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