Non-Metals
137
Table 7.9
Reproducibility of pristane analyses (from [403])
Analyst
Cod Liver Sample A
Quinn, Wade
Farrington
Cod Liver Sample B
Farrington
IDOE-5
Quinn, Wade
Teal, Burns
Farrington
Tuna meat
Quinn, Wade
Teal
Farrington
Technique
Saponification-TLC, GC'
Saponification-TLC, GC, 3 analyses by GC
Saponification-CC, 2 analyses by GC
No saponification-CC, GC, Subsample A-I
No saponification-CC, GC, Subsample A-2
No saponification-CC-GC
Subsample 1
Subsample 2
Pristane concentration Lipid mg kg- 1
30.1
35.8 ± 1.6
39.4 ± 2.3 b
36.4 ± 1.6 b
37.3 ± LOb
mean = 35.7 ± 3.5
38.7 (n-C 14 )C
40.3 (n-C 28 )
37.1 (n-C I4 )
39.7 (n-C 28 )
mean = 39.0 ± 1.2
Saponification-TLC, GC, 2 analyses 259, 268;
mean = 264
Saponification-CC, GC, 1 analysis
276
Saponification-CC, GC, 6 analyses, range 225 to 308; mean = 272
Mean for 3 laboratories
Saponification-TLC, GC, 2 analyses 3.0, 3.6;
Saponification-CC, GC, 1 analysis
Saponification-CC, GC, 2 analyses; 1.9, 2.0;
Mean for 3 laboratories
271 ± 4.5
mean = 3.3
2.0
mean = 2.0
2.4 ± 1.5
• TLC = Thin layer chromatography; CC = Column chromatography; GC = Gas chromatography
b Mean ± 1 (J estimated from 2 or 3 analyses by GC of hydrocarbons isolated from same sample
C Internal standard used to calculate concentration. Both n-C 14 and n-C 28 added to subsarnples as
internal standard
Table 7.9 gives the results of naturally occuring pristane determinations in unspiked cod liver oil and tuna meat samples analysed by different methods. Agreement
and precision are good for cod liver oil, but not so good for tuna meat.
Table 7.10 shows the results obtained for a sample of cod liver [402-404] spiked
with a known amount of crude oil. The measured concentration of petroleum hydrocarbons is in fair agreement with the actual concentration spiked to the sample
- 372 mg kg- 1 lipid.
Law [405] and Chesler et al. [406] have discussed the application of gas chromatography-mass spectrometry to the determination of traces of hydrocarbons in fish.
Chesler et al. [406] used dynamic headspace analysis of an alkaline digest of the
sample to prepare extracts for gas chromatography.
7.3.2
Po/yaromatic Hydrocarbons
Vassilaros et al. [407] have described a method for determining polyaromatic hydrocarbons down to 0.2 J..Lg kg- 1 in fish tissue. The analytical procedure includes the
137
Table 7.9
Reproducibility of pristane analyses (from [403])
Analyst
Cod Liver Sample A
Quinn, Wade
Farrington
Cod Liver Sample B
Farrington
IDOE-5
Quinn, Wade
Teal, Burns
Farrington
Tuna meat
Quinn, Wade
Teal
Farrington
Technique
Saponification-TLC, GC'
Saponification-TLC, GC, 3 analyses by GC
Saponification-CC, 2 analyses by GC
No saponification-CC, GC, Subsample A-I
No saponification-CC, GC, Subsample A-2
No saponification-CC-GC
Subsample 1
Subsample 2
Pristane concentration Lipid mg kg- 1
30.1
35.8 ± 1.6
39.4 ± 2.3 b
36.4 ± 1.6 b
37.3 ± LOb
mean = 35.7 ± 3.5
38.7 (n-C 14 )C
40.3 (n-C 28 )
37.1 (n-C I4 )
39.7 (n-C 28 )
mean = 39.0 ± 1.2
Saponification-TLC, GC, 2 analyses 259, 268;
mean = 264
Saponification-CC, GC, 1 analysis
276
Saponification-CC, GC, 6 analyses, range 225 to 308; mean = 272
Mean for 3 laboratories
Saponification-TLC, GC, 2 analyses 3.0, 3.6;
Saponification-CC, GC, 1 analysis
Saponification-CC, GC, 2 analyses; 1.9, 2.0;
Mean for 3 laboratories
271 ± 4.5
mean = 3.3
2.0
mean = 2.0
2.4 ± 1.5
• TLC = Thin layer chromatography; CC = Column chromatography; GC = Gas chromatography
b Mean ± 1 (J estimated from 2 or 3 analyses by GC of hydrocarbons isolated from same sample
C Internal standard used to calculate concentration. Both n-C 14 and n-C 28 added to subsarnples as
internal standard
Table 7.9 gives the results of naturally occuring pristane determinations in unspiked cod liver oil and tuna meat samples analysed by different methods. Agreement
and precision are good for cod liver oil, but not so good for tuna meat.
Table 7.10 shows the results obtained for a sample of cod liver [402-404] spiked
with a known amount of crude oil. The measured concentration of petroleum hydrocarbons is in fair agreement with the actual concentration spiked to the sample
- 372 mg kg- 1 lipid.
Law [405] and Chesler et al. [406] have discussed the application of gas chromatography-mass spectrometry to the determination of traces of hydrocarbons in fish.
Chesler et al. [406] used dynamic headspace analysis of an alkaline digest of the
sample to prepare extracts for gas chromatography.
7.3.2
Po/yaromatic Hydrocarbons
Vassilaros et al. [407] have described a method for determining polyaromatic hydrocarbons down to 0.2 J..Lg kg- 1 in fish tissue. The analytical procedure includes the