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.
Continue reading Can you live a PFAS free Life?
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.
Continue reading Extraction of 1,4 Dioxane from Drinking Water
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.
Continue reading SVOCs – Should I be Worried About Those?
Another Tuesday is upon us. Let’s Expand Your Horizon with the following trivia question (read through one of the previous posts to brush up on your trivia skills, if needed).
Continue reading Tuesday Trivia – August 28, 2018
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.
Continue reading The Basics of Solvent Drying
If I had to use a single word to describe aquariums, it would be “magical.” Whether you’re a child or a child at heart (like me!), it is easy to get lost with the turtles, sea lions, eels, sharks and any other aquatic life you can imagine. The exhibits closely mimic the sights, sounds and smells of each aquatic environment – so closely, that you might think you’re out in the ocean or in the middle of the Antarctic.
Continue reading PFCs in the Antarctic