MOSCOW, April 5. /TASS/. A device for mass spectrometers, enabling the study of selected substance in order to ascertain its composition from "four perspectives", has been developed by researchers from the Skolkovo Institute of Science and Technology (Skoltech) and the Moscow Institute of Physics and Technology (MIPT), Skoltech’s press office reported.
The new device makes it possible to simultaneously study a selected substance from "four perspectives," and to work at the same time with several substances at one mass spectrometer. A classical mass spectrometer implies that work with different substances must be done sequentially. The results of the study were published in the journal Analytical Chemistry.
The principles of mass spectrometry
The most efficient way to determine the composition of an unknown mixture is the way in which the molecular ions (charged molecules) that are included in its composition are weighed. Using electric and magnetic fields, scientists can control the motion of charged molecules and also separate them by the mass and charge values. The device, which uses such an approach for determining molecular mass, is called a mass spectrometer.
Nowadays, mass spectrometry is used to determine the composition of mixtures in the pharmaceutical industry, metallurgy, oil and gas, nuclear power and food industries, as well as in cosmetology. Moreover, all doping-control probes are analyzed with mass spectrometers.
This device is usually composed of three main elements: an ion source where neutral molecules are transformed to ions, a mass analyzer where the ions are sorted by their mass and charge, and a detector where the information on the sorted ions are recorded.
Several ionization methods exist that might be applied to a wide variety of substances, but at the same time, each method fits well into certain substances. A classical mass spectrometer assumes a choice of a single ion source, which decreases a set of molecules under investigation.
Full analysis of substance
To solve this problem, the Russian researchers, corresponding member of Russian Academy of Sciences Professor Evgeny Nikolaev and Candidate of Physical and Mathematical Sciences Yuri Kostyukevich suggested fusing four ionization methods into one mass spectrometer: usual and intact electrospray (ESI), radioactive ionization, and photoionization at atmospheric pressure (APPI).
"The ionization stage is the most problematic one, because precisely at this point the substance undergoes a transformation from its natural state to the gas phase. Various ionization methods provide the means for analyzing various fractions of a sample. For the first time ever, we managed to combine five different methods (four ionization techniques and a method of thermal dissociation) into a single mass spectrometer. Such a device will enable the most complete analysis of a substance under study," Nikolaev commented.
Furthermore, the scientists not only combined four ionization into a single mass-spectrometer method but also spread them out in space to ensure that different parts do not affect each other. The design of the new device is very flexible - it can be easily modified by adding new ionization tools. Moreover, it can be used for carrying out independent experiments simultaneously.
"Our development in the long run will allow us to implement in analytical chemistry a concept of parallel analysis in complete analogy with the well-known parallel calculations in computational sciences. In our case, each ionization tool represents an independent core making computation (ionization of a certain fraction of a mixture), while the mass spectrometer collects the data from various sources and transmits them to an investigator," said Yuri Kostyukevich, research assistant at Skoltech and MIPT's Laboratory of Ionic and Molecular Physics.
In the future, this device might have a broad application not only in scientific laboratories but also in various branches of industry. The researchers have already tested their device for simultaneous analysis of oil and biological molecules.