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The D etection of the Concentrations of Multiple U nknowns in a Hazardous Organic Solvent Waste C ontainer. Problem. To find the concentrations of the major components of an unlabeled organic hazardous waste bottle that was left over from an experiment in an undergraduate lab. Purpose.
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The Detection of the Concentrations of Multiple Unknowns in a Hazardous Organic Solvent Waste Container
Problem To find the concentrations of the major components of an unlabeled organic hazardous waste bottle that was left over from an experiment in an undergraduate lab Purpose The labeling of hazardous chemicals is required by law for transport and disposal. The solvent bottle needs to be labeled so that the chemical disposal company can dispose of the contents safely
The Hypothetical Concentration The solvent bottle is certain to contain the results of the current experiment : Acetone Water Isoamyl Acetate The other proposed solvents are leftover starting materials and results from other experiments that were being done in the lab. Isoamyl alcohol, H2SO4, Camphor, NaBH4, MeOH, Isoborneol, Borneol, Methyl-3-nitrobenzoate, Methylbenzoate
GC/MS Choice GC/MS was chosen because: • Short analysis times • Relatively cheap • Separation of the complex sample • Concentration sensitive • All of the relevant compounds can be analyzed • Reproducibility • Very accurate for the price • Ease of use • Small sample • Semi-portable (desktop)
Diagram of GC/MS Quadrupole
HP/Agilent 6890 GC/ 5973 MSD2 Price:$22,5001 Features: 7694A Headspace Auto Sampler • GC • 0-120oC /min per ramp • Max temp 450oC • Carrier gas Helium • MS • Quadrapole type • 350oC operational temp • 1.6-800 amu in .1 amu steps • 5200 amu/sec in .1 amu steps • S/N 20:1 within the 50-300amu range • Up to 30 masses at a time • Sensitivity 1pg • Resolution .1 amu
Experiment First, determine the retention times for a set of standards present in the sample matrix. The standards would be acetone, water and DCM Second, Sort the potential components by Ionic strength Third, take samples from the bottle at various places. Dilute with DCM to two mL. Finally run the samples through and determine the molecule by retention time and molecular mass.
Proposed Analysis of the Data Selected m/z 182 Measure the relative concentration by using the area of the peaks. Determine if further separation is needed for appropriate analysis Check to see if the molecular masses align with the proposed position relative to the other peaks. Then label the solvent bottle accordingly
Sources • www.labx.com, accessed 12/03/09 • Agilent Technologies, www.chem.agilent.com accessed 12/03/09 • Skoog, D.; Holler, F.; Crouch, S. Principles of Instrumental Analysis, 6th ed. • US Department of Transportation, Pipeline and Hazardous Materials Safety Administration, Title 49 CFR parts 100-185 • Makas, A.; Troshkov, M. Field Gas chromatography-mass spectrometry for fast analysis, Journal of Chromatography B, Vol. 800, iss. 1-2,2/5/04 pg55-61 fig. 2 • Moran Farhi, Natalia Dudareva, Tania Masci, David Weiss, Alexander Vainstein and Hagai Abeliovich, Synthesis of the food flavoring methyl benzoate by genetically engineered Saccharomyces cerevisiae, Journal of Biotechnology, Vol. 122 Iss. 3 4/10/06 pg307-315 GC/MS diagram • Introduction to Gas Chromatography, Sheffield Hallam University • Wikipedia, Block MS Image