Thirty-three surface sediment samples were collected around the Clyde Sea and were analyzed for fatty acids, fatty alcohols and sterols by the GC-MS detection. Cluster analysis (Ward’s method with correlation coefficient) performed separately on fatty acids, fatty alcohols and sterols showed that they were grouped according to their geochemical sources. However, terrestrial derived compounds can be seen grouping with marine and bacterial derived compounds in every analysis. Bacterial derived compounds can be found in all clusters in the mixed compound cluster analysis showing that bacterial inputs occurred together with marine and terrestrial inputs.
Thirty two compounds of fatty acids were found in a 50 cm sediment core taken from Conwy Estuary, United Kingdom. Their distribution pattern changed with depth from short chain fatty acids (C12 - C20) predominance to long chain compounds (C21 – C25). The decrease of short chain fatty acids along the core suggested that early diagenesis occurred due to microbial and chemical degradation. The increase of longer chain compounds was probably caused by greater preservation or greater contribution from terrestrial organic matter. The percentage of branched fatty acids, odd/even and 18:1ω7/18:0 ratios showed similar distribution, linking them with bacterial activity in the sediment. Principal Component Analysis (PCA) separated the terrestrial derived fatty acids (long chain compounds) from the marine (short chain saturated compounds, mono and polyunsaturated fatty acids) and bacterial (odd chain length with their branched derivatives and 18:1ω7 acid) derived compounds.
Kajian ini adalah mengenai peranan sterol sebagai penunjuk bio-lipid untuk mengenal pasti variasi dan sumber bahan organik yang hadir bersama sedimen permukaan dari Kuala Selangor, Selangor. Kajian melibatkan kaedah pengekstrakan sterol daripada sampel sedimen dan seterusnya dianalisis menggunakan GC-MS untuk menentukan kehadiran sebatian tersebut. Sepuluh sebatian sterol dikenal pasti hadir dengan fitosterol merupakan sebatian dominan di kawasan kajian iaitu 79% daripada jumlah keseluruhan sterol. Ini diikuti oleh kolesterol serta sterol kumbahan masing-masing menyumbangkan 6% daripada jumlah keseluruhan sterol manakala selebihnya berada dalam julat 1-5%. Indeks Sumber Sterol (SSI) juga menunjukkan kandungan fitosterol yang tinggi walaupun hadir pada kadar yang berbeza di setiap stesen pensampelan. Penilaian pencemaran kumbahan menggunakan nisbah koprostanol/kolesterol, koprostanol/(koprostanol+kholestanol) serta epikoprostanol/koprostanol menunjukkan kawasan kajian tidak mengalami pencemaran kumbahan walaupun sterol daripada sumber kumbahan hadir di persekitarannya. Kesimpulannya sedimen permukaan di Kuala Selangor, Selangor mengandungi campuran sterol daripada pelbagai sumber yang hadir di persekitarannya dengan didominasi oleh fitosterol yang berasal daripada tumbuhan terestrial.
Analyses activities of 226 Ra and 228 Ra were conducted at ten stations of Pulau Redang, Malaysia. Dissolved radium isotopes such as 226 Ra and 228 Ra had shown enrichment at coastal area stations. Meanwhile, activities of both nuclides in the suspended particle matters were slightly in equilibrium with the activity ratio ranging from 0.88 – 1.86. The calculated distribution coefficient values (Kd) of 226 Ra and 228 Ra were in the range of 0.78 x 10 5 L g -1 to 5.56 x 10 5 L g -1 and 0.21 x 10 5 L g -1 to 1.86 x 10 5 L g -1 , respectively, indicate that most of the radium nuclides in the study area are strongly absorbed into the particulate phases. Therefore, low concentrations of suspended particles matter in the water column (< 10 mg L -1 ) have insignificant effects on the Kd values.
This study explores the role of sterols as lipid biomarkers to indicate their input which originates from various sources in the marine environment. Sterols and their ratios were investigated in sediments taken from sixteen sampling stations at Pulau Tinggi, Johor in order to assess the sources of organic matter. The compounds extracted from the sediments were quantified using a gas chromatography-mass spectrometry (GC-MS). The distributions of sterols indicated that organic matter at all sampling stations originated from a mixture of marine source and terrestrial origins at different proportions. A total of eleven sterols were quantified, with the major compounds being phytosterols (44% of total sterols), cholesterol (11%), brassicasterol (11%) and fecal sterols (12%).
Kajian taburan sterol di Sungai Sepang Besar telah dijalankan pada 17 September 2005 dan 20 Disember 2005. Sampel sedimen telah diambil dengan menggunakan pensampel cekau dari 12 stesen untuk menentukan sumber-sumber yang berbeza bagi sterol dan untuk menentukan aras pencemaran bahan kumbahan di sungai tersebut. Kromatografi Gas-Spektrometri Jisim telah digunakan untuk menganalisis data. Hasil yang diperolehi menunjukkan kawasan Sungai Sepang Besar didominasi oleh kolesterol, β-sitosterol dan stigmasterol, manakala kawasan laut didominasi oleh ergosterol. Secara keseluruhan, Sungai Sepang Besar diklasifikasikan sebagai tercemar dengan kumbahan berdasarkan nisbah coprostanol/kolesterol yang diperolehi.
Kandungan alkohol lemak di dalam 19 sampel sedimen permukaan di Sungai Sepang Besar, Sepang, Selangor telah dianalisis menggunakan kromatografi gas-spektrometer jisim (GC-MS). Sebanyak 19 sebatian alkohol lemak dengan julat kepekatan 0.02 μg/g – 9.01 μg/g berat kering dikenalpasti yang terdiri daripada alkohol lemak C12 sehingga C30 termasuk 4 sebatian bercabang. Alkohol lemak C26 mendominasi kebanyakan stesen persampelan dengan julat 0.29 – 5.43 μg/g berat kering, iaitu 15.5% daripada jumlah alkohol lemak. Berdasarkan kepekatan individu sebatian alkohol lemak dan nisbah [Σ(C12 - C20)/Σ(C22 - C30)], Sungai Sepang Besar boleh dikatakan mengandungi alkohol lemak berantai pendek (C12 - C20) yang tinggi berasal daripada organisma marin. Walau bagaimanapun, nilai Indeks Sumber Alkohol (ASI) tidak menunjukkan Sungai Sepang Besar didominasi oleh alkohol lemak rantai pendek kerana faktor kandungan sebatian C26 yang tinggi di kebanyakan stesen persampelan. Nilai nisbah alkohol lemak (rantai ganjil)/(rantai genap) adalah tinggi bagi hampir kesemua stesen persampelan yang dipengaruhi oleh aktiviti bakteria yang tinggi. Dengan itu dapat disimpulkan bahawa sedimen permukaan Sungai Sepang Besar mengandungi campuran bahan organik yang berasal dari marin, terestrial dan bakteria.
Kandungan sebatian alkohol lemak di dalam tujuh sampel sedimen permukaan dari muara Sungai Kapar, Selangor telah dikenal pasti menggunakan gas kromatografi-spektrometri jisim (GC-MS) dan hasilnya menunjukkan wujudnya 13 sebatian alkohol lemak (C12- C24) termasuk enam sebatian bercabang (-iso dan -anteiso) hadir. Secara keseluruhannya, sampel yang dikaji terdiri daripada 65% alkohol lemak rantai pendek (C12- C20) yang dihasilkan oleh organisma marin manakala 14% adalah alkohol lemak rantai panjang (C21- C24) yang berpunca daripada tumbuhan terestrial dan selebihnya merupakan sebatian bercabang yang dihasilkan oleh proses metabolisme bakteria. Sebatian C16 mendominasi kesemua stesen pensampelan dengan julat kepekatan 29.69-164.35 μgg-1 berat kering iaitu 32% daripada jumlah keseluruhan alkohol lemak. Nisbah antara alkohol lemak rantai pendek dan rantai panjang [Σ(C12- C20)/Σ(C21- C22)] bagi setiap stesen pensampelan memberikan nilai >1, menunjukkan kandungan alkohol lemak rantai pendek sumber marin adalah lebih tinggi daripada kandungan alkohol lemak rantai panjang. Indeks Sumber Alkohol (ASI) pula diguna untuk menganggar kesan input alkohol lemak terestrial ke dalam sedimen marin berdasarkan nisbah alkohol lemak C22/C14 menunjukkan stesen Kp1, Kp2, Kp5 dan Kp6 mempunyai nilai >1; iaitu kandungan C22 adalah lebih tinggi berbanding C14. Walau bagaimanapun, nisbah C22/C16 memberikan hasil yang sebaliknya dengan kesemua stesen didominasi oleh C16 berbanding C22. Kajian ini menunjukkan alkohol lemak (C12- C20) terutamanya sebatian C16 mendominasi kawasan muara Sungai Kapar, Selangor berbanding alkohol lemak rantai panjang (C21- C24).
The individual compounds and sources of polycyclic aromatic hydrocarbon (PAHs) were studied in the surface sediments
at 32 locations in the tourism area of Langkawi Island. A total of 15 PAHs were determined and quantified by gas
chromatography coupled with mass spectrometry (GC-MS). The total PAH concentrations of surface sediments from
Langkawi Island ranged from 228.13 to 990.25 ng/g and they were classified as being in the low to moderate pollution
range. All sampling stations were dominated by high molecular weight PAHs with 4 rings (31.59%) and 5-6 rings (42.73%).
The diagnostic ratio results showed that in most cases, the sampling stations have pyrogenic input. Further analysis
using principal component analysis (PCA) combined with absolute principal component score (APCS) and multiple linear
regression (MLR) showed that the natural gas emissions contributed to 57% of the total PAH concentration, 22% from the
incomplete combustion and pyrolysis of fuel, 15% from pyrogenic and petrogenic sources and 6% from an undefined source.