Penetration of Sodium Lauryl Sulfate in Gallus Gallus Domesticus Egg Shell Thousand Oaks High School AP Research STEM
Overview Detecting sodium lauryl sulfate through high performance liquid chromatography (HPLC) Treating eggs with SLS at various exposure times Not enough studies have been done on penetration ability of chemicals on chicken eggs
Chicken Eggs An average of 259.2 eggs consumed per person in 20151 Eggs are popular source of protein in diet Do you wash your eggs? If so what do you wash your eggs with? U.S. requires egg producing companies to wash eggs More studies conducted on bacteria 1 Poultry Facts. Purdue Food Animal Education Network, Purdue University, 2008, www.ansc.purdue.edu/faen/poultry%20facts.html. Accessed 6 Apr. 2017.
Why Sodium Lauryl Sulfate? Very common washing agent Found in soaps, shampoos, detergents Cleans off residues and oil1
Purpose Testing the penetration ability of SLS on chicken eggs Bring awareness to washing eggs Change the view of what to wash eggs with
Research Questions Does sodium lauryl penetrate chicken egg shell when it is used as a cleaning sanitizer? Does rinsing the eggs with tap water have an effect on the penetration of sodium lauryl sulfate?
Hypothesis SLS will penetrate the eggs that have been rinsed and treated with SLS for 5 minutes. The HPLC will show very little detection of SLS in the eggs that were washed for 1 minute. Also the eggs that were rinsed before treatment will have a higher chance of showing SLS detection.
Materials High Performance Liquid Chromatography (HPLC) Column C18 Solvent of 70% Acetonitrile and 30% Water 7 of 0.45 µm syringe filters 21 Unwashed Chicken Eggs from family owned chickens Liquid form and solid form of sodium lauryl sulfate 21 Falcon Tubes, Microtubes, and HPLC vials Stock solution of 100 ml 1000 ppm Sodium Lauryl Sulfate P1000 micropipette and tips P200 micropipette and tips Serological Pipettes 500 ml or 250 ml beakers Volumetric flask 100 ml 2 100 ml bottles (one glass and one plastic) Tap Water Stop watch Spoon Gloves Lab coat Goggles Lab refrigerator kept at 4 C
Safety Take careful precaution while working in the lab Wear goggles at all times when working with HPLC Wear gloves and lab while : Treating eggs with SLS as well as preparing stock solution Store all chemicals in appropriate places
Treating the Eggs with SLS 2 Stock solution of 100 ml of 1000 ppm SLS All eggs treated with 350 ppm2 3 eggs were submerged for 1, 2.5, or 5 minutes Eggs dried and stored in lab refrigerator Sodium Lauryl Sulfate (SLS). For Better Living, The American Cleaning Institute, www.cleaninginstitute.org/policy/sls.aspx. Accessed 6 Apr. 2017.
Table of Egg Rinsing and Treating Time Rinsed with Tap Water Rinsed Eggs Not Rinsed Eggs Control Group 0 minutes None were rinsed 3 eggs not rinsed or treated Experimental Group 1 1 minute 3 eggs rinsed and treated with 350 ppm SLS 3 eggs not rinsed and treated with 350 ppm SLS Experimental Group 2 2.5 minutes 3 eggs rinsed and treated with 350 ppm SLS 3 eggs not rinsed and treated with 350 ppm SLS Experimental Group 3 5 minutes 3 eggs rinsed and treated with 350 ppm SLS 3 eggs not rinsed and treated with 350 ppm SLS
Sample Preparation Eggs cracked and and yolk and albumen put in falcon tubes 2 ml of egg transferred to a microtube Centrifuged for 10 min at 9000 RCF Collected supernatant Filtered supernatant with 0.45 µm syringe filters
High Performance Liquid Chromatography Isocratic Solvent : 70:30 Acetonitrile and Water C18 Column Reverse Phase Flow Rate : 0.5 ml/min Thermostat : 35 C Standard Samples : 50, 100, 300, 400 ppm Wavelength : 254 nm
Results Chromatograms of standards show peak of 2.5 minutes SLS found in eggs not rinsed but treated for 5 minutes No detection in eggs treated for 1 minute No correlation between rinsed and unrinsed eggs
Chromatogram of Standard 400 ppm Sodium Lauryl Sulfate
HPLC 3D Plot of 400 ppm Standard Sodium Lauryl Sulfate
Chromatogram of Eggs not rinsed but treated for 5 minutes
Discussion Sodium lauryl sulfate penetrated the eggs that were rinsed for 5 minutes Egg producing company should avoid using SLS or reduce exposure time Higher concentration and more exposure time increase chances of penetration With more time, run experimental group 2 samples
Conclusion Avoid using Sodium lauryl sulfate as cleaning agent for eggs Continue further studies on penetration of chemicals More results = better understanding of penetration ability of SLS
Possible Sources of Error HPLC sources of error : Used 2 columns while running samples Standard chromatogram had multiple peaks Not all of SLS was extracted from yolk
Further Research Test the effects of SLS on respiration rate of yeast Effects of SLS on the eggs proteins Testing other possible chemicals on eggs Test different concentrations of SLS on eggs
Acknowledgements A BIG thanks to : Dr. Niki Malhotra Christina Tokatlian Dr. Greg Cauchon Mr. Jeff Lewis My Parents
References 1 Poultry Facts. Purdue Food Animal Education Network, Purdue University, 2008, www.ansc.purdue.edu/faen/poultry%20facts.html. Accessed 6 Apr. 2017. 2 Sodium Lauryl Sulfate (SLS). For Better Living, The American Cleaning Institute, www.cleaninginstitute.org/policy/sls.aspx. Accessed 6 Apr. 2017.
Penetration of Sodium Lauryl Sulfate in Gallus Gallus Domesticus Egg Shell Thousand Oaks High School AP Research STEM