selected based on the approximate temperature experienced by
the packagingmaterial when heated according to label direc-
tions.
Based on this study, the highest level of volatile compounds
was observed at the label seam. Residual styrene, ethyl ben-
zene, and trace levels of solvents such as THF and toluenewere
detected. The label sampled away from the seam showedmuch
lower levels of all of these components, except the styrene. The
lid sample showed trace levels of ethylbenzene and styrene,
while the inner bowl sample showed no significant levels of
any volatile compounds. This procedure has proven to be an
effectiveway to screen packagingmaterials for the presence of
volatile compounds (Figure 3).
Restek Corporation • (800) 356-1688 • (814) 353-1300 •
CaseStudy of aMicrowavableBowl
Asingle-servingmicrowavable bowl was analyzed using the
protocol outlined in the experimental conditions. The goal was
to determinewhich volatiles the packagingmaterial generates
duringmicrowave heating of this product. Testingwas per-
formed by sampling each of the discretematerials used in the
package. In this study, this resulted in four samples: an inner
bowl that contains the food; a plastic lid; a printed shrink-
wrapped label sampled both at the seam and away from the
seam. Thematerialswere sampled by cutting a 10mm by 65mm
piece into thin strips. Each samplewas placed in aTekmar
purge and trap tube, alongwith 100mLof IS solution. Blanks
(i.e., 100mLof IS solution) were analyzed prior to each sample.
The sampleswere preheated to 60°C and held at this tempera-
ture for 10minutes during purging. This temperaturewas
Figure 3
Screeningmicrowave bowl materials for volatile compounds can be accomplished
using the Rtx
®
-5MS column and themethod outlined here.
2 4 6 8 10 12 14 16 18 20
1
2
3
4
5
GC_FF00460
1
2
3
4 5
6
2 4 6 8 10 12 14 16 18 20
GC_FF00462
1 2
3 4
5
6
7
8
9
10
11 12
13
14 15
2 4 6 8 10 12 14 16 18 20
GC_FF00459
1
2
3
4
5
6 7 8
2 4 6 8 10 12 14 16 18 20
GC_FF00461
Label overwrap sampled at the seam
Label overwrap sampled away from the seam
Inner bowl sample
Lid sample
1. tetrahydrofuran
2. ethylbenzene
3.4-heptanone
4. styrene
5.benzaldehyde
1. tetrahydrofuran
2. 1-butanol
3. toluene
4. hexanal
5. ethylbenzene
6. 4-heptanone
7. butyl ether
8. styrene
9. 1-methylethylbenzene
10.propylbenzene
11.benzaldehyde
12.benzeneacetaldehyde
13.acetophenone
14.benzoic acid, methyl ester
15.decanal
1. ethyl acetate
2. toluene
3. 4-heptanone
4. n-butyl ether
5. styrene
6. alkanes
1. tetrahydrofuran
2. ethylbenzene
3. 4-heptanone
4. styrene
5. benzaldehyde
6. nonanal
7. decanal
8. cinnamaldehyde
See Table I, back page,
for analysis conditions.
