The first mass spectrometer in the country was built in the Laboratory of Physical Chemistry of the Czechoslovak Academy of Sciences. Four young scientists, Vladimír Čermák, Vladimír Hanuš, Čestmír Jech and Josef Cabicar, took part in its construction. At the time of the post-war shortage, it was very difficult to find the necessary components; some parts originated from captured German military equipment. The mass spectrometer was of the Nier type with simple focusing and 60° magnetic field, pumped by a mercury diffusion pump. The device was completed after two years, in 1953. The construction of this instrument was an extraordinary achievement awarded a year later by the State Prize. [Z. Herman, Chem. Listy 104, 955, 2010]
The International Prototype of the Kilogram was a cylinder with a height and diameter of 39 mm made of an alloy of 90% platinum and 10% iridium.
In the spectrographs used by Thomson until 1910, the rays of positive electricity were detected by the phosphorescence they produced on a willemite screen. The screen was made by grinding rare zinc mineral willemite into a fine powder. After shaking in alcohol, the suspension was allowed to deposit slowly on a glass plate. Later, a photographic plate inside the spectrograph was used for more sensitive detection.
During the war, copper was preferably used for the production of brass shell casings and it was not available for the construction of calutrons. The designers came up with the idea of replacing copper with silver. They borrowed about 13,300 tons of silver from the West Point Bullion Depository in West Point, NY. After the war, the silver was returned to the Treasury with virtually no loss.
If a positive charge is moving in the same direction as the electric field vector the particle's velocity will increase. If it is moving in the opposite direction it will decelerate. If a negative charge is moving in the same direction as the electric field vector the particle will decelerate. If it is moving in the opposite direction it will accelerate.
Mass spectrometry was used to sequence peptides for the first time in 1959 when K. Biemann described an innovative method based on the reduction of small peptides to polyamino alcohols with characteristic EI spectra. [https://doi.org/10.1021/ja01518a069]
The base peak is the peak with the greatest intensity among all peaks in the spectrum. The intensity of each peak in the spectrum is expressed as a percentage relative to the intensity of the base peak.
His father, Joseph James Thomson, ran an antiquarian bookshop founded by Thomson’s great-grandfather. [Wikipedia]
The monoisotopic masses of these compounds are 31.989829 Da (oxygen), 32.026215 Da (methanol), and 32.037448 Da (hydrazine).
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