Talk:Gas chromatography–mass spectrometry

message: I started to redo quite a bit of this article.  I felt while some things were not necessarily incorrect, they seemed as if they could be misleading.  Furthermore what I felt was important information was totally missing from this article.
Babbles 04:52, 24 July 2007 (UTC)
thread_title: Cleanup and revision

message: "Law Enforcement
GC-MS is increasingly used for detection of illegal narcotic, and may eventually supplant drug-sniffing dogs."
Anybody have some solid information on this?  While there are some quasi-portable GC's that can be taken into the field (they put one on the Mars rover), there are most certainly not hand portable units.  Additionally there are certain factors like instrument maintenance, run times, and quality control which makes it unlikely that it would replace a drug sniffing dog.  At least not in the near future.
Babbles 01:27, 24 July 2007 (UTC)
replies: text: Actually, I think I was too harsh on this article. I think it'll require a lot of work, but all of this legal information is actually a very good thing. Although it probably needs to be reorganized and made less verbose, I think most of this information is appropriate. I would imagine lots of folk in chemical sciences would find the article interesting just for the legal aspects of a familiar technique. Unfortunatly, I don't have very much time to work on it now. Cool Hand Luke (Communicate!) 08:29, 17 Oct 2004 (UTC)

text: The article shows some promise - I have added links to the text but that in itself took me an hour. It needs de-essaying and things like "needle in a haystack" need to come out. I reckon it would make a really good article if you removed the half of the content that was making it too verbose. I will continue to edit it over the next few weeks, but it will take many revisions as it's too much to do in one go. It probably needs about 10 hours work in total. GregRobson 20:23, 30 Nov 2004 (UTC)
thread_title: Other comments

message: The latter third of this article about the implications of GC/MS and related technologies in the American legal system is very interesting. In fact I thought it must have been copied from somewhere else becaue it was very clearly written not as a Wikipedia article. However it seems the author has put it here so it's legit. However, I think it doesn't really fit on this page. I think there should be a page on scientific evidence in the legal system, and this section can serve as the foundation of that article. I'm not going to move it or anything, I just wanted to provide my thoughts and how best to organize this information. I don't think the legal stuff should stay on this page in the current level of detail, but we should keep it somewhere else and link to it. Nohat 00:53, 16 Dec 2004 (UTC)
thread_title:  Legal implications section 

message: "Alternatively, the single-magnet analyzer chamber will deflect the various particles through an electromagnetic field within a long curved tube. The lighter particles traverse the analyzer tube the fastest. The particles emerge from the magnetic region and strike the detector, transferring its charge. This activates the recorder which takes note of the atomic mass through the mass/charge ratio and evaluates concentration of that molecule contained in the sample."
Please clarify the above paragrapgh.  So how exactly does the single-magnet analyzer discriminate between particles of different mass to charge ratios?  I've read websites that suggest that single magnet is tunned to allow particles of a certain mass to charge ratio to be able to complete the journey through the long curved tube.  Particles with a different mass to charge ratio has a trajectory that is incompatible with the pathway offered by the long curved tube and therefore these particles collide on the wall of the tube. Allentchang 20:59, 24 Dec 2004 (UTC)
thread_title:  Clarify this paragraph 

message: I invite anyone to cleanup sections after MS components.  There's already a complaint that this article is more than 32k.  There are sections of the article after MS compennts that I cannot properly clean up without consulting the book by Giannelli, Paul C. and Imwinkelried, Edward J.  The UC Berkeley library does not have that book for some reason. Allentchang 22:43, 7 Jan 2005 (UTC)
thread_title:  I invite anyone to cleanup sections after MS components 

message: I've looked at the section on GC/MS analysis and got very confused.  You said that two kinds of analysis are possible: comparative and original.  You then proceed to explain about the comparative analysis in the first paragraph.  Then in the second paragraph you vaguely mention about "another analysis."  Is this other analysis the "original analysis"?  If not, then there is no where in your GC/MS section that talks about original analysis.
Additionally, you later mention "full spectrum" analysis and  selective ion monitoring.  It seems to me that you are talking at most five different types of analysis instead of two: "comparative," "original," "another," "full spectrum," and "selective ion monitoring." Allentchang 22:54, 7 Jan 2005 (UTC)
thread_title:  GC/MS analysis 

message: Heres the original bits.
:See http://www.chemistrydaily.com/chemistry/Gas_chromatography-mass_spectrometry - the rest cut per WP:C --Kkmurray 02:18, 15 June 2007 (UTC)
thread_title:  Ruthlessly Excised sections for clarity 

message: See HHO gas.  A scientist by the name of Ruggero Santilli wrote a journal paper claiming a new gas based on electrolysis of water with all kinds of "anomalous properties" like not obeying the normal gas laws and having a different amount of energy in different circumstances.  Most of his evidence is in the form of spectrometry scans, like a scan showing a peak at 5 amu and one showing monoatomic oxygen that "can only be explained" by his pet fringe theory of physics, etc.  Can someone familiar with these devices help me out?  Look over the paper (in the References section) and the graphs and point out any:
* Glaring errors (there are several typos and incorrect units in the paper)
* Internal inconsistencies (why do the same scans of the same compound look so different from each other?)
* Obvious misinterpretations of the graphs (is there normally a peak for monoatomic oxygen because of the electrical dissociation in the spectrometer?)
* Areas that would have to be looked into further to determine the validity of these tests or other places these claims would likely be responded to
— Omegatron 15:04, 8 June 2007 (UTC)
thread_title:  If you know about these machines, please help with a related article 

message: Just added two new sections.  Not sure if they should be independent sections or part of 'Instrumentation'.  Anyway, I need to add references but most of the info is from training materials not available to the public (I am a GC-MS operator).  I will be making articles about Purge and Trap GC-MS when I get chance.  Also I think we should standardise the form we express GCMS.  In this article the forms GC/MS and GC-MS are both in use.
Tangaloomaflyer 11:12, 10 October 2007 (UTC)
thread_title:  new sections: split/splitless and purge and trap 

message: This page, as it stands, should be koskoskoksoksoko GC-scanning MS.
As this topic relates to both GC and MS, it is important to bear in mind that there is a page dedicated to Mass Spectrometry, where most Mass Spectrometers are described. 
A scanning mass spectrometer looks at 1 ion at a time and throws away the rest. It then moves onto the next ion. If one looks at it critically, one will see that a SCAN is just a very long and sequential SIM.
A Time-of-Flight Mass Spectrometer does not "scan". It records complete "snapshots" or spectra, not throwing away any masses.
This has 2 implications:
1) A TOFMS cannot do SIM.
2) A TOFMS provides you with more accurate repesentations of the GC peaks.
By claiming that SIM is more sensitive than SCAN, one also assumes that one is looking at a smaller number of ions under SIM than under SCAN. This last claim is a very difficult one to make, especially if one considers TOFMS instruments as included under "SCAN".
A TOFMS can be just as sensitive as other Mass Spectrometers running under SIM. This has been shown over and over by TOFMS users. It really does depend on whether one does 1 ion SIM (nice to show off SIM, but useless in real life) or whether one does 3+ ions SIM (Retention Time + 3 ions seems to be the bare minimum for positively identifying chemicals). At 3 ion SIM level, a TOFMS is often just as sensitive.
12:53, 11 November 2007 (UTC)
replies: text: A triple collector IRMS doesn't scan. GraemeLeggett 10:38, 12 November 2007 (UTC)
thread_title:  Technical Error on Page 

message: Does anyone have an opinion on whether the applications section could be split off into a page of its own?  This article is quite long as it is, and adding more detail about applications (which could easily be done) will only make it more unwieldy.  Thoughts, before I take a crack at it?  Canada Hky (talk) 00:22, 15 May 2010 (UTC)
thread_title: Splitting off Applications

message: There is a move discussion in progress on Talk:Liquid chromatography-mass spectrometry which affects this page. Please participate on that page and not in this talk page section. Thank you.  —RM bot 19:30, 18 March 2011 (UTC)
thread_title: Move discussion in progress

message: I have removed the following section from the paragraph about Finnigan. If someone can find sources linking Friedman to Finnigan, and integrate this information into the paragraph, that would be helpful. As was, it didn't connect with the rest of the section. Mary Mark Ockerbloom (talk) 21:10, 23 January 2015 (UTC)
thread_title:  Questionable section 

message: These two references had been added after the reflist, but it's not clear to what statements, if any, they relate.  I'm moving them here; if someone can identify a relevant place for their citation, please do. Mary Mark Ockerbloom (talk) 13:28, 24 January 2015 (UTC)
thread_title:  Possible unrelated references 

message: Hello fellow Wikipedians,
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thread_title:  External links modified 

message: The begining section needs to be fixed. This sentence is completely wrong. "The use of a mass spectrometer as the detector in gas chromatography was developed during the 1950s after being originated by James and Martin in 1952.[1]" Read the article. The method of detection described in that reference IS NOT a mass spectrometer, it is a titration cell fitted with a photoelectric detector to detect the phenol red in the solution. I don't have time to fix this, and don't know how to edit it properly. I am putting this note here, so, someone with the expertise can fix it.   — Preceding unsigned comment added by 155.41.226.36 (talk) 17:21, 23 April 2017 (UTC)
replies: text: History lead sentence and 2x secondary source refs added. From  "The invention of gas chromatography is commonly attributed to A. T. James and A. J. P. Martin in 1952 ... The first GC/MS experiments were carried out by Fred McLafferty and Roland Gohlke at Dow Chemical with Bill Wiley and Ian McLaren at Bendix Research Laboratories sometime in the winter of 1955–1956." --Kkmurray (talk) 19:24, 23 April 2017 (UTC)
thread_title:  Introduction is WRONG, WRONG, WRONG! 

message: It seems like this article is lacking citations in several of the major sections. For example, "Types of mass spectrometer detectors," "GC-tandem MS," and the "Analysis" sections have no in-text citations! As a graduate student in chemistry, I really like the information in these sections. But there needs to be citations so people who are less familiar with chemistry can validate the information given. Is anyone willing to take on this task? Any analytical chemistry textbook would probably be a good place to start. Paiges8 (talk) 01:55, 19 January 2018 (UTC)
thread_title:  Needs citations