“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