Talk:High-performance liquid chromatography

message: We have published an open access 3D printed device that connects to an autosampler and allows for continuous stirring. Do you think it is relevant to add to this page? 
https://en.wikipedia.org/wiki/User:Omermar 18:09, 3 December 2020 (UTC)
thread_title: 5.7 Autosamplers

message: Some subtopics (e.g. particle diameter, pore size) could be expanded upon for examples and benefits/drawbacks for each. Also discussing trends in terms of how that effects the resulting chromatogram and throughput for the instrument. References could also be added throughout the article as HPLC is a well-studied analytical instrument. Tvanneel (talk) 05:38, 17 January 2018 (UTC)
thread_title: Suggestions

message: It is actually called "High Presure Liquid Chromatography"!  — Preceding unsigned comment added by 144.41.157.41 (talk) 19:20, 12 September 2013 (UTC)
replies: text: right, but historically at the beginning any pressure above gravity or back pressure against a peristaltic pump was considered to be "high". That's why it was corrected to "formerly"   Shulalevin (talk) 10:06, 16 October 2023 (UTC)
thread_title:  false 

message: I read the entry for High performance... and found it hard (as a student who is not familiar with analytical methods) to understand. The terminology was not explained. A diagram (or two) would have been helpful. I am sure that someone who already knows the material might find it well written.
ahandel
----
I agree that the introduction of the article is a little too technical after the second paragraph.
I think the easiest solution would be to relocate technical and theory tips from the preamble (first two to three paragraphs)to the operation section. It might also help the article's organization to add a "Theory" section early in the article.
Hero of Ludi (talk) 03:02, 30 August 2012 (UTC)
thread_title:  article hard to understand 

message: I have reworked the beginning. I have corrected the error pointed out, added some general easy to understand language at the definition and split the previous language into Isocratic and Gradient HPLC. These two sections could still use some improvement. Perhaps they need to be further split into definition and practical example subsections. On the sensitivity error: this error is an exceptionally common error as to almost be acceptable. I chose not to use LLOD because it is not always relevant; however, signal to noise is always what is being spoken about when people say sensitivity (except when using the term correctly).--Nick Y. 21:23, 5 May 2006 (UTC)
thread_title:  Effort to improve the article 

message: Bizarrely in the 10 years I've worked with LC I've never come across the term "Bead" or "bead size" - it has always been referred to as particle or particle size.  I wonder if this is a regional thing (I work in a UK university lab)?
138.37.170.200
I presume bead size is a term mainly used in low pressure chromatography, or pellicular methods? I tend to agree that particle size is the usual terminology for modern HPLC.
: Well, I have heard the term somewhat frequently from people who actually manufacture stationary phases ( I am one of them). Not sure why. Could be a historic reason. I agree that in all HPLC literature we refer to it as particles.--Xenofonos 00:16, 26 October 2007 (UTC)
thread_title:  Bead size 

message: UPLC is a Waters trademark. These systems are now available from a number of other manufacturers.
True, but it looks likely that UPLC will become the "generic" name - like Hoover, Kleenex etc..  Other comapnies are calling them different things but usually with the word Ultra, or Ultra-high pressure/performance LC - which I am hearing more and more as "UPLC". --Daeve 22:16, 17 July 2006 (UTC)
thread_title:  UPLC 

message: In the Reversed phase chromatography section one can read the following sentence:
:... Eluent time is increased by addition of less polar solvent. 
Although I'm not sure what Eluent time means, I think this deduction is wrong. In a RPLC the stationary phase is non-polar. Addition of a less polar solvent will make the solvent compete for the stationary phase with the analyte, thus freeing it more quickly, which, in turn, decreases the time needed for a substance to elute. jοτομικρόν (talk, email) 23:00, 5 November 2006 (UTC)
replies: text: Corrected. There were a series of edits a while back that suffered from imprecise and somewhat confusing language. They did however make some valid point as is the case here, which is why they were not reverted. Adding polar solvent to the mobile phase does indeed increase retention time. But "less polar solvent...increasing elutant time" is definately wrong however you slice it but seems very close to correct on first look. E.g. change the unusual phrasing of "retention time" as "elution time" to the more common phrase "elution rate". Anyway I have ment to clean the whole thing up but was hoping the contributor of these additions would do so himself. Feel free to improve the article as you see fit. Someday I will give it a thorough cleaning but some other good editing would be appreciated before I tackle it.--Nick Y. 18:25, 6 November 2006 (UTC)
replies: text: For some reason I went ahead and cleaned up the article. Any feed back is good though. --Nick Y. 20:35, 7 November 2006 (UTC)
thread_title:  Another possible error (?) 

message: Please keep this section a resource deserving the name "manufacturers". Thus, any company not designing and manufacturing HPLC systems or instruments, should not be named in the "chromatographs" section and companies not manufacturing HPLC columns and supplies should not be listed in the "columns and accessories" section. Otherwise this list will become as irrelevant as many other lists published by magazines, buyers guides and so on. The instrument manufacturers list on "Links for Chemists (part of the WWW Virtual Library)" maintained by the Liverpool University (UK) is a relevant one, but not limited to chromatography. Letters a-j: , letters k-z: .--Chemist at work 13:30, 3 February 2007 (UTC)
replies: text: I don't see why an encyclopedia needs a buyers guide of manufacturers at all. This type of section begs for advertising like contributions, so I propose we delete them.Heckendorf 21:17, 14 March 2007 (UTC)
replies: text: Although I see value to these links, I also think that the section is a little out of hand and turning into somewhat of a spamvertisement section. I might suggest that we turn all of them into internal links only, and then only those with articles of at least stub size that is properly referenced and claims and demonstrates notability as a manufacturer. I may proceed with this if I don't hear any other suggestions.--Nick Y. 17:18, 21 March 2007 (UTC)
replies: text: I'm a Wiki writer newbie and want to agree to Nick Y.'s opinion to just keep internal links to real manufacturers, not resellers. What means stub in this respect? -- guest —The preceding unsigned comment was added by 84.191.232.11 (talk) 10:37, 11 May 2007 (UTC)

text: But they don't - they used to, but they spun their instrument operations (including HPLC stuff) off as Agilent in 1999.  Agilent is already listed. -- Jaeger5432 | Talk 16:53, 10 November 2008 (UTC)
thread_title:  Manufacturers sections 

message: The first paragraph previously started with "In isocratic HPLC..." but has been changed to "The basic operating principle of HPLC is...". Although the first sentence is clearly generic, other sentences in the first paragraph describe isocratic HPLC. Specifically the sample being retarded as it traverses the column is very isocratic. In gradient elution one might say that the analyte is retained by the column until the solvent composition changes to bring the analyte into solution and traverse the column freely.--Nick Y. 17:12, 2 August 2007 (UTC)
thread_title:  Principle 

message: I am testing a new infobox . Comments? --Kkmurray 19:15, 15 August 2007 (UTC)
thread_title: Added infobox

message: I don't agree that RPC is a commonly used abbreviation for reversed-phase HPLC.  —Preceding unsigned comment added by 82.45.237.9 (talk) 14:56, August 27, 2007 (UTC) 
:I guess if I saw the abbreviation RPC within the context of HPLC, I would assume it had something to do with reversed phase chromatography. However, if someone said merely I do a lot of RPC at work, I'd have no idea what they meant unless given a context. It's probably best to say reversed-phase HPLC. Pdcook (talk) 19:25, 28 September 2009 (UTC)
thread_title:  RPC 

message: I deleted the sentence "An investigator can also decrease retention time by adding a polar solvent to the mobile phase, or increase retention time by adding a more hydrophobic solvent." from the section on Reversed Phase chromatography.  This claim or its reverse seems to be controversial, eg see this edit, the section "Another possible error (?)" above, and in particular this archived thread at Wikiproject Chemistry.  Rather than risk error, it seems safest to omit the sentence entirely, at least until we can cite a clear, authoritative source.  Adrian J. Hunter(talk•contribs) 07:22, 10 February 2009 (UTC)
replies: text: Not a bad move. However, it is not at all controversial and has been established for half a century. Simply either a bad edit from a mistaken person or an intentional effort at subtle vandalism. The previous version is correct and essential to how RP-HPLC works.--Nick Y. (talk) 18:03, 10 February 2009 (UTC)
replies: text: I have reintroduced the information since it is fundamental to the technology but explained and clarified the statement to avoid confusion and future mistaken editing.  --Nick Y. (talk) 18:13, 10 February 2009 (UTC)
thread_title:  Deleted sentence (solvent polarity and retention time) 

message: The article contains the following mysterious statement:
"In isocratic elution, the selectivity does not change if the column dimensions (length and inner diameter) change - that is, the peaks elute in the same order. In gradient elution, the elution order may change as the dimensions or flow rate change.[citation needed]"
I am struggling to think of a situation where I could reverse peak-order in a gradient elution merely by changing the flow rate. If no one else can think of such a situation, and no one can cite anything, perhaps this line should be removed? 149.155.96.5 (talk) 16:39, 28 September 2009 (UTC)
thread_title:  selectivity in gradient elution, is this right? 

message: To someone with a poor understanding of chemistry this article is entirely unintelligible. Could a simplified explanation be added or a simple English article be created?  —Preceding unsigned comment added by 66.57.19.140 (talk) 00:09, 11 May 2010 (UTC)
thread_title:  Simple English article? 

message: There's a request in the article for a citation that Dr. Czaba invented the HPLC or at least "isocratic" terminology. 
I suspect there are earlier theory-based articles by other authors, 
but I think the following journal article is a candidate for a proper citation:
http://pubs.acs.org/doi/abs/10.1021/ac60256a003.  It is titled, "Fast Liquid Chromatography..." authored from Yale University (note there are three authors, and it is unclear if there was a primary author for the article). The article is from 1967.  I do not have full access to the article currently. Perhaps someone could read the full article and verify that it is the "first" practical article on HPLC?
Hero of Ludi (talk) 02:51, 30 August 2012 (UTC)
thread_title: Possible reference for first HPLC article in peer-reviewed journal

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thread_title:  External links modified