EPA Method 1664B
Have you ever had days of extracting oil and grease samples and thought to yourself “there must be an easier way to work with wastewater samples”? Whether you run oil and grease samples by liquid-liquid extraction (LLE) or by solid-phase extraction (SPE) it can be challenging at times to efficiently extract 1-liter samples due to the sample matrix. Wastewater is challenging and can be very complicated and contain many types of particulates and or detergents. The makeup of the sample not only interferes with efficient extractions due to matrix issues (such as emulsions) but can also cause slow flow rates.
Have you ever thought to yourself I wish there was one way to effectively extract all of our aqueous samples? For instance, there are several methods available to extract aqueous samples, such as extraction method 3510 liquid-liquid extraction (LLE), method 3520 continuous liquid-liquid extraction (CLLE), and method 3535 solid-phase extraction (SPE). Wouldn’t it be more convenient to use one extraction method within the lab for most if not all of your aqueous extractions?
Working in an environmental lab requires a lot of concentration, both mentally and for the samples that you are working with. When New England finally begins to thaw and local companies rush to get their samples completed, a bottleneck that is usually experienced is the drying and concentration of so many samples. This bottleneck is partly due to ensuring that samples are extracted within their holding times. There have been many times I have had to multitask while concentrating samples on the TurboVap® classic, leading to some extra work when that rare sample was overconcentrated. Many of my past coworkers brought up the challenge they faced with the extraction of water and soils. In my opinion, the bigger issue was drying and concentrating. My main complaint with these steps was it was never efficient enough and I always had to baby each step so that all of my hard work (shaking the sample) did not go to waste. What I strived for most in the lab was an efficient and streamlined workflow for this part of the process.
Have you ever thought to yourself am I using the best solid phase extraction disk offering for my application? Or can our prep lab turn samples around more efficiently if we choose a different SPE disk platform such as a single-use disk holder instead of cleaning our reusable holders? Those are just a few questions I receive when working with sample prep solutions with customers when SPE disks are brought up in the conversion.
It is that time of year again when laboratories are fulfilling accreditation requirements for the methods that they offer. One of the requirements that must be met for each method is called proficiency testing (PT). If you are not familiar with proficiency testing, it is a sample purchased from an approved vendor to evaluate the ability of a lab to meet the acceptance criteria of the method. If the labs’ results are out of the PT samples acceptance criteria, they can redo the testing.
Believe it or not, we’re all familiar with emulsions. Have you ever added food oil to a pot of water while cooking? That’s an emulsion. Do you put dressing on your salad? It should be called salad emulsion – although, that may not have the same edible appeal. Do you drink milk? Emulsion. What about milk? Butter? Eggs? All emulsions.
If we’re referring to emulsions in the laboratory, the examples are different, but the chemistry involved is very similar – as are the mechanisms for breaking them. Continue reading Tackling Emulsions Just Got Easier
Liquid-liquid extraction (LLE), supported liquid extraction (SLE), and solid-phase extraction (SPE) have existed for decades and if you’re doing organic sample preparation, you’re probably quite familiar with at least one of these techniques. But are you familiar with all of them? How are they similar? How are they different? Let’s review! Continue reading SLE, SPE and LLE – How are Those Different?
“There is a child in every one of us who is still a trick-or-treater looking for a brightly-lit front porch.” – Robert Brault