Talk:Chromatography
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what is procedure for colum chromatography of lipid?
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[edit] This page needs a lot of more details
This page needs a lot of more details, what the procedures for the columns are, and the pros and cons to make a decision when to use which one. massa 16:10, 14 Nov 2004 (UTC)
[edit] Chromabarography
This was included in the article by User:Invent, the content needs to be verified, a search for chromabarography on the Web of Science gives no results. Could be a hoax
Chromatography is nothing else than the mirror of analytical chemistry. What do you think, what does the analytical instrumentation-making expect in the near future?
Truly - a new technology!
XXI century puts the task for the qualitative improvement of the possibilities of the chromatographic apparatus. One of them is the new technology of Chromatography - Chromabarography. In the development of chromatography, a process that goes on up to day, a definite tendency is traced. After the substantial theoretical and technological "gush" it follows to provide the equipment with additional parts allowing the enlargement of the analytical possibilities of the chromatograph. On this background it is considered in-time to develop such a rich with its possibilities and effective technology a gas chromatography as Chromabarography - a new basic technology of chromatography.
What does it present itself, what does it give to the user and producer of the equipment?
After all, the heart of chromatography is the chromatographic column. The theory of gas chromatography, presented by the equation of Van Deemter, shows that for each chromatographic separation there exists an optimal flow rate above and below which the column efficiency is reduced. In practice, the linear speed of the sample zone moved by the carrier gas, is changed continuously and increases as it approaches the outlet, which results in a non-effective use of a part of the column. In this case equation characterizes the optimal separation process only in that section of the chromatographic column through which the sample passes at an optional speed.
However the linear speed of the sample zone moving with the carrier-gas can be kept constant by programming the pressure gradient movement along the column in time, realizing the function: pressure - location - time by keeping constant the pressure difference ∆ p at the ends of the chromatographic column during the whole cycle of the analysis (Russia Patent "Chromatograph of A. S. Hayrapetyan").
For the first time in the world this basic technology was worked out and proposed, based on the investigation of the factors of diffusion and kinetics, and includes the meaning "bar-gradient chromatography" or Chromabarography, not included in the standard terminology for gas chromatography of the International Union of Theoretical and Applied Chemistry (IUTAC).
For the realization of the basic technology an equipment was invented and defended by a Russia patent. As a result a maximum possible efficiency (Hayrapetyan's Effect) of column is obtained at a minimum length, which at the same time is optimal as well, as in difference to the ordinary column a further increase in column length increases the analysis time.
These are not the only advantages of Chromabarography. On the contrary, interesting possibilities of its modification have been revealed, which envisage:
A combined application of the moving pressure gradient and temperature (Chromabarothermography)
Or the moving pressure gradient along the column in combination with temperature programming equally inflicted to the whole chromatographic column (Chromabarograph with temperature programming).
- Looks like self promotion or hype for a dubious technology. Google search returns around 700 hits for the term, but a good number on the first pages appear to be hype written by the same person that wrote this - based on style and wording. Several were discussion on blogs or whatever signed by one ARAM HAYRAPETYAN, presumably the inventor of Chromabarography. Many Russian sites on the Google list. If it is real it is yet too new and unverified to include here. -Vsmith 02:03, 31 Jan 2005 (UTC)
Very entertaining, indeed. Packed column supercritical fluid chromatography uses a pressure regulator at the column outlet keeping the pressure constant, should the user so desire, irrespective (within the design limitations of the equipment) of flowrate, mobile phase composition, and temperature. The body governing nomenclature conventions is the IUPAC, International Union of Pure and Applied Chemistry, http://www.iupac.org BTW, the original invention by Tswett (pick your transcription) held the column outlet at constant pressure: it was held at ambient pressure.
[edit] Paper chromatography
Correct me if I'm wrong, but I think that paper chromatography is really a very minor subject in modern chromatography. I don't think it should have such prominence in the article. I can understand how it is good as a demonstration of the principle. If it is actually used in any modern analytic procedures, these should be mentioned. ike9898
- It's used a tiny bit for pigement seperation by some botanists, although TLC would be more commonly used for the same procedure. The paper chromotography section is quite well written, and does clearly explain the principle of chromotography, plus it is a technique that a high-school or undergrad student may come across, so I'd be hesitant to see it cut. Mabye we should add a sentence to say that it is no longer a procedure widely used in labs --nixie 23:28, 15 Feb 2005 (UTC)
As an encyclopedic topic, paper chromatography occupies a critical position in the historic development of the science of chromatography. I support nixie's contention about the quality and relevance of the section. If an edit is needed, it is the moving of the IMAC description to the affinity chromatography section and the drafting of an accurate ion exchange section, arguably one of the most important techniques in the modern chromatographic arsenal. :M Signs 16:49, 11 Mar 2005 (UTC)
[edit] Gas-liquid chromatography
I am I just being biased, or is this a rather cursory, and incorrect (GC is useful for both non-polar and polar compounds--it just depends on what column you use), comment on GC compared to the other sections? On the whole, this article seems to give a bio-researcher's POV of GC. Pi3832 15:34, 22 May 2006 (UTC)
[edit] Structure
Any objections to restructuring the article to make it more organised? It would look a little like this:
Chromatography
- History
- Chromatography theory
-
- Retention
- Plate theory
- Solid-liquid chromatography
-
- Affinity chromatography
- Column chromatography
- Ion exchange chromatography
- High performance liquid chromatography
- Normal phase (NP) liquid chromatography
- Reversed phase (NP) liquid chromatography
- Paper chromatography
- Thin layer chromatography
- Size exclusion chromatography
- Liquid-liquid chromatography
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- Countercurrent chromatography
- Gas-liquid chromatography
Or does anyone have any improvements? The whole array of chromatographic techniques on Wikipedia is jumbled and in need of some order -- Serephine ♠ talk - 14:05, 20 June 2006 (UTC)
- Go for it.--Pi3832 16:05, 21 June 2006 (UTC)
[edit] My Recent Edits
Here's the explanation of what I changed:
- 1. Saying that chromatography paper is "dipped" makes it sound like the paper is completely submerged in solvent. This would be disastrous.
- 2. TLC stationary phase is bonded to a substrate, not a carrier. The use of this word here could be confused with, e.g. carrier gas.
- 3. A substances retention time, Rf value, etc. is not definitive proof of its identity. Although it is very useful, spectroscopic methods are always used for further verification.
- 4. In GC, the stationary phase, whether in a capillary or packed column, is always solid. A liquid stationary phase would not stay stationary for very long, especially with a stream of gas flowing over it.
- 5. The entire TLC plate is not made out of silica, so I changed it to say "layer."
I hope you find my edits to be helpful. Mihovil 02:39, 19 September 2006 (UTC)
[edit] Mikhail Semyonovich Tsvet
A user at IP address 66.71.48.70 has repeatedly changed the spelling of "Mikhail Semyonovich Tsvet". The alternate spelling is referenced at the article Mikhail Tsvet. The persistent revision of the spelling in this article seems to be bordering on vandalism. -- Pi3832 00:51, 28 February 2007 (UTC)
- IP user 66.71.58.169 does it also. I concur that it's inappropriate. Can't figure out why we should be using anything other than the guy's own page's name and primary spelling when linking to his page and spelling his name. DMacks 02:26, 28 February 2007 (UTC)
