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Determination of organophosphorus insecticide residues in some vegetables and detection of drainage water pollution with insecticides.
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Abstract: Environment pollution is one of the most serious problems facing humans recently; this is due to its effects on human health. From which is the pesticide residues pollution.
1- Determination of organophosphorus pesticide residues in e vegetables.
Before marketing vegetables need to be chected of to be sure that they are free fan any pesticide residues for consumer health thus the pesticide residues in these crops RL5o and safety period should be determined before marketing.
Lettuce:
Lettuce was sprayed 52 days after cultivation with prothiofos and chlorpyrifos-methyl 50% EC in rates 1.2 and 1L/Fed. respectively which have been recommended by Ministry of Agriculturer Samples were collected randomly at different intervals, one hour,3,9,15,21 days after spraying. The results show that the residue of both prothiofos and chlorpyrifos-methyl were , 47.27 and 27.84 ppm respectively that had been decreased one hour after treatment to 43.47 and 23.08 ppm respectively. After 21 treatment days the residues of both compounds were 7.09 and 1.0 ppm.
It was concluded from these results that the persistance of prothiofos is more than the persistance of chlorpyrifos-methyl at the same intervals. The half life lof prothiofos is 7.9 days and chlorpyrifos-methyl is 2.3 days.
The pre-harvest intervals (PHI) of both compounds can not be determined during the experiment, that is due to the presence of the residues more than maximum residues limit MRL after 21 days.
Spinach:
Spinach was sprayed with pirimiphos-methyl 50% EC in the rate of 1.5 L/fedan. Representative samples were chosen at random at the intervals one hour, 1,3,6,9,15 and 21 days after treatment.It was noted that pirimiphos-methyl detected one hour after treatment was 157.3 ppm. This amount dropped to 78.81 ppm after 24 hours. The residue decrease gradually reaching to 0.30 ppm after 15 days. The residues of this compound disappear after 21 days. The halfllife of pirimiphos-methyl is 1 day and the preharvest interval (PHI) is 5.3 days following application.
Green Peas:
Green peas was sprayed with pirimiphos-methyl 50% EC at the rate of 1.5 L/fedan. Representative samples were chosen at random at the intervals one hour, 1,3,6,9 and 15 days after treatment.
The effect of peeling process was investigated. The amount of pirimiphos-methyl residues was 0.621 ppm in green peas pod (without peeling), however, it was 0.02 ppm in peeled peas after one hour treatment. Gradual decrease of pirimiphos-methyl residues was observed giving 100% loss after 15 days of treatment.
The PHI obtained of pirimiphos-methyl in green peas was 9 days and the half life was 1.8 day in green peas pod according to the CCPR value 1994 (0.05 ppm).
Garlic:
Garlic was sprayed with fenitrothion 50% EC at the rate of 1 L/fedan. Representative samples were chosen at random at the intervals one hour, 1,3,6,9,12,15 and 21 days following application. Garlic heads subjected for analysis during 6 months of storage to show the loss rate of fenitrothion.
It was observed that the initial concentration of fenitrothion detected on garlic head was 1.11 ppm after one hour treatment which has been decreased sharply during first three days to reach 0.23 ppm. The residue of this compound detected in very minuted amount (0.01 ppm) after 21 days of treatment that is in non stored samples. In stored garlic sample, the residues of fenitrothion was 0.21 ppm after one month, 0.01 ppm after 5 months and disappeared completely after 6 months of treatment. According to maximum residue value (0.05 ppm), the preharhvest interval (PHI) was 14 days following application.
11- Monitoring pesticide in drainge Water
IMonitoring of pesticide residues in water samples collected from different sites was carried out through the subsurface tile drainage system in a rice field in Mashtoul, Zgazig, Sharkeya governorate during the period from July to October 1991. The samples were taken from Laterals, Manhole, Collectors, Open drain). The results can be summarized as follows:
1- High amounts of total HCH isomers were detected at the end of the rice cultivation season as 1.359, 1.780, 1.695 and 0.925 ppb were shown in samples of lateral, manhole, collector and open drain, respectively.
2- Aldrin was detected only once in the sample from lateral site with the concentration 0.013 ppb. No dieldrin residues were detected in any of the analyzed samples.
3- Heptachlor and its epoxide were detected in low concentrations in samples of lateral sites with 0.057 and 0.091 ppb for heptachlor and 0.021 and 0.033 ppb for heptachlor epoxide, respectively.
4- p,p-DDE was the main DDTs derivatives found in drainage water samples from the different sites throughout the experimental period. This derivative was frequently found and with noticeable concentrations. p,p-DDE varied between 0.080 ppb in samples from collector to 0.931 ppb in samples from open drain.
5- The organophosphate pesticides, triazophos, methamidophos, and monocrotophos were not found in any of the samples.
6- The herbicide Simetryne was not found.
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| Publication year |
1996
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| Availability location |
7 شارع نادى الصيد - الدقى - الجيزة(المعمل المركزى لتحليل متبقيات المبيدات والعناصر الثقيلة فى الأغذية)
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| Availability number |
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| Organization Name |
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| Country |
Egypt
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| Department |
Pesticides Residue Analysis
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| Author(s) from ARC |
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| Agris Categories |
Pests of plantsPlant diseases
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| Proposed Agrovoc |
Insecticide residues;Plants, Effect of insecticides;Vegetables--Diseases and pests;
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| Publication Type |
Master Thesis
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