Determination of δ13C of Trace Hydrocarbons in Natural Gas Using Syringe Solid Phase Extraction (SSPE) Coupled with Gas Chromatography/Isotope Ratio Mass Spectrometry (GC/IRMS)
Table 3
δ13C ratios of standard natural gas sample and its SDs at different conditions.
Compound
SD-A
Adsorption temperature (°C)
Desorption temperature (°C)
Adsorption time (s)
Desorption time (s)
()
SD-1
SD-2
()
SD-1
SD-2
()
SD-1
SD-2
()
SD-1
SD-2
CH4
-41.84
-42.40
0.97
0.40
-41.88
0.44
0.03
-41.55
0.24
0.20
-41.52
0.24
0.23
C2H6
-29.45
-30.85
0.53
0.99
-29.78
0.57
0.23
-30.08
0.32
0.44
-29.75
0.80
0.21
C3H8
-26.70
-26.96
0.40
0.18
-27.99
0.46
0.91
-27.05
0.42
0.25
-27.62
0.41
0.65
i-C4H10
-26.48
-25.72
0.70
0.54
-27.03
0.61
0.39
-26.87
0.16
0.28
-21.31
0.33
3.66
n-C4H10
-25.58
-25.39
0.79
0.13
-25.37
0.44
0.15
-25.60
0.39
0.02
-23.98
0.36
1.13
i-C5H12
-24.78
-24.97
1.80
0.13
-20.13
0.61
3.29
-25.26
0.41
0.34
-17.25
0.28
5.32
n-C5H12
-23.12
-22.92
1.08
0.14
-19.71
0.81
2.41
-23.47
0.28
0.25
-16.9
0.44
4.40
SD-A: the average ratios of the standard natural gas sample, V-PDB, ‰; : average ratios at different experimental conditions, V-PDB, ‰; SD-1: standard deviations obtained from average ratios at different experimental conditions; SD-2: standard deviations between STDA and .
