Identifying Unknown Compounds Using Gas Chromatography/Mass Spectrometry

The sample lab report is attached, just look over the format.

1 - Condition'the Solid Phase Micro Extractor (SPME) at 280°C for 5 min in. a flow of helium.
2. Carefully insert the SPME devise into the headspace of a vial containing blue cheese and allow the SPME filament to be exposed for 5 min.
3. Carefully withdraw the SPME and insert it into the injector of the GC/MS following fbe instructors guidance.
4. Record the resulting chromatograms and search 1he computers data "base of mass spectra to tentatively identify the major volatile compounds.Questions:
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1. What appears to be the five major volatile compounds from the
2. What was tbs quality factor of the computer identification of these compounds (i.e., how close was the mass spectra obtained from your sample to the library mass spectra) ?
3. Describe the chemical structure of the 4 major component fragments resulting from any one . of the compounds.
4. What advantages does the mass spectrometer detector have over the flame ionization detector (FID)?

FSC 535 Food Analysis Gas Chromatography/Mass SpectroscopyMass spectroscopy (MS) is an extremely powerful tool for the identification of unknown compounds. A mass spectrometer can also be combined with gas chromatography (GC) to detect eluting compounds and provide structural information about these compounds. Mass spectroscopy provides a unique “fingerprint” of the fragments resulting from the parent compound being exposed to high energy electrons.*

This lab will use the volatile extract from blue cheese (see Food Chemistry (FSC 434) lab on food flavors). Hie compounds extracted into the organic solvent will be separated by • • GC/Flame ionization detection (FDD) and GC/MS. Tentative identification of the major compounds will be obtained by their mass spectras.
Reagents and Materials:
Volatile extract from bke533teB&-^
Equipment:
GC/FED (Agilent Model 6890N)
GC/MS (Agilent Model 6890N GC with 5973 MS detector)
Solid Phase Micro Extractor (SPME) with 100 jim polydimethylsiloxane fiber
GC/MS operating conditions:
Inlet temperature: 240°C Detector interface temperature: 25.0 °C GC oven temperature program:
Hold at 50 °C for 2 min.
Ramp to 150DC at 5°C/min.
Ramp to 230°C at 20°C/min & hold at 230°C for 4 min.
Mass spectra conditions:
70 electron volts applied to the filament System vacuum: 25 mtorr MS Temp. 194°C M/Z range: 35-175
Column DB-5-0.25[un, 30 meters * 0.25 mm Helium flow rate: 1.0 ml/min.
Solvent delay 34 3 min