2
Oven Method
Initial Temperature (°C)
35
Initial Time (min)
4
Heating Rate (°C/min)
4
Final Temperature (°C)
200
Hold Time (min)
0
SSL Method
Temperature (°C)
200
Mode
split
Split Flow (mL/min)
80
Carrier Method
Mode
Helium, Constant Flow
Value (mL/min)
1
TriPlus RSH Method
Sample Volume (
μ
L)
1000
Incubation Time (min)
15
Incubation Temperature (°C)
80
Syringe Temperature (°C)
120
Use the first calibration to check the linearity of the
system and the accuracy of the overall sample preparation
procedure. The autosampler automates this calibration by
adding various volumes (from 1 to 5 µL) of diluted
solution to a set of empty vials before the headspace
analysis of the vials.
For quantification by means of the standard addition
method, cut samples of foil packaging from a
commercially produced croissant product into square
pieces of 48 cm
2
each. Prepare five 20 mL sample vials
by placing a foil piece in a headspace vial which is then
crimped. For each sample, these five vials are then further
prepared and analyzed by the TriPlus RSH autosampler.
The autosampler adds selected amounts of standard into
the headspace vials, plus a volume of a solvent calculated
to mantain constancy in the total volume of liquid in
the vial. This ensures that the same conditions are kept
constant across all vials.
For example, in this study the following volumes have
been used:
• Vial 1 (sample + 7 μL water)
• Vial 2 (sample + 1 μL standard + 6 μL water)
• Vial 3 (sample + 3 μL standard + 4 μL water)
• Vial 4 (sample + 5 μL standard + 2 μL water)
• Vial 5 (sample + 7 μL standard)
Separations
Perform the sampling of the prepared vials by means of
headspace injection on the TRACE
™
1310 GC coupled
with the ISQ
™
Single Quadrupole GC-MS system (Figure
1).
Perform analysis of the sample in full-scan mode for the
identification of components. Run the quantification
step in selected ion monitoring (SIM) mode of masses:
31, 43, 45, 55, 56, 59, and 91
m/z
. Both modes alternat-
ing full-scan/SIM are performed simultaneously per each
sample injection.
Use the TraceGOLD TG-624 column for separation of the
VOCs.
Table 1 shows the GC and headspace parameters.
Figure 1. TriPlus RSH Autosampler and TRACE 1310 GC with the ISQ
Single Quadrupole GC-MS system.
Table 1. GC and headspace parameters
