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PS 26 Playground - Soil Analysis Analytical Chemistry of Pollutants Dr. Joe Gardella Todd M. Alonzo, Dominic O. Hull, Doris J. Glykys, Ed Tasber, and David G. Twoey
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Why Did We Choose PS26? b Soil Analysis b GC/MS b Elemental Analysis - Why Lead? Requested by CommunityRequested by Community Buffalo ChinaBuffalo China Very Toxic MetalVery Toxic Metal
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Sampling Technique b Donned Gloves and Safety Glasses b Spade Rinsed with 50/50 v/v Nitric Acid/DI Water b Dig Hole and Obtain sample at 6” Depth b Refill Hole b Jars Amber to Avoid Photolysis No Head Space Above Sample Sealed with Foil Cooled on Dry Ice
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Sampling Sites Synthetic Organic Compounds Lead Harrison St. (Dead End)
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Sampling Sites Synthetic Organic Compounds Lead Harrison St. (Dead End)
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Sampling Sites Synthetic Organic Compounds Lead Harrison St. (Dead End)
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Sampling Sites Synthetic Organic Compounds Lead Harrison St. (Dead End)
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Sampling Sites Synthetic Organic Compounds Lead Harrison St. (Dead End)
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Sampling Sites Synthetic Organic Compounds Lead Harrison St. (Dead End)
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Sampling Sites Synthetic Organic Compounds Lead Harrison St. (Dead End)
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Sampling Sites Synthetic Organic Compounds Lead Harrison St. (Dead End)
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Elemental Analysis b Digestion b Flame Atomic Absorption Spectroscopy b Inductively Coupled Plasma / Atomic Emission Spectroscopy b Standard Addition b Results
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Digestion b EPA Method 3050 Successive Nitric Acid Additions and RefluxSuccessive Nitric Acid Additions and Reflux Reduce VolumeReduce Volume Peroxide NeutralizationPeroxide Neutralization Reduce VolumeReduce Volume –GFAA and ICP/MS Addition of HCl AcidAddition of HCl Acid –FLAA and ICP/AES
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Direct Aspiration Atomic Absorption Spectroscopy (FLAA) b A sample is aspirated and atomized in a flame. b A characteristic light beam is directed through the flame into a monochromator, and onto a detector that measures the amount of absorbed light. b Absorption depends upon the presence of free unexcited ground-state atoms in the flame. »Beer-Lambert Law
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Standard Addition b The preparation of standards that match the samples is often impossible or extremely difficult. b The preparation of standards that match the samples is often impossible or extremely difficult. b Accurate determinations are possible by making the concentration calibration in the presence of the matrix. b By adding aliquots of a standard to portions of the sample, any interferent present in the sample will affect the standard and sample absorbance similarly.
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If Interferences are present: b The number of ground state atoms producing atomic absorption will be affected. b The absorbance increase from the added standard will also change by the same proportional amount since the concentration of interferent is the same in each solution.
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Determination of Concentration
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Comparison of Lead Results
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Synthetic Organic Analysis b Digestion b Volume Reduction b GC-MS Analysis b Qualitative Analysis b Quantitative Analysis
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Digestion b EPA Method 3550 –Addition of NaSO 4 –Successive Addition of 50/50 v/v Methylene Chloride/Acetone with Ultrasonic Extraction –Vacuum Filtration –Reduce Volume
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GC-MS Analysis b Separation of Components –Using Capillary Column –by Molecular Weight b Mass Analysis –Fragmentation of Compounds –Mass Separation by Mass-Charge Ratio
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Qualitative Results b Acenaphthene b Anthracene b Bis(2-ethylhexyl) Phthalate b Dibenzofuran b Fluranthene b Fluorene b 2-Methyl- Naphthalene b Naphthalene b Pyrene b 4-Fluoro-1,1’-Biphenyl b 1,2-Dihydro- Acenaphthylene
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Quantitative Analysis
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Conclusions b Lead and PAHs were detected in the soil b Concentration of lead in the park was below action level b Concentration of lead at the dead end was above 400 ppm level b Many of the PAHs detected could not be quantified
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