Tackling Emulsions Just Got Easier

Believe it or not, we’re all familiar with emulsions.  Have you ever added food oil to a pot of water while cooking?  That’s an emulsion.  Do you put dressing on your salad?  It should be called salad emulsion – although, that may not have the same edible appeal.  Do you drink milk?  Emulsion.  What about milk?  Butter?  Eggs?  All emulsions.

If we’re referring to emulsions in the laboratory, the examples are different, but the chemistry involved is very similar – as are the mechanisms for breaking them. Continue reading Tackling Emulsions Just Got Easier

SLE, SPE and LLE – How are Those Different?

Liquid-liquid extraction (LLE), supported liquid extraction (SLE), and solid-phase extraction (SPE) have existed for decades and if you’re doing organic sample preparation, you’re probably quite familiar with at least one of these techniques.  But are you familiar with all of them?  How are they similar?  How are they different?  Let’s review! Continue reading SLE, SPE and LLE – How are Those Different?

Spooky Stories or Laboratory Mishaps?

“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

It’s Halloween!  I assume you’ve carefully assembled your favorite movie character, comic book superhero or animal costume for a night of spooky fun.  If you’re me, this is the day you get to wear your superhero cape out in public.  As an applications chemist, I consider myself to be a bit of a superhero – but a humble one, as I wear my cape underneath my t-shirt and lab coat.  I consider myself to be a superhero when I’m able to use my background and my experiences to think quickly on my feet and help troubleshoot challenges that chemists face all the time.  It’s one of the best parts of my job and I’m thrilled each time I get to wear my cape – metaphorically speaking.

Continue reading Spooky Stories or Laboratory Mishaps?

10 Facts About Pesticides You Didn’t (Want to) Know

Pesticides have been widely used in the U.S. for decades to combat everything from weeds to insects to bacteria.  These compounds allow farmers to cultivate acres of successful crops and keep food on our dinner tables.  But every chemical poses a risk, so I always like to familiarize myself with the chemicals I’m being exposed to, in order to make informed decisions about the health and safety of me and my family.  Here are a few facts about pesticides I thought I’d share – just in case you’re on the same fact-finding journey I am.

Continue reading 10 Facts About Pesticides You Didn’t (Want to) Know

UCMR 5 – Will PFAS Make an Appearance?

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…

Continue reading UCMR 5 – Will PFAS Make an Appearance?

Environmental Pollution – Are We All Doomed?

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.

Continue reading Environmental Pollution – Are We All Doomed?

5 Sources of Phthalate and Adipate Contamination You Probably Didn’t Know 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

Improvements in Processing Drinking Water Samples by Method 525, Part 2: Extraction Procedure

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.

Continue reading Improvements in Processing Drinking Water Samples by Method 525, Part 2: Extraction Procedure

Do Flow Rates Matter in SPE?

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.

Continue reading Do Flow Rates Matter in SPE?

Why It’s Easier to Succeed With Wastewater Extractions Than You Might Think

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.

Continue reading Why It’s Easier to Succeed With Wastewater Extractions Than You Might Think