Procedia Environmental Sciences 30 ( 2015 ) 162 – 167

1878-0296 © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Peer-review under responsibility of organizing committee of Environmental Forensics Research Centre, Faculty of Environmental Studies, Universiti Putra Malaysia.doi: 10.1016/j.proenv.2015.10.029

Available online at www.sciencedirect.com

ScienceDirect

*Corresponding author. Tel.:+0-012-649-3598; fax:+0-03-8925-3357 Email address: masni@ukm.edu.my

International Conference on Environmental Forensics 2015 (iENFORCE2015)

Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in surface sediments of Kapas Island, Terengganu, Malaysia

Terence Ricky Chiua, Nurul Fathihah Mt Nanyana, Masni Mohd Alia,b* aSchool of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM

Bangi, Malaysia bInstitute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Malaysia

Abstract

Twelve surface sediment samples were taken from selected sampling points in Kapas Island, Terengganu. Soxhlet extraction with two steps chromatography was applied to extract the PAH compounds. Collection of PAH fraction was carried out and taken for Gas Chromatography-Mass Spectrometry (GC-MS) analysis. The concentration of individual compound ranged from 0.002 to 0.076 µg/g dry weight. The highest total PAH concentration was found in S10 with 0.336 µg/g dry weight while the lowest was detected in S6 with 0.043 µg/g dry weight. Molecular index using selected compound shows that Kapas Island is dominated by pyrolytic sources. Further analysis by principle component analysis (PCA) shown that stations were divided into two distinct groups based on their location. The total PAHs of surface sediments in Kapas Island classified as being low to moderate pollution range. © 2015 The Authors. Published by Elsevier B.V. Peer-review under responsibility of organizing committee of Environmental Forensics Research Centre, Faculty of Environmental Studies, Universiti Putra Malaysia.

Keywords: PAHs; surface sediments; GC-MS; molecular index; Kapas Island

1. Introduction

Massive developments in the industrial sector largely contribute to a nation’s economic development. Many studies has been conducted by researchers around the world in identifying Polycyclic Aromatic Hydrocarbons (PAHs) and Malaysia is not an exception as previous studies have been carried out to evaluate the latest status of

© 2015 The Authors. Published by Elsevier B.V This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Peer-review under responsibility of organizing committee of Environmental Forensics Research Centre, Faculty of Environmental Studies, Universiti Putra Malaysia.

163 Terence Ricky Chiu et al. / Procedia Environmental Sciences 30 ( 2015 ) 162 – 167

PAHs in environment [1,2,3,4,5,6]. Generally, PAHs are defined as compounds consisting of two or more fused aromatic benzene rings and is one of the most crucial types of environmental pollutants [7,8]. There are two types of anthropogenic sources of PAHs which are pyrogenic source that originated from combustion of fossil fuel and biomass which are expelled into the surroundings as exhaust and solid residue [9] and petrogenic source which originated from crude and refined petroleum that are expelled to the surroundings through oil spills, off shore exploration and natural oil seeps in open sea [10]. Pyrogenic PAHs consist of high molecular weight (HMW) molecules with 4 to 7 fused aromatic benzene rings while petrogenic PAHs are abundant with low molecular weight (LMW) molecules containing 2 to 3 fused aromatic benzene rings [10]. However, they give a negative impact on the environment, particularly the marine environment. Based on findings from previous studies, the concentrations of PAHs in sediments around Malaysia ranged from the lowest value of 0.002 µg/g to the highest value of 1.689 µg/g [1,2,3,4,5,6]. Therefore, the aim of this study was to determine the distribution of PAH compounds in Kapas Island, Malaysia by means of Gas Chromatography-Mass Spectrometry.

2. Materials and methods

Kapas Island is an island located in the east coast of Peninsular Malaysia in the state of Terengganu (Fig. 1). In order to collect sediment samples from the 12 sampling points (Fig.1 and Table 1) in the area surrounding the island, a sediment grab was used and the samples were then preserved in pre-cleaned glass jar. The samples were taken around the island based on its proximity to the jetty, resort and open sea area. All samples were frozen at 4°C prior to analysis.

Fig.1. Sampling locations around Kapas Island

164 Terence Ricky Chiu et al. / Procedia Environmental Sciences 30 ( 2015 ) 162 – 167

Table 1 Description of sampling stations around Kapas Island

Besides, PCA also has been applied in this study. Briefly, PCA is a statistical approach, which is often used to shrink a huge dataset to produce a small set of uncorrelated factors, which can describe the most of the variance. Mathematically, PCA can be defined with the following equation (Eq. 1) proposed by Hopke [11]:

where Xik is the ith species concentration of the kth sample; gip is the ith species concentration from the pth source; fpk is the pth source contribution to the kth sample and eik is the error involved the analysis.

3. PAH extraction

A total of 20 g of sediment sample from each station was taken and mixed with sodium anhydrous to eliminate water content. The dried sample was put into a thimble extractor (30 mm x 150 mm) and extracted with dichloromethane for about 10 h. About 250 mL of dichloromethane was put into a round bottom flask and was heated to 60oC on a heater. After 10 hours, the extract was evaporated to near dryness by using a rotary evaporator. The residue was later diluted with dichloromethane and was transferred into a 5 mL vial. The residue is called total extractable lipid (TEL). The TEL extracts were divided through two stages of silica gel column chromatography. Concentrated sample was then transferred into the silica gel column and washed with 2 mL (0.4 mL, 0.3 mL, 0.3 mL, 0.5 mL and 0.5 mL) hexane/dichloromethane (3:1) and subsequently followed by 18 mL hexane/dichloromethane (3:1). Hydrocarbons that ranged from n-alkanes to PAHs were then collected into a conical flask. Eluent from the first step chromatography was concentrated by the rotary evaporator and PAH fraction was collected with 14 mL mixture of hexane/dichloromethane (3:1). The PAH fraction was labeled and stored in the freezer until further analysis. The PAH sample was then transferred to a 1 mL vial and injected to determine the concentration of PAH compounds.

4. Results and discussion

4.1 Composition of PAHs

The compounds measured were benzo(ghi)perylene, phenanthrene, anthracene, naphthalene, benzo[k]fluoranthene, chrysene and benzo[e]pyrene (Table 1). The concentration of individual compound ranged from 0.002 to 0.076 µg/g dry weight. The highest total PAH concentration was found in S10 with 0.336 µg/g dry weight while the lowest was detected in S6 with 0.043 µg/g dry weight (Fig. 2). According to Malaysian Meteorological Agency, the sampling occurs in July during which the Southwest monsoon brings wind from the peninsular Malaysia towards South China Sea thus bringing along terrestrial particle to settle. The low concentration

Station Latitude (N) Longitude (E) Water Depth (m) Description S1 05° 14.162’ 103° 15.679’ 17.0 Resort area S2 05° 13.816’ 103° 16.435’ 24.7 Rocky Beach with terrestrial trees S3 05° 13.356’ 103° 16.547’ 23.4 Rocky Beach with terrestrial trees S4 05° 12.866’ 103° 16.642’ 22.8 Rocky Beach with terrestrial trees S5 05° 12.356’ 103° 16.470’ 20.2 Rocky Beach with terrestrial trees S6 05° 12.491’ 103° 15.902’ 11.0 Resort area with terrestrial trees S7 05° 12.710’ 103° 15.681’ 9.5 Resort area S8 05° 13.195’ 103° 15.519’ 10.5 Jetty and resort area S9 05° 13.409’ 103° 15.564’ 10.8 Resort area S10 05° 13.648’ 103° 15.715’ 5.9 Sandy bay S11 05° 13.790’ 103° 15.861’ 3.5 Sandy bay S12 05° 13.840’ 103° 15.543’ 11.5 Sandy near resort area

165 Terence Ricky Chiu et al. / Procedia Environmental Sciences 30 ( 2015 ) 162 – 167

of PAHs found in S8 was due the location which is slightly far from the influence of human activities. This has been supported by Bakhtiari et al.[4] which states that low human activities contributes to low concentration of PAHs.

Fig.2. Total concentration of PAHs by stations around Kapas Island

Based on Table 2, the compound with the highest percentage was anthracene comprising 26% of all other compounds combined, with a total concentration of 0.260 µg/g dry weight. Meanwhile, the compound with the lowest percentage was benzo(g,h,i)pyrene (8.8%), with a total concentration of 0.088 µg/g dry weight. In order to assess the current status of PAH pollution in Kapas Island, concentration of PAHs in Kapas Island were compared with the data observed from [12], where 0-1000 ng/g of PAH in sediment is classified low to moderately contagion while 1000-10000 ng/g is classified as being moderate to highly polluted, the concentration’s value range in this research indicated that Kapas Island was not heavily polluted compared to other parts of Malaysia.

Table 2 Concentration of individual PAHs in surface sediments of Kapas Island

COMPOUNDS/STATIONS

Concentrations (µg/g)

S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12

Naphthalene 0.017 0.018 0.019 0.018 0.017 0.016 0.012 0.004 0.004 0.018 0.014 0.016

Phenanthrene 0.019 0.026 0.018 0.020 0.022 0.008 0.007 0.006 0.016 0.023 0.015 0.015

Anthracene 0.028 0.035 0.026 n.d 0.028 0.017 0.026 0.009 0.018 0.028 0.026 0.019

Chrysene 0.014 0.018 n.d n.d n.d n.d 0.004 n.d n.d 0.065 n.d 0.005

Benzo (k) fluoranthene n.d 0.006 0.006 0.002 0.003 0.002 0.005 n.d 0.005 0.076 0.005 0.006

Benzo (a) pyrene 0.008 0.008 0.008 0.003 0.005 n.d 0.015 n.d 0.008 0.068 0.007 n.d

Benzo (g,h,i) pyrene 0.004 n.d 0.007 0.007 n.d n.d n.d n.d 0.007 0.058 n.d 0.005

Total PAHs 0.090 0.111 0.084 0.050 0.075 0.043 0.069 0.019 0.058 0.336 0.067 0.066

Total LMW PAHs 0.047 0.061 0.044 0.020 0.050 0.025 0.033 0.015 0.034 0.051 0.041 0.034

Total HMW PAHs 0.026 0.032 0.021 0.012 0.008 0.005 0.024 0.000 0.020 0.304 0.012 0.016

Penantherene/Anthracene 0.679 0.743 0.692 0.000 0.786 0.471 0.269 0.667 0.889 0.821 0.577 0.789

LMW/HMW 1.808 1.906 2.095 1.667 6.250 5.000 1.375 0.000 1.700 0.168 3.417 2.125

TOC (%) 2.340 0.910 0.620 0.520 2.110 6.440 7.496 6.990 9.100 8.770 9.480 10.210 *LMW : Low Molecular Weight; HMW : High Molecular Weight *TOC : Total Organic Carbon *n.d : Not Detected

166 Terence Ricky Chiu et al. / Procedia Environmental Sciences 30 ( 2015 ) 162 – 167

4.2 Molecular ratio index

For phenanthrene /anthracene molecular index, all the sampling stations indicated that the main source type was pyrolytic (Table 2). For Low Molecular Weight (LMR)/High Molecular Weight (HMR) index, the only station that obtained values of less than 1 (petrogenic) was S10 while the rest attained values of more than 1(pyrolytic) (Table 2). This means that all the sampling stations in Kapas Island were based on pyrolytic source type of sediment. This shows that Kapas Island was dominated by pyrolitic sources such as fossil fuel combustion, vehicle engine combustion, waste combustion, open wood combustion and charcoal combustion. 4.3 Multivariate statistical analysis

Principle Component Analysis (PCA) was also carried out in this study. The purpose of principal component analysis (PCA) is to perform the total variation of PAHs data with minimum number of the factor loadings. This type of analysis has been proven to be able to increase the weight of the significant factor loadings by the varimax rotation in PCA and thus reduce the weight of the non-significant ones [13]. The PCA of sampling locations is reported in Fig. 3 which shows the loadings of the variable. The first two components, which are PC1 (54.1%) and PC2 (25.8%), accounted for 79.9% of the total of the variance. As can be seen from Fig. 3, it is clear that the sampling stations were divided into two distinct groups.

Fig. 3. The loadings of first two components of sampling stations of Kapas Island

The first group comprises 9 sampling locations that were loaded negatively in PC1, namely S3, S4, S5, S6, S7,

S8, S9, S11 and S12 while the second group consist of 3 sampling locations were loaded positively, namely S1, S2 and S10. Apart from that, there are 7 sampling locations that were loaded positively in PC2 and these are S6, S7, S8, S9, S10, S11 and S12, while the other sampling locations, namely S1, S2, S3, S4 and S5 were loaded negatively in PC2. While the two are grouped into two large groups together, there was one station that was loaded far away from the others, which was loaded positively in both PC1 and PC2. The first group (S6, S7, S8, S9, S11, S12) is grouped together because of the location of these stations which was within the inner area, located between the mainland of Peninsular Malaysia and the island itself. The second group (S1, S2, S3, S4, S5) is grouped together because of the location of these stations which was in the outer open sea of the island, facing South China Sea. 5. Conclusion The value measured of the concentrations in this study shows that Kapas Island was not heavily polluted. Based on the molecular index calculations, some concentrations ratios were considered between the PAHs it was likely to imply pyrolysis processes as the most probable source of contamination. The basic and statistical method analysis used in this study provided worthy and better understanding of organic matter composition and its sources.

167 Terence Ricky Chiu et al. / Procedia Environmental Sciences 30 ( 2015 ) 162 – 167

Acknowledgements

The authors gratefully acknowledge the support provided by the Science Fund grant No. 04-01-02-SF0698 and Universiti Kebangsaan Malaysia (UKM). The authors also would like to thank Mr. Haris Hafizal for technical support.

References

1. Shahbazi A, Zakaria MP, Yap CK, Surif S, Bakhtiari AR, Chandru K, Bahry PS, Sakari M. Spatial distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in green mussels (Perna viridis) from coastal areas of Peninsular Malaysia; implication for source identification of perylene. Int J Env Anal Chem 2010; 90: 14-30.

2. Saha M, Togo A, Mizukawa K, Murakami M, Takada H, Zakaria MP, Chiem NH, Tuyen BC, Prudente M, Boonyatumanond R, Sarkar SK, Bhattacharya B, Misha P, Tana. Sources of sedimentary PAHs in tropical Asians waters; Differentiation between pyrogenic and petrogenic sources by alkyl homologue abundance. Mar Pol Bul. 2009;58: 189-200.

3. Bahry PS, Zakaria MP, Abdullah AM, Abdullah DK, Sakari M, Chandru K, Shahbazi A. Forensiccharacterization of polycyclic aromatic hydrocarbons and hopanes in aerosols from peninsular Malaysia. Env Forensics. 2009;10(3):240-252.

4. Bakhtiari AR, Zakaria MP, Yaziz MI, Lajis MN, Bi X. Polycyclic aromatic hydrocarbons and n-alkanes in suspended particulate matter and sediments from the Langat river, peninsular Malaysia. Env Asia. 2009; 2: 1-10.

5. Chandru K, Zakaria MP, Anita S, Shahbazi A, Sakari M, Bahry PS, Mohamed CAR. Characterization of alkanes, hopanes and polycyclic aromatic hydrocarbons (PAHs) in tar-balls collected from the east coast of peninsular Malaysia. Mar Poll Bull. 2008;56(5): 950-962.

6. Sakari M, Zakaria MP, Lajis N, Mohamed CAR, Chandru K, Sahpoury. Polycyclic aromatic hydrocarbons and hopane in Malacca coastal water: 130 years of evidence for their land-based sources. Environ Forensics. 2011; 12: 1-16.

7. Blumer M. Polycyclic aromatic compounds in nature. Sc American. 1976;243(3):34-35. 8. Neff JM. Polycyclic aromatic hydrocarbons in the aquatic environment. Source, fate and biological effects. London: App Sc Pub. 1979. 9. Wang DG, Yang M, Jia HL, Zhou L, Li YF. Polycyclic aromatic hydrocarbon in urban street dust and surface soil: comparisons of

concentration, profile and sources. Arch Env Cont Toxic. 2009;56:173-180. 10.Jiang YF, Wang XT, Wang F, Jia Y, Wu MH, Sheng GY, Fu JM. Levels, composition profiles and sources of polycyclic aromatic

hydrocarbons in urban soil of Shanghai, China. Chemosphere. 2009;75(8): 1112-1118. 11.Hopke,P.K. Recent developments in receptor modeling. J Chem. 2003;17: 255-265. 12.Baumard P, Budzinski H, Garrigues P. PAHs in Arcachon bay, France: Origin and biomonitoring with caged organisms. Mar Poll Bull.

1998;36:577–586. 13. Osman R, Saim N, Juahir H, Abdullah MP. Chemometric application in identifying sources of organic contaminants in Langat River Basin. Env Monit assess. 2011;8: 1-14.