The plant was on a cycle of oil this week (rather than petrolatums / wax), so all of my work was with white oils and raw feed. The week opened with us interns testing stripper samples (samples of oil from various points in the treatment process, analyzed for record), which takes up a bit of time to perform the various analytical methods, and twice, later in the week, I was tasked with analyzing incoming samples from railcars (testing sulfur content with XRF, UV absorbance, etc.).
For clarification, when I say we "test" and "analyze" these oils, we are mostly determining the presence of sulfur, unsaturated carbon chains (double and triple carbon-carbon bonds), aromatic compounds, and insufficiently small carbon chains, to which the general term "crack" is given. The photo to the right is an example of a jar filled with "crack." While this may sound rather suspicious and legally questionable, all it is is a mixture of smaller hydrocarbons (think in the ranges of cyclohexane, trimethyl pentane, etc... its chemical profile is comparable to that of gasoline) that does not display the same oily properties as our final products. It is removed from the oils and sold to a customer who will make use of it.
Something new that I learned this week was about USP testing of white oils (United States Pharmacopoeia). This is a series of tests performed in order to verify oils for drug safety, as a number of our customers are in the pharmaceutical industry. We test for universally acceptable thresholds of acidity, alkalinity, sulfur compounds, and solid paraffins (waxy content). They are rather redundant and time-consuming tests (perfect job for an intern).
On top of the working experience, I have also been constructing presentations about certain instruments in the lab that I share during morning meetings. So far, I have presented about the TGA (thermogravimetric analysis) and the difference between IR and FTIR (infrared spec. vs Fourier-Transform infrared spec.). I have also held a brief lesson on how our GC (gas chromatograph) works.
Now that I'm halfway through my internship, I feel like I'm a much more educated and experienced chemist than I was just five weeks ago. I look forward to seeing what the back 9 has in store for me.