Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Organophosphorus and Carbamate Pesticide Residues Detected in Water Samples Collected from Paddy and Vegetable Fields of the Savar and Dhamrai Upazilas in Bangladesh

Md. Alamgir Zaman Chowdhury
Agrochemicals and Environmental Research Division, Institute of Food & Radiation Biology, Atomic Energy Research Establishment, Savar, Dhaka 1349, Bangladesh

Sanjoy Banik
Agrochemicals and Environmental Research Division, Institute of Food & Radiation Biology, Atomic Energy Research Establishment, Savar, Dhaka 1349, Bangladesh, and Department of Biochemistry and Molecular Biology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh

Borhan Uddin
Department of Biochemistry and Molecular Biology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh

Mohammed Moniruzzaman
Agrochemicals and Environmental Research Division, Institute of Food & Radiation Biology, Atomic Energy Research Establishment, Savar, Dhaka 1349, Bangladesh and Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia

Nurul Karim
Department of Biochemistry and Molecular Biology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh

Siew Hua Gan
Human Genome Centre, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia

Abstract/ Executive Summary:

Several types of organophosphorous and carbamate pesticides have been used extensively by the farmers in Bangladesh during the last few decades. Twenty seven water samples collected from both paddy and vegetable fields in the Savar and Dhamrai Upazilas in Bangladesh were analyzed to determine the occurrence and distribution of organo-phosphorus (chlorpyrifos, malathion and diazinon) and carbamate (carbaryl and carbofuran) pesticide residues. A high performance liquid chromatograph instrument equipped with a photodiode array detector was used to determine the concentrations of these pesticide residues. Diazinon and carbofuran were detected in water samples collected from Savar Upazila at 0.9 μg/L and 198.7 μg/L, respectively. Malathion was also detected in a single water sample at 105.2 μg/L from Dhamrai Upazila. Carbaryl was the most common pesticide detected in Dhamrai Upazila at 14.1 and 18.1 μg/L, while another water sample from Dhamrai Upazila was contaminated with carbofuran at 105.2 μg/L. Chlorpyrifos was not detected in any sample. Overall, the pesticide residues detected were well above the maximum acceptable levels of total and individual pesticide contamination, at 0.5 and 0.1 μg/L, respectively, in water samples recommended by the European Economic Community (Directive 98/83/EC). The presence of these pesticide residues may be attributed by their intense use by the farmers living in these areas. Proper handling of these pesticides should be ensured to avoid direct or indirect exposure to these pesticides.

Keywords: Pesticides; Organophosphorus; Carbamate; HPLC

Location: Savar and Dhamrai Upazilas in Dhaka, Bangladesh

Start Date: 00-05-2009

End Date: 00-07-2009

Program Area: Risk Management in Agriculture

Commodity: Pesticide, Rice, Vegetables

Objectives:

To determine the presence of organophosphorus and carbamate pesticide residues in Savar and Dhamrai Upazilas so that the inhabitants as well as the farmers of this region will be informed about the level of pesticide exposure and the quality of water in their environment.

Methodology:

Chemicals and Reagents: Chlorpyrifos (99.0%), carbofuran (99.5%), carbaryl (98.5%), malathion (97.5%) and diazinon (99.0%) standards were of reference grade and were purchased from Dr. Ehrenstorfer GmbH, D-86199 Augsburg, Germany. The solvents, such as acetone (BDH, England), n-hexane (Merck, Germany), and diethyl ether (BDH, UK) were of analytical grade, while acetonitrile (Scharlau, Barcelona, Spain) was of HPLC grade.

Collection and Preservation of Water Samples: Surface water samples (n = 27) from both the paddy and vegetable fields of Savar (n = 16) and Dhamrai Upazilas (n = 11), in Dhaka, Bangladesh were collected from May–July, 2009. The samples were kept in clean amber glass bottles, put into ice boxes and immediately transferred to the laboratory at the Institute of Food and Radiation Biology, Bangladesh Atomic Energy Commission, Savar, Dhaka. The samples were stored at −20 °C prior to analysis. A brief survey was also conducted at the location of the sample collection. Questionnaires were randomly administered to the farmers for gathering information on the types of pesticide commonly used, to verify the findings and also to determine if there was any unauthorized or authorized pesticide use by the farmers in the two districts.

Sample Extraction: Five hundred mL water samples were transferred to a 1,000 mL capacity separating funnel before extraction, using 100 mL of solvent mixture of 2% diethyl ether in double-distilled n-hexane. The organic solvent was collected in a conical flask. This was followed by two further extractions with 25 mL of solvent mixture using a similar procedure. The organic solvent layers were aspirated and combined before the addition of 20 g of anhydrous sodium sulfate (Merck, Germany), to remove the residual water. The solvent was then rotary vacuum evaporated (Buchi, Switzerland) to a smaller volume of 5 mL, based on the method described in the Deutsche Forschungsgemeinschaft. The concentrated samples were passed through a column (10 mm ID) packed with 10 g of deactivated florisil (Sigma, USA) and synthetic magnesium silicate (60–100 mesh). The top 1.5 cm of the florisil column was packed with anhydrous sodium sulfate. This extract was eluted with 2% diethyl ether (double distilled using a fractional distillation plant, Schott Duran, Germany) in n-hexane (double distilled) at 5 mL/min. The eluent was further concentrated in a rotary vacuum evaporator (Buchi, Switzerland) before being transferred to a glass vial. The solvent was completely dried under a gentle nitrogen flow. The dried sample was reconstituted in 1 mL of ACN for a subsequent analysis using high performance liquid chromatography (HPLC).

Positive Controls: Four hundred micro-liters of chlorpyrifos, carbofuran, carbaryl, malathion and diazinon standards (100 ng/µL) were added to 500 mL of blank water samples in triplicate as a positive control. The standards were left standing for 10 min to produce a better interaction with the samples. Subsequently, the fortified sample volume was processed to 2 mL, as mentioned in the “extraction and clean-up section of materials and methods”, before their injection into the HPLC.

HPLC Analysis: Following the sample cleanup, aliquots of the final volume were quantified using an HPLC (Shimadzu, Japan) LC-10 ADvp, equipped with an SPD-M 10 Avp attached to a photo-diode array detector (PDA) (Shimadzu SPD-M 10 Avp, 200–800 nm). The analytical column was a C18 Reverse Phase Alltech (250 × 4.6 mm, 5 µm) that was maintained at 30 °C in a column oven. The mobile phase, a combination of 70% ACN and 30% water, was filtered using a cellulose filter of 0.45 µm before each use. The flow rate was 1.0 mL/min, and all solvents used were of HPLC grade. Prior to HPLC analysis, the samples were passed through 0.45 µm of nylon (Alltech Associates, IL, USA) syringe filters. The 20 µL samples were manually injected each time. The identification of the suspected pesticide was performed, relative to the retention time of the pure analytical standard. Quantification was performed.

Calibration Curve: The calibration curves for chlorpyrifos, carbofuran, carbaryl, malathion and diazinon were prepared at four concentrations of 0, 5, 10, 20 and 40 µg/L (R² = 96.46).

Recovery

The mean percentage recoveries for the various pesticides were calculated using the following equation: Percentage Recovery = (C_E/C_MX100)

where C_E is the experimental concentration determined from the calibration curve and C_M is the spiked concentration.

Source of Information: Int. J. Environ. Res. Public Health 2012, 9(9), 3318-3329; ISSN 1660-4601, doi:10.3390/ijerph9093318

Article Link (Online Journal): http://www.mdpi.com/1660-4601/9/9/3318/htm

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

The present study reports that 22% of water samples collected from the paddy and vegetable fields of Savar and Dhamrai Upazilas are highly polluted with pesticide residues, particularly with carbaryl. Other pesticides detected were malathion, diazinon and carbofuran. In general, the levels were higher than those reported from other countries. The presence of these pesticide residues may be attributed by their intense use by the farmers living in these areas. Proper handling of these pesticides should be ensured to avoid direct or indirect exposure to these pesticides. New and strict enforcement should be implemented by the authorities as soon as possible in this region of Bangladesh to control the indiscriminate use of pesticides.

Knowledge Management: Journal

Calibration Curve: The calibration curves for chlorpyrifos, carbofuran, carbaryl, malathion and diazinon were prepared at four concentrations of 0, 5, 10, 20 and 40 µg/L (R2 = 96.46).

Recovery

Calibration Curve: The calibration curves for chlorpyrifos, carbofuran, carbaryl, malathion and diazinon were prepared at four concentrations of 0, 5, 10, 20 and 40 µg/L (R² = 96.46).