Citations taken from JOC, 2007, 72, 3981-3987, by Bruce Ganem and Roland R. Franke.
Where observation is concerned, chance favors only the prepared mind. -Louis Pasteur
Necessity is the mother of invention. -Anonymous Latin saying
Git ‘er done! -Southern country male expression (recently popularized by Larry, the Cable Guy)
That’s hilarious! I’m not sure, but this may be the first reference to a Comedy Central character in an ACS publication. Well, I’m fairly sure.
OK, it’s time to poll the thundering masses. If you had to make a choice between subscribing to Beilstein or SciFinder for general access to the chemical literature, which would you take?? Let’s say that you needed to find compounds, articles, procedures, or see what the IP picture looked like. Forget TSCA registry and nomenclature services for purposes of this query.
Obviously, each has strengths. But if you had to take a side, what service would you take and why??
A few of us took the course offered by Scientific Update called Secrets of Batch Process Scale-up. It is a 2 1/2 day whirlwind of slides and class exercises. In my estimation it is a very worthwhile course for process chemists and I certainly got a lot out of it. It is taught by Francis X. McConville who is a gifted teacher as well as experienced process guy. He is the author of “The Pilot Plant Real Book“. Th’ Gaussling is pleased to toot this horn because this class is a great example of how such things should be done.
Most chemists know that the changes that occur in scale-up come in large part from differences in heat transfer and mixing. There are certainly other contributions, but these are the big issues. The parameter that is viewed as most useful in mixing is the mixing energy parameter, Ei, which has units of watts/kg soln. Many of the parameters are subject to large exponents, so one needs to be cautious about how well your intuition works in this non-linear space. The point is, eyeballing the mixing speed in your benchtop apparatus is almost certainly inadequate in comparing conditions in scaleup.
Ei=(Np*N^3*d^5)/V, where Np = impeller power number (contains density and power units), N = rotational speed (1/sec), d = impeller diameter (m), and V = volume (cubic meters). Because the mixing energy varies as the 5th power of the impeller diameter and the cube of the rotation speed, small changes in agitator speed or impeller diameter can result in large changes in power demands on the agitator motor. Obviously, one should be cautious in hand waving comparisons between your 1 liter kettle and that baffled 500 gallon pot in the plant.
If you were to look at me, Th’ Gaussling, as a chemist, you might suppose that the biggest obstacle I or other industrielle Ubermenschen faced in our exalted careers related to the transmutation of matter. Easy conclusion. To civilians who can barely mix Ovaltine in their 2 % milk, making a metric ton of sensitive, high value-added product to specification from dirt and motor oil would seem daunting. And to be sure, it is. But it’s all in a days work. (wink wink, nod nod)
However … (dramatic pause) … chemistry is easy when compared to other issues in the fabulous world of work. The truly challenging part of work is having to deal with difficult people. Overexposure to toxic personalities can cause chronic chafing, distress, or worse.
It is amazing how outrageous some people can be. A while back we interviewed a swaggering gasbag who proved to be 4 or 5 standard deviations from the mean in his cockiness. The word that comes to mind is sphincter. I hadn’t seen this chap in nearly 10 years. But in the first 5 sentences of our brief reunion he had already established his career and organizational superiority. It was only partly in jest. Then to top it off, he declared after 3 minutes of awkward discussion and glances at the watch that he had no more time to talk. No doubt in his absence there would be utter chaos back at work.
Afterwards I stood there in awe of the natural phenomenon I had just witnessed. What do you do with such people? We’re not supposed to shoot them. This fellow is one of those alpha males who consume all of the air when they walk into a room. If he isn’t able to dominate the situation, he just leaves. When he walks in, the room lights up due to all of the sunlight shining out of his arse.
When asked about the hardest group of people to manage, this chemical engineer said without hesitation “Ph.D. Chemists”. He said that he greatly preferred to work with hourly plant people and that Ph.D. chemists tend to pose problems that are more intractable than plant operators. Chemists on salary tend to argue and hourly folk just shrug and do what they are told. Damned right, bucko!!
If you have ever met a company president, you may notice that they are peculiar sorts who seem to be cut from a certain kind of cloth. Those who aspire to such elevated status have to rework themselves from mere management soldiers into an executive. Executives are beings who become organic manifestations of the company. When the CEO of NewCo visits, later you would say that “NewCo was here”. And you’d be right.
It is not enough to be merely competent to be a company executive. Luck, organizational skill, and a bit of ruthlessness are the stars that have to line up to get to the top. Ruthlessness by itself usually isn’t enough.
>>>End Rant Subroutine<<<
I’m having to search far-off China for raw materials much more frequently these days. The availability of many US manufactured chemicals is slowly falling off. Especially for really basic materials. I’m not referring to those mundane elements like iron or soda ash or copper. No no. materials from the folds and deep recesses of the periodic table. Elements with relativistic electrons. There are short term economic pluses and minuses to this migration of manufacturing.
On the plus side, Chinese prices are often, well, quite low. Even with multimodal freight charges from across the Pacific. When you pay peasants fresh off the farm $40/month (or whatever insane wage it is), you can undercut nearly everyone in pricing.
But there is a down side to spot buying from China. This is to be distinguished from contract purchasing. In contract purchasing, you work out an agreement with a manufacturer and you lock in quality, price, and delivery in exchange for long term business. Spot buying, however, is much more risky. What do I mean by that?
Spot buying is where you find a merchant supplier who can furnish material without the fuss and obligations of a contract. Either they have it in inventory, they can source it quickly, or they themselves will make it pronto. A supply contract has to be managed or enforced. For raw materials that are less than critical, finding a spot supplier makes sense.
Locating a spot supplier in China that you can trust is problematic. I’m not suggesting that Chinese suppliers are dishonest. I am saying, however, that culling out a supplier from a list of unfamiliar names from the other side of the world without the benefit of a site visit or a Dunn and Bradstreet report can be risky. Spot buying anywhere is risky, but when it is complicated by international transactions, the risk multiplies a bit.
It is relatively easy to find contacts on the web that will reply to an RFQ (request for quotation) by email (often “hotmail” accounts) and make an offer. But what you find is that you may be in contact with an agent of some description in an office suite in Shanghai, far from the factory. Indeed, it is hard to tell just what the relationship is between the factory and your contact. To salve over some of the uncertainty westerners may have, it is common now for these web contacts take on western names.
Brokering goods is common in some parts of the world and scarce in others. In the USA, brokering chemicals is fairly uncommon. Most US companies prefer to do bulk business with the manufacturer or a catalog house. Sigma Aldrich, for instance, is both a catalog company and a manfacturer of bulk and semi-bulk materials. Purchasing from a broker (as opposed to a distributor) rather than the manufacturer will add costs to the transaction. A broker is someone who connects the purchaser with the supplier. Usually they perform drop shipments to the purchaser directly from the manufacturer. A broker is a sort of “free agent” sales group.
I have found that there is a greater reliance on brokering in Asia and to a lesser extent, the EU. The internet has made life a bit trickier for brokers in that a search for manufacturers is a lot less painful than it used to be.
A company will work through a broker for several reasons. Brokers are usually specialists, so a company can tap into considerable expertise in supply chain management. And, the broker only gets paid if they find a qualifying supplier, so a manufacturer could conceivably keep the head count down. Brokers might be better at the intricacies of negotiation as well. There are a lot of tough guys running companies out there who are actually poor negotiators.
These agents seem to work in organizations that carry on the sales and marketing activity for a factory or a series of factories. In addition to unfamiliar business practices, there is the matter of payment. Many Chinese companies want prepayment- they do not automatically offer 30 days net. This makes company controllers and project managers nervous. Since this is an international transaction, customary business laws covering remedies are not applicable. In other words, you can get royally screwed. But from their perspective, it is the same issue. So settling into a supply relationship can take time.
As everyone knows, the price of gasoline in the USA has been steadily marching up into the low US$3.00 per gallon range to achieve all-time high pricing. Reliable sources state that the price run-up is due to simple shortage of supply. According to testimony from energy analyst Paul Sankey of Deutsche Bank, the US refines 17 million barrels of petroleum per day against a demand of 22 million barrels per day. An interesting analysis can be found at the Oil Drum.
We are in a very precarious position here. An oil shock caused by a catastrophic loss of refining capacity will result in a wild price spike (some estimate US$100/bbl) while gasoline is in the mid $3.00 range already and a major perturbation to the economy- or worse. Unfortunately, we are bogged down in the ill-conceived GW-II, the second of the energy wars.
A sad day it will be when the last image is captured on a photographic emulsion. The transition from chemical photography to digital photography is well underway. Indeed, it is clear by a simple visit to a big box store that the amount of shelf space given to film cassettes vs digital cameras & accessories is rapidly tipping in favor of the digital. Consumer demand is well past the cautious early-adopter stage in its evolution. Many people are several generations into digital photographic equipment.
I own a low end Hewlett Packard Model P.O.S. digital camera with a 4.1 megapixel chip. I suppose I’d be happier with it if it still worked. Even when it did work, it was a P.O.S. As long as nothing moved, the image was sharp and the colors were true. But given the slow shutter response, the slow shutter speed, and the heavy power demand on the battery, using it was a maddening experience. Evidently a capacitor has failed because the flash fails to fully charge.
Printing is still a chemical process, one way or other. Printing consumables like paper and inks/dyes are a major cash cow for all of the manufacturers of printers.
I do not consider photocopier xerography to be strictly digital imaging. I consider it to be a form of chemical photography because, despite the use of computer driven laser arrays and electrostatics in image formation, there remains a deep and intricate art in the chemistry of the toner composition. I have actually done some color toner R&D and can attest to the high art required in that field.
Th’ Gaussling laments the demise of chemical photography, at least on the camera side, because of the highly advanced color chemistry knowledge that will inevitably be lost. Lost because skilled practitioners in the manufacture of color films will retire, labs and plants will be shuttered, and the use of color films will dwindle to low volume. Soon, say 20 years from now, only eccentric purists and “hobbyists” will capture images on emulsions. Drug stores will sell off their developing equipment to people who drive VW Beetles in Guatemala and fill the space with racks of diabetic candy, NASA diapers, and $4.99 DVDs.
Soon, the experience of dodging a poorly exposed image under the projector, swishing print paper in developing solution under red light, and experiencing the magic of seeing an image appear will be lost to future generations. The smell of acetic acid and the darkroom clutter of wet film hanging from string will be but a distant memory of the “old ones”.
When I get to the nursing home I’ll regale my fellow geezers and codgers with harrowing tales of nights spent outside at the telescope shooting time exposures with hypersensitized Tri-X. They’ll nod off in boredom and I’ll switch on a Star Trek rerun and fall into a deep slumber while Kirk and Spock contend with the Tholian Web. ZZzzzzz.
Over the years I have interviewed many hopeful candidates for a position of entry level BS/BA bench chemist in a synthesis lab. Recently, I have interviewed a couple of candidates for synthesis chemist position and have refreshed myself with the challenge.
It is surprisingly difficult to find and hire a decent candidate for position as a synthetic chemist at the bachelors level. In fact, I am having trouble finding fresh BS/BA graduates that can show me the mechanism for the acid catalyzed hydrolysis of an ester, or can suggest a reagent for the reduction of benzaldehyde to benzyl alcohol. These are fundamental transformations and a BA/BS in chemist should be able to go to the board and noodle through a little bit of arrow pushing.
Most of the candidates sent in by our favorite temp agency are analysts either by temperament or by experience. Granted, analysts may be the meat and potatoes of the temp chemist trade. But what astonishes me is the small number of candidates out there with more than 2 semesters of organic chemistry and an even smaller number with any inorganic lab experience at all.
In previous searches we have looked for BA/BS people from an ad in C&EN. Rarely did we find that students had taken an advanced organic class/lab, let alone an organic qual class. I know that such classes are offered out there. Are all of these bachelors level students who take advances coursework going to grad school or med school? Maybe most of them are.
As a former supervisor of undergraduate research, I am tickled pink that bachelors students are getting experience with advanced equipment, but we still need to graduate people who can make a target molecule and fish it out of a product mixture. I’m glad that Bobby or Suzie can do capillary electrophoresis or use a peptide synthesizer to make a decapeptide. I just hope that a few students are learning how to take a substrate through at least two steps of a literature procedure synthesis and then purify by fractional distillation or a recrystallization. Furthermore, I hope that chemistry departments are still hiring an occasional mainstream organic chemist or inorganic chemist who can pass along lab techniques.
Perhaps the bachelors organikkers are drawn to grad school for advanced education. That is what I did. But I’m still shocked by the number of bachelors level candidates I see that show very little retention of organic concepts, apparently the result of disuse in their junior or senior years.
Part of this problem might be geography as well. My region does not have the industrial legacy that other regions have. Perhaps the situation might be different in NJ, CT, or TX.
Sorry. I’ve filled the position, so don’t send a resume.
The issue of melamine in pet food has come up again as more lots of pet food are found to be contaminated with it. At least a few news outlets have published a proposed reason for this contamination by a monomer from another industrial sector. Melamine is very nitrogen rich- 6 equivalents per mole- so if you spike grain products with it you can cause the nitrogen analysis to read higher than it normally would. Protein content is one of the factors in the pricing of animal feed, so an additive that would contribute to an uptick in nitrogen content would raise the price or even make a non-saleable lot of feed qualify for sale.
The nitrogen test that most people think of is the Kjeldahl test. It is a digestion-distillation-titration method that affords total nitrogen. This test is still in wide use and is inexpensive to conduct. A friend who has an Ag Lab still does the test on a bank of burners in his lab for total nitrogen in feed samples.
The practice of adulteration of foodstuffs not limited to China. As an undergraduate I worked in a dairy processing plant lab and we had to screen for several kinds of mischief. Dilution of milk with water is an old trick, given that pricing is on a per pound basis, so we had to test each raw milk tanker for total solids content. We also tested for pH and temperature.
Neutralization of partially fermented raw milk with NaOH was also practiced at one time, so we taste tested each tanker as well since neutralization could not mask off-flavor. Finally, we had to carefully screen raw milk for residual antibiotics. Mastitis is an inflamation of the udder and has many causes. One aggravating factor is the common practice of milking ol’ Bessie three times a day. A sick cow has to be taken off-line to recover. This reduces the productivity of the cow.
Farmers were often tempted to give sick cows a big jolt of antibiotic and get her milking again before the time needed to fully recover and clear the system of antibiotic. This could lead to antibiotic contamination in the tanker. We performed two tests for penicillin at our plant. The microbiological test we performed was the Bacillus stearothermophilus disk assay. The other was a radiological assay called the Charm test utilizing C-14. This test could be performed in 20 minutes, whereas the B. stearothermophilus test took 6 hours or so. The newer Charm tests now take only a few minutes.
Residual antibiotics found in dairy products on the Grocers shelf could put a dairy out of business for repeated infractions. The state health authorities took (take) a dim view of penicillin in milk.
Th’ Gaussling is getting an eye-opening introduction to the maddening world high purity products and trace element analysis. Multiple analytical methods seems to translate to multiple layers of confusion. I’m a 3-Nines pilgrim in a 4-Nines land of opportunity. Ya picks yer analytical method and ya stays with it. Cripes.
It’s an alphabet soup of methods- GDMS, ICPMS, and XRF. Gonna hafta crack the books again. Watch out. That shadow darkening the library stacks could be cast by a trustee of the f-block.
Lamentations on Chemistry 