Osmium, Osmium, Everywhere

I don’t use osmium much. In fact, I don’t think I’ve ever used an osmium compound, although I’m fairly certain I once picked up a bottle of OsO4. The sum total of my osmium knowledge consists of knowing OsO4 (osmium tetroxide) is quite toxic. However, it now appears that if I ever do have need of osmium, I can just go outside and grab some. A group of researchers has studied the distribution of osmium across the globe and found that a surprising amount of the element is now present in rain, in snow, and in our rivers.

Osmium naturally occurs along with copper and nickel and is a by-product of their manufacture. But all this osmium in our water system comes from another source – during the production of platinum – much of which is used for the manufacture of automotive exhaust catalysts. During the process of refining platinum, the ore is subjected to high temperatures to burn out sulfur impurities. But volatile OsO4 is also produced and it has been spreading. According to the researchers, the levels of osmium are still small enough that this may not be a health concern, at least so far….

Russia and South Africa produce over 90% of the world’s supply of platinum and neither country regulates these osmium emissions. The demand for platinum may have dropped temporarily due to the worldwide plunge in car and truck sales, but it will return eventually. In addition, the current generation of hydrogen fuel cells also depend upon platinum for their electrodes, which means the rate of osmium release will probably only increase in the future.
---------------------------------------

Since I did mention platinum, I’ll point out that this week’s Chemistry In Its Element podcast covers platinum and its chemistry. Podcasts for many other elements are also available, including osmium, so feel free to see if your favorite element has been discussed yet.

Error Analysis

I just ran across a discussion of errors, R values, and Gaussian distributions over at “The Curious Wavefunction” blog. Being able to estimate, understand, and interpret sources of experimental error is perhaps one of the most important skills you can develop. It can save your career, for one thing. I once attended an in-house presentation by a coworker who felt the need to explain what he was currently doing for the company. The coworker presented the following chart to summarize his data.

No, I’m not giving away valuable corporate data here. This chart is just something I whipped up using a random number generator, which, as it turns out, makes it a damn good representation of what we were shown at this presentation. Seriously. Members of the audience began looking at one another, wondering where this talk might be heading. Basically, the black dots represented the data under standard conditions (obviously noisy data), while the red dots represented the data after changing the variable of interest. After spending ten minutes describing the experimental procedure, he summed up his results by comparing the average of the standard data (black) with the average of the four red data points and then had the audacity to conclude that the variable did indeed have a small effect. Audacity is probably not the correct term here since that implies a certain knowledge on the part of the speaker as to the outrageousness of his statement. He was totally surprised by the general outrage displayed by certain members of the audience and the discussion became rather heated, which is rare at this company. Eventually, he countered with “Well, this is the data I got. What else can I say?”

A simple “My data is inconclusive” would have sufficed.

By the way, the guy no longer works at this company. To be honest, he left of his own accord and jumped to a new company, one which is actually in better financial shape than this one. He’s actually a nice guy and I wish him luck, especially since I may be calling on him for a job some day.

Miscellaneous Friday

I was temporarily unemployed for a couple of months at the end of last year, but I never considered expressing my disappointment in the same manner as this unemployed chemist. I cannot imagine this sort of thing looking good on a resume, but I’ve been wrong before.
------------------------------

Now I need to rant a bit.

Yesterday, I needed to download a software driver for a National Instruments GPIB interface card from the company’s website. It should have been a quick 50K download at most, requiring only about a minute of my “valuable” time. Annoyingly, the entire process took 45 minutes -- time that could have been better spent searching the Web for more antics by unemployed chemists. First, the website required me to register before downloading the file. Swine! I already paid for the hardware! Forcing me to register just to download the accompanying software is sooooooo last millennium. Check out your competitors’ web sites. And what’s with all the “required” questions? I can understand asking for my email address so I can be spammed, but do you really need the name of my firstborn?

After being granted access to the download page, I discovered the “driver” file was over 108MB. WTF??? Are they sending an operating system along with the driver? Please: make non-essential utilities a separate download. If I had been downloading this from home, it would have not been that big a deal, but my company’s firewall insisted on scanning the entire 108MB file for porn and viruses, and the scanner is not very fast.

Anyway, I feel better now.
-------------------------------------------

Our governor here in Michigan has been desperately trying to make the state less reliant on the automotive industry. For the past few years, she’s been pushing to make Michigan the biodiesel capital of the world. Last year, she was promoting solar cell technology, partly since we have several companies (Dow Corning, for example) which are in the photovoltaic arena. And yesterday, she announced a program designed to (hopefully) make Michigan the nation’s leader in the manufacturing of lithium ion batteries for electric and hybrid cars. $300M in tax credits, among other things, with an eye on grabbing a piece of the $2 billion earmarked by the federal government for advanced battery projects. Basically, she want s Michigan to be the "alternative energy" state -- not to be confused with the "alternative lifestyle" state. According to Governor Granholm, “We are going from rust to green.” Will this work? I don’t know, but all three areas have need of inorganic chemists and that’s definitely okay by me. All the chemistry based jobs listed around here are pharmaceutical based.

PAHs -- Not Found at Your Local Health Food Store

Yesterday, my family and I returned from a five day visit with my parents in southwestern Missouri. This, of course, means I’ll be spending most of today actually recovering from the “vacation”. You have to love how that works. The travel part of the trip went smoothly, thankfully. No one got sick, the plane was on time, and there were no traffic problems; so we arrived in Springfield at the appointed time – only two hours before the tornadoes passed through. Ah, the joys of traveling!
-------------------------------

Several of the houses in our neighborhood (not mine) have asphalt driveways. They’re a popular option since they cost less to build than concrete driveways, but they require a yearly application of sealant for protection from the elements. Apparently, that sealant contains polycyclic aromatic hydrocarbons (PAHs). PAHs (sometimes referred to as polynuclear aromatics or PNAs) consist of three or more fused aromatic rings (anthracene is one example), and as you might guess, are not always the most healthy of chemicals. And according to a recent study, the PAHs from these sealants are making their way into the water system. Since many PAHs are carcinogenic, you can kind of understand the concern.

As an inorganic chemist, I never really had much contact with PAHs, but I did run into them a few years ago while working on reforming catalysts. These catalysts convert air and hydrocarbons (like gasoline or diesel fuel) into CO and H2, along with smaller amounts of methane. I began to notice the buildup of an orange/yellow/brown solid all throughout my vent lines, sometimes as far as 10 feet away from the reactor. This necessitated not only the periodic replacement of these lines, but also, to my great joy, a massive clean out of my mass spectrometer. An NMR revealed this solid to be a mixture of PAHs. A little research revealed that under hot (700C), reducing conditions, methane forms PAHs quite happily. A little more research revealed that PAHs have been found responsible for the higher than usual rates of testicular cancer among workers in the metal cutting industry. Cutting fluids contain PAHs, and wearing clothes which are constantly soaked with them was found to be a bad idea.

I elected to start wearing gloves. Anybody else have any interesting stories about carcinogenic materials with which they’ve worked?


On the lighter side, David Bradley has managed to convince a few people to reveal some of the more stupid things they have done in the lab. .
-------------------------------

I’ve decided to add a verification check in the comments section. I apologize for the inconvenience, but this blog seems to have been targeted by a bot which feels the need to leave garbage in the comments section and I’m getting tired of deleting it. Hopefully I’ll be able to drop it again in a couple of weeks.

New Chemistry Game!

If you enjoyed playing the Spectral Game , here’s another one for you. The people over at Useful Chemistry have created the Chem Tiles Game. If you enjoy Newman projections, Lewis structures, and nomenclature, this is the game/quiz for you. Reminds me how much organic chemistry I’ve forgotten since my sophomore year.

Also, I congratulation the Michigan State basketball team on their amazing season. The Spartans went a lot farther in the tournament than most prognosticators had predicted. Unfortunately, they appeared to run out of gas last night when they were pretty much pounded by North Carolina. I’m not a particularly big fan of college basketball, but I can still appreciate the tenacity of underdogs.

Potassium Ferrate - The "Green" Oxidant

K₂FeO₄ is pretty cool stuff. It’s relatively easy to make, has a nice purple color, and it’s a stronger oxidant than permanganate. Oh… and it reacts with water. You can dissolve it in water, but unless the solution is fairly alkaline, it will decompose rapidly, generating O₂ as a product. It is being investigated for use as a cathode material for so-called “super-iron” batteries (using zinc anodes) and for its use as an oxidant for organic reactions. But its biggest claim to fame is its role in the area of water treatment.

A description of the methods used in water treatment facilities is too large to describe here, but one common method is flocculation, a technique used by both the Egyptians and Romans. The addition of alum and/or iron salts to the water to be treated, along with some lime, results in the precipitation of Al(OH)₃, Fe(OH)₂, and Fe(OH)₃. As these precipitates sink, they drag undesirable particulate material along with them, resulting in cleaner water. Chlorine (or chloramines) is then added for disinfection purposes. Chlorine treatments are very successful at removing harmful bacteria, but there has always been a concern that its reaction with organic material still present in the water might form harmful compounds.

This concern has been confirmed by a recently completed 10-year study. Michael Plewa, a geneticist at the University of Illinois, has quantified the toxicity, genotoxicity, and carcinogenicity of these disinfectant by-products (DBPs) using a mammalian cell line specifically developed for this study. He found not only that these DBPs are harmful, but that the degree of toxicity can depend on other factors. For example, it was found that water which contained bromine and iodine (seawater or aquifers associated with ancient sea beds) generated even more toxic DBPs. And DBPs which contained nitrogen were more toxic, genotoxic, and carcinogenic than DBPs which contained no nitrogen.

Plewa is especially concerned with swimming pools and hot tubs, which he refers to as DBP reactors. Organic material from swimmers -- sweat, urine, sunscreen, cosmetics, as well as some disgusting stuff – sits in contact with the chlorinated water for long periods of time, generating DBP levels up to ten times higher than drinking water. This may explain the higher levels of bladder cancer found in people who spend a lot of time swimming in pools.

This is where potassium ferrate comes into play, at least for water treatment applications. If all the organic material could be removed prior to the application of chlorine, then DBPs couldn’t form. So instead of adding iron salts and lime to the water, one could just throw in some K₂FeO₄. Ferrate would chew up the organic material in the water and then decompose to form the Fe(OH)₃ precipitant which removes the particulate matter as usual. And unlike chlorine, you cannot really add too much ferrate – you’ll just end up with more harmless Fe(OH)3. For this reason, ferrate is often referred to as a "green" oxidant. And once the ferrrate has done its work, you can add chlorine without the fear of forming DBPs.

The use of ferrate for this purpose has been investigated for over thirty years. One of the big drawbacks has always been the cost of manufacturing K₂FeO₄, but last year Battelle announced a lower cost method for its production, so it may yet come to pass.

Chemists vs. Engineers

One of the guys in our group at work is a co-op student from a local university. As part of his engineering degree, he spends every other semester working in our lab receiving a massive dose of industrial reality and forced indoctrination into the world of engineering. His current stint ends this week, so yesterday he presented a summation of this semester’s work to the group. It wasn’t supposed to be a big deal -- a quick, informal 15 minute talk -- but the head of our division (3 or 4 steps up the corporate ladder) decided she’d attend the presentation, and the intensity level ratcheted up a notch or two. Of course, the division head ended up asking all the questions while the rest of us just smiled and watched the student sweat.

The questions were all good, although many of them concerned engineering protocols and methodologies of which I am woefully (and thankfully ignorant). Unfortunately for the student, there wasn’t much data with which to defend himself, due to situations mostly beyond his control. There had been a two month delay in getting the equipment up and running, due to the time required to implement various safety features in our labs. For some unfathomable reason, the safety guys had been (and still are) very nervous about the prospect of piping pure hydrogen and carbon monoxide throughout the building. They take safety much more seriously in industry than they do in graduate school, where safety protocols often involve nothing more than wearing safety glasses and not eating food in the lab, both of which are largely ignored anyway.

Anyway, the presentation ended, 90 minutes later, with very little blood spilt, and with the conclusion that several of the test variables would need to be quantified (by me, unfortunately) before the student’s return in July. So less than two hours later I was attending a meeting to discuss the quantification of these variables – a meeting attended by myself and 3 engineers. I recall the various good-natured rivalries between chemists and chemical engineers back in school, but we all generally thought alike. But these guys are process engineers. Acronyms like DFSS, MCE, Green Y, Red X, and MFEA were flying fast and furious. Process engineers have a very different way of approaching these types of problems. As a chemist, I just want to understand which variables are of interest and how they affect the final results. Process engineers are more interested in maximizing the reproducibility and repeatability of those variables.

For example, let’s suppose I were tasked with improving a known chemical synthesis. I would try to understand the chemical steps involved, I would isolate the important variables, and I would systematically make changes to the procedure to increase the product yield. Process engineers would be more interested in making the prep more reproducible and operator independent (meaning that everyone who followed the written procedure would get exactly the same yield). As a chemist, I might try different methods of cleaning/drying/purifying the starting materials/solvents. Process engineers would rather write solvent specifications and protocols to ensure that the level of impurities were reproducible, although not necessarily lower. They would sacrifice yield for the holy grail of repeatability. In their world, attempts to maximize yields shouldn’t occur until later. Process engineers feel this mindset allows them to solve chemical related problems without having to actually understand the chemistry.

In yesterday’s meeting, these engineers actually wanted to devote almost half of our allotted time just verifying the repeatability of our test as a function of which of us was actually running the test. An analysis of the test variables in question would be squeezed in later. It’s going to be a long three months.
-----------------------------------------

Note: I'm not trying to rag on process engineers too much here. Their techniques are exactly what you need when you are trying to design and operate an industrial process. I would fail miserably were I to ever attempt such a thing. But these techniques don't work so well in the research arena. There is a reason why advanced development groups and product development groups are generally kept apart.