Author Archive
Cargo cult science in the Gulf, news at 11
by Chemjobber on Jul 20 2010 (13988 Views)
Credit: WKRG/Mediaite
The Gulf oil tragedy has already shown the ignorance of some reporters about chemistry. However, a Mobile TV station and their chemist has taken it to new heights when they blamed the oil spill for (likely) bad glassware.
WKRG is a local TV news station in Mobile, Alabama; they sent intrepid reporter Jessica Taloney to collect samples of local beach water. (See video of story below.) They asked a local lab to analyze the samples for oil and grease; the lab owner and analytical chemist, Bob Naman, suggested that the level of oil and grease should be pretty close to 5 ppm.
Of course, all the samples showed the presence of oil and grease, with amounts up to 200 ppm. While these results are not particularly surprising, the result of one sample was not obtainable because the chemist claimed that the sample exploded during the extraction. Rather than blame the broken separatory funnel on a star crack or a lack of venting, the chemist said that “We think that it most likely happened due to the presence of methanol, or methane gas, or the presence of the dispersant Corexit.”
No. This is just wrong. Having actually shaken separatory funnels full of mixtures of water and flammable solvents (including methanol!) on a daily or weekly basis for about 10 years now, I have yet to see any of them explode. Surfactants like Corexit are not known for being particularly explosive, especially at room temperature.
I think it is far more likely to be coincidental; in addition, wouldn’t a true explosion have left much less of the funnel? Heaven help us. (When the reporter obtained another sample from the same area 4 days later, the oil and grease concentrations were at the 1 ppm level. Not explosive enough? (That’s a joke, non-chemists.))
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The most bracing (and sad) chemical sentence you will read today
by Chemjobber on Jun 28 2010 (11688 Views)“I will roar argon into chlorine, xenon into fluorine, all the noble gases into reactive ones… My lament will terrify even the stars.” – Jessica Stern, Denial: A Memoir of Terror
From Dwight Gardner’s review in the New York Times. Dr. Stern is an expert on terrorism; she believes her interest in terror stems from a brutal and violent incident from her childhood.
Puzzling polymorphs
by Chemjobber on Jun 07 2010 (10613 Views)
Polymorphism is a common and sorta crazy issue in pharmaceutical process chemistry. Basically put, a drug molecule in the solid state can have multiple crystal forms. Different impurity profiles and different crystallization techniques (solvents, heating/cooling rates) can produce different polymorphs, which can have wildly different physical properties and bioavailabilities. A famous story of troublesome polymorphism is Abbott’s ritonavir, where in the middle of manufacturing for sale (not during the R&D phase!), a new, much less soluble polymorph started showing up in batches. Moreover, once the new polymorph showed up, it was very difficult to generate the previous polymorph. Even crazier, a team of scientists went to another plant in Italy where the process was still working as desired, and soon after the team left, the new polymorph appeared. It took a crash program to understand which conditions were generating the new crystal form to get it under control.
A recent article by Pradash et al. in Organic Process Research and Development illustrates the problems of polymorphism similarly: once the authors determined that there was another crystal form (‘Form A’) than the original (‘Form B’), they undertook a screening process (looking at varieties of solvent and crystallization techniques) to find other polymorphs. Interestingly, once they discovered a new polymorph (‘Form C’), they found that it was impossible to generate Form B in their laboratories. They selected Form C for its physical properties and moved it into the pilot plant; lo, they then found Form D. This new crystal form began predominating and “those seeded crystallization processes that consistently produced Forms A and C started to produce predominately Form D in the laboratory.” (Click on image to see pictures of the polymorphs and the structure itself.)
When I read these accounts, I am filled with admiration for pharmaceutical process chemists, the interesting science that they get to do and the vast reserves of patience and sangfroid they must have. Chemistry (and manufacturing chemistry, especially!) is based on reproducibility and consistency; when issues arise, I suspect that there is a great deal of checking and double-checking to make sure that “this is really happening to us.” Also, I can’t help but wonder if those process chemists, when these issues are discovered, wonder if the laws of the physical universe are being temporarily suspended and some Loki-like diety is having its way with them.
How’s your laundry’s chemical hygiene?
by Chemjobber on May 16 2010 (29601 Views)
Credit: University of Ottawa EH&S
A recent report from the President’s Cancer Panel on the environmental causes of cancer* had a rather interesting recommendation relevant to chemists. As to what you could do to lower your risk and your family’s, here’s what it said (page 111):
“Family exposure to numerous occupational chemicals can be reduced by removing shoes before entering the home and washing work clothes separately from the other family laundry.”
So what do you think of that? As chemists, we are presumably more exposed than the typical person, although I suspect that there are industrial workers (coal miners?) who are even more exposed than us.
I know that I have typically avoided bringing my shoes into the home (but, then again, I’ve always taken off my shoes before I enter my home). Recently, I have begun washing my work clothes separately from my family’s. Due to my work circumstances, I’m guessing that I carry home more compound that the average chemist. Then again, it’s the same washing machine. Short of running an ethanol rinse between washes (can you imagine the cost?), I don’t know if there’s a good answer for that one.
I’m terribly interested to know what other people’s habits are about their clothing and chemical hygiene? Do you let your kids hug you when you walk in the door from work? Do you let your dog chew on your work shoes? Inquiring minds want to know…
*Folks (e.g. Derek Lowe) have been pretty critical of the report. I’ve noticed that it’s pretty long on assertion myself. Nonetheless, it’s an interesting topic.
Photo from the University of Ottawa’s lab EH&S site.
Art from molecular models
by Chemjobber on Apr 28 2010 (8262 Views)
"Heme", by Alexander Kobulnicky
In my travels here and about online, I recently found the paintings of Alexander Kobulnicky. He paints molecular models of, well, molecules, ranging from the life-giving (“Heme”, to the left) to the fun-related (THC, if that’s your thing) to the life-taking (CO.) The background of the artwork is most noteworthy — Mr. Kobulnicky paints what comes to mind with each different molecule. I think that thorazine is the one with the best background, although psilocybin comes in a close second.
Each painting comes with a little description of the relevant chemistry and an interesting structural note to make a chemist’s heart warm: “These molecules are rendered as space-filling models, in a natural, low-energy conformation, and displayed from an angle that shows off as much of their structure as possible.”
While I’m not quite to the art-collecting stage of my life yet, I have to say that I’m pretty enthusiastic about owning one of these someday.
Counterfeit drugs: an opportunity for innovative chemical thinking?
by Chemjobber on Apr 11 2010 (5992 Views)
Can you tell the difference? Left is authentic sample. Right is fake.
A recent article [1] in “Trends in Pharmaceutical Sciences” illustrates the interesting problem of counterfeit pharmaceuticals, especially fake anti-malarials. In the long term, I suspect that as pharmaceutical prices trend upwards, folks at the margins will be looking for ways to cut costs. Doubtless that some will be taken in by the global trade in fake or substandard pharmaceuticals, possibly even in the US.
One village in Burma was definitely taken in [2]: a young man with malaria was treated with what was thought to be arteminisin, the natural product that is an effective means of treating the disease. After he died of malaria, experts discovered that the packages had fake authentication holograms and the tablets failed a colorimetric test. MS results indicated that the main ingredient was acetaminophen and HPLC indicated that the levels of arteminisin was only 20% of the claimed dosage.
The authors ([1], Newton et al.) argue for more support for governmental medicinal regulatory agencies in developing countries; they also push for more inspections of GMP facilities. While I think both of these strategies will bear long-term fruit, there is potential room for innovation from the chemistry front.
Presented with this problem (questionable organic starting materials), the typical university-equipped chemist would perform a number of tests (NMR, MS) to determine the identity of the unknown material. The articles I looked at also mentioned colorimetric tests and TLC, both relatively low-tech analytical chemistry techniques. I like TLC as a potential answer for part of this problem; you’d want something that didn’t rely on silica gel plates, a UV light or complicated stains. You’d want something that worked with paper chromatography and very common chemicals (H2SO4?)
This might be the first foray into a chemical version of “appropriate technology”, which attempts to improve the lives of people in developing countries using materials that are available and sustainable. What do you all think?
References:
1. Newton, P.N., Green, M.D., Fernandex, F.M. “Impact of poor-quality medicines in the ‘developing’ world.” Trends in Pharmacological Sciences, 2010, 31 (3), 99-101.
Scientific shopping
by Chemjobber on Mar 17 2010 (3106 Views)
In the process of explaining the process of buying scientific equipment to a layperson, I was struck that I could not adequately explain Sigma-Aldrich’s role in the market.
If you take two extremes of retail shopping, there’s WalMart (broad selection, low prices, relatively few outlets) and there’s 7-11 (narrow selection, relatively high prices, lots of corner outlets). With 7-11, you presumably pay a little more for a little more convenience.
To the organic chemist, Aldrich is convenient (free shipping!), it’s typically high cost and the quality ranges for completely satisfactory to below average. The convenience and the high cost = 7-11; the extraordinarily broad selection of compounds, a little more WalMart-like. My experience with the customer service has been pretty good, actually.
So what is Aldrich? I think it’s more like a department store than anything (you can buy Aldrich brand glassware, not that I know a lot of people who do.) What do you all think? Do you have any favorite suppliers? (Seeing as how Acros is an advertiser, I have nothing but good to say about them.) What store do you equate with your favorite supplier?
Biology professor allegedly involved in shooting
by Chemjobber on Feb 13 2010 (6878 Views)
Suspect in UAH shooting - credit Huntsville Times, Dave Dieter
News broke this afternoon that there was a shooting at the University of Alabama in Huntsville’s Shelby Hall. It took me a while to find that this is (among other things) the home of UAH’s chemistry department. While CNN hasn’t filled in the details, the Huntsville Times already has reported that biology Professor Amy Bishop was taken into custody and her husband has been detained for the deaths of 3 faculty members and the wounding of 3 others.
While stunning and tragic, this would not have rated a post except for the alleged reason for the shooting: denial of tenure. According to the New York Times:
WAFF, the NBC affiliate in Huntsville, quoted university officials as saying the professor began shooting after learning at the faculty meeting that she was being denied tenure…
Dr. Bishop had told acquaintances recently that she was worried about getting tenure, said a business associate who met her at a business technology open house at the end of January and asked not to be named because of the close-knit nature of the science community in Huntsville. “She began to talk about her problems getting tenure in a very forceful and animated way, saying it was unfair,” the associate said, referring to a conversation in which she blamed specific colleagues for her problems.
Wow. Denial of tenure must be crushing for an assistant professor, especially since the process must seem protracted, random and unfair (at times). The really surprising detail is that (allegedly) she brought a gun; that’s an indication of a willingness to use violence and a certain level of forethought as to the potential outcome of the meeting. (CORRECTED: see update below.) Academic science is high pressure indeed.
My (our) thoughts are with the families of the victims.
UPDATE: From the AP:
University spokesman Ray Garner said Saturday that the professor, Amy Bishop, had been informed months ago that she would not be granted tenure. He said the faculty meeting where she is accused of gunning down colleagues was not called to discuss tenure.
Dissolution is the solution to pollution?
by Chemjobber on Dec 13 2009 (12890 Views)
The machine that eats human bodies
Want a solution to cremation pollution? In the 9th annual “Year in Ideas” issue, the New York Times Sunday Magazine covers a new Scottish company that wants people to “resomate” human remains as opposed to traditional cremation.
The company’s web site mentions that resomation “uses less energy than cremation and produces significantly less CO2 and avoids putting mercury and other harmful contaminants into the atmosphere.”
How does this work? According to the NYT: “The corpse is placed in a pressurized chamber. The vessel is then filled with water and potassium hydroxide, creating a highly alkaline solution, and heated to 330 degrees. After about three hours, all that’s left are a soft, white calcium phosphate from bone and teeth and a light brown primordial soup of amino acids and peptides.”
Huh. Even though it’s kinda grody, I have to say that it makes a lot of sense. Will alkaline hydrolysis be your body’s ultimate fate?
