LiXEdrom: Innovative measuring chamber for X-ray study of liquid jets

September 10, 2010

X-rays are the medium of choice for many scientific studies. When you shine them on a sample, they literally shed light on the material's structure, providing loads of information about it. Unfortunately, this mostly applies to solids only, since the sample has to be in a vacuum for the entire time it is being irradiated with soft X-rays. For liquids, that means you have to remove all the water. In the case of biological samples such as proteins, however, this destroys their natural environment. The solution to this problems has always been to measure liquids through membranes. These membranes keep the evacuated side separate from the non-evacuated side. The trouble is, one can never really be sure whether or not membrane effects are distorting the measurement results.

At Helmholtz-Zentrum Berlin (HZB), Emad Aziz, head of a junior research group, has shown that can be investigated by X-ray emission spectroscopy without using membranes after all. At the synchrotron source BESSY II, the group has built a special setup - the LiXEdrom. It is unique in that the liquid is shot as a jet through the X-ray beam. The jet from the becomes so thin and, at 80 metres per second, so fast that the vacuum can be maintained without the need of a membrane.

"On our LiXEdrom, we create a vacuum in the liquid chamber of up to 10-6 millibar, and can now perform both absorption and emission measurements, giving us even more precise information about the structure of a material," says Emad Aziz. It also allows a clear "view" of elements that possess and emission energies similar to the energies of the membrane materials, and would therefore overlap with the membrane in the spectrum when measured. This concerns above all carbon and nitrogen - precisely those elements of interest in biological samples.

In their first measurements, published in and selected for the cover, the group demonstrated they can achieve energy resolutions on their LiXEdrom comparable to those of the latest high resolution XES spectrometers. For water, they have proven that results obtained from an earlier setup were not overlapped by disturbing membrane effects. They have also studied the electronic structure of nickel ions, unhampered by a risk of deposits on a wall distorting the results. For many applications such as protein studies, this is a significant step towards obtaining reliable structural information.

Explore further: Scientists devise method to study membrane proteins

More information: "High Resolution X-ray Emission Spectroscopy of Water and Aqueous Ions Using the Micro-Jet Technique", K.M. Lange et al. Chem. Phys., DOI:10.1016/JChemPhys.2010.08.023

Related Stories

Scientists devise method to study membrane proteins

April 14, 2004

Scientists at the University of Virginia Health System have come up with a protocol to extract proteins from membranes by using chemicals that allow them to be reversibly folded and refolded. The proteins can then be studied ...

Biologists search for 'half-fusion'

May 16, 2005

Every living cell is surrounded by a membrane, a thin barrier that separates the genetic machinery of life from the non-living world outside. Though barriers, membranes are not impervious. Cells use a complex hierarchy of ...

Nanomaterials to Mimic Cells

August 23, 2005

Mimicking a real living cell by combining artificial membranes and nanomaterials in one construction is the aim of a new research grant at UC Davis. The Nanoscale Integrated Research Team grant, funded by the National Science ...

Instruction Manual for Creating a Molecular Nose

February 12, 2007

An artificial nose could be a real benefit at times: this kind of biosensor could sniff out poisons, explosives or drugs, for instance. Researchers at the Max Planck Institute for Polymer Research and the Max Planck Institute ...

Recommended for you

A new form of real gold, almost as light as air

November 25, 2015

Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible ...

New 'self-healing' gel makes electronics more flexible

November 25, 2015

Researchers in the Cockrell School of Engineering at The University of Texas at Austin have developed a first-of-its-kind self-healing gel that repairs and connects electronic circuits, creating opportunities to advance the ...

Getting under the skin of a medieval mystery

November 23, 2015

A simple PVC eraser has helped an international team of scientists led by bioarchaeologists at the University of York to resolve the mystery surrounding the tissue-thin parchment used by medieval scribes to produce the first ...

Atom-sized craters make a catalyst much more active

November 24, 2015

Bombarding and stretching an important industrial catalyst opens up tiny holes on its surface where atoms can attach and react, greatly increasing its activity as a promoter of chemical reactions, according to a study by ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.