1. Determination of Precipitation Contamination Derek Anderson Teri Wilson

2. Hypothesis We believe that snow is purer than rain.

3. The Six Common Air Pollutants Ozone Particulate Matter Carbon Monoxide Nitrogen Oxides Sulfur Dioxide Lead

4. Nitrogen Oxides (NOx) Most common are: nitrogen dioxide (NO 2 ) and nitric oxide (NO) Primary sources are: kerosene heaters, un- vented gas stoves/heaters, and environmental tobacco smoke Causes eye, nose, and throat irritation National Ambient Air Quality Standard for Nitrogen Dioxide: <0.053ppm

5. Lead (Pb) A metal found naturally in the environment as well as in manufactured products Once taken into the body, lead distributes throughout the body in the blood and accumulates in the bones Lead exposure affects the oxygen carrying capacity of the blood National Ambient Air Quality Standard for Lead: <0.15μg/m 3

6. Collection Method Samples were collected outside of Teri’s garage Collected in clean, dry plastic containers Poured into sterile glass jars and covered securely Stored in the refrigerator until testing

7. Collection of Precipitation SampleType of Precipitation DateOutside Temperature Sample 1Freezing Rain2-5-1131.2 F Sample 2Rain2-5-1135.7 F Sample 3Snow2-5-1134.8 F Sample 4Rain3-6-1153.2 F Sample 5Rain/Snow Mix3-30-1142.9 F Sample 6Snow3-30-1138.8 F

8. Testing Dionex ICS-90 Ion Chromatography (IC) HP 8453 Diode Array UV/Vis Spectrophotometer Varian Inductively Coupled Plasma (ICP-OES)

9. IC Experiment Analyte of Interest – Nitrate and Nitrite Standards Used – 7 Anion Standard Standard 1 – 10 ppm Standard 2 – 15 ppm Standard 3 – 20 ppm Standard 4 – 25 ppm Standard 5 – 100 ppm

10. IC Parameters Pressure: 890 psi Flow rate: 1 mL/min Pressure Gauge: Slightly above 9

11. IC Nitrite Results TypePeak Height (μS) Standard 110 ppm3.433 Standard 215 ppm4.497 Standard 320 ppm4.907 Standard 425 ppm7.354 Standard 5100 ppm25.178 Sample 1Freezing Rain6.867 Sample 2Rain0.465 Sample 3Snow0.043 Sample 4Rain0.052 Sample 5Rain/Snow MixN/A Sample 6SnowN/A

12. Nitrite Calibration Curve

13. Calculated Nitrite Concentrations SampleTypeConcentration (ppm) Sample 1Freezing Rain 24.95451 Sample 2Rain -1.2832 Sample 3Snow -3.0127 Sample 4Rain -2.97582 Sample 5Rain/Snow Mix N/A Sample 6Snow N/A * Negative numbers denote negligible values

14. IC Nitrate Results TypePeak Height (μS) Standard 110 ppm2.308 Standard 215 ppm3.024 Standard 320 ppm3.552 Standard 425 ppm5.177 Standard 5100 ppm20.651 Sample 1Freezing Rain4.792 Sample 2Rain0.406 Sample 3Snow0.352 Sample 4Rain0.320 Sample 5Rain/Snow Mix0.472 Sample 6Snow0.288

15. Nitrate Calibration Curve

16. Calculated Nitrate Concentrations SampleTypeConcentration (ppm) Sample 1Freezing Rain 23.62385 Sample 2Rain 2.445678 Sample 3Snow 2.184935 Sample 4Rain 2.03042 Sample 5Rain/Snow Mix 2.764365 Sample 6Snow 1.875905

17. UV/Vis Experiment Analyte of Interest – Nitrate Standards Used – Standard 1 – 5 ppm – Standard 2 – 10 ppm – Standard 3 – 15 ppm – Standard 4 – 20 ppm – Standard 5 – 25 ppm

18. UV/Vis Parameters Mode: Standard Task: Fixed Wavelength – 224 nm Data Type: Absorbance & Second Derivative Path Length: 1 cm

19. UV/Vis Nitrate Results TypeMean Absorbance Standard 15 ppm 0.500813 Standard 210 ppm 0.99299 Standard 315 ppm 1.463267 Standard 420 ppm 1.773733 Standard 525 ppm 2.1732 Sample 1Freezing Rain 0.060441 Sample 2Rain 0.031449 Sample 3Snow 0.088468 Sample 4Rain 0.017756 Sample 5Rain/Snow Mix 0.129787 Sample 6Snow 0.050405

20. Nitrate Calibration Curve

21. Calculated Nitrate Concentrations SampleTypeConcentration (ppm) Sample 1Freezing Rain -1.00193 Sample 2Rain -1.35334 Sample 3Snow -0.66221 Sample 4Rain -1.51933 Sample 5Rain/Snow Mix -0.16137 Sample 6Snow -1.12358 * Negative numbers denote negligible values Results produced indicate method is not compatible and did not work for our purposes.

22. UV/Vis Nitrate Results TypeSecond Derivative Standard 15 ppm 0.002654 Standard 210 ppm 0.004063 Standard 315 ppm 0.001349 Standard 420 ppm -0.00754 Standard 525 ppm -0.02788 Sample 1Freezing Rain -- Sample 2Rain -- Sample 3Snow -- Sample 4Rain -- Sample 5Rain/Snow Mix -- Sample 6Snow --

23. Nitrate Calibration Curve

24. Calculated Nitrate Concentrations Even using the Second Derivative Mode, results indicated the method did not work and was not compatible for our purposes.

25. ICP Experiment Analyte of Interest – Lead (II) Standards Used – Blank – 0 ppm – Standard 2 – 40 ppm – Standard 3 – 60 ppm – Standard 4 – 80 ppm – Standard 5 – 100 ppm

26. ICP Parameters Search for Pb(II) at: – 179.605 – 182.143 – 220.353 Used Pb(II) at 220 based upon UV/Vis wavelength obtained

27. ICP Lead Results TypeIntensity Blank0 ppm 80.891 Standard 240 ppm 152.27 Standard 360 ppm 205.55 Standard 480 ppm 241.31 Standard 5100 ppm 295.66 Sample 1Freezing Rain 73.989 Sample 2Rain 73.286 Sample 3Snow 75.383 Sample 4Rain 73.505 Sample 5Rain/Snow Mix 75.403 Sample 6Snow 74.098

28. Lead Calibration Curve

29. Calculated Lead Concentrations SampleTypeConcentration (ppm) Sample 1Freezing Rain -0.666074185 Sample 2Rain -0.994901539 Sample 3Snow -0.014032462 Sample 4Rain -0.892464568 Sample 5Rain/Snow Mix -0.004677487 Sample 6Snow -0.615089574

30. Discussion UV/Vis data did not provide results of significance ICP yielded negligible concentrations of lead in samples Overall results support Freezing Rain to contain higher levels of Nitrogen Oxides (NOx)

31. Troubleshooting Sample Nitrite values are below IC sensitivities IC baseline is below 0.00 UV/Vis protocol not understood

32. Summary The original hypothesis that snow is purer than rain was rejected based on our findings No specific precipitation type yielded more pure results than another Only that Freezing Rain contained significantly higher concentrations of Nitrogen Oxides

33. References Evaluation of a second derivative UV/visible spectroscopy technique for nitrate and total nitrogen analysis of wastewater samples Michelle A. Ferree and Robert D. Shannon Water Research 2001 35 (1), p. 327-332. What Are the Six Common Air Pollutants. http://www.epa.gov/ebtpages/airairpollutants.html. 2 April 2011.