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?
“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
On the surface, EPA Method 8270 seems pretty straightforward. The first version of this method was published over a decade ago and many environmental labs are processing samples according to the guidelines in this method. The EPA summarizes the goals of the method in a single sentence on their website:
“This method [is] for analysis of solid, non-drinking water, drinking water and/or wipe samples containing select semi-volatile organic compounds.”
Continue reading Everything You Wanted to Know About EPA Method 8270 But Were Afraid to Ask
“Pesticides” is one of those terms that invokes a wide range of emotions in people. Some people smile when they think of the insecticides that keep their award-winning flower garden looking beautiful all season. Some people feel grateful for the algaecides in their fish tank that let their kids’ pet fish (who’ve probably been given cute names like “Nemo” and “Frankie Fish”) swim around freely, without having to navigate around huge algae blooms. Then there are other people who hear the word “pesticides” and think of dangerous chemicals that are sprayed onto our crops, eventually ending up in our food and water supply. In this post, I’m going to walk through the good, the bad and the ugly when it comes to pesticides, but that term actually includes a huge number of compounds, so I’m going to narrow my focus to just organochlorine pesticides for the purposes of this post.
Continue reading Organochlorine Pesticides: The Good, the Bad and the Ugly
The U.S. EPA monitors a variety of compounds that pose public health risks when they are present in our air, soil or water and they have spent decades publishing methods to help us extract and quantify those compounds. The 8000 Series EPA Methods describe the extraction and analysis of contaminants in groundwater and Method 8270 specifically covers semi-volatile compounds. The EPA has been monitoring semi-volatile compounds in solid waste, soils and groundwater for almost 40 years, and Method 8270 has undergone several revisions during that time. For example, revision C allowed air samples to be included in the list of sample matrices that can be analyzed under this method.
Continue reading 6 Changes to EPA Method 8270 That You May Not Be Aware Of
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
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
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?
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
Since its release in 1995, EPA method 525.2 has been one of the most widely used methods for quantifying semi-volatile compounds in drinking water. Chances are, if you work for or own a drinking water lab, you probably analyze for compounds in this method – at the very least, you’re probably at least familiar with the method. This is a widely accepted method for quantifying semi-volatile organic compounds; however, there are some glaring issues with the method that the EPA has recognized and addressed. These changes have been collected and implemented in a new revision – Method 525.3 – which was published in 2012. Method 525.2 is still more frequently used by laboratories processing drinking water samples; however, I would argue that Method 525.3 is more scientifically sound. In this 2-part blog series, I will address multiple aspects of Method 525.2 that have been modified to improve the collection, preservation, and processing of drinking water samples. In this first part, I will focus on the improvements that have been made with respect to the sample preservation process.
Continue reading Improvements in Processing Drinking Water Samples by Method 525, Part 1 Sample Preservation