Tuesday, August 30, 2011

HPLC

Ha. Maybe I will post this month. Though it's older-from last September. I was working at a company I've been at before, though this time doing HPLC as well as ICP. Very exciting, I've wanted to do HPLC. Also, it seems like the wave of the future. I'm analyzing amino acids, using pre-column derivitization. it's pretty cool, actually.
However, that instrument is being a little punk this week. Already, I've changed column and pre column, had to totally replace one solvent bottle due to algae growth, and deal with blockages, since it looks like I didn't get it totally in time. Very frustrating. However, I am already getting to be so much more confident on that instrument.
My favorite things about the technique so far-
1. Getting an appreciation of just exactly how high pressure 200 bar really is. If it's not 100% lined up and tightened there are leaks. and I get to see them. really fast. They aren't lying when they say high pressure.
2. automatic mixing-really most forms of automatic chemistry-is also just really fun.
3. Pretty chromatograms. I do get very pretty peaks-symmetrical, thin, and no tails. I like success.

What I don't like about this technique-
leaks, blockages, anything else. See above.

Sunday, August 28, 2011

out of town

You may have noticed that my posting has been less than usual this month. I have been out of town at a wedding/family trip, and looking for work. So, forgive me, this will have to be a slow month.

TiO2

TiO2. Used for so many things. A report a couple of weeks ago in C&E news talked about how it is used in sunscreen. But I'd like to talk more about the compound in general here. What is it? How does it work?
Firstly-what is it?
A combination of titanium and 2 oxygen atoms. A solid crystal with a crystal structure.
How does that work? Shouldn't I have listed a structure? The way it works is that TiO2 has a variety of forms. The three most common ones are rultile and anatase and brookite. Anatase and Rutlie are tetrahedral. Brookite is orthorombic. Control over these forms can usually be accomplished in the design stage through temperature control at synthesis.
Which form do you want? That depends on your application.
Anatase is generally more reactive. The article I linked to above contains interesting experiments about sunscreens on metal. Anatase TiO2 was seen to increase radical production.
It is also used in solar cell designs.
Rutile is what seems to be better for sunscreens. Less reactive, it sticks to reflecting. Another common use is white paint. Reflecting all wavelengths of light ends up looking white. The UV reflectance gives TiO2 sunscreen capabilities.
Brookite, the last of our forms, is not white. It is a rare form, and doesn't seem to be commonly commercially used

Saturday, August 13, 2011

Tensions in green classes

So, these past two weeks, I took the Society of Mechanical Engineers' Green Specialist certificate classes. Taking the test will be at some future time. One of the classes was "green chemistry". Now, I am in support of this idea-a lot of pretty harsh solvents don't need to be used nearly as much as they are, and looking for ways around that can be both good business sense and environmentally important. Because let's be honest, a 2 step process with 77% yield is an improvement on a 5 step process with 44%.
My problem, however, is the assumption in that class, and in the sustainability community in general that chemical free is even a legitimate term.
Water is a chemical. You can't sell something chemical free. Fear marketing like that is the reason I won't buy anything from Burt's Bee's-they have some ideas that I like(tea tree oil works better on my pimples than salicylic acid, but I'll get my own oil and mix it in other company's products-and this is as much personal info as needed on this blog) because I won't give them money to promote fear of my industry.
My other concern about the class is the image of chemists as misguided, not knowing what we do that may be harmful to the environment, "not understanding some of the risks". I would argue that most chemists have a better understanding than the public about the risks of most chemicals. We look at the MSDS. We have to learn what protective measures are important.
This idea also erases the contribution by many chemists looking specifically to do things like find a safer/more efficient route to synthesize ibuprofen, or looking to develop environmental remediation technologies. Or people like professors Vicki Grassian and Mark Young that I used to work with that study the effects of what we put in the atmosphere on the many process happening up there.