Happy Tuesday! This week’s question will focus on the EPA method for performing n-hexane extractions, otherwise known as “oil and grease” extractions. If you are ready to Expand Your Horizon, read on.
Today’s question: According to EPA Method 1664 A/B, n-hexane is used as an extraction solvent and must have a minimum purity level of…
(e) None of the above
Hazard a guess in the comments below! (need a hint? The answer isn’t “none of the above”)
Stay tuned next Tuesday….
1,4 dioxane – sometimes referred to as just dioxane – has gotten a lot of press since the U.S. EPA added it to the third Unregulated Contaminant Monitoring Rule (UCMR 3). It is a relatively common solvent in analytical laboratories; however, it also finds use as a stabilizer for manufacturing items such as shampoo, cosmetics and food additives. After the EPA deemed this compound “likely to be carcinogenic to humans” and found it in a number of groundwater sources across the U.S., 1,4 dioxane was added to the UCMR 3 list and is now a regulated, routinely monitored contaminant.
Just to recap last week’s Tuesday Trivia post: Due to rising levels of ______ (fill in the blank) ________, some species of fish are slowly losing their ability to smell.
Answer: Carbon dioxide (CO2)
As the levels of carbon dioxide rise in a body of water, carbon dioxide converts to carbonic acid which increases the acidity of the water. It turns out, acidic conditions reduce the sensitivity of the olfactory sensors in a fish (i.e. the nerves responsible for being able to smell).
As we’ve demonstrated with posts and trivia questions in the past, protecting, testing and treating our fresh water sources is important to the health of everyone. Read through this helpful infographic for a quick review of the potential contaminants that could find their way into our water sources.
Join us next week to Expand Your Horizon!
If you’ve ever taken on a home renovation project and needed to purchase wall paint, you may have looked at “low VOC” or “no VOC” paint. Even if you don’t know what VOCs are, you are likely familiar with the terrible, headache-inducing smell that greets you when you pry the lid off a new can. Not only is the odor unpleasant, but the fumes are harmful when you breathe them in over a prolonged period of time.
Solvent drying is a key step in many laboratories that are using organic solvents for syntheses and extractions. In the case of hexane extractions during oil and grease measurements, this step is necessary to ensure that the extracts are accurately dried, concentrated and weighed.
Just a reminder of last week’s post: EPA Method 625.1 has recently made a significant change to allow the use of which technique?