“There is a child in every one of us who is still a trick-or-treater looking for a brightly-lit front porch.” – Robert Brault
If you’re reading this blog and hoping for a sneak peek at the list of contaminants that will be on the next UCMR list, you’ll want to keep reading…
If you’re familiar with methylene chloride (which I’m sure you are since it’s one of the most widely used laboratory solvents), you know that it’s developed a reputation for being one of the “bad boys” of the solvent world. The bad press has certainly been earned. It’s been attributed to over 60 deaths in the last 4 decades. It’s also pretty aggressive – exposure to just a few ounces for a few minutes can be enough to cause severe damage or death. And since it’s a colorless liquid, an innocent-looking spill could be a severely harmful hazard.
Have you ever stopped to enjoy a bright, vibrant sunset, only to have that really annoying friend interrupt your thoughts with a comment like “you know you’re just looking at all the pollution in the air, right?”
I used to wonder how someone could focus on pollution while looking at a stunning landscape, but it’s becoming a topic that more and more people are thinking about.
“Why do I keep seeing background contamination from phthalate and adipate when I do extractions for semi-volatiles?”
This is one of the most common questions I’ve been asked when I’m traveling in the field. It’s an issue I’ve come across in my own lab on occasion and if you can’t find the source of your contamination, it can turn routine application work into a troubleshooting nightmare. Given how often I’ve seen these compounds cause contamination issues, I thought I’d review some of the most common sources for these. Continue reading 5 Sources of Phthalate and Adipate Contamination You Probably Didn’t Know About
“Our laboratory uses organic solvents every day. Should we be concerned about solvent exposure?”
I hear this question fairly often and the short and simple answer is: YES.
But if this were a simple yes/no question, I wouldn’t have anything else to say, and this would be the shortest blog post that’s ever been written.
In the first part of this 2-part blog series, I highlighted the improvements made by the EPA regarding the preparation and preservation of samples. In this post, I will focus more on the changes the EPA has made to Method 525 which affect the analysis of the prepared samples.
Have you ever wondered why solution flow rates are so important when performing sample preparation with solid phase extraction (SPE)? If you have, read on – I have the answer for you!
Throughout my college career, the phrase “like dissolves like” was referred to quite frequently. This phrase was particularly relevant when we did solubility experiments and for good reason – it’s 100% true! Solvents tend to dissolve solutes with physical and chemical properties that are similar to theirs. Other factors such as temperature, pressure and pH can affect the solubility of solutes as well, but let’s just keep it simple for the purposes of this discussion and keep it focused on physical and chemical properties. Given this simplistic definition of solubility, the opposite stands true as well – solutes don’t tend to dissolve into solvents with differing physical and chemical properties. These solvents and solutes want to stay as far from each other as is possible.
There’s nothing more satisfying than successfully extracting a really challenging sample. Solid phase extraction (SPE) is a powerful technique for extracting semi-volatile organic compounds and hexane-extractable materials (HEMs). When the chemistry is tailored to meet the requirements of the application, literally hundreds of compounds can be extracted with a single pass of solution through an SPE disk.