Proteins are the workhorses of the cell. Their activity is often controlled by adding or removing chemicals called phosphates, like switching an electrical current on or off. Measuring how many proteins are phosphorylated, ...
Analytical Chemistry
May 10, 2019
0
112
A team of agrochemists from Russia, Germany, and Chile confirmed the so-called ferrous wheel hypothesis—the turnover of iron in the soil that enriches it with organic nitrogen. The results of the study were published in ...
Earth Sciences
Apr 12, 2019
0
7
Matter is composed of chemical elements mainly created in stars via nuclear reactions and complex nuclear reaction networks. To understand these processes, we need to know properties of participating nuclei, such as their ...
Astronomy
Mar 08, 2019
0
85
By taking nitrogen out of the air and turning it into plant nutrients, some bacteria help plants like beans, peas, and clovers thrive. How? A study shows that the traditional view of this symbiotic relationship doesn't capture ...
Plants & Animals
Feb 28, 2019
0
6
University of Groningen scientists have developed nanopores to directly measure the mass of peptides. Although the resolution needs improvement, this proof of principle shows that a cheap and portable peptide mass spectrometer ...
Analytical Chemistry
Feb 20, 2019
0
92
Fossil-hunting can be grueling, but it's usually not gross. Paleontologists typically work with things that have been dead for millions of years, mineralized into rock and no longer smelly. At the end of a day in the field, ...
Plants & Animals
Feb 19, 2019
0
69
For more than a decade, scientists have worked to understand the connection between colibactin, a compound produced by certain strains of E. coli, and colorectal cancer, but have been hampered by their inability to isolate ...
Biochemistry
Feb 14, 2019
0
59
Fuel cells powered by electrocatalytic reactions have the potential to eliminate pollution caused by burning fossil fuels, if they could be made more efficient. Key to higher efficiency are the chemical reactions at the surfaces ...
Analytical Chemistry
Feb 12, 2019
0
8
How are chemicals distributed in a cell? Chinese scientists have developed a combined mass spectrometry and biological imaging device that enables direct, label-free detection, and high-resolution mapping of chemicals inside ...
Analytical Chemistry
Feb 07, 2019
0
58
Southwest Research Institute has developed a high-reliability, high-voltage optocoupler for spaceflight applications. NASA has selected the device as a power interface between the Europa Clipper spacecraft and three instruments ...
Space Exploration
Feb 06, 2019
0
8
Mass spectrometry (MS) is an analytical technique for the determination of the elemental composition of a sample or molecule. It is also used for elucidating the chemical structures of molecules, such as peptides and other chemical compounds. The MS principle consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their mass-to-charge ratios. In a typical MS procedure:
MS instruments consist of three modules: an ion source, which can convert gas phase sample molecules into ions (or, in the case of electrospray ionization, move ions that exist in solution into the gas phase); a mass analyzer, which sorts the ions by their masses by applying electromagnetic fields; and a detector, which measures the value of an indicator quantity and thus provides data for calculating the abundances of each ion present. The technique has both qualitative and quantitative uses. These include identifying unknown compounds, determining the isotopic composition of elements in a molecule, and determining the structure of a compound by observing its fragmentation. Other uses include quantifying the amount of a compound in a sample or studying the fundamentals of gas phase ion chemistry (the chemistry of ions and neutrals in a vacuum). MS is now in very common use in analytical laboratories that study physical, chemical, or biological properties of a great variety of compounds.
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