Expanding Capabilities of the MPS for
GC/MS Applications: Packaging
Malodors and Food Flavors
Kurt ThaxtonGERSTEL
Intro to GERSTEL automated sample preparation
technology for GC/MS
Applications for Flavor and Fragrance Analyses:
Stir Bar Sorptive Extraction (SBSE) of Benzophenone in Paperboard
Full aroma and flavor profiling of Beer samples
Fraction Collection, Re-visited
Outline
CTC
PAL
HS
Liq
SP
ME
What Can you do with
a CombiPAL?
TD
Dual
Head
Pyro
MPS GC
ATEX Thermal
Extraction in µVials
TDU Thermal Desorption
•and PYROlysis
Dynamic
Headspace
DHS
Solid Phase
Extraction SPE
Dispersive Pipette
Extraction DPX
SPME & Multi-
Fiber EXchange
MFX
ALEX Automated
Liner EXchangeHeadspace
MPS GC
TDU Thermal Desorption
•and PYROlysis
Cooled Injection System - CIS
Thermal Desorption Unit - TDU
TDU Tube
TDU
No Transfer line !
Universal Thermal Desorption Unit
TDU
TDU liner with frit for thermal
extraction of solid samples
TDU liner packed with adsorbent
TDU liner for Twister desorption
TDU liner for thermal extraction in µ-vials
Analysis of Malodors
(Baltimore NCIS*)
*Nasty Chemicals Insulting the Senses
• PDMS coated magnetic stir bar
PDMS or PDMS/PEG
coating
Magnetic core
Glass mantle
Twister (SBSE) Sample Preparation
Add GERSTEL Twister to vial
Stir for 1 hour
Rinse in distilled water
Dry with tissue
Analyze in TDU
Up to 1000 times more sensitive
than SPME
Widely used with food simulants
Applications:- http://www.gerstel.com/en/apps-twister-
sbse.htm
Time for the Big Guns
Approach: Identifying odor compounds
- Choosing the sampling technique
How do you know you have trapped the target
compound? Aim for non-selectivity
- Put enough mass on column
- Couple MS with olfactometry
- Manage complex sample matrix with GC-GC
Standard modes
- Liquid, HS, SPME
Thermal extraction
- Solids
- Liquids (ATEX)
Thermal Desorption
- Adsorbent tubes
- SBSE (Twister)
Dynamic Headspace
Choose an introduction
mode that is compatible
with the sample and
provides enough mass
on column to detect the
target analyte.
Ideally NON-
SELECTIVE
Two Approaches to Multidimensional GC
Heartcutting GC-GC- Standard (30m) precolumn
- Standard (30m) second column
- Selected portions of the first chromatogram “cut” to second
dimension
- Compatible with splitting to several detectors- FPD, ODP
Comprehensive GCxGC- Standard (30m) precolumn
- Very short (1m) second column
- All compounds from precolumn are sent to second column
- Usually requires fast data acquisition (TOF)
Olfactory
Detection
Port
GC-Olfactometry
Split column
effluent between
MS and ODP
Voice recognition
software to
capture analyst
descriptors
Non-dedicated system
- can be used for both 1DGC-MS and 2DGC-MS without
• any instrumental set-up change
The selection of 1D or 2DGC-MS is only performed
by a “Change of the method” (click of the mouse).
No preliminary injection before heart-cutting
- 2DGC-MS can be performed just after 1DGC-MS run2DGC-MS can be performed just after 1DGC-MS run
Selectable 1D or 2DGC-MS
We developed a Selectable 1D or 2DGC-MS with
selective detection using CFT and dual LTM-GC
•CFT
+ +
“Monitor TIC” can be obtained as the 1st dimension for 2DGC-MS
Heart-cutting
1D TIC (DB-Wax)
SBSE – GC – O/MS:
Beer Sample: 10 mL, Twister: 1 cm x 500 µm, SBSE: 120 min, Injection: Splitless
1st Column: DB-Wax, 2nd Column: DB-5, Sniffing device: GERSTEL ODP2,
GC-MS: Agilent 7890GC/5975MSD, ODP/MS Split ratio: 1/1
SBSE-TD-1DGC-O/MS: Beer
Sweet & Honey
Phenethyl acetate + ??
“Change of the method
by click of the mouse”
•SBSE – GC – GC – O/MS:
•Beer Sample: 10 mL, Twister: 1 cm x 500
•
SBSE-TD-2DGC-O/MS: Heart-cutting & Back Flush
Back Flush
1DGC-MS
2DGC-MS
w/Back Flush
Heart-cutting
2D TIC (DB-5)
Both the 1D TIC and the 2D TIC could be obtained on the
same chromatogram in a single run.
1D TIC (DB-Wax)
•SBSE – GC – GC – O/MS:
•Beer Sample: 10 mL, Twister: 1 cm x 500
•
SBSE-TD-2DGC-O/MS: Beer
GC-O Signal
Back Flush
Heart-cutting 2D TIC (DB-5)1D TIC (DB-Wax)
Phenethyl acetate
?
2D TIC (DB-5)
SBSE-TD-2DGC-O/MS: Beer
?
•GC-O SignalMass Spectrum
NIST Library Search Result: β-Damascenone
β-Damascenone
β-Damascenone is known as kind of rose ketone. The odor description is “Sweet, Fruity,
Plum, Raspberry, etc.”, and the odor threshold in water is quite low, with values in the
literature in the range of 20 to 90 ng/L 7).
Fraction Collection:Sometimes You Really Do Want to Repeat Yourself
Preparative
Fraction
Collector
PFC•Transfer line from GC
•Waste trap in cooled
compartment
•Fraction traps•Fraction traps
•Preparative
Switching
•Device
•Cooled trap compartment •Cooled trap compartment
Setup for ODP 3
Replace ODP cone with Tenax TA
“Simple Fraction Collection”Selectable 0:1, 1:0, or 1:1 w MSD
Advantages of Post-Column Collection
ODP Port!
Independent of Sample Introduction Technique
“Selective” Fraction Collection
- Can Collect “Splitless” Injections at 50%
- Solvent not Collected
- Tail-end Junk not Collected (or Middle Stuff too!)
For Split, Little “Cost” Compared to Pre-Column- Based on 1:10 Splitting, only about 1.8x Less but no solvent or junk
Manual or Automated- Simple, Easy to Manually Time Recollection
- Alternately Can Be Automatic, Software-Selectable
- Can Automatically Recollect Several Fractions or Samples with PFC
Let’s Build
Something
Cool Together!
(and let
Maestro &
Mass Hunter
run it…)
Diesel Range Organic (DRO) Mix
50 ppm in MeOH
100% to 5975 MSD
Kovats Index Hydrocarbons
Kovats Index Hydrocarbons
50 ppm in MeOH
100% to 5975 MSD…
…Sometimes
Re-Use those Fractions for the
ULTIMATE FFF ANALYZER
N. Ochiai et. al. “Multidimensional gas chromatography
in combination with accurate mass, tandem mass
spectrometry, and element-specific detection for
identification of sulfur compounds in tobacco smoke”
J. Chromatography A 1358(2014) 240-251
DHS-Large Autosampler
Coming
Soon!
SummaryGERSTEL Enhancements and Improvements for
Food-Flavor-Fragrance Analysis
Do Better than L-L Extraction: Use Twister on Packaging Simulants
Sophisticated GC-GC Tools for Malodor Analyses are Easy to Use with Maestro as your Platform
Old Dogs have Cool Tricks: Fraction Collection is the Best Way to Re-Analzye and/or Aggregate Samples