Letters: March 2020

Calibrating expectations

Tim Wogan’s article about calibration in x-ray photoelectron spectroscopy (XPS) gives a very misleading impression of one of the most widely used methods of surface analysis (Chemistry World, March 2020, p10). XPS is a tool that is essential to many aspects of industry, including corrosion, semiconductors and catalysts, as well as an enormous amount of more fundamental research, as the number of papers published using the technique demonstrates.

As presented, the reader may be forgiven for believing the technique is fundamentally flawed, ignoring the fact that a wealth of information is available regardless of energy calibration. For many applications, even on insulators, energy calibration is not essential to the analysis; XPS gives quantitative compositional information and can identify chemical environments from relative peak shifts.

Every experienced user knows that it can be tricky to calibrate XP spectra. The ‘adventitious carbon’ peak is a convenient but sometimes misleading internal standard. A competent user will always seek an alternative calibration point and always include the information about the calibration applied in any report or paper that uses the data, in line with ISO standards (see for example ISO 19318).

A very important point the article does raise is that advances in technology have created systems that record, and in some cases analyse, spectra almost automatically. This can lead to inexperienced users reporting spectra they do not properly understand. This problem that can arise with any technique that has become automated, not just XPS.

At HarwellXPS, the EPSRC’s National Research Facility in XPS, we are well aware of this issue and have been working with the community to provide free training courses in XPS acquisition and analysis for beginners and experts alike. We also offer free advice on data analysis from our centre in the research complex at Harwell, UK, as well as a new Youtube channel on which we are building a library of short, accessible training courses.

Our next two day training session will take place at the headquarters of the Society of Chemical Industry on 14-15 April 2020. Interested readers can visit harwellxps.uk/events to reserve a place.

HarwellXPS

Wide applications

Kristy Turner makes some interesting observations about the reduction in applications to study chemistry at university (Chemistry World, February 2020, p5). We had a similar issue a few years ago when I was head of chemistry at Newcastle University, and resolved it by firstly recruiting an excellent outreach officer who proactively interacted with over 150 schools and really got the message out there. On open days we highlighted the number and variety of job opportunities available to chemists, particularly in discussions with parents (who were in many instances paying for the courses and remain significant influencers). The RSC helped with their survey on the size of the UK chemical-related industry. We also improved our facilities to really impress teachers and prospective students alike. Our numbers doubled.

What we couldn’t compensate for was the drastic decline in laboratory facilities in schools, and the associated uninspiring hands-on experiments that take all the fun out of the subject.

Mike Green FRSC
Newcastle, UK

Make it LaTeX

The article ‘How long do scientists spend formatting manuscripts for publication each year?’ (Chemistry World, December 2019, p13) was a disappointing reminder of days gone by when preparing papers for submission was a soul-destroying secretarial task, and scientists were not encouraged (nor even allowed) to use the typewriter.

I retired a while ago, but had to return to this game when pressed to submit an article to a journal way outside my field. While the journal in question accepts LaTeX documents, they supply neither a template nor even the macro package that’s necessary for handling numerous references. The alternative was to use a commercial word processor.

Following common practice I use a bibliographic database system that downloads references straight from the web. The software provides a set of journal-specific plugins that format references, which are then inserted into your word processor document via an operating system software link. I thought such links had died out years ago; they tend to be flaky and the one I used kept breaking, for example when I saved successive drafts under different file names.

When using LaTeX, your bibliographic database outputs a plain-text file in a standard format. You mark up references by typing the citation key, and a LaTeX macro package handles the rest. Numerous journals provide this function as a macro, in a complete submission-ready template. Besides literature citations, references and cross-references to tables, figures and document sections are coded and modified in user-readable form; the compiler flags up any errors.

There’s a plethora of material online about how to use LaTeX. This is just as well because, while it isn’t hard to get started, LaTeX can be maddening at times.

Christopher R Lee MRSC
St Martin de Bréthencourt, France

Stand-up comics

As a counter point to the letter about the recently concluded series of comic articles (Chemistry World, January 2020, p4), I was delighted to see this medium used last year and eagerly awaited each instalment. I was disheartened to find its absence in January along with the ‘On the spot’ cartoon strip that does a great job of getting people thinking about safety issues.

I run a comic creators club at my university, which gets students engaged in the various disciplines involved in the comic making process. We often see how the mix of art and writing can help both readers and creators comprehend a subject more completely. The first comic book, the Glasgow Looking Glass, was published in 1825, and since then comics have been used to convey complex information, social commentary or entertainment to a general audience in an especially relatable way. They also do a great service to those who struggle with lengthy text. A comic panel is simply a figure or diagram that illustrates a scene. Yet the stigma of ‘funny books are just for kids’ is hard to shake.

I applaud Chemistry World for using the form so well over the course of the year; the excellent research and scripting efforts were clearly on display and the varied artwork was dynamic and engaging. I hopefully look forward to the return of comics in future issues.

Ross McFadzean AMRSC
Glasgow, UK

Editor’s note: Happily, ‘On the spot’ returns on March’s puzzle page