Gas time-of-flight TOF-MS Mass Spectrometer Process Gas Analyzer at Atmospheric pressure EI-TOF-MS-HR-TOF-MS

Appointment
High-resolution electron impact mass spectrometer for the analysis of process gases at atmospheric pressure.The high-resolution time-of-flight mass analyzer (TOF-MS) is designed for the analysis of process gases for solving production and research tasks. The gas analyzer is located on a 19-inch rack, equipped with anti-vibration suspensions for easy and safe transportation. The TOF-MS capability for the quantitative analysis of inorganic gases, as well as the detection and analysis of volatile organic compounds (VOC) at a pressure of 10 millibars bar makes the equipment suitable for monitoring the process, as well as the study of products of catalysis, combustion, pyrolysis.
Gas input system
The device is equipped with a double inlet system, which includes a heated capillary inlet for inorganic gases and a permeable membrane concentrator at the inlet for collecting volatile organic compounds. The intake system and capillaries are heated to prevent moisture and other low temperature condensates from entering, separating the required phase from the gas before reaching the ion source. The membranes provide a long service life and low operating costs, a strong concentrating inlet, which reduces the achievable detection limits of many volatile organic compounds. This intake system concentrates VOC, but not gases such as N2, Ar, CO, CO2 and H2O. We have used these concentrator membranes in our portable MS-200 mass spectrometers) for many years and, as a rule, a single membrane can achieve an x100 increase in the concentration of VOC such as benzene.
Mass spectrometer
The instrument is based on a new time-of-flight mass spectrometer capable of producing more than 6000 units of mass resolution. 
In the device, the ion source feeds the TOF-MS through transmitting optics in orthogonal geometry by separate pumping by electronic shock (EI). Electron impact ionization (EI) is the most well-known method for producing ions and thus provides data that can be interpreted with well-established techniques by comparing with extensive libraries of data collected using automated methods. For example, the NIST EI of mass spectral data contains almost 200,000 simple compounds with various search facilities and library data.

Unlike a quadrupole mass spectrometer, TOF-MS offers the possibility of accurate mass analysis and high mass resolution. Mass accuracy (the position of the peak centroid ) is a matter of tool stability . The interpolated mass accuracy (3 calibration points) is 1mamu, the extrapolated mass accuracy (low mass, three calibration points) can be as small as 2mamu.

The mass resolution is often expressed as the peak of the mass divided by its width (in this case by half the height, hence the phrase 'Full Width at Half Height', or FWHM. The high resolution allows the separation of the so-called isobaric species, i.e. species that have the same nominal mass. However, due to the small difference in the exact masses of the constituent atoms, dissimilar molecules with the same nominal mass will have different exact masses. As the resolution of the gas analyzer increases, it becomes possible to isolate peaks with precise masses that are closer and closer.
ANALYTICAL MODES
The TOF-MS system used offers real-time, high time resolution, high sensitivity detection of all types of gas in parallel.All the masses are collected, keeping the maximum amount of information.

GAS INTAKE SYSTEM
The device is equipped with a dual intake system, including a heated capillary inlet for inorganic gases and an inlet membrane concentrator at the inlet assembly for VOCs.The intake system and capillary are heated to prevent the separation of moisture and other low-temperature condensates from the gas phase before reaching the ion source.The membrane assemblies provide a long service life, low operating costs, strong inlet pipes for concentration, which allows you to achieve lower detection limits for many VOCs compounds. 
MASS SPECTRA
The device will generate a single mass spectrum lasting less than 0.5 seconds to several minutes, if required.Getting the spectrum quickly is the key to verifying the correct operation of the instrument and to deciding how to proceed with the further experiment of interest. 
HIGH RESOLUTION MODE
The "chromatogram" mode, in which data is usually collected within a few minutes.The data is transferred to the disk for this period, and the data can be checked retrospectively by looking at time intervals of only 100 ms in the direction of the chromatogram. 
PROCESS MONITOR MODE
The process monitoring mode is more suitable for long-term monitoring for several hours or days.In real time, the user views the update schedule up to 16 views that have been selected in advance.The spectra for each measurement are saved to disk, and the user can return to the data for a retrospective construction of any kind. 
DATA SYSTEM
The data is displayed on a PC using the Windows®-based GRAMS/AI™ software from Thermo Scientific.This standard software has been configured by Kore to make collecting spectra a simple click of a button.The software allows the user to track trends in multiple gases over long periods of time.


For example, C2H3O+ and C3H7+both appear with a mass of 43, but C2H3O+ has an exact mass value of 43.0184 and C3H7+has an exact mass value of 43.0546. If both peaks have equal intensities, then to resolve these peaks into two separate peaks up to half their height, a spectrometer with a resolution of about 1200 will be required. To resolve them lower, closer to the baseline, a much higher resolution will be required.

As a second example, H2S+ has the same nominal mass (34) as the oxygen isotope, 16O18O+. The exact masses are 33.9878 and 33.9940 respectively. Now the mass difference is smaller, and therefore the resolution should be better. 5,500 resolution is required to divide two peaks of equal intensity down to half their height.