Mode of functioning
For ionization of test splinters of division of a radioactive element - Californium - 252 are used. At radioactive disintegration of a nucleus Californium - 252 two quasi collinear splinters with mass = 100 a.m.u., energies= 100 MeV and charges from +18 up to +22 are formed. One of splinters ionizes test, another - is used for start of time of flight measurements. With the help of a computer time of flight scale is recalculated in a scale of mass.
The mass - spectrometer is equipped with oil free evacuation system . Fore vacuum is provided with compact cryogetter pumps (the complete set of oil preevacuation pump is possible, that, as practice has shown, does not result in appreciable changes in received spectra and work of the instrument as a whole). Silent high vacuum ion pump with evacuation speed 160 l/s provides vacuum in the working chamber at a level 10-5 - 10-6 Pа (10-7 - 10-8 тоrr).
A radioactive source
Preparation Californium - 252 has a low level of activity - not more than 10 mcCu, that allows to work with the device in usual rooms and does not impose restrictions on the attendants.
Management of the device, accumulation, storage, processing and output of the information is carried out by a personal computer. The software includes programs of testing of the device, calibration of a scale of mass, subtraction of a background, automatic search of peaks and definitions of their centres of gravity, etc. The Software allows to operate on the device in an automatic mode without the operator with the analysis up to 12 samples.
|Resolution on mass||1000|
|Range of mass numbers, a.m.u||1 - 30000|
|Threshold of sensitivity the bull insulin, pmol||1|
Accelerating voltage of both polarities, кV
with step, кV
|0 - 30
Relative error of measurement of mass in a range, %
1 - 6000 a.m.u
6000 - 20000 a.m.u
|Power consumption, кW||1,5|
There is an extensive library of publications on PDМS (plasma-desorption mass - spectrometry).
Test applying installation - electro spray UNP-2
Installation is irreplaceable for applying tests for mass - spectrometer analysis in the instrument MSBH.
Work of installation is based on the phenomenon of electro dispersion - spontaneous spraying of micro drops of substance solution (or nitrocellulose matrix) from an edge of the capillary placed in an electric field of a high tension. Solutions of substance in easy volatile organic solvents (methanol, ethanol, acetone, acids, easy ethers, hydrocarbons, etc.), and also water mixes of these solvents with contents of water not more than 30 % give in to electro dispersion.
Sructure of installation comprises:
- A high-voltage power supply unit;
- The device of dispersion;
- The automated micro pump;
- A low-voltage power supply unit;
- A lantern of illumination.
As an additional regulating element the moved focusing ring is used, allowing to pick up an optimum mode of dispersion and, at the sputtering of solid-state film, diameter of sputtering stain.
The device of electro dispersion can be connected directly to highly effective liquid chromatograph.
|Volume of the pump, µl||100|
Speed of submission
|Quantity of steps of the step-by-step motor in 1 µl||600|
|Limits of adjustment of high voltage, кV||1 - 10|
|Diameter of sputtering stain of test, mm||6 - 16|
|Voltage of a feed of a network, V||220|
|Power consumption, W||100|