ASSESSMENT OF SOME PESTICIDE RESIDUES IN FRESH FRUITS AND VEGETABLES AND ITS ACCEPTABLE DAILY INTAKE
Ali Saad Mohammed Mohammed;
Abstract
Pesticides are used to control and protect crops before and after harvest from infestation by pests and plant diseases. A possible consequence of their use may be the presence of pesticide residues in the treated products. It is clearly that the high concentration of pesticide residues in agriculture products was due to bad application used pest control without take in consideration Pre-harvest interval (PHI).
The objective of present study was to monitor and assess the concentration of some organophosphorus and pyrethroids in fruits and vegetables, collected from Egyptian wholesales markets to generate awareness about the lethal effects of these pesticides on human beings as well as to estimate the potential health risks associated with the pesticide residue with regard to studied products.
Grapes, tomato, and pepper were selected not only for their wide consumption and presence throughout the year in the local market but also because they are promising exporting products to the international markets and so important to check in quarantine. According to FAOSTAT monitor: 2012; Egypt production of grapes was 1,378,815.00 tonnes; the rate of 32% of Africa Production (Total was 4,313,356.00 tonnes) and 2% of World Production (Total was 67,067,129.00 tonnes), Egypt production of tomato was 8,625,219.00 tonnes the rate of 48% of Africa Production (Production Total was 17,937,834.00 tonnes) and the rate of 5% of World Production (Total was 161,793,834.00 tonnes). Apple is considered one of the promising imported crops in Egypt.
Pesticide residues are critical factor for allowing crops shipments to enter the importing countries, especially EU countries. Whereas from 1 September 2008, Regulation (EC) No 396/2005 of the European Parliament and of the Council on maximum residue levels (MRLs) of pesticideresidues in products of plant and animal origin.
The present study used the simple, rapid, and reliable multi-residue method (QuEChERS) for determination of pesticide in apple, grape, pepper and tomato samples using acetonitrile extraction before LC-MS/MS determination, then we did method optimization starting by sample extraction tell instrument determination.
1. LC-MS/MS optimization
In the present study, optimization of tested pesticides using triple quadrupole mass spectrometer with atmospheric pressure electro-spray ionization in positive mode by injected these compounds individually to optimize for parent ion (MS1 scanning & MS2 static) by scanning at different cone voltages (CV). The optimum CV, which gave the highest sensitivity, was used and changing the collision energy (CE) to optimize for the daughter ion (MS1 static & MS2 scanning). The standard solutions were injected directly into LC/MS/MS system without analytical column. The protonated ions were chosen in ESI+ (MW+1) mode.
The chosen parameter with the highest sensitivity were collected and used in LC-MS/MS method to detect the 51 pesticides in the same run time using the precursor and two products ion in MRM mode one of them as quantifier and the other as qualifier.
2. Spiking recovery test and method validation
The method performance was tested by carrying out recovery tests at different levels on representative some agricultural products samples. Six replicates of recovery tests were done at concentration levels 0.01 mg/kg, 0.05 mg/kg and 0.1 mg/kg on apple, grapes, pepper and tomato and recovery was (70-120%) for most of pesticides.
The use of methanol: ammonium formate 10mM in pH 4 as final dilution was the more effective in pesticides stability, also the same buffer concentration and pH was found as the better mobile phase using for compounds separation, signal sensitivities and peak shapes.
3. Monitoring and Dietary exposure
A total of 230 domestic samples of different types of fruits and vegetables were collected from Egyptian local markets in the year 2015 (Apple (60), grapes (50), pepper (60), and tomato (60) samples). All samples were examined for 51 organophosphorus and pyrethroides pesticides. Reliable residue analysis data resulting from monitoring programs in foods, even if limited, may be of great value indicating the possible risks of pesticide exposure on human health and on international trade.
The objective of present study was to monitor and assess the concentration of some organophosphorus and pyrethroids in fruits and vegetables, collected from Egyptian wholesales markets to generate awareness about the lethal effects of these pesticides on human beings as well as to estimate the potential health risks associated with the pesticide residue with regard to studied products.
Grapes, tomato, and pepper were selected not only for their wide consumption and presence throughout the year in the local market but also because they are promising exporting products to the international markets and so important to check in quarantine. According to FAOSTAT monitor: 2012; Egypt production of grapes was 1,378,815.00 tonnes; the rate of 32% of Africa Production (Total was 4,313,356.00 tonnes) and 2% of World Production (Total was 67,067,129.00 tonnes), Egypt production of tomato was 8,625,219.00 tonnes the rate of 48% of Africa Production (Production Total was 17,937,834.00 tonnes) and the rate of 5% of World Production (Total was 161,793,834.00 tonnes). Apple is considered one of the promising imported crops in Egypt.
Pesticide residues are critical factor for allowing crops shipments to enter the importing countries, especially EU countries. Whereas from 1 September 2008, Regulation (EC) No 396/2005 of the European Parliament and of the Council on maximum residue levels (MRLs) of pesticideresidues in products of plant and animal origin.
The present study used the simple, rapid, and reliable multi-residue method (QuEChERS) for determination of pesticide in apple, grape, pepper and tomato samples using acetonitrile extraction before LC-MS/MS determination, then we did method optimization starting by sample extraction tell instrument determination.
1. LC-MS/MS optimization
In the present study, optimization of tested pesticides using triple quadrupole mass spectrometer with atmospheric pressure electro-spray ionization in positive mode by injected these compounds individually to optimize for parent ion (MS1 scanning & MS2 static) by scanning at different cone voltages (CV). The optimum CV, which gave the highest sensitivity, was used and changing the collision energy (CE) to optimize for the daughter ion (MS1 static & MS2 scanning). The standard solutions were injected directly into LC/MS/MS system without analytical column. The protonated ions were chosen in ESI+ (MW+1) mode.
The chosen parameter with the highest sensitivity were collected and used in LC-MS/MS method to detect the 51 pesticides in the same run time using the precursor and two products ion in MRM mode one of them as quantifier and the other as qualifier.
2. Spiking recovery test and method validation
The method performance was tested by carrying out recovery tests at different levels on representative some agricultural products samples. Six replicates of recovery tests were done at concentration levels 0.01 mg/kg, 0.05 mg/kg and 0.1 mg/kg on apple, grapes, pepper and tomato and recovery was (70-120%) for most of pesticides.
The use of methanol: ammonium formate 10mM in pH 4 as final dilution was the more effective in pesticides stability, also the same buffer concentration and pH was found as the better mobile phase using for compounds separation, signal sensitivities and peak shapes.
3. Monitoring and Dietary exposure
A total of 230 domestic samples of different types of fruits and vegetables were collected from Egyptian local markets in the year 2015 (Apple (60), grapes (50), pepper (60), and tomato (60) samples). All samples were examined for 51 organophosphorus and pyrethroides pesticides. Reliable residue analysis data resulting from monitoring programs in foods, even if limited, may be of great value indicating the possible risks of pesticide exposure on human health and on international trade.
Other data
| Title | ASSESSMENT OF SOME PESTICIDE RESIDUES IN FRESH FRUITS AND VEGETABLES AND ITS ACCEPTABLE DAILY INTAKE | Other Titles | تقييم بعض متبقيات المبيدات في الفواكه والخضراوات الطازجة والمتناول اليومي المقبول منها | Authors | Ali Saad Mohammed Mohammed | Issue Date | 2016 |
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