Identifying hazardous chemicals from soil using nitrogen blowdown evaporation and mass spec
In a video produced by the California Department of Toxic Substances Control (DTSC), Organomation’s 24 position N-EVAP is seen in the background of DTSC’s state-of-the art Environmental Chemistry Lab (ECL) in Berkeley, California. The ECL provides analytical and environmental chemistry support to DTSC programs at all stages of their projects. By sharing this data and technical information, the ECL is able to help protect public health and the environment from the effects of emerging chemical concerns. Activities include proactively identifying the usage of chemicals in the wastewaters of California, pollution prevention, and other chemical exposure intervention efforts.
The DTSC video sets the scene with the hustle and noise of construction sites and many dug up holes. The physical environment around us is constantly changing and evolving over time; one's daily commute to work may involve passing at least a few new construction sites. Amid detours and new traffic patterns, health and safety concerns lie within the earth's ground.
New dug up soil may be contaminated with hazardous chemicals that may be toxic to humans, and therefore needs to be tested. DTSC's Environmental Chemistry Lab is where many samples are sent to be tested. One scientist explains the department's process of testing large amounts of chemicals and analyzing them for a collector that sends in a sample. The scientist states, “Take a sample, for example sand, and the goal is to create a liquid extract out of it. The soil sample is mixed with a solvent and shaken to absorb any hazardous chemicals from the soil. If after being shaken there is still soil in it, it is important to filter it out, and let the remainder be all liquid.”
This tedious process may take hours or days. Once all that remains is the solvent with different chemicals, the liquids are concentrated into smaller vials. This step is where Organomations 24 Position N-EVAP® would be used. The N-EVAP® is a dependable sample prep tool in labs worldwide. These units provide controlled concentrations of samples through the application of nitrogen gas within a heated bath. The instrument has many customizable options for sample preparation needs. For example, the nitrogen evaporators are able to hold a large amount of various vial sizes; the samples are easy to remove and insert due to the rotating design, and the standard N-EVAP comes with a water bath, which provides uniform heat controlled by a mechanical thermostat.
After the concentration into smaller vials, the samples are taken for tests on the mass spectrometry— a large oven that contains a column that's used to separate out the compounds. The scientist illustrates that once the mass spectrometer takes part of the sample, it injects it into the column where the sample is heated into a vapor. Helium gas then carries it through the column which then creates an ion scan. This particular compound creates this specific type of scan, and helps identify the compounds in the end. This process can help identify large amounts of compounds all from one liquid.
The test results help to identify if chemicals are present, and whether the contamination levels are toxic. By using this vital information, scientists can better inform clients or the public of the potentially harmful elements that lie within the dirt.