Figure8
Stablebaselines, excellent peak symmetry, and rapid,
baseline resolutionof all compounds characterize FAMEs
analyses on a Stabilwax® column.
RapeseedFAMEsonStabilwax®
1. myristic acid C14:0
2. palmitic acid C16:0
3. palmitoleic acid C16:1
IS methyl heptadecanoate
4. stearic acid
C18:0
5. oleic acid
C18:1
6. linoleic acid
C18:2
7. linolenic acid C18:3
8. arachidic acid C20:0
9. gadoleic acid C20:1
10. behenic acid C22:0
11. erucic acid
C22:1
12. lignoceric acid C24:0
13. nervonic acid C24:1
GC_PC00917
Soy
Tallow
Rapeseed
YellowGrease
Myristic acid
C14:0
0.21
1.7
0.11
0.68
Palmitic acid
C16:0
11.24
25.5
4.1
16.35
Palmitoleic acid C16:1
0.2
3.27
0.27
1.23
Stearic acid
C18:0
4.04
14.41
1.8
9.32
Oleic acid
C18:1
21.93
40.34
58.57
47.8
Linoleic acid
C18:2
53.84
12.02
22.2
20.01
Linolenic acid
C18:3
7.29
0.99
13.26
2.93
Arachidic acid
C20:0
0.36
0.4
0.79
0.46
Gadoleic acid
C20:1
0.26
1.03
1.79
0.39
Behenic acid
C22:0
0.45
0.57
0.44
Erucic acid
C22:1
0.13
0.23
Lignoceric acid
C24:0
0.16
0.34
0.3
0.24
Nervonic acid
C24:1
0.17
0.54
Table
I Sourcesof FAMEs inB100biodiesel fuel (%m/m).
AnalyzingMethanol inBiodiesel
Methanol is commonly used to produce biodiesel
byderivatizing the fattyacids tomethyl esters.The
amount of residualmethanolmust bedetermined
because engine performance can be negatively
affected if themethanol concentration in the final
product is toohigh.Methanol inbiodiesel isquan-
tified using a headspacemethod (e.g. EN 14110).
We recommend anRtx®-1 column (30m, 0.32mm
ID, 3µm) for this analysis. The selectivity of the
Rtx®-1 column is ideal for resolving methanol
from interferingpeaks inbiodiesel fuels.
Conclusion
Whether testing forglycerin,FAMEs,ormethanol,
Restek can supply the high quality chromatogra-
phy products required for biodiesel testing. We
offer an array of metal and fused silica GC
columns designed for high performance biodiesel
analysis, including our innovative MXT®-
Biodiesel TG columnwith an Integra-Gap™ inte-
grated retention gap (Table II). Our columns,
accessories, and analytical reference materials are
designed to improveanalytical quality, simplify lab
work,and increaseproductivity.RelyonRestek for
innovative solutions to your biodiesel testing
needs.
AnalyzingFAMES inBiodiesel
FAMEs are thedesired endproduct of biodiesel production and they are ana-
lyzed todetermine thepercentof usable fuel in the finalproduct.AStabilwax®
fused silica GC column affords excellent peak symmetry, resolution, and
reproducibility for determining the FAMEs and linolenic acid methyl ester
content in B100 biodiesel fuel, following European standard method EN
14103.
As shown inFigure8,C14:0-C24:1FAMEs and linolenicacidmethyl ester can
be determined in less than 11minutes using a 30m x 0.32mm ID x 0.25µm
Stabilwax®column.Particularlynotableare the stabilityof thebaseline, excel-
lentpeak symmetry, andbaseline resolutionof all compoundsof interest.The
Stabilwax® column shows excellent peak shape for all FAMEs, even at low
concentrations,which is critical for accurate quantification (Table 1).
Stabilwax®Column (fusedsilica)
(Crossbond
®
Carbowax
®
polyethylene glycol)
ID df (µm)
temp. limits
length cat.#
price
0.32mm 0.25
40 to 250°C
30-Meter 10624
$460
Rtx®-1Columns (fusedsilica)
(Crossbond® 100% dimethyl polysiloxane)
ID df (µm)
temp. limits
length cat.#
price
0.32mm 3.00 -60 to 280/300°C 30-Meter 10184
$465
Column:
Stabilwax
®
, 30m, 0.32mm ID, 0.25µm (cat.# 10624)
Sample:
rapeseed source of biodiesel (B100), prepared according to EuropeanMethod EN 14103
Inj.:
1.0µL split (split ratio 100:1), Cyclosplitter
®
inlet liner (cat.# 20706)
Inj. temp.:
250°C
Carrier gas:
hydrogen, constant flow, 3mL/min.
Linear velocity: 60cm/sec.
Oven temp.:
210°C (hold 5min.) to 230°C@ 20°C/min. (hold 5min.)
Det.:
FID
Det. temp.:
250°C
•
800-356-1688
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