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?

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?

In Defense of Methylene Chloride

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.

Continue reading In Defense of Methylene Chloride

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?

The Hidden Dangers of Organic Solvents

“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.

Continue reading The Hidden Dangers of Organic Solvents

7 Horrible Mistakes You’re Making with Solid Phase Extraction

Solid phase extraction (SPE) is a powerful sample preparation tool that makes it possible to extract semi-volatile organic compounds with varying physical and chemical properties.  When used properly, this tool will simultaneously extract hundreds of analytes from the most challenging sample matrices.  When used improperly – well, this tool can quickly become as effective as using a hammer to paint the walls in your house.

Continue reading 7 Horrible Mistakes You’re Making with Solid Phase Extraction

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

Tips for Improving Your Oil & Grease Recoveries

On the surface, EPA Method 1664B seems pretty straightforward – use n-hexane to extract compounds (commonly referred to as “oil and grease”) from an acidified water sample.  Evaporate the hexane from the extract, weigh the residue that gets left behind, and report that weight in terms of a concentration (often as mg/L of HEM).  Yet many laboratories have found themselves looking at data which indicates that their spikes aren’t being recovered at levels that are compliant with the method.  Unfortunately, there are a few details in the method that can cause trouble, regardless of whether you are extracting your samples using liquid-liquid extraction (LLE) or solid phase extraction (SPE).  Keep reading for some tips to improve your analyte recoveries when doing oil and grease extractions.

Continue reading Tips for Improving Your Oil & Grease Recoveries