The GCT Premier is a high-performance, bench-sized mass spectrometer with orthogonal acceleration and time-of-flight (oa-TOF). To identify volatile sample components, the device is coupled to a gas chromatograph (GC). To determine non-volatile components, it is operated as a standalone device that receives samples via a direct inlet probe (DI) or a direct chemical ionization probe (DCI). Unlike scanning devices, a TOF device performs parallel detection of all masses in the spectrum with high sensitivity and acquisition rates. This is particularly advantageous when the instrument is coupled to fast chromatography, as each spectrum represents the sample composition at a particular moment, regardless of how quickly the sample's composition changes. Mass range: 4000 Daltons. Resolution: 7000 resolution (FWHM) at m/z 614. Acquisition rate: Up to 20 complete spectra (up to m/z 800) per second in normal operation. Up to 10 complete spectra (up to m/z 800) per second in extended DRE mode. GC sensitivity: EI positive ionization mode: 1 pg hexachlorobenzene (m/z 283.8) gives a peak-to-peak signal-to-noise ratio (S:N) >10:1 when acquiring full spectra over a mass range up to to m/z 800. CI positive ionization mode: 100 pg benzophenone (m/z 183.1) results in an S:N >150:1 when acquiring full spectra over a mass range up to m/z 800. CI negative ionization mode: 1 pg octafluoronaphthalene (m/z 272.0) gives an S:N >100:1 when acquiring full spectra over a mass range up to m/z 800. Mass accuracy: When using a suitable, known mass peak as an internal reference, the RMS Error between measured and calculated mass for measurements below m/z 200 at less than 1 mDa and for measurements above m/z 200 at less than 5 ppm. Peaks must be sufficiently intense and free from interference from other masses. Example: In EI positive ionization mode, less than 10 ng of methyl stearate (m/z 298.3) applied to a capillary column results in an RMS error of for all peaks above mass 70 and greater than 10% of the intensity of the base peak 1.25 mDa or better, with the 4.0 GHz TDC. Dynamic range: Through dynamic range extension (DRE) and digital dead time correction (DDTC), the instrument's dynamic range extends to more than four orders of magnitude. Labprocure is responsible for this device.