Everything You Wanted to Know About EPA Method 8270 But Were Afraid to Ask

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

6 Changes to EPA Method 8270 That You May Not Be Aware Of

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

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?