Harold Colon & Greysi Tavarez South Mall Analytical Lab Dr. Michael Miller Freeport High School *THE EFFECTS OF SURFACTANTS AND CONTAMINATION ON AND CONTAMINATION ON NPM ANALYSIS*

Vocabulary Surfactants: detergents;to "cut" grease and to wet surfaces NPM: Non-Polar Material HEM: Hexane Extractable Material NonPolar: compound that does not have concentrations of positive or negative electric charge Polar: Relating to or characterized by a dipole (A molecule having two such charges or poles) Major Equipment Used Step Saver Desicator Analytical Balance Desiccator

OTHER EQUIPMENT USED

Analysis of Hexane Extractable Material and Non-Polar Material HEM - all organic chemicals (not metals) –Cooking oils –Fats –Petroleum (Oil, Gasoline, etc.) NPM is a test looking for only non-polar materials –Petroleum –Citrus-based cleaners (Goo-Gone) Study shows test procedure has some problems separating the two types of materials

Problem Samples contaminated with polar material such as surfactants, grease, fats, and oils, seem to indicate that there are non-polar materials in the sample. NPM analysis limit is 50 mg/L. Samples often exceed the above limit when tested. Silica gel treatment does not always remove 100% of material that should be removed. Question: Do surfactants in the samples effect the result? Do the types of contamination effect the results?

HYPOTHESIS The surfactants in the sample are causing an effect on the analysis’ results. It is expected that the surfactants have a positive interference with the analysis. Depending on the fats, oils, and greases used the results are going to vary. As the silica gel is added (NPM) the results will remain the same. Materials used: Surfactants: Commercial Laundry Detergent Tide F.O.G. : Fats (Kitchen fat), Oils (Wesson Oil) and Grease (Diesel Fuel)

Percent recovered

Percent Recovered

Results Mg\L

CONCLUSIONS Surfactants have a varying interference with the results of the analysis depending on how much and type of surfactant. -Industrial soap interferes with the analysis, giving a smaller amount of analyte than is truly there. -Tide is opposite of industrial soap because it gave a positive interference with larger amounts Depending on the type of contamination, multiple silica gel treatments may be required to obtain valid results. -Wesson oil demonstrated problems with removal by silica gel

Presearch. “Determining Hexane-Extractable Material”. Nov URL: M.B. Labs LTD. “Hydrocarbons-Definitions and Explanations”. URL: South Mall Analytical Labs. Renee Cohen. Total Petroleum Material Non Polar Material Non-Polar Material (NPM) Standard Operating Procedure The Environmental Protection Agency. “Guideline Establishing Test Procedure For The Analysis of Oil and Grease and Non-Polar Material under the Clean Water Act and Resource Conservation and Recovery Act; Final Rule”. May 1999 URL: United States Environmental Protection Agency. “Extractable Material (HEM; Oil and Greases) and Silica Gel Treated n-Hexane Extractable Material (SEG-HEM; Non-Polar Material) by Extraction and Gravimetry. Feb URL: United States Environmental Protection Agency. “Approval of EPA Methods 1664, Revision A, and 9071B for Determination of Oil and Grease and Non-polar Material in EPA's Wastewater and Hazardous Waste Programs”. Feb URL: