In TOF-MS a sample is first ionized, typically by a laser pulse or using an electrospray technique, after which the ions are accelerated using an electrically charged grid. The speed they reach by the time they pass the grid is principally dependent on their charge to mass (m/z) ratio, with the heavier ions being slower than the lighter ones. After the grid the enter a field-free "flight tube" and so become separated in time. At the far end of the tube they are detected by a microchannel plate detector, which gives a pulse output whose amplitude is proportional to the number of ions being detected, and where the pulse time position corresponds to the flight time through the tube. From this signal it is possible to build a mass spectral plot of number of ions (Y axis) vs. m/z ratio (X axis), and since different materials give rise to different spectra, the data can be used to determine the sample material content.
SIGNAL RECOVERY supplies a number of products that are suited to use in this application. We offer a range of specialist preamplifiers, that can be positioned close to the detector to minimize noise pickup and maintain a fast time response, and a digital signal averager, that is ideal for processing the detected signals. It uses hardware averaging techniques and data reduction algorithms optimized for this application to allow data acquisition over extended periods of time at rates that are much higher than can be achieved using other acquisition electronics, such as digital storage oscilloscopes.
- FastFlight-2 Digital Signal Averager
- 9306-P Preamplifier
- VT120 Series Preamplifiers
In addition to selling these products direct to end users, we also supply a number of them as well as some customized modules to a number of leading TOF-MS instrument suppliers, who incorporate them into their systems.