Toxicity is a hazardous waste

Today I came across an opinion article in Chemistry World which highlights what I believe is a very important issue – chemists today are not being properly trained and prepared in reducing toxicity in their methods.

Now, this isn’t only an issue for the green chemists out there – as chemistry undergraduates and postgraduates we’re often completely unaware of how significant the toxicity of solvents, reagents and products are further down the development pipeline of a new material. We’re simply overjoyed if we manage to make the product we’ve been working on for months, and we’re thrilled if it exhibits the properties we’ve been hoping for, such as cancer killing activity. Never do we step back and consider the carcinogenic chloroform we carried out a work-up with, or the explosive starting materials which couldn’t possibly be used on an industrial scale.

And, why would we? I personally only remember the reduction of toxicity being mentioned in specific green/environmental chemistry modules I chose as an undergraduate, which often leads students to only considering these issues in this context. It’s a green chemistry issue, not one to think about in every day synthetic laboratory work, right? I have come across some of these issues in my PhD, as its industrially funded, so I have some appreciation of what solvents might not be desirable/scaleable, but this has only been mentioned in passing, and I’ve had no formal training in this area.

It’s a common problem throughout chemistry degrees/PhDs, which his highlighted throughout this article. Newly trained chemists give very little thought to the toxicity issues of their work and, crucially, it isn’t instilled in them by their professors or supervisors that they should be. Indeed, many supervisors are more interested in results which they can publish than whether or not their methodology would be commercially viable. However, when these students venture out of academia into the world of industry, this is something they’ll very much have to be aware of, and this knowledge would be extremely useful if taught beforehand.

Unless we want to hide in academia forever, it’s about time we opened our eyes to how our chemistry might affect the real world, and whether the work we’re carrying out would be remotely industrially viable. If we came together with engineers, process chemists and industrial chemists, we could all save ourselves valuable time, energy and resources by knowing what our final goals really are.

Of course, chemistry for the sake of chemistry is still something I advocate – we always need to learn more about the world around us – but, if we’re going to have a grand goal for our research, we need to take a step back and no our limits right from the beginning. Only then, will we reach a conclusion everyone can benefit from.

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The Chemistry of Chocolate

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If you’ve got a sweet tooth, like me, you’ll be interested in this article published in Chemistry World this month outlining the chemistry behind perfectly tempered chocolate.

Tempering of chocolate involves the alteration of the crystal structure of the cocoa butter within chocolate to the highly desired V polymorph, and maintaining this high-gloss state means tempering must be carried out every time chocolate is heated and manipulated.

With cocoa butter being able to crystallise in 7 different polymorphs, the temperature of the chocolate must be carefully controlled and held between 27 and 35 degrees Celsius to achieve the desired effect. The process sounds simple, but is in fact terribly tricky.

Indeed, Matt Hartings, who teaches the chemistry of cooking classes at  American University, Washington DC, states that ‘Chocolate is one of the more demanding things chemically to work with.’

The changing crystal structures of cocoa butter explains why chocolate tends to go white over time, as the more stable polymorph VI is formed, which diffuse light and give the paler, less glossy colour. They can even explain how flavour can be changed, as smaller crystals release flavour more slowly into the mouth. It’s then down to the organic molecules within the chocolate to fully define what the flavour will be like.

The article goes on to describe how water emulsions can be used instead of traditional chocolate fillings such as creams and butter to give a creamy sensation in the mouth without taking over the chocolate flavour and giving the chocolates fewer calories.

The chemistry of chocolate is more complex and more intricate than I’m sure many of us imagined, and I found it fascinating reading about the level of control and thought required to make high-quality chocolate.

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VW Emission Scandal – the Chemistry Behind the Headlines

It’s been all over the news this week – Volkswagen have admitted to cheating emissions tests and have recalled millions of cars around the world. Exactly how they have achieved this remains unclear, but stock prices in the company have plummeted and its reputation may never recover from this scandal.

But what emissions have VW been illegally controlling, and what is there to worry about?

Well, this article on the Chemistry World website explains everything.

It would seem that VW have been using sophisticated software to control NOx emissions during testing – leading to up to 40 times more NOx being released outside of testing. NOx nitrogen oxide and nitrogen dioxide – are extremely hazardous to health, and have been linked to many respiratory issues. It can also cause smog and ground-level ozone to be produced, further risking public health.

The production of nitrogen oxides is difficult to avoid – at the high temperatures found within car engines, nitrogen and oxygen in the atmosphere will inevitably react. They must instead by cleaned up post-combustion, which is achieved through the ‘lean NOx trap’, or selective catalytic reduction (SCL). The NOx trap involves using alkali earth oxides to convert the NOx emissions into nitrates, whilst SCL injects urea into the exhaust, which evaporates and reacts with the NOx gases in a zeolite catalyst to form nitrogen and water. Neither method is perfect, as the NOx trap continually uses fuel to keep itself clear, and SCL can fail when cars are stuck in traffic, as the exhaust temperature isn’t high enough for the required reactions to take place.

The unfortunate reality for car manufacturers is that lower NOx emissions generally means lower fuel economy, greater wear and tear on engine parts or higher cost for the consumer, all of which they want to avoid. There’s a real worry amongst experts and customers alike that this will lead to manufacturers building engines specifically to pass lab tests, which might not perform nearly as well on real road situations. This could prove catastrophic for the environment, and will diminish trust completely in the sector, and is unfortunately what appears to have happened in VW’s case.

Obviously, there’s a real need for improved technology in this area, so that the challenge of lowering NOx emissions whilst maintaining a high-quality car can be conquered once and for all.

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Spicing Up MOFs

This article on the Chemistry World website describes interesting new research into Metal Organic Frameworks (MOFs) made from bio-friendly curcumin – one of the ingredients of turmeric.

A MOF is a 3D framework constructed with metal centres joined together by an organic linker capable of binding to 2 or more metals, and their chemistry has really exploded in recent years, with them being peddled as solutions to a variety of the world’s main chemical problems, such as hydrogen storage and the capture of carbon dioxide. Indeed, we have a large MOF research group right here in Nottingham focusing on such applications. MOFs for these uses typically need to have high porosity and surface area, and measuring this is often an early indication of their performance.

However, many of the highest performing MOFs are constructed from expensive rare metals or petrochemical-derived ligands. This limits their eventual applications as, if they’re to compete industrially, they need to be cheap and sustainable. A team of researchers led by Guangshan Zhu from China may have overcome this in their construction of a MOF designed to deliver drugs.by using the naturally-occurring pigment curcumin, which has anti-cancer properties itself.

The group used biologically-friendly zinc as their metal centres, with curcumin ligating between them. The resulting framework was found to be highly porous, and initial studies have shown it is able to deliver ibuprofen into the body. What’s more, the MOF degrades under biological conditions to also deliver curcumin, which means both drugs can be delivered effectively using this framework.

This really is exciting news for both the MOF and science communities, as it could pave the way for a new method of drug delivery into the body which has real potential for the future.

You can find the original research article here on the Royal Society of Chemistry website.

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With great blogging power… comes great responsibility

Click the link for a great article from Chemistry World, which discusses some recent news of fraud and false data in chemistry journals.

A major talking point in the article is the recent outrage regarding a paper published in Organometallics by Reto Dorta. I was aware of this myself because my supervisor found it so shocking that she e-mailed us all with the supplementary information so that we could witness it ourselves. It really does beggar belief – somehow the paper had been published online, even though this line was present underneath the experimental for a particular compound in the supplementary information:

“Emma, please insert NMR data here! where are they? and for this compound, just make up an elemental analysis…”

This discovery has sent shockwaves around the chemistry community, and has no doubt shattered Dorta’s reputation. It would be a little embarrassing for the editors if it was simply a case of missing NMR data which the author had forgotten to include, but the apparent admittance of falsifying elemental analysis data is very serious, and will call into question all of Dorta’s results and publications.

Not much more can be said as Dorta has refused to comment further and the issue is still under investigation, but whether there is any sort of reasonable excuse for this or not, journals will no doubt seriously question any manuscripts submitted by him and his group in the future. It is unfortunate for his students who may have to carry this with them throughout their careers, even though their data might be impeccable.

The article goes on to describe cases of altered TEM images and doctored NMR spectra, with peaks being erased entirely in order to hide them.

These examples all point to a worrying trend of pressure for results and publications leading to students, post-docs and academics feeling the need to falsify data. In a world where research jobs are getting more and more competitive, pressure to publish and to be more known to the academic community is greater than ever, This is no excuse for producing false data, but does offer some sort of explanation.

The article rounds up by calling into question the role of popular chemistry bloggers in exposing such manuscripts before they can be properly investigated. Students such as Emma, mentioned in the quote above, have their reputations destroyed beyond repair before they can explain or defend themselves, and guilt is presumed before the incident has been looked into.

While I appreciate avid chemistry bloggers discovering these issues and bringing them to attention, I do agree that the proper channels should be used and these cases should be investigated thoroughly before a possible innocent name is tarnished forever. Sometimes, bloggers are so keen to reveal the truth (which is perfectly understandable) that they may forget whose lives may be affected by the aftermath.

Now, the pressure is on editors and referees of these journals to check papers thoroughly, to ensure images aren’t tampered with, data isn’t left out, and that embarrassing slip-ups in supplementary information are dealt with before they go to publication. It’s worrying that these papers have been slipping through the net, and more needs to be done by people at all levels, from the academic instilling good ethics into their students, to the editors putting these manuscripts in for publication.

If you’re interested in this topic, you can find an article demonstrating how publishers can detect falsified images on the Chemistry World website, here.

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