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This article was the subject of a Wiki Education Foundation-supported course assignment, between 19 January 2021 and 27 April 2021. Further details are available on the course page. Student editor(s): Amassey1. Peer reviewers: Maskewmo, MaryGrace J. Larsen.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 22:04, 16 January 2022 (UTC)
I disagree that TCD is the most common GC detector. FID (from my experience) seems to be the general standard for most basic analyses... any thoughts? Blckdmnd99 18:59, 16 May 2006 (UTC)
wat happens when the column length is increased -- (msg from December 2004) — Preceding unsigned comment added by 62.252.64.14 ( talk) 03:10, 8 December 2004 (UTC)
The article states that packed columns can be up to 10m long but I used a packed column that is 12m... 148.177.1.215 ( talk) 15:43, 22 December 2008 (UTC)
It would be excellent if someone came up with drawings for this article. After all, "a picture is worth a thousands of words." Allentchang 00:14, 15 Dec 2004 (UTC)
Added the diagram. Would appreciate some feedback to improve it. --
Rune Welsh
ταλκ 21:25, July 13, 2005 (UTC)
I'm an engineer for a manufacturer of GCs and detectors. I'll look through our expired patents and see if I can find anything useful to add on. Rune, your drawing hits pretty well on the concept anyway, that's how I illustrate it when I explain it to people :-) -- Eigenvalue 05:08, 2 January 2007 (UTC)
Added some more links to manufacturers and added hydrogen to the list of carrier gases. - Babbles 23:00, 24 September 2005 (UTC)
I'm thinking this thing needs an overhaul, I don't think it does a decent job of addressing various things such as column phases, length, diameter, film thickness, injector port, retention time, solvents, Gaussian peaks, solvent/Grob effects and so forth. - Babbles 23:19, 24 September 2005 (UTC)
I think it would be great to see a little more discussion on temperature programs and software used in GC analysis. (Yes, I say this because I'm struggling with setting up a GC at work and can't seem to find much on information.) jz
What issues are you having? One possible online resource could be: http://www.chromatographyforum.com/ I do not post there and don't really keep up with it, but perhaps it could help you out some. Babbles 17:20, 2 October 2005 (UTC)
For the pop culture references, I'd like to add a reference, but I'm not sure how to merge it with the current text, which is less about the references to GC's and more criticism of its use in pop culture. Here's my reference: In the novel "Zodiac" by Neal Stephenson, the protagonist Sangamon Taylor relies on a GC to do his vigilante environmental detective work. -- MM 22:03, 23 June 2006 (UTC)
Another often remembered popular misconception of what GCs can do is Sean Connery's 15-minute complete GC analysis of a cancer drug in the movie "Medicine Man" (1992). Great jungle lab. I would beleive a Helium/TCD analysis of atmospheric gases on a Molsieve column, or a CFC analysis, in that time, not one of a pharmaceutical compound. -- Carboxen 05:35, 7 July 2006 (UTC)
The history section is in desperate need of an overhaul. Fuzzform 19:24, 06 Dec 2005 (UTC)
The Chromatography article has all of two sentences about GC. And they aren't even entirely correct. Anyone want to volunteer to go edit/expand that? Pi3832 15:38, 22 May 2006 (UTC)
I have seen the sensitivity of chromatographs expressed in fg/s. Can someone explain what this measure is please. Lumos3 22:29, 22 May 2006 (UTC)
I've added a section on Methods, in which to discuss some general information on method developement. If it gets too detailed we may want to make a separate article(s), but I think this is a good place too start. Please, please, please feel free to compose stuff for this section--the subsections, especially.-- Pi3832 14:33, 7 June 2006 (UTC)
Heya all, I have reordered the article a bit a few days ago, to make it be more organized. Various great sections had sprouted recently and it became a collection of subsections without much order (I am not innocent), that I thought distracted from the big picture. Let me know if there are any such changes you disapprove of. Also, volunteers are sought for the sections Data Reduction and analysis (software, integrators, retention indices, databases, mass fragmentograms, etc) and Column selection (phases, dimensions) - I wouldnt mind collaborating. Carboxen 00:57, 22 October 2006 (UTC)
Not including external links for vendors on this page is fairly clearly covered in the WP:External links guideline. Links to be avoided #4: "Links to sites that primarily exist to sell products or services."
Links to help sites, I feel, fall under the Important points to remember part of the WP:External links guideline. Specifically:
DMOZ already has a category for Gas Chromatography, and I have put a link to it in the article.
If there is some external link that can be included within the
WP:External links guideline, and explanation on this page would help to keep it from being removed from the article. Thanks. --
Pi3832
18:24, 12 March 2007 (UTC)
Hi -- this article bears the marks of TMCGS (Too Many Chemistry Grad Students). It's highly technical and detailed in its topic coverage, but the introduction doesn't even explain in a simple way *what GC is used for*. Perhaps this could be worked on? -- YACGS (yet another chemistry grad student) —The preceding unsigned comment was added by 66.240.10.170 ( talk) 03:32, 16 April 2007 (UTC).
Sometimes "HPGC" is used. Should it be mentioned in the article, or redirected?
— DIV (
128.250.204.118
06:53, 11 July 2007 (UTC))
And "HPGLC".
— DIV (
128.250.204.118
06:55, 11 July 2007 (UTC))
We really don't need a section that does nothing more than list the makers of gas-liquid chromatography equipment and gas-liquid chromatography accessories. It is not encyclopedic, and it is a magnet for spam. -- Jaysweet 21:33, 13 July 2007 (UTC)
I want the picture present in 9th cbse NCERT book. Can you please help me?? —Preceding unsigned comment added by 125.62.100.167 ( talk) 04:52, 12 October 2007 (UTC)
This section sounds very opinionated. — Preceding unsigned comment added by 35.9.128.119 ( talk) 21:36, 18 February 2014 (UTC)
"In the U.S. TV show CSI, for example, GCs are used to rapidly identify unknown samples. "This is gasoline bought at a Chevron station in the past two weeks," the analyst will say fifteen minutes after receiving the sample." Is this SO unreasonable? Some GC programs are fast, and given gasoline is volatile, no reason why this should not be. GCs tend to be repeatable; no need to do more than one trace (when it goes to court you might want to, but that can be done later, once the detectives have gone). The "heat out" should be done afterthe previous sample, not just before this one. Are you sure hey are not using GC-MS? They are common on TV (not sure about CSI). Is it possible the analyst has been told in advance to expect a gasoline sample, and has loaded the program already. Once that is done, put the sample in the vial, push the button, and wait for the answer.
Totally different issue: The GC is mentioned in a Simpson's episode. Bart's classmate Martin tells the clas about his hero, the guy who invented the GC. Later in the episode, a GC is used to analyse a "flaming moe".
[1]
F2Andy (
talk)
15:02, 14 January 2008 (UTC)
As a side note regarding the same passage, episodes of CSI only rarely have solid markers of the flow of time in them. "Fifteen minutes" appears, thus, to be a complete guess. The show also has a few meta-jokes about how tests that take hours to days only occupy about thirty seconds of screen time, but that's neither here nor there. Point is, complaining about too-fast analysis on a show that's not meant to be a 24-style minute-by-minute account is mildly ridiculous. Since I'm an anonymous I'm not going to take it out myself, but unless there's a strong counter-reason (or even a citation) I'd think someone should, no? 69.29.95.100 ( talk) 14:32, 25 January 2008 (UTC)
I think the information here is quite reliable but no source material is stated. Could the author/authors maybe look them up and write them? Would mean a lot since I need to qoute this for an important project. —Preceding unsigned comment added by 83.183.74.61 ( talk) 12:53, 18 January 2009 (UTC)
i find thhis data to be wrong :/ —Preceding unsigned comment added by 148.197.214.196 ( talk) 13:46, 2 December 2009 (UTC)
The result of the move request was: Page moved. Ucucha 02:19, 15 March 2010 (UTC)
Gas-liquid chromatography →
Gas chromatography — This article is about gas chromatography
[2]. Gas-liquid chromatography is a particular kind of gas chromatography where the stationary phase is a liquid on a solid support.
[3] (as opposed to gas-solid chromatography
[4] or bonded stationary phases
[5] - see also Rotzsche, Harald (1991). Stationary phases in gas chromatography. Amsterdam: Elsevier.
ISBN
0-444-98733-9.). The current conetents of the gas-liquid chromatography should be moved over redirect to gas chromatography.
Kkmurray (
talk)
17:44, 7 March 2010 (UTC)
-- 222.67.205.143 ( talk) 05:24, 31 March 2010 (UTC)
-- 222.67.205.143 ( talk) 05:59, 31 March 2010 (UTC)
As I understand it, fractional distillation can be configured in a plant as a continuous process, whereas, at least as I have always seen it implemented, gas chromatography, because of its analytic task, is alwasy a batch process. This is an important distinction, as well, which I feel should be mentioned. —Preceding unsigned comment added by 50.46.82.18 ( talk) 14:48, 6 April 2011 (UTC)
I have changed this sentence ... FROM
"The atomic emission spectra is diffracted by a diffraction gradient and detected by a series of photomultiplier tubes." TO ...
"The atomic emission spectra is diffracted by a diffraction grating and detected by a series of photomultiplier tubes or photo diodes." To correct an error and to include a more recent technology. SUPERHETRODYNE ( talk) 20:16, 6 March 2015 (UTC)
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I suggest adding the olfactometric detector to this section, and adding an article on gas chromatography-olfactory (GC-O).
Gas chromatography-olfactometry (GC-O) is a technique that integrates the separation of volatile compounds using a gas chromatograph with the detection of odour using an olfactometer (human assessor). [1] While GC separates and quantifies volatile compounds from an extract, human olfaction detects the odour activity of each eluting compound. In this olfactometric detection, a human assessor may qualitatively determine whether a compound has odour activity or describe the odour perceived, or quantitatively evaluate the intensity of the odour or the duration of the odour activity. [2] The olfactometric detection of compounds allows the assessment of the relationship between a quantified substance and the human perception of its odour, without instrumental detection limits present in other kinds of detectors.
The apparatus consists of a gas chromatograph equipped with an odour port (ODP), in place of or in addition to conventional detectors, from with human assessors sniff the eluates. The odour port is characterised by its nose-cone design connected to the GC instrument by a transfer line. The odour port is commonly glass or polytetrafluoroethylene. [3] It is generally placed 30 – 60 cm away from the instrument, extending from the side such that it is not affected by the hot GC oven. The deactivated silica transfer line is generally heated to prevent the condensation of less-volatile compounds. It is flexible so that the assessor can adjust it according to their comfortable sitting position. As traditional warm and dry carrier gases may dehydrate the mucous membrane of the nose, volatiles are delivered via auxiliary gas or humidified carrier gas, with relative humidity (RH) of 50 – 75%, to ease the dehydration. [4]
The olfactometric detector may be coupled with, or connected in parallel to, a flame ionization detector (FID) or mass spectrometer (MS). Moreover, multiple odour ports may be set-up. In these cases, the eluate is generally split evenly between the detectors to allow it to reach the detectors simultaneously. [3]
References
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link)
{{
cite journal}}
: CS1 maint: unflagged free DOI (
link)
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link)
This is the
talk page for discussing improvements to the
Gas chromatography article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
This
level-5 vital article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||
|
This article was the subject of a Wiki Education Foundation-supported course assignment, between 19 January 2021 and 27 April 2021. Further details are available on the course page. Student editor(s): Amassey1. Peer reviewers: Maskewmo, MaryGrace J. Larsen.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 22:04, 16 January 2022 (UTC)
I disagree that TCD is the most common GC detector. FID (from my experience) seems to be the general standard for most basic analyses... any thoughts? Blckdmnd99 18:59, 16 May 2006 (UTC)
wat happens when the column length is increased -- (msg from December 2004) — Preceding unsigned comment added by 62.252.64.14 ( talk) 03:10, 8 December 2004 (UTC)
The article states that packed columns can be up to 10m long but I used a packed column that is 12m... 148.177.1.215 ( talk) 15:43, 22 December 2008 (UTC)
It would be excellent if someone came up with drawings for this article. After all, "a picture is worth a thousands of words." Allentchang 00:14, 15 Dec 2004 (UTC)
Added the diagram. Would appreciate some feedback to improve it. --
Rune Welsh
ταλκ 21:25, July 13, 2005 (UTC)
I'm an engineer for a manufacturer of GCs and detectors. I'll look through our expired patents and see if I can find anything useful to add on. Rune, your drawing hits pretty well on the concept anyway, that's how I illustrate it when I explain it to people :-) -- Eigenvalue 05:08, 2 January 2007 (UTC)
Added some more links to manufacturers and added hydrogen to the list of carrier gases. - Babbles 23:00, 24 September 2005 (UTC)
I'm thinking this thing needs an overhaul, I don't think it does a decent job of addressing various things such as column phases, length, diameter, film thickness, injector port, retention time, solvents, Gaussian peaks, solvent/Grob effects and so forth. - Babbles 23:19, 24 September 2005 (UTC)
I think it would be great to see a little more discussion on temperature programs and software used in GC analysis. (Yes, I say this because I'm struggling with setting up a GC at work and can't seem to find much on information.) jz
What issues are you having? One possible online resource could be: http://www.chromatographyforum.com/ I do not post there and don't really keep up with it, but perhaps it could help you out some. Babbles 17:20, 2 October 2005 (UTC)
For the pop culture references, I'd like to add a reference, but I'm not sure how to merge it with the current text, which is less about the references to GC's and more criticism of its use in pop culture. Here's my reference: In the novel "Zodiac" by Neal Stephenson, the protagonist Sangamon Taylor relies on a GC to do his vigilante environmental detective work. -- MM 22:03, 23 June 2006 (UTC)
Another often remembered popular misconception of what GCs can do is Sean Connery's 15-minute complete GC analysis of a cancer drug in the movie "Medicine Man" (1992). Great jungle lab. I would beleive a Helium/TCD analysis of atmospheric gases on a Molsieve column, or a CFC analysis, in that time, not one of a pharmaceutical compound. -- Carboxen 05:35, 7 July 2006 (UTC)
The history section is in desperate need of an overhaul. Fuzzform 19:24, 06 Dec 2005 (UTC)
The Chromatography article has all of two sentences about GC. And they aren't even entirely correct. Anyone want to volunteer to go edit/expand that? Pi3832 15:38, 22 May 2006 (UTC)
I have seen the sensitivity of chromatographs expressed in fg/s. Can someone explain what this measure is please. Lumos3 22:29, 22 May 2006 (UTC)
I've added a section on Methods, in which to discuss some general information on method developement. If it gets too detailed we may want to make a separate article(s), but I think this is a good place too start. Please, please, please feel free to compose stuff for this section--the subsections, especially.-- Pi3832 14:33, 7 June 2006 (UTC)
Heya all, I have reordered the article a bit a few days ago, to make it be more organized. Various great sections had sprouted recently and it became a collection of subsections without much order (I am not innocent), that I thought distracted from the big picture. Let me know if there are any such changes you disapprove of. Also, volunteers are sought for the sections Data Reduction and analysis (software, integrators, retention indices, databases, mass fragmentograms, etc) and Column selection (phases, dimensions) - I wouldnt mind collaborating. Carboxen 00:57, 22 October 2006 (UTC)
Not including external links for vendors on this page is fairly clearly covered in the WP:External links guideline. Links to be avoided #4: "Links to sites that primarily exist to sell products or services."
Links to help sites, I feel, fall under the Important points to remember part of the WP:External links guideline. Specifically:
DMOZ already has a category for Gas Chromatography, and I have put a link to it in the article.
If there is some external link that can be included within the
WP:External links guideline, and explanation on this page would help to keep it from being removed from the article. Thanks. --
Pi3832
18:24, 12 March 2007 (UTC)
Hi -- this article bears the marks of TMCGS (Too Many Chemistry Grad Students). It's highly technical and detailed in its topic coverage, but the introduction doesn't even explain in a simple way *what GC is used for*. Perhaps this could be worked on? -- YACGS (yet another chemistry grad student) —The preceding unsigned comment was added by 66.240.10.170 ( talk) 03:32, 16 April 2007 (UTC).
Sometimes "HPGC" is used. Should it be mentioned in the article, or redirected?
— DIV (
128.250.204.118
06:53, 11 July 2007 (UTC))
And "HPGLC".
— DIV (
128.250.204.118
06:55, 11 July 2007 (UTC))
We really don't need a section that does nothing more than list the makers of gas-liquid chromatography equipment and gas-liquid chromatography accessories. It is not encyclopedic, and it is a magnet for spam. -- Jaysweet 21:33, 13 July 2007 (UTC)
I want the picture present in 9th cbse NCERT book. Can you please help me?? —Preceding unsigned comment added by 125.62.100.167 ( talk) 04:52, 12 October 2007 (UTC)
This section sounds very opinionated. — Preceding unsigned comment added by 35.9.128.119 ( talk) 21:36, 18 February 2014 (UTC)
"In the U.S. TV show CSI, for example, GCs are used to rapidly identify unknown samples. "This is gasoline bought at a Chevron station in the past two weeks," the analyst will say fifteen minutes after receiving the sample." Is this SO unreasonable? Some GC programs are fast, and given gasoline is volatile, no reason why this should not be. GCs tend to be repeatable; no need to do more than one trace (when it goes to court you might want to, but that can be done later, once the detectives have gone). The "heat out" should be done afterthe previous sample, not just before this one. Are you sure hey are not using GC-MS? They are common on TV (not sure about CSI). Is it possible the analyst has been told in advance to expect a gasoline sample, and has loaded the program already. Once that is done, put the sample in the vial, push the button, and wait for the answer.
Totally different issue: The GC is mentioned in a Simpson's episode. Bart's classmate Martin tells the clas about his hero, the guy who invented the GC. Later in the episode, a GC is used to analyse a "flaming moe".
[1]
F2Andy (
talk)
15:02, 14 January 2008 (UTC)
As a side note regarding the same passage, episodes of CSI only rarely have solid markers of the flow of time in them. "Fifteen minutes" appears, thus, to be a complete guess. The show also has a few meta-jokes about how tests that take hours to days only occupy about thirty seconds of screen time, but that's neither here nor there. Point is, complaining about too-fast analysis on a show that's not meant to be a 24-style minute-by-minute account is mildly ridiculous. Since I'm an anonymous I'm not going to take it out myself, but unless there's a strong counter-reason (or even a citation) I'd think someone should, no? 69.29.95.100 ( talk) 14:32, 25 January 2008 (UTC)
I think the information here is quite reliable but no source material is stated. Could the author/authors maybe look them up and write them? Would mean a lot since I need to qoute this for an important project. —Preceding unsigned comment added by 83.183.74.61 ( talk) 12:53, 18 January 2009 (UTC)
i find thhis data to be wrong :/ —Preceding unsigned comment added by 148.197.214.196 ( talk) 13:46, 2 December 2009 (UTC)
The result of the move request was: Page moved. Ucucha 02:19, 15 March 2010 (UTC)
Gas-liquid chromatography →
Gas chromatography — This article is about gas chromatography
[2]. Gas-liquid chromatography is a particular kind of gas chromatography where the stationary phase is a liquid on a solid support.
[3] (as opposed to gas-solid chromatography
[4] or bonded stationary phases
[5] - see also Rotzsche, Harald (1991). Stationary phases in gas chromatography. Amsterdam: Elsevier.
ISBN
0-444-98733-9.). The current conetents of the gas-liquid chromatography should be moved over redirect to gas chromatography.
Kkmurray (
talk)
17:44, 7 March 2010 (UTC)
-- 222.67.205.143 ( talk) 05:24, 31 March 2010 (UTC)
-- 222.67.205.143 ( talk) 05:59, 31 March 2010 (UTC)
As I understand it, fractional distillation can be configured in a plant as a continuous process, whereas, at least as I have always seen it implemented, gas chromatography, because of its analytic task, is alwasy a batch process. This is an important distinction, as well, which I feel should be mentioned. —Preceding unsigned comment added by 50.46.82.18 ( talk) 14:48, 6 April 2011 (UTC)
I have changed this sentence ... FROM
"The atomic emission spectra is diffracted by a diffraction gradient and detected by a series of photomultiplier tubes." TO ...
"The atomic emission spectra is diffracted by a diffraction grating and detected by a series of photomultiplier tubes or photo diodes." To correct an error and to include a more recent technology. SUPERHETRODYNE ( talk) 20:16, 6 March 2015 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Gas chromatography. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
This message was posted before February 2018.
After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than
regular verification using the archive tool instructions below. Editors
have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the
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source check}}
(last update: 5 June 2024).
Cheers.— InternetArchiveBot ( Report bug) 15:44, 11 October 2017 (UTC)
I suggest adding the olfactometric detector to this section, and adding an article on gas chromatography-olfactory (GC-O).
Gas chromatography-olfactometry (GC-O) is a technique that integrates the separation of volatile compounds using a gas chromatograph with the detection of odour using an olfactometer (human assessor). [1] While GC separates and quantifies volatile compounds from an extract, human olfaction detects the odour activity of each eluting compound. In this olfactometric detection, a human assessor may qualitatively determine whether a compound has odour activity or describe the odour perceived, or quantitatively evaluate the intensity of the odour or the duration of the odour activity. [2] The olfactometric detection of compounds allows the assessment of the relationship between a quantified substance and the human perception of its odour, without instrumental detection limits present in other kinds of detectors.
The apparatus consists of a gas chromatograph equipped with an odour port (ODP), in place of or in addition to conventional detectors, from with human assessors sniff the eluates. The odour port is characterised by its nose-cone design connected to the GC instrument by a transfer line. The odour port is commonly glass or polytetrafluoroethylene. [3] It is generally placed 30 – 60 cm away from the instrument, extending from the side such that it is not affected by the hot GC oven. The deactivated silica transfer line is generally heated to prevent the condensation of less-volatile compounds. It is flexible so that the assessor can adjust it according to their comfortable sitting position. As traditional warm and dry carrier gases may dehydrate the mucous membrane of the nose, volatiles are delivered via auxiliary gas or humidified carrier gas, with relative humidity (RH) of 50 – 75%, to ease the dehydration. [4]
The olfactometric detector may be coupled with, or connected in parallel to, a flame ionization detector (FID) or mass spectrometer (MS). Moreover, multiple odour ports may be set-up. In these cases, the eluate is generally split evenly between the detectors to allow it to reach the detectors simultaneously. [3]
References
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link)
{{
cite journal}}
: CS1 maint: unflagged free DOI (
link)
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link)