Contaminants Everywhere

If you are processing environmental samples then you’ve probably dealt with contamination at some point.  If you haven’t, then you should be congratulated for creating the only laboratory on Earth that has ever been completely free of all sources of contamination!  There are many (in some cases, many many many) sources of contamination and the severity of your contamination issues can vary significantly depending on what types of samples you run, the cleanliness of your laboratory, the systems that are running, and the care with which samples are being collected, stored, prepared, run and disposed of.

Continue reading Contaminants Everywhere

Question and Answer Time with EPA Method 8270

It is a regular occurrence for me to get various questions about EPA methods but recently I have had quite a few about EPA Method 8270 and I wanted to share them in case someone else has the same questions.    You can find a great summary of Method 8270 in this blog that one of my colleagues recently wrote – Extraction of Polyphenols in Tea with Lemon Juice.

Continue reading Question and Answer Time with EPA Method 8270

What’s Your Grade?

“I’m usually ACS, although sometimes I’m Reagent.”

If you’re reading this and raising your eyebrows, you’ve never had, what I like to call, the “grade discussion.”  I don’t mean the discussion between high school or college students who are comparing grades after a big mid-term or final exam (although I used to do that too).  I mean the discussion over the solvent grade you use in your laboratory.

Continue reading What’s Your Grade?

What does a thermistor do anyway?

It is easier to understand something when you know what the actual word means.  Thermistor is a portmanteau (yes, sometimes I do pay attention to linguistics) of the words thermal and resistor.  This means that when a thermistor is heated, its resistance is either increased or decreased based on the properties of that particular thermistor.  This property makes it very useful for many different applications all over the world.  But thermistors are most useful, at least from my perspective, when they’re used in automated solid phase extraction systems.

Continue reading What does a thermistor do anyway?