On the surface, EPA Method 1664B seems pretty straightforward – use n-hexane to extract compounds (commonly referred to as “oil and grease”) from an acidified water sample. Evaporate the hexane from the extract, weigh the residue that gets left behind, and report that weight in terms of a concentration (often as mg/L of HEM). Yet many laboratories have found themselves looking at data which indicates that their spikes aren’t being recovered at levels that are compliant with the method. Unfortunately, there are a few details in the method that can cause trouble, regardless of whether you are extracting your samples using liquid-liquid extraction (LLE) or solid phase extraction (SPE). Keep reading for some tips to improve your analyte recoveries when doing oil and grease extractions.
Continue reading Tips for Improving Your Oil & Grease Recoveries
If you are unfamiliar with terms like “fatberg” and “FOG,” you might not realize the significance and environmental ramifications of this phenomenon. Your perspective will change if you look through recent news articles where fatbergs have blocked and damaged sewer systems in major cities.
Photo credit: Thames Water
Continue reading Fats, Oils and Grease, Oh My!