International Journal of Marine Science 2016, Vol.6, No.48, 1-10
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phenyl Methyl silicone with dimensions for PAHs the temperature of column was held at 80 °C for 2 minute then
rate 8 °C /minute to 280°C for 12 min. The individual of PAHs were identified based on the retention time of an
authentic mixed standard procured from Supelco, USA. The concentrations and PAHs compounds were calculated
based on the standard calibration curve of corresponding standard compounds. 80 % to 92 % are the range of
recovery assays for PAHs compounds. Standard deviation for the method was less than 10 % based on replicate
analysis. Great care was taken to avoid contamination of the samples throughout the analytical procedure. All
solvents were distilled twice before use; glassware was rinsed with distilled water and heated in an oven at 250 °C
for 24 hours. However, procedural blanks consisting of all reagents and glassware used during the analysis were
periodically determined which had shown no detectable interference. Total Organic Carbon (TOC) content in the
soil samples is determined according to Riley and Chester method (1981).
Results and Discussion
Seventeen compounds of PAHs were identified in soil samples in the present study in West Qurna-2 oil field. They
were divided into two major groups with respect to their molecular weight. The first included the light (low
molecular weight) compounds with two-three fused aromatic rings which consisting of seven compounds:
naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, and carbazole. The second
included the heavy ( high molecular weight) compounds with four or more fused aromatic rings consisting of ten
compounds: floranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)flouranthene, benzo(k)flouranthene,
benzo(a)pyrene, indeno(1,2,3,c,d)pyrene, dibenzo(a,h)anthracene, and benzo(g,h,i)perylene.
The total concentrations of total PAHs in soil samples at ten stations were range as following: Station 1 from 0.378
ng/g during summer to 1.595 ng/g during winter, station 2 from 0.807 ng/g during winter to 1.845 ng/g during spring,
station 3 from 0.819 ng/g during summer to 2.145 ng/g during winter, station 4 from 0.852 ng/g during summer to
2.792 ng/g during spring, station 5 from 1.286 ng/g during summer to 3.725 ng/g during winter, station 6 from 1.096
ng/g during summer to 3.321 ng/g during winter, station 7 from 1.379 ng/g during summer to 4.892 ng/g during
winter, station 8 from 1.517 ng/g during summer to 5.038 ng/g during winter, station 9 from 1.572 ng/g during
summer to 7.222ng/g during winter and station 10 from 2.438 ng/g during summer to 9.966 ng/g during winter
Tables (1-4). The highest of total PAHs mean concentrations in soil (5.906 ng/g) dry weight was recorded at station
10, while the lowest mean concentrations (1.125 ng/g) was recorded at station 1 (Table 5) (Fig. 2).
Fig. (2) Seasonal and mean concentration of polycyclic aromatic hydrocarbons at west Qurna- 2 oil field.
