الفهرس 
ACKNOWLEDGEMENTS
Monitoring of pesticide residues in tomato samplesOnly 14 pages are availabe for public view
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Abstract
The present study was carried out to provide a strong pattern of information on the contamination levels of pesticide residues and the potential health risks in cucumber, tomato and green pepper samples collected from six markets in two governorates in Egypt, i.e. Giza (Dokki) and Assiut (El-Zahraa, El-Gomhoria, El-Welidia, El-Fath, and Abnoub) using LC-MS/MS and GC-MS.
Results procured throughout this work could be summarized as follows:
I. Monitoring of pesticide residues in cucumber samples
1- The most frequently pesticide residues found were iprodione (El-Zahraa, El-Welidia, El-Fath, and Abnoub markets) and propamocarb (El-Zahraa, El-Gomhoria, El-Welidia, and Abnoub markets) followed by carbendazim (Dokki, El-Zahraa, El-Gomhoria markets), metalaxyl (El-Zahraa, El-Welidia, and El-Fath), and azoxystrobin (El-Gomhoria, El-Welidia, and El-Fath).
2- Thiophanate-methyl was found to be the only pesticide residue that slightly exceeded the MRL level (0.12 mg/kg) in Assiut (El-Gomhoria market).
3- None of HRI values were found to be greater than one. Thus none of the pesticide residues found in selected markets represent health risk issue in cucumber samples.
II. Monitoring of pesticide residues in tomato samples
1- The most frequently pesticide residues were (Dokki, El-Gomhoria, El-Welidia, and Abnoub markets) and propamocarb (El-Gomhoria, El-Welidia, El-Fath, and Abnoub markets) followed by carbendazim (El-Gomhoria, El-Welidia, and Abnoub markets.
2- Emamectin, chlorpyrifos and diazinon residues exceeded the MRL level in tomato samples collected from Assiut (El-Zahraa, El-Gomhoria, and El-Welidia markets, respectively).
3- Based on the HRI values, none of the pesticide residues found in the studied markets represent health risk in tomato samples.
III. Monitoring of pesticide residues in green pepper samples
1- The most frequently pesticide residues were boscalid (Dokki, El-Gomhoria, El-Fath, and Abnoub markets) followed by acetamiprid (Dokki, El-Gomhoria, and El-Fath markets) and difenoconazole (El-Zahraa, El-Welidia, and Abnoub markets).
2- Thiophanate-methyl, chlorpyrifos and chlorfenpyr residues surpassed the MRL level in green pepper samples of Assiut (El-Welidia, El-Fath, and Abnoub markets, respectively).
3- According to HRI values, none of the pesticide residues in the studied markets represent health risk in the green pepper samples.
Eventually, 32 pesticides were found in cucumber, tomato, and green pepper samples (17 fungicides, 13 insecticides, and 2 acaricides). Interestingly, the most frequently present pesticide residues found in all samples were carbendazim and propamocarb (8 times each), followed by (7 times), thiophanate-methyl (6 times) and boscalid (6 times).
In conclusion, certain pesticide residues found in collected samples, especially that exceeded the MRL, are being sold in the Egyptian markets. Thus, it is proposed that the application of pesticides in fields and greenhouses should be controlled and their residue levels have to be followed up using the multi-residue method before distribution by using highly efficient pesticide residue programs. The findings in this study, demonstrated that the multi-residue method with LC-MS/MS and GC-MS could detect a large number of pesticide residues at the same time with high accuracy. Furthermore, it is suggested that this method could be generalized for all vegetables and fruits in order to assess the pesticide residues before reaching the markets.