Rain and thunderstorms (with lightning) are common in the Tampa Bay Area. When there is rainfall, environmental samples are not collected, and therefore, samples cannot be analyzed. During the 3rd and 4th weeks in the Environmental Protection Commission of Hillsborough County (EPCHC) laboratory, there were many rainy days. So, when there are few analyses to be run, reagents and standards are made. The reagents and standards are the quality control (QC) solutions to ensure the analyses are processing correctly and producing accurate results. Laboratory Control Standards (LCS) are usually duplicated every 10-20 samples, depending on the analysis. The LCS is an important QC within every analysis as they provide an expected result per analysis and without an LCS, the run is not valid. These reagents and QCs have various expiration dates, and most commonly they need to be re-made weekly.
Standards for sulfate analysis was prepared by measuring out 0.237-0.240g (grams) of Potassium Persulfate into glass tubes on a highly sensitive scale, which is atop a marble table. The marble table and scale are calibrated and ensured to be balanced and evenly equal for accuracy. The Potassium Persulfate is kept in the glass tubes and sealed with a cap until the analyst is ready to prepare the solutions to make the QC standards.
Usually on Fridays, two runs (~35-60 samples) are combined for nutrient analysis. These samples need to be filtered before placed into the sample tubes to be analyzed. About 5-10mL (milliliters) of each nutrient sample is filtered into a glass tube, and once all the samples have been filtered then they are wrapped in this stretchable plastic called parafilm and placed into a sample refrigerator for storage until the analyst is ready to run the samples.
Another crucial portion in the laboratory is the cleanliness of workspace, tools, and collection containers. Every laboratory is different, and at the EPCHC, the containers are rinsed with UV-DI (Ultraviolet-Deionized) water 3-5 times without salt. UV-DI is pure water with little to no other materials, minerals, or contaminants. Every week, if it is helpful, I will rinse tubes, collection containers (glass and plastic), and volumetric pipettes with UV-DI then set them to dry overnight.
Every day when I leave my volunteering internship at the EPCHC laboratory, I am happy! I absolutely love working in the lab, especially within this one! I’ve never experienced such nice, down to earth people who all share a common passion for the environment.