Ismail Sahid

National University of Malaysia, Putrajaya, Putrajaya, Malaysia

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Publications (17)5.96 Total impact

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    ABSTRACT: The objective of this study was to develop a method for the determination of diuron (3-(3,4-dichlorophenyl)-1,1-dimethyl urea) residue in crude palm oil (CPO) and crude palm kernel oil (CPKO) matrices. The method involves the extraction of the herbicide from the oil matrix using low temperature precipitation and solid phase extraction techniques, detected by high performance liquid chromatography-ultra violet (HPLC-UV). The HPLC separation was carried out on an AscentisTM RP-Amide column and elution with acetonitrile (solvent A) and water-methanol (2:1, v/v) (solvent B) as a suitable solvent system, at ratio of 4:6 (v/v). The optimum volume of acetonitrile for the extraction of diuron was 30 mL and 4 mL was obtained as the optimum volume of the solvent for elution analyte through the SPE cartridge. A linear correlation was obtained for the concentration of diuron from 0.05–1.0 μg mL-1 with a correlation coefficient of 0.99. The recovery of diuron from CPO was 83.2–101.4% with a relative standard deviation of 1.4–9.9% and 79.4–87.9% with relative standard deviation of 0.9–5.6% for CPKO. The method detection limit and limit of quantification obtained were 0.018 μg g-1 and 0.058 μg g-1, respectively. The method was used to determine diuron residues in palm oil from different refineries situated at different locations throughout Malaysia
    Sains Malaysiana 11/2012; 41(11):1451-1459. · 0.41 Impact Factor
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    ABSTRACT: In oil palm plantations, the fungicide hexaconazole is used to control Ganoderma infection that threatens to destroy or compromisethe palm. The application of hexaconazole is usually through soil drenching, trunk injection, or a combination of these two methods. It is therefore important to have a method to determine the residual amount of hexaconazole in the field such as in samples of water, soil, and leaf to monitor the use and fate of the fungicide in oil palm plantations. This study on the behaviour of hexaconazole in oil palm agro-environment was carried out at the UKM-MPOB Research Station, Bangi Lama, Selangor. Three experimental plots in this estate with 7-year-old Dura x Pisifera (DxP) palms were selected for the field trial. One plot was sprayed with hexaconazole at the manufacturer's recommended dosage, one at double the recommended dosage, and the third plot was untreated control. Hexaconazole residues in the soil, leaf, and water were determined before and after fungicide treatment. Soil samples were randomly collected from three locations at different depths (0-50 cm) and soil collected fromthe same depth were bulked together. Soil, water, and palm leaf were collected at -1 (day before treatment), 0 (day of treatment), 1, 3, 7, 14, 21, 70, 90, and 120 days after treatment. Hexaconazole was detected in soil and oil palm leaf, but was not detected in water from the nearby stream.
    Drug Testing and Analysis 08/2012; 4 Suppl 1:112-7. · 3.17 Impact Factor
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    ABSTRACT: The palm oil industry has played an important role in the economic development of Malaysia and has enhanced the economic welfare of its people. To determine the environmental impact of the oil palm seedling at the nursery stage, information on inputs and outputs need to be assessed. The oil palm nursery is the first link in the palm oil supply chain. A gate-to-gate study was carried out whereby the system boundary was set to only include the process of the oil palm seedling. The starting point was a germinated seed in a small polyethylene bag (6 in × 9 in) in which it remained until the seedling was approximately 3 to 4 months old. The seedling was then transferred into a larger polyethylene bag (12 in × 15 in), where it remained until it was 10-12 months old, when it was planted in the field (plantation). The functional unit for this life cycle inventory (LCI) is based on the production of one seedling. Generally, within the system boundary, the production of an oil palm seedling has only two major environmental impact points, the polybags used to grow the seedling and the fungicide (dithiocarbamate) used to control pathogenic fungi, as both the polybags and the dithiocarbamate are derived from fossil fuel.
    Tropical life sciences research. 05/2012; 23(1):15-23.
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    ABSTRACT: A study on the leaching of chlorpyrifos in an oil palm agro ecosystem was conducted in an oil palm plantation in Sepang, Selangor. The insecticide chlorpyrifos was sprayed using a knapsack sprayer at the recommended and double the recommended dosage. Soil samples were collected at different depths, viz. 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm and 40-50 cm at the following intervals: -1 day (before treatment), 0 day (day of treatment, 6 hr later), 1 day, 3, 7, 14, 30 and 60 days after treatment. Recovery of chlorpyrifos from the soil spiked with chlorpyrifos at 4-50 μg kg-1 ranged from 88%-99% with the coefficients of variation ranging from 2.0% to 7.5%. Chlorpyrifos residue was detected at 0-10 cm and 10-20 cm depths when applied at the recommended and double the recommended dosages, respectively. The residue was only detected in the soil for up to five and seven days after treatment, respectively, when applied at the recommended and double the recommended dosages.
    Journal of oil palm research 04/2010; 22(April-1):721-728. · 0.23 Impact Factor
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    ABSTRACT: A study on the leaching of chlorpyrifos in an oil palm agro ecosystem was conducted in an oil palm plantation in Sepang, Selangor. The insecticide chlorpyrifos was sprayed using a knapsack sprayer at the recommended and double the recommended dosage. Soil samples were collected at different depths, viz. 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm and 40-50 cm at the following intervals: -1 day (before treatment), 0 day (day of treatment, 6 hr later), 1 day, 3, 7, 14, 30 and 60 days after treatment. Recovery of chlorpyrifos from the soil spiked with chlorpyrifos at 4-50 μg kg-1 ranged from 88%-99% with the coefficients of variation ranging from 2.0% to 7.5%. Chlorpyrifos residue was detected at 0-10 cm and 10-20 cm depths when applied at the recommended and double the recommended dosages, respectively. The residue was only detected in the soil for up to five and seven days after treatment, respectively, when applied at the recommended and double the recommended dosages.
    Journal of oil palm research 04/2010; 22(1):721-728. · 0.23 Impact Factor
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    ABSTRACT: Leaching of fluroxypyr-MHE in an oil palm agroecosystem was conducted for two seasons; the dry and wet season. The oil palm estate is situated in central Selangor, Peninsular Malaysia at an altitude of 70 m to 100 m above sea level. The study plot covered six ha, and consisted of nine subplots of 0.66 ha each. The nine subplots received three treatments namely; the manufacturer's recommended dosage (T1), double the manufacturer's recommended dosage (T2), and the control (T3) with no herbicide treatment. Each treatment was done in triplicate each subplot was separated by a two meter buffer zone. The herbicide fluroxypyr-MHE (Starane  200 EC; Dow Elanco Ltd.) was applied as an aqueous spray using a knapsack sprayer at a spraying volume of 250 L/ha. Soil samples collected at different depths (viz. 0-10, 10-20, 20-30, 30-40 and 40-50 cm) and at the following intervals -1 (before treatment), 1, 3, 7, 14, 30 and 60 days after treatment. Fluroxypyr-MHE was observed at all depths (0-50 cm) for the wet season when applied at the recommended and doubles the recommended dosages. Meanwhile for the dry season, fluroxypyr-MHE was detected in the soil up to 1 and 5 days after treatment when applied at the recommended and double the recommended dosages, respectively.
    01/2010; 1:59-68.
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    ABSTRACT: Leaching of fluroxypyr-MHE in an oil palm agroecosystem was conducted for two seasons; the dry and wet season. The oil palm estate is situated in central Selangor, Peninsular Malaysia at an altitude of 70 m to 100 m above sea level. The study plot covered six ha, and consisted of nine subplots of 0.66 ha each. The nine subplots received three treatments namely; the manufacturer's recommended dosage (T1), double the manufacturer's recommended dosage (T2), and the control (T3) with no herbicide treatment. Each treatment was done in triplicate each subplot was separated by a two meter buffer zone. The herbicide fluroxypyr-MHE (Starane  200 EC; Dow Elanco Ltd.) was applied as an aqueous spray using a knapsack sprayer at a spraying volume of 250 L/ha. Soil samples collected at different depths (viz. 0-10, 10-20, 20-30, 30-40 and 40-50 cm) and at the following intervals -1 (before treatment), 1, 3, 7, 14, 30 and 60 days after treatment. Fluroxypyr-MHE was observed at all depths (0-50 cm) for the wet season when applied at the recommended and doubles the recommended dosages. Meanwhile for the dry season, fluroxypyr-MHE was detected in the soil up to 1 and 5 days after treatment when applied at the recommended and double the recommended dosages, respectively.
    Journal of Agrobiotechnology. 01/2009; 1:50-58.
  • Halimah B Muhamad, Tan Yew Ai, Ismail B Sahid
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    ABSTRACT: The purpose of this study was to develop a method for the determination of fluroxypyr (4-amino-3,5-dichloro-6-fluro2-pyridyloxyacetic acid) residue in palm oil namely crude palm oil (CPO) and crude palm kernel oil (CPKO). The method involves the extraction of the herbicide from the oil matrix followed by low temperature precipitation and finally quantification of the residues using the high performance liquid chromatography (HPLC). The extraction efficiency of the method was evaluated by conducting recovery studies. The recovery of fluroxypyr from the fortified CPO samples ranged from 78%-111% with the relative values for the coefficient of variation ranging from 1.4 to 8.6%. Furthermore, the recovery of fluroxypyr from the spiked CPKO samples ranged from 91-107% with the relative values for the coefficient of variation ranging from 0.6 to 4.5%. The minimum detection limit of fluroxypyr in CPO and CPKO was 0.05 microg/g. The method was used to determine fluroxypyr residues from the field-treated samples of CPO and CPKO. When fluroxypyr was used for weed control in oil palm plantations no residue was detected in CPO and CPKO irrespective of the sampling interval and the dosage applied at the recommended or double the manufacturer's recommended dosage.
    Journal of Environmental Science and Health Part B 03/2008; 43(2):134-40. · 1.21 Impact Factor
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    ABSTRACT: The purpose of this study was to determine the adsorption coefficient (K oc) of chlorpyrifos in clay soil by measuring the Freundlich adsorption coefficient (K ads(f)) and desorption coefficient (1/n value) of chlorpyrifos. It was found that the Freundlich adsorption coefficient (K ads(f)) and the linear regression (r 2) of the Freundlich adsorption isotherm for chlorpyrifos in the clay soil were 52.6 L/kg and 0.5344, respectively. Adsoprtion equilibrium time was achieved within 24 hours for clay soil. This adsoprtion equilibrium time was used to determine the effect of concentration on adsorption. The adsorption coefficient (K oc) of clay soil was found to be 2783 L/kg with an initial concentration solution of 1 µg/g, soil-solution ratio (1:5) at 30 o C when the equilibrium between the soil matrix and solution was 24 hours. The K des decreased over four repetitions of the desorption process. The chlorpyrifos residues may be strongly adsorbed onto the surface of clay.
    Journal of Nuclear and Related Technologies. 01/2005; 2(2):27-34.
  • REZAUL S.M. KARIM, AZMI B. MAN, ISMAIL B. SAHID
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    ABSTRACT: The available literature on weed problems and weed control in rice fields in Malaysia is reviewed and suggestions for future research are included. The problem of weed competition with rice is of great economic importance in the country because it causes a 10–35% reduction in grain yield. About US$4.10 million is spent annually on herbicides for rice alone, and this amounts to approximately 7% of the total expenditure on herbicides. The shift in methods of rice culture from transplanting to direct seeding has magnified the weed problem. The problem of weedy rice is particularly acute in the direct-seeding rice areas. Although a number of sulfonylurea herbicides (e.g. cinosulfuron, metsulfuron, bensulfuron and pyrazosulfuron) have been found to be suitable alternatives to the old herbicide 2,4-D, an integrated weed management program must be developed in order to reduce the problem of herbicide resistance in weeds. Weed control methods that are more friendly to the environment and affordable to farmers must be sought. Weed-competitive and allelopathic rice varieties must be produced. The problem of weeds in rice calls for systematic studies on biotechnological methods of control of weedy rice. Detailed studies on the biology and ecology of notorious rice weeds, particularly Oryza sativa L. (weedy rice), Echinochloa spp., Leptochloa chinensis (L.) Nees, Fimbristylis miliacea (L.) Vahl. and Limnocharis flava (L.) Buch. need to be done in order to formulate successful weed control measures.
    Weed Biology and Management 11/2004; 4(4):177 - 186. · 0.72 Impact Factor
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    ABSTRACT: This book is a compendium of works carried out by various institutions on subjects related to sustainable rice production. The institutions comprise Department of Agriculture, Malaysian Agricultural Research and Development Institute, Malaysian Institute for Nuclear Technology Research, Muda Agricultural Development Authority, Universiti Kebangsaan Malaysia, Universiti Putra Malaysia, Universiti Sains Malaysia, International Islamic University of Malaysia and the agrochemical company of Monsanto. Integrated Biodiversity Management in parallel with the Integrated Weed/Pest/Disease Management, rice-fish farming networking, (agro)chemical residue monitoring in rice and marine ecosystems, and application of biotechnology in rice productivity are taken as the future direction towards achieving sustainable rice production beyond 2000. Challenges from social and technical agroecosystem constraints, agricultural input mismanagement and maintenance of agroecosystem biodiversity are highlighted. It is imperative that the challenges are surmounted to attain the target that would be reflected by tangible rice output of 10 t/ha, and at the same time maintaining the well-being of rice farmers. Activities or directions leading to sustainable higher rice production in Malaysia are varied. Scientists naturally prioritised the R&D activities according to their own fields of expertise. Nevertheless ecologists, hydrologists, agronomists, biotechnologists, plant breeders, botanists, entomologists and chemists must all have their share of contribution for achieving the targeted average national yield of 10 t/ha. It is the schedule of activities leading to the implementation of Integrated Sustainable Plan that needs to be carefully monitored and assured.
    Edited by Nashriyah binti Mat, Ho Nai-Kin, Ismail bin Sahid, Ahyaudin bin Ali, Lum Keng-Yeang & Mashhor bin Mansor, 01/2002; Malaysian Institute for Nuclear Technology Research (MINT) and Muda Agricultural Development Authority (MADA)., ISBN: 983-99341-4-7
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    ABSTRACT: The adsorption-desorption and degradation of glyphosate (Roundup R) have been studied using 14C-glyphosate in two soils, namely Serdang Series and Sungai Buloh Series. The percentage of adsorption was not significantly different (p>0.05) between the Sungai Buloh and the Serdang Series soil, at concentrations of 10 and 50 ug/mL. On the other hand, the percentage of desorption in the Serdang Series was higher (p<0.05) than in the Sungai Buloh Series, at two concentrations tested. Higher activity of 14C-glyphosate was detected in 0-10 cm zone of the two soils studied. However, in Sungai Buloh Series, a significant amount of 14C-glyphosate was detected in the 10-20 cm zone. A small amount of 14C-radioactivity was also detected in the leachate of the two soils. The percentage of degradation in the Sungai Buloh and Serdang Series soils was higher at 10 ug/mL and 50 ug/mL, concentration, respectively. At 50 ug/ml concentration, the Sungai Buloh Series showed higher glyphosate residue (83%) as compared to Serdang Series (48%). In contrast, the glyphosate residue was found to be higher in the Serdang Series (73%) as compared to the Sungai Buloh Series (30%) at 10 ug/mL concentration.
    Jurnal Sains Nuklear Malaysia (Nuclear Science Journal of Malaysia). 01/2002; 20(1&2):17-29.
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    ABSTRACT: Pesticides have become one of the major components of modern farming practice. However, their usage needs to be properly carried out and regulated. Farmers need to be made aware of the potential hazards arising out of improper use of pesticides, to them as well as to the environment. This book presents the results of a comprehensive study on the impact of pesticide usage in the largest rice agroecosystem in Malaysia, the Muda Irrigation Scheme. The study, carried out by a group of local scientists, covers the impact of pesticide usage on biodiversity and bioresources (forest, weed, insect, fish, and bird). In addition to farmers education, it shows the potential of crop establishment, irrigation method and double cropping of rice as useful factors that can be employed in minimizing the impact. The book also provides good foundation for future work and points out areas for further studies. It is a valuable reference to policy makers, researchers, regulators, agriculture-related agencies, chemical/fertilizer companies as well as those concerned with sustainable farming. The ecologists, botanists, microbiologists, agronomists and medical practitioners involved in this study are congratulated for their efforts.
    Edited by Nashriyah binti Mat, Ho Nai-Kin, Ismail bin Sahid, Ahyaudin bin Ali & Lum Keng-Yeang, 01/1998; Malaysian Institute for Nuclear Technology Research (MINT) and Muda Agricultural Development Authority (MADA)., ISBN: 967-9970-04-3
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    ABSTRACT: Carbofuran is a broad spectrum, systemic insecticide-nematicide currently used in Tanjung Karang paddy fields to control rice stem borer. A study to monitor the effects of carbofuran on soil microbial respiration and bacterial and fungal populations in the presence or abscence of rice straw was carried out at the 1X and 2X recommended doses of the insecticide. Microbial respiration was enhanced by carbofuran in the presence of straw. At 8 days after treatment (DAT), application of the 1X recommended dose in the abscence of straw significantly inhibited microbial respiration. At 45 DAT, carbofuran at 1X or 2X dose with straw significantly enhanced bacterial population. The bacterial population, however, was reduced when carbofuran was applied at 1X dose without straw. Fungal population was also reduced at both concentrations, with or without straw. Carbofuran showed both stimulatory and inhibitory effects on bacterial population but only an inhibitory effect on fungal population at 45 DAT. The bacterial population was found to be the most important factor in carbofuran degradation in the Jawa Series paddy soil.
    Malaysian Applied Biology. 01/1996; 25(1):81-85.
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    Ismail Sahid, Ainon Hamzah, Paridah M Aris
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    ABSTRACT: ABSTRAK Satu kajian telah dijalankan untuk melihat kesan alachlor dan paraquat ke atas aktiviti mikrob dalam tanah gambut. Kesan racun rumpai ke atas pembebasan CO 2 dan aktiviti phosphatase dimonitor selama 12 minggu. Hasil yang diperolehi menunjukkan paraquat dan alachlor yang disembur kepada tanah menyebabkan peningkatan pembebasan CO 2 di peringkat awal pengeraman tetapi berkurangan selepas 53 han. Lebih banyak CO 2 dibebaskan dari tanah yang dirawat dengan alachlor berbanding dengan tanah yang dirawat dengan paraquat. Aktiviti phosphatase meningkat di peringkat awal pengeraman bagi tanah yang diperlakukan dengan sama ada alachlor atau paraquat. Aktiviti phosphatase meningkat di peringkat awal pengeraman bagi tanah yang diperlakukan dengan sama ada alachlor atau paraquat tetapi aktiviti phosphatase berkurangan seiepas 12 han eraman. Populasi kulat dan bakteria dipengaruhi oleh kedua-dua racun rumpai yang diuji. Pada kepekatan 250 ppm, alachlor dan paraquat, masing-masing menyebabkan pengurangan populasi bakteria kira-kira 78 dan 95%. Alachlor didapati lebih toksik terhadap kulat berbanding paraquat. ABSTRACT A study was carried out to investigate the effects of alachlor and paraquat on microbial activities in peat soil. Effects of the herbicides on CO 2 evolution and phosphatase activity were monitored for 12 weeks in ambient conditions. The results showed that paraquat and alachlor caused an initial increase in CO 2 released and subsequently decreased after 53 days of incubation. Comparatively, more CO 2 was released from the soil treated with alachlor than that treated with paraquat. An initial increase in phosphatase activity was observed for both herbicides but the level of activity was substantially reduced after 12 days of incubation. Fungal and bacterial populations in the soil were also affected by both herbicides. At 250 ppm, alachlor and paraquat caused a reduction in bacterial population of 78 % and 95 % respectively. Alachlor was shown to be more toxic to fungal populations in the soil than paraquat.
  • Ismail Sahid, Zayda Kasim
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    ABSTRACT: ABSTRAK Satu kajian telah dijalankan untuk melihat kesan dua herbisid asetanilid, iaitu alachlor dan metolachlor ke atas akitiviti mikrob dalam tanah loam berpasir. Pengaruh herbisid ke atas pembebasan CO 2 telah dijalankan selama 50 hari dalam keadaan ambien. Pada amnya, hasil kajian mendapati yang alachlor dan metolachlor menyebabkan pembebasan CO 2 berkurangan di peringkat awal tetapi selepas 25 hari ia meningkat sama seperti kawalan. Pada kepekatan yang rendah, kedua-dua herbisid tersebut kurang berkesan terhadap pembebasan CO z Populasi kulat dan bakteria dalam tanah didapati menurun pada kepekatan herbisid yang tinggi. Pada amnya kedua-dua herbisid, kecuali metolachlor pada 20 ppm didapati mempengaruhi aktiviti phosphatase di dalam tanah. ABSTRACT A study was carried out to investigate the effects of the two acetanilide herbicides alachlor and metolachlor on microbial activities in sandy loam soil. Effects of the herbicides on CO 2 evolution were monitored for 50 d in ambient conditions. The results showed that alachlor and metolachlor generally caused an initial decrease in CO 2 release, which subsequently increased to control level after 25 d of incubation. Both herbicides exert less effect on CO 2 evolution at lower concentrations. Fungal and bacterial populations in the soil also declined in the presence of either herbicide at higher concentrations. Phosphatase activity was generally affected in the presence of either herbicide except in soil treated with metolachlor at 20 ppm.