The Ion Source
In a single sentence, the Ion Source is the element of the Mass Spectrometer that attributes a charge to sample particles so that they can be identified by device.
What is the Ion Source’s function?
The sample being analysed is pulled through the Ion Source and into the Mass Spec due to the partial vacuum present within the instrument. As the sample exits the Ion Source it passes through a voltage field where individual particles pick up a level of charge based on their mass. The level of charge attributed to the individual particle influences the speed with which it passes through the device and the Mass Spec uses this speed to determine the mass of the particles that pass through it. The length of time it takes for a particle to pass through the Mass Spec is what’s called a Time of Flight (TOF).
The diagram below shows a rudimentary Mass Spectrometer with the Ion Source represented by the area to the left of the red line.
When the sample initially enters the Mass Spec, it does so in a scattered manner. At this point, it passes through the Ion Source’s voltage field and its particles become charged. Once charged, the particles are pulled through the focusing plates in a concentrated beam and make their way towards the detector shown at the right-hand side of the diagram.
In its most basic form, the Ion Source instrument itself only needs to have a chamber that has a vacuum put on it and a probe where the sample can be introduced – like a basic carburetor in your car. However, several mass spectrometry techniques involve controlled amounts of gases flowing into the instrument. In order to maintain instrument resolution and sensitivity, this flow needs to be precise, stable, and repeatable across the full range of flow rates. Mass Spectrometers also need to be constantly recalibrated throughout use due to the fact that as the machine’s temperature increases, its chamber length expands, altering the distance from the ion source to the detector.
How Does a Mass Spectrometer Maintain Calibration?
In order to achieve this uniformity, many modern Ion Source assemblies include what is called a Calibrant Injector. This is essentially a rotary valve that switches between a sample stream and a calibrant liquid, the mass of which is known.
The Calibrant Injector ensures that at set intervals, a known sample is entered into the machine and recognized by the spectrometer. Once the known sample is recognised, the Mass Spec adjusts its power levels and sensitivity to optimize for that signal. This allows the machine to consistently calibrate itself throughout use and maintain optimal sensitivity.
Schivo Medical’s Ion Source Expertise
Schivo are specialists in the contract manufacture of precision components and electro-mechanical cleanroom sub-assembly completion with more than 35 years of experience working with industry leaders in the Life Sciences space. We have the expertise and the experience required to ensure that your Life Science instrument is brought to market efficiently and your competitive advantage is solidified.
The table below shows the various components that Schivo currently produce before completing the cleanroom assembly of a single part number on our clients’ behalf.
If you would like to talk to us about producing components for your upcoming Life Science instruments or want to learn more about our precision engineering capabilities, you can reach out to our engineers through the form below.