were obtained with a combination of enhanced molecular ions and fragment information plus some isomer mass spectral effects.
- Very good TIC signal to noise that approached 10+5 was obtained which enabled the detection of low levels (<0.1%) of impurities and isomers in the drugs with good signal to noise ratio. The achievement of such high TIC S/N emerged from a combination of high TIC S/N of the 5975-SMB plus increased column capacity for polar drugs with high column flow rates.
- Simultaneous full scan and SIM was used on suspected drug impurities masses (based on previous full scan analysis). This procedure was used in order to enable accurate monitoring, by having very high signal to noise ratios, of the efficiency of the impurities cleaning process.
- Ramelteon is not in the NIST library but our Tal-Aviv Molecule Identifier software based on isotope abundance analysis properly identified its elemental formula as number 1 thereby provided the value of high resolution accurate mass MS combined with molecular ions of SMB.
- The GC-MS with Cold EI analysis times were about three times faster than of standard GC-MS.