Talk:Electrospray ionization

How does this sentence make sense ("The electrospray ionization technique was first reported by Masamichi Yamashita and John Fenn in 1984."), when it is clearly later stated that actually Dole already published his research on "Molecular Beams of Macroions" in 1968 and clearly called the ionization technique an electrospray? — Preceding unsigned comment added by 131.181.47.221 (talk) 07:21, 18 January 2018 (UTC)

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"As like charges repel, the liquid pushes itself out of the capillary and forms a mist or an aerosol of small droplets about 10μm across." Since the size of the droplets generated by electrospray depends on too many factors, I would suggest leaving it at "small droplets", without giving a size estimate.

"The proximity of the molecules becomes unstable as the similarly charged molecules come closer together and the droplets once again explode." This would be a good place to talk about the Rayleigh limit. "Explosion" is not the most accurate way of describing the process, there are wonderful pictures outthere showing what happens when a droplet reaches the Rayleigh limit (Gomez and Tang Phys Fluids 1994, Duft et al, Nature 2003).

The images from Duft et al.'s papers would be great to show the process of a droplet's "explosion."134.253.26.6 (talk) 19:27, 10 March 2009 (UTC)

"Schulz, F.; Franzka, S.; Schmid, G.; Nanostructured Surfaces by Deposition of Metal Nanoparticles by Means of Spray Techniques. Advanced Functional Materials 2002, 12,532-536." Shouldn't we wait a little to see what is the impact of a paper before adding it as a reference? Would I be surprised if it was added here by one of the authors? What would happen if everybody who writes a paper on electrospray adds a referece here?

At >2000 peer reviewed papers a year, it would indeed get messy134.253.26.6 (talk) 19:27, 10 March 2009 (UTC)

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I thought that in a bulk material like the liquid here there is no net charge so what does this "As like charges repel, the liquid pushes itself out of the capillary" refer to? Is this really a accurate description of what's happening?

Dougher 04:42, 10 August 2006 (UTC)

i dont think so. I believe there is in fact a high voltage power supply on the needle tip which causes the taylor cone to form. the counterelectrode of the high voltage supply goes to a plate which attracts the positively charged droplets. this article doesnt mention it, of course. http://www.chm.bris.ac.uk/ms/images/esi-mechanism.gif

Added overview diagram Egmason (talk) 10:05, 21 January 2015 (UTC)

External link to thesis

I don't see any issues with the linking to Dr. Bokman's dissertation. We are not violating coi, npov or link. It is selective and useful not random or exhaustive, represents scientific consensus, and was not added by Dr. Bokman or any of his associates. I personally would respect a request by Dr. Bokman to not link to his publicly available dissertation if he requests that we not, but there is no rule preventing it being linked to here. Perhaps there may be a better choice of external link but this one is not a bad choice.--Nick Y. 17:44, 2 November 2007 (UTC)

I do see an issue with linking to a thesis. Who decided that this thesis is so relevant to deserve a link in an Encyclopedia? —Preceding unsigned comment added by Mgnelu (talk • contribs) 00:54, 17 February 2008 (UTC)

ES-MS vs. ESI-MS

I see ESI-MS much more than ES-MS. The former makes more sense as an abbreviation for electrospray ionization mass spectrometry. --Kkmurray 14:33, 6 November 2007 (UTC)

Good point. I added the ES-MS and related abbreviations because I found them in a paper and wasn't certain what they meant. I usually find that Wikipedia is excellent for finding a quick answer to the meaning of an acronym, but it didn't have this one yet. So, after I found what it meant, I added it. I think both ES-MS and ESI-MS should be mentioned, as both are in use. A search in Google books gives hundreds of hits for all these abbreviations, although ESI-MS seems to be the most common indeed. --Itub 14:41, 6 November 2007 (UTC)

Both is best. Google seems to like "ESI-MS" over " ES-MS" but both are clearly used. --Kkmurray 16:15, 6 November 2007 (UTC)

Electrospray is used as ion source for mass spectrometry, so ESI-MS makes perfect sense. ES-MS... not really. I don't think both ESI-MS and ES-MS should be featured here as acceptable abbreviations. Clearly, the one that doesn't make much sense is used less. Mgnelu (talk) 02:43, 18 February 2008 (UTC)

I agree in that that ESI-MS[1] sounds better to me than ES-MS.[2] On the other hand fast atom bombardment (FAB) is used as ion source for mass spectrometry, but no one uses "FABI-MS" (or ICPI-MS, etc.) --Kkmurray (talk) 17:46, 18 February 2008 (UTC)

199 thousand hits for ICP-MS? --Rifleman 82 (talk) 18:09, 18 February 2008 (UTC)

I assume that people started using FAB and ICP without questioning whether adding an "I" would make sense or not. And it is good that others payed attention and didn't start using another abbreviation - at least there is no confusion. What do you think about the use of MALD-MS[3]? I know, I know, the ratio is much smaller than in the case of ES-MS, but ES-MS makes as much sense as MALD-MS. Having two acronym for the same thing can get confusing. At least we could encourage the use of the one that makes more sense. Mgnelu (talk) 02:34, 19 February 2008 (UTC)

It's somewhat arbitrary (unfortunately). I remember using MALD and MALDI interchangeably in the early 90's and now the former seems completely wrong. I think that we're left with general consensus aided by counting Google hits (etc). --Kkmurray (talk) 02:58, 10 March 2008 (UTC)

How it works

I intend to remove this section. Most of the text would go into the "Ionization Mechanism" section, except the discussion of the charged droplets formation, which would be replaced by a reference to "Electrospray". Mgnelu (talk) 03:59, 19 February 2008 (UTC)

Static nanospray mass spectrometry

I haven't heard of "static nanospray" - does that imply the existence of a "dynamic nanospray"? Fraction collection during liquid chromatography followed by off-line analysis (by any method) is not an application of electrosprays. It could be mentioned in the topic dedicated to liquid chromatography, but I don't think it belongs here. Any other opinions? Mgnelu (talk) 06:11, 7 March 2008 (UTC)

I hadn't heard of it either, but it apparently means nanospray not connected to a separation (e.g. [4]). It should be defined in the section on nanospray (once someone writes that section). --Kkmurray (talk) 02:46, 10 March 2008 (UTC)

Do you really think it should be defined? A Google search for "static nanospray" returns only 490 hits, it is clearly not widely used. I wonder if those who used this unfortunate expression ever thought how meaningless it was. Mgnelu (talk) 02:18, 11 March 2008 (UTC)

This is also synonymous with "direct infusion nanospray"--Nick Y. (talk) 19:37, 17 March 2009 (UTC)

I wonder what makes them synonymous. "Static" is quite a dumb way of saying "direct infusion". Mgnelu (talk) 01:04, 19 March 2009 (UTC)

It's static because there is no pump forcing the liquid through the capillary. You load the tip with solution and it will spray for a long time with just the voltage driving the fluid flow. --Kkmurray (talk) 02:02, 19 March 2009 (UTC)

The liquid is not static whether you pump it or not. Maybe "passive" would better describe that the liquid is not pumped.Mgnelu (talk) 07:03, 19 March 2009 (UTC)

There is a subtle difference between the two but the end result is the same. I agree that the naming is bad but it is what it is. To clarify the difference: in "static nanospray" the liquid sample is not pumped from behind whereas "direct infusion nanospray" is pumped from behind. They both move the sample forward and spray it out the tip.--Nick Y. (talk) 14:02, 19 March 2009 (UTC)

I think I get the "subtle difference". At some point somebody wondered: "What buzzword can I come up with? Static would sound kinda scientific." It is not what it is because the term does not have a large circulation yet. On the other hand, if we keep it in Wikipedia it will get advertised more than it deserves. If we accept all the garbage people come up with, soon we start a Wikipedia page for bio-electrosprays. Mgnelu (talk) 01:04, 20 March 2009 (UTC)

Commercial Air purifiers

As I understand, this article discusses the use of electrospray as ionization source for mass spectrometry. Certain models of commercial air purifiers use electrosprays to ionize airborne particles and remove them from the air, but they are certainly not an application of electrospray ionization in the context of this article. This application seems more appropriate in the context of electrospray. Plus, the reference added in this section is obviously different than the others, I would say in conflict with WP:ADVERT. Mgnelu (talk) 23:22, 8 November 2008 (UTC)

Although most air purifiers work as you correctly stated in the context of electrospray. I placed this section in Liquid Ionisation as the page Electrospray ionisation states that the liquid contains two elements the volatile carrier that evaporates off leaving behind the chemical that is to be studied. This is also how air purifiers that use LiquidIon's work, where a volatile evaporates off and leave behind LiquidIon. As the rest of the applications section describes uses with mass spectrometry, I thought it would be appropriate to include the word 'commercial' before Air Purifier so as to separate it slightly from the other applications. I do not think the reference can be viewed as an advert as it links to a charity that lists many competitive air purifiers that efficiently remove particles from the air Mike (talk) 10:25, 11 November 2008 (UTC)

I am not sure what LiquidIon means - it sounds like a(nother) commercial nonsense. I still believe that this paragraph is out of place here and suggest to be moved to electrospray or air purifier. Even if the reference is not an advertisement, I am sure you noticed that all the other references point to scientific articles, published in prestigious journals. A charity webpage that lists many types of air purifiers does not constitute a good reference especially in the context of electrospray ionization for mass spectrometry (or in the context of electrospray for that matter). Mgnelu (talk) 06:45, 13 November 2008 (UTC)

WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 09:49, 10 November 2007 (UTC)

Recent changes to How it works and ionization mechanism

The recent changes, while definitely part of a well intentioned and generally well executed effort by User:Mgnelu to improve this article and other related articles, has resulted in loss of important information and is even misleading. I generally agree with the concept of at least partial merging how it works with ionization mechanism the two are separate for a good reason. How it works is simple and accessible to the non-expert and the ionization mechanism section contains subtle details and ongoing issues of debate for the expert or exceptionally curious. Overall important details have been lost and some statements are now not scientifically well supported as they have been over-simplified. The effort is appreciated but a step backwards might be best before trying this again.--Nick Y. (talk) 20:53, 17 April 2009 (UTC)

Nick Y., it's been more than a year since I wrote that I would eliminate the section How it works. Nobody expressed disagreement, so I finally got to it. I kept the last paragraph, but the first one was too simplistic and really awkward at points. Regarding the original presentation of the two ionization models, presenting them as mutually exclusive is not scientifically accurate; I am not aware of any ESI expert who thinks about the issue in black and white (as it was presented here). I also removed the paragraph questioning the term "ionization" because the ions are preformed in the solution. As long as the electrospray creates gas-phase ions that can be analyzed by mass spectrometry, it is an ionization source, it doesn't matter if the ions are pre-formed in the solution or not. This (philosophical) topic is not in the mainstream of ESI research, plus it confuses more than clarifies. Please let me know what is the important information that got lost, and what is the misleading information. Mgnelu (talk) 01:11, 18 April 2009 (UTC)

The area of greatest concern and the best place to start is the simplification of IEM vs. CRM. The statement currently present "Small ions are liberated into the gas phase through this ion evaporation mechanism (IEM). Larger ions remain trapped inside the droplets until all the solvent molecules evaporate, in what is known as charged residue mechanism (CRM)", is generally correct in my personal opinion and is a widely held supposition but is not a scientifically proven fact as far as I know. I am not suggesting that your efforts are misguided, simply that accuracy and completeness are reduced by recent changes. I think you can craft a better section but I encourage you to look at the previous version for guidance on what you may have lost in the process and reintroduce accurate and complete information and back up your changes with citations.--Nick Y. (talk) 15:01, 21 April 2009 (UTC)

There is a large body of indirect evidence that the statement is correct, even though (I agree) there is no definite scientific proof. The summary I wrote is the scientific consensus, which is repeated over and over again by many papers published in the last decade. It is hard to pick one that is trully the most relevant (maybe de la Mora's 2000 Anal Chim Acta?), but I think that references to the papers that originally described the two models should suffice. I am still not sure what is the accurate and complete information that got lost. Mgnelu (talk) 03:49, 22 April 2009 (UTC)

There is an important distinction between the discussion that takes place in the literature and the factual way which you make this statement. There is nothing resolved about this issue. There are lines of evidence which support this concept and coalescing opinions but not consensus. To a large degree people have given up on figuring this out, not found the answer to the question. Also what the models are are completely lost in your text.--Nick Y. (talk) 01:00, 23 April 2009 (UTC)

Your additions today are excellent and cover much of the IEM/CRM material even better than before. One point lost however is the convergence of the models in their limits. IEM does have a solvation sphere surrounding the evaporated ion. This is not very different than a coulombic fission event. The only real difference is the scale of the solvation sphere relative to the charge and size of the droplet. The debate is about if the process scales uniformly and the coulomb limit continues to dominate or the field strength dominates and solvated ions are liberated before the coulomb limit at small scales.

Additional points lost:

• Volatility of solvents and additives. (This is critical to the non-expert. Perhaps the most important thing to know.)
• There is no mention of sampling of the ion plume into the mass spectrometer (or other device).
• Although poorly covered before all mention of the electrospray circuit, how charge is carried through different portions of the circuit and that it is a galvanic cell is completely lost.
• Similarly the mention of redox reactions and electrolysis are lost (although poorly covered before as well).

In general I think improvement would have been better than deletion. It now needs to be rebuilt and I think you can make it better in teh end but these issues need to be included or it was a step back (from a poor start to nothing) not forward.--Nick Y. (talk) 14:54, 23 April 2009 (UTC)

Thank you for your suggestions. I mentioned the solvent volatility - good point. The sampling of the aerosol in the first vacuum stage of the mass spectrometer was mentioned in the previous version. I also brought up that some analytes might be involved in the electrochemistry. I covered the circuit and the electrochemistry in the topic electrospray, I don't think there is a need to repeat it here. Mgnelu (talk) 04:11, 29 April 2009 (UTC)

PNAS reference

Kkmurray, I have serious doubts that the reference you added is relevant in the context. Fenn did have very important contributions to electrospray ionization, but he did not discover the liquid dispersion into a fine aerosol by electrosprays and his PNAS paper does not bring anything new in this regard. There are papers that don't deserve the visibility that comes with a reference in wikipedia. I think we should be conservative and cite established papers, with general acceptance in the community. IMHO, the new papers should be scrutinized in the scientific literature before being referenced in wikipedia. Mgnelu (talk) 03:49, 22 April 2009 (UTC)

If you have a better reference covering recent work elucidating the electrospray ionization mechanism, feel free to swap it. I don't think that the current references in the mechanism section (Dole's 1968 and Iribarne and Thompson's 1976 papers) are sufficient for a discussion of the current understanding of the electrospray mechanism. --Kkmurray (talk) 17:06, 22 April 2009 (UTC)

Images of electrospray

I took some photos recently of an ESI source in action. Perhaps one of these photos might be a better illustration of the topics discussed here?

TheTweaker (talk) 19:57, 15 September 2009 (UTC)

strange sentence, what does this mean? (ionization mechanism)

I am really puzzled by the last section of Ionization mechanism: "The analytes are sometimes involved in electrochemical processes, leading to shifts of the corresponding peaks in the mass spectrum." What does this sentence mean? It means nothing to me, and I use ESI daily. The link from "electrochemical processes" takes you to a random point in the middle of the general electrospray page. 149.155.96.6 (talk) 16:01, 6 July 2010 (UTC)

Shifts in mass due to chemical reaction? Electrochemical processes (e.g. Abonnenc, MéLanie; Qiao, Liang; Liu, Baohong; Girault, Hubert H. (2010), "Electrochemical Aspects of Electrospray and Laser Desorption/Ionization for Mass Spectrometry", Annual Review of Analytical Chemistry, 3: 231–54, doi:10.1146/annurev.anchem.111808.073740, PMID 20636041) should get their own section anyway. --Kkmurray (talk) 20:10, 6 July 2010 (UTC)

Made some edits...

I have added some extra depth in places...hope you don't mind too much!

I think these are some important points.

I also plan to expand on the LC-MS application section and possibly add LC-MS/MS if you wouldn't mind. — Preceding unsigned comment added by JCoopsflamethrower (talk • contribs) 09:38, 9 February 2013 (UTC)

Merging Desorption electrospray ionization into Electrospray ionization

Desorption electrospray ionization seems to be a variant of electrospray ionization in which the sample is a (solid) surface while an electrospray gun is used to desorb and ionize small fractions of analytes present in/on it. The way the sample is delivered is slightly different than in the standard electrospray ionization but the concept seems to be too similar to justify separation into two articles. — Preceding unsigned comment added by Natriumchloratum (talk • contribs) 15:27, 9 January 2014 (UTC)

From an analytical chemist's view point, ESI and DESI should not be merged, as ESI is an established technique with numerous applications, while DESI is a relatively new technique that has not been adopted by routine laboratories to a larger extent. If the ESI and DESI texts were merged, it would give the impression that DESI is a significant variant of ESI, while, e.g., the relatively short description of LC-ESI-MS in the ESI article would imply it to be a minor application. In reality, LC-ESI-MS is much more popular than DESI. Also, as DESI does not need sample preparation and enables mass spectrometry imaging unlike traditional ESI, DESI deserves an independent article where these issues are described.Neuloja (talk) 11:36, 18 January 2014 (UTC)

I agree that there should not be a merge and am removing the tags. --Kkmurray (talk) 16:11, 20 July 2014 (UTC)

Proposed merge with Electrostatic Spray Ionization

merge to general topic � DGG ( talk ) 19:43, 20 February 2015 (UTC)

Support - "Electrostatic spray ionization" is a form of pulsed electrospray and should be covered in the electrospray article. --Kkmurray (talk) 19:13, 21 February 2015 (UTC)

Oppose - Many of the other ambient methods have their own pages, each of which is (arguably) independently notable. So, these include Desorption electrospray ionization, Extractive electrospray ionization, electrospray laser desorption ionization, matrix-assisted laser desorption electrospray ionization and laser ablation electrospray ionization in addition to Electrostatic Spray Ionization. So, either they should all be merge, or none should be merged; I lean towards the latter on the grounds that there is enough to discuss that combining onto one page would be unwieldy. Klbrain (talk) 15:46, 10 August 2017 (UTC)

Proposed merge with contactless atmospheric pressure ionization

The contactless atmospheric pressure ionization stub is another variant of electrospray ionization that should be covered in the main electrospray ionization article. --Kkmurray (talk) 16:15, 24 February 2015 (UTC)

Looks like this was done some time ago. Klbrain (talk) 15:38, 10 August 2017 (UTC)

The article is difficult to understand

I think intelligent people wrote it - but for average people it is all quite complicated.

I think it would be better if these large articles would be split-up a bit more; introduce the topics, perhaps split it into subpages or something (like history gets a separate article or so). As it is, I was trying to find a simple answer how the charge is generated/measured, and please ... look at how CONVOLUTED the article is. It's not simple at all. Wikipedia is actually becoming worse in the last years compared to other websites that are shorter and simpler, and to the point - often written for pupils. Wikipedia needs to focus on BOTH simplicity, but also accuracy and details; not on the expense of simplicity though. We don't want wikipedia to become only usable for the super-braineys. 2A02:8388:1641:8380:3AD5:47FF:FE18:CC7F (talk) 23:00, 28 May 2020 (UTC)

Link change

Never edited Wikipedia before so hoping someone else can help out.

Under Ionization mechanism, Rayleigh limit leads to Angular resolution. This isn't helpful and is unrelated to the way the term is used here. Ideally I think this would go to something like "Rayleigh Limit of Charge" (which doesn't exist) or some explanation of the mechanism of coulomb explosions/fission — Preceding unsigned comment added by 108.29.138.204 (talk) 18:07, 23 December 2020 (UTC)