Measuring instruments

Description

GC-Exactive is equipped with Orbitrap technology for high resolution mass spectrometry which is patented by ThermoFisher Scientific. The instrument has a mass resolution of 60 000 (at mass 200), which gives high mass accuracy. This results in a mass error <1 ppm for almost all GC suitable substances. At present, no other company can provide instruments with such high mass resolution and high mass accuracy. GC-Exactive consists of an orbitrap mass spectometer and is delivered as an integrated system with a Trace 1310 Gas Chromatograph, EI and CI ion sources, Tracefinder General with "Unkown Screening Software" and NIST 17 MS Library. In addition, the instrument comes with Triplus au-tosampler, SSl and PTV injectors, both equipped with backflush system. Pesticide library is included as well. There are currently no other GC-High Resolution Mass Spectrometry (GC-HRMS) instruments on the market that have a resolution of 60 000 (at mass 200). Because of the complexity of the samples to be analyzed with the instrument, it is crucial with high mass accuracy which the high mass resolution gives. Our samples include all types of food, feed and packaging materials, where complex matrix substances interfere with the substances we want to determine (pesticides, drugs, contaminants and natural substances). A high mass accuracy is therefore essential to distinguish between the thousands of compounds detected the samples. In relation to the more widespread Time of Flight instruments, the Orbitrap technology has the additional advantage that the mass resolution is higher at low masses (120 000 at mass 100), which is an advantages for the small molecules that are determined by GC separation and are analysed in the projects the research group for Chemical Food Analysis conducts for both Danish food authorities and the EU Commission. Additional, the sensitivity of the GC-Exactive (IDL <6 fg OFN) is lower than for the competing High Resolution TOF instruments. Finally, the linearity and dynamic range of instrument calibration is far better than competing instruments, especially for screening for unknown substances. However, the instrument is intended to be used for quantitative reason as well as for screening for unknown substances. The Orbitrap Mass Spectrometer can at a later stage be upgraded with collision cell so different kind of MS/MS analyses will be possible. Furthermore, the instrument can be upgraded to a mass resolution at 120 000. It is scientifically essential that, as far as it is economically possible, the various mass spectrometry technologies are represented in the research group's analytical platform. Until now, we have only had access to High Resolution Time of Flight instruments and unit mass analyzers like triple quadrupole mass spectrometer. The various technologies will also be used in the education of students.