The Detection of the Concentrations of Multiple Unknowns in a Hazardous Organic Solvent Waste Contai

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The Detection of the Concentrations of Multiple
Unknowns in a Hazardous Organic Solvent Waste
Container
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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
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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
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Usable Methods of Detection
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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)

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Diagram of GC/MS
Quadrupole
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HP/Agilent 6890 GC/ 5973 MSD2

• Price22,5001
• 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 201 within the 50-300amu range
• Up to 30 masses at a time

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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.
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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

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Sample Readout
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Disadvantages of the other methods
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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