How does your sample prep change for LC/MS vs GC/MS

When preparing your extracts for analysis, it is important to know which instrument to use and why you should be using that specific one.  Of course, we know that each EPA method dictates which analysis instrument must be used within each method, however, we will be determining why that option was chosen in the first place in this blog post! Continue reading How does your sample prep change for LC/MS vs GC/MS

What does gas vortex shearing do in evaporation? Why should I care?

It is question and answer time and we are starting with TurboVap® evaporators and their use in an environmental lab.  The TurboVap® evaporation system by design utilizes a patented gas vortex shearing technology. You may be asking yourself, “what does that mean?” I know I did when I first heard about it!  Read on to learn more about what this does for your lab evaporation.

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Why are my phenol recoveries low on my EPA Method 8270/625.1 extractions?

Do you have issues seeing acceptable recovery of your phenols?  I know I do.  These compounds can be challenging to recover and quantitate, and are also found just about everywhere!  Read on to learn a couple of fun facts about phenols, but first, let’s explain why phenols can be difficult to work with.

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Hydrophilic Solution for Your Vapor Lock Dilemma

Have you ever put your water sample onto your Biotage® Horizon 3100 extractor and all your prewet/conditioning steps worked great and then suddenly, the water inlet valve opens, and nothing happens!  This can be terrifying because a lot is riding on those samples!  If you notice this right when it happens, a simple wiggle of the sample bottle should introduce air into the bottle releasing the water, in turn loading your sample.  However, you do not want this happening all the time, especially when you leave your extractor for a while, come back, and see that your sample never loaded!

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EPA Methods and the Use of Drying Techniques

Do you ever tire of using sodium sulfate to dry your extracts?  I know I do.  That is why, whenever I get the chance to avoid using it, I do.  The worst experience when using sodium sulfate is when you do not use enough of it, and the sodium sulfate reaches its maximum capacity leading to water breakthrough into your ‘what was supposed to be a dried extract.’  Then, you must dry the extract again with more sodium sulfate.  When you are a high throughput lab, redoing steps is not ideal.  Unfortunately, EPA Methods 525.2 and 525.3 require sodium sulfate drying as the drying technique, to name a couple, but not all EPA methods require sodium sulfate for drying.  That is why when there is an alternative technique available and you are permitted to use it, why not use it?!

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To Be or Not to Be Water Miscible

“Oh my!  This is crystal clear!” – said nobody who has ever read through an EPA Method.

For anyone who processes samples in an EPA-regulated laboratory, you know that these methods can be very specific in some spots, and incredibly vague in others.  The complexity worsens if you’re following one method for sample cleanup and another method for sample preparation and data collection.  Consult this handy infographic to make sure you’re following the right methods for sample cleanup, processing and analysis.

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Are You Contaminating Your Samples During Evaporation?

“Water in my extracts again?!?!”

How many of you have been in that position?  You’ve worked hard to extract your samples, you’ve dried your extracts to remove the last droplets of water from your organic solvent – only to add that water back in during your evaporation step!  There are fewer frustrating situations than losing a set of extracts in this manner.

If you’re like me, you work hard, follow all the precautionary step-by-step procedures to carefully produce extracts in a timely fashion.  It’s frustrating to think that a whole day’s work can be ruined with just a few milliliters of water.  When you see the water, you make an attempt to remove it and save your extracts, but there’s no guarantee that it’ll work.  Is there any way to avoid this?

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Your Sample Prep is Only as Good as Your Evaporator

“I love doing maintenance.  It’s the best part of my week” – said nobody ever.

Let’s be honest.  We all dread performing maintenance.  Why?

  1.  It’s boring. I’m a chemist and I’d rather spend my time using my instrument than maintaining it.
  2. It seems unnecessary. I’m a fan of what I call “sensory maintenance” – that water looks pretty clean, that pump sounds pretty good.
  3. I don’t always know what I should be doing for preventative maintenance.

Continue reading Your Sample Prep is Only as Good as Your Evaporator

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