On the eve of World Water Monitoring Day, we thought we would post last Tuesday’s response a day earlier! Celebrations for tomorrow’s epic event might otherwise interfere.
Just a reminder of last week’s post:
According to EPA Method 1664 A/B, n-hexane is used as an extraction solvent and must have a minimum purity level of…
EPA Method 1664 B outlines the use of n-hexane as an extraction solvent and Section 1.7.2 specifies a minimum purity level of 85% (Method 1664 A has the same requirement).
Believe it or not, hexane solutions typically contain a mixture of 5 structural isomers (i.e. same molecular formula, different arrangement of atoms). N-hexane is the longest (least branched) of the 5 isomers, which gives it the highest boiling point and lowest vapor pressure. Therefore, specifying a minimum purity level of 85% means you’re dictating that at least 85% of the solution must contain the x-hexane isomer.
Join us next week to Expand Your Horizon!
PFAS chemicals can be found in every aspect of our life from nonstick pans and cleaning products to firefighting foam. This group of chemicals has caused concern nationwide as it has been found in drinking water and has shown to have negative effects on our health. Starting in the 1980s, chemicals in the PFAS family, PFOS and PFOA, were linked to a number of health concerns, from cancer to hormonal disruption. (See our earlier blog for terms and definitions). These chemicals are extremely difficult to get rid of because they do not break down in the environment and they build up in the body.
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….
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.
If you are unfamiliar with terms like “fatberg” and “FOG,” you might not realize the significance and environmental ramifications of this phenomenon. Your perspective will change if you look through recent news articles where fatbergs have blocked and damaged sewer systems in major cities.
Photo credit: Thames Water
For those who saw last week’s Tuesday Trivia post, read on for the answer you’ve been waiting for.
For those who are unfamiliar with these posts, every other Tuesday, a trivia question will get posted to allow us to test our wits and expand our horizons.
As a reminder, the question that was posed last week:
Imagine shrinking the Earth’s water supply down to 100 liters. The volume of fresh, usable water would be roughly ____(fill in the blank)____ liters.
Answer: 0.003 liters!
This may seem like a surprising answer, given that water is everywhere on the Earth – glaciers, lakes, rivers, streams, oceans and aquifers. There’s even moisture in the atmosphere! However, you must first take into account that most of the water on Earth (roughly 97%) is contained within our oceans which makes it salt water, not fresh water. A significant portion of the remaining fresh water is tied up in glaciers, too polluted for safe consumption, or is buried too deep under the Earth’s crust. Obviously, we could make attempts to clean up our polluted waters or pull fresh water out of the Earth, but those quickly become cost-prohibitive options for the planet’s growing population.
Clearly, fresh water is a precious resource for us. Click here to learn more about methods for monitoring and protecting our water sources.
Stay tuned for a new trivia question next week. In the meantime, wrack your brain for your best trivia questions and send them to me in the comments section. We’re eager to expand our horizons!
It’s Tuesday again – ready to Expand Your Horizon? For those who are joining us for the first time, every Tuesday is Trivia Tuesday where we test our wits on various topics. We welcome all reasonable – as well as creative – guesses!
The Tuesday Trivia question for this week:
Imagine shrinking the Earth’s water supply down to 100 liters. The volume of fresh, usable water would be roughly _____(fill in the blank)_____ liters.
Keep an eye out for the answer next Tuesday …