Detection of Chlorpyrifos and Penconazole Residues in Grape Leaves and Fruit by Gas Chromatography/ Mass Spectrometry

Abstract

An orchard of grapevine was used to determine the residues of chlorpyrifos (Dursban) and penconazole (Ofir ) pesticides during the growing season 2003. Samples of grape leaves and fruits (cortex and flesh) were taken from the orchard after application of both pesticides to determine these residues. The effect of the number of sprays, and the time after the spray application on the residues of both pesticides was studied. The effect of washing the previously treated fruits with both pesticides on the residues of the two pesticides was also investigated.

Gas Chromatography / Mass Spectrometry (GC- MS) was used to determine the residues in grapevine organs and in washing water of treated fruit. Results obtained in this study have indicated the presence of both pesticide residues in all tested samples, but chlorpyrifos residues were detected in larger quantities than penconazole residues. Amounts of residues of both pesticides determined in the fruit cortex were larger than that in the fruit flesh. Their residues in washing water of treated fruits were always lower than that in both cortex and flesh. This indicates the systemic action of both pesticides and therefore the process of washing treated fruit with water two weeks after application of the last spray was not efficient in removing the residues in fruit.

Overall results indicated that the determined quantities of chlorpyrifos and penconazole residues in the cortical tissues of treated fruit after application of the 6th sprays of both pesticides were higher than the quantities determined by other authors but they were less than the maximum residue limits (MRLs) defined by the residue legislation in the other countries. This will lead us to compensate the increase in the pesticide usage by using other non-chemical practices such as integrated pest management (IPM).

تم استخدام حقل من العنب لقياس كمية المتبقيات ( (Residuesمن مبيد الدرسبان ومبيد الاوفير خلال موسم 2003 م. حيث تم جمع عينات من الأوراق والثمار (اللب, القشرة) من الحقل بعد الرش بالمبيدين من اجل قياس كمية المتبقيات فيها. تم دراسة تأثير عدد الرشات والزمن بعد الرش على كمية المتبقيات للمبيدين, إضافة إلى دراسة تأثير عملية غسيل الثمار المرشوشة على كمية المتبقيات من المبيدين المذكورين. تم استخدام جهاز التحليل الكروماتوغرافي (GC-MS) من اجل قياس كمية المتبقيات في أوراق وثمار العنب وماء غسيل الثمار المرشوشة.

أظهرت النتائج في هذه الدراسة وجود متبقيات للمبيدين في جميع العينات التي تم تحليلها. ولكن متبقيات مبيد الدرسبان ظهرت بكميات اكبر من متبقيات الاوفير. كما أن المتبقيات للمبيدين في جميع عينات القشرة كانت أعلى من.