Sarhad J. Agric. Vol. 23, No. 3, 2007 DETERMINATION OF PESTICIDES RESIDUES IN SELECTED MANGO AVAILABLE AT LOCAL MARKETS IN PESHAWAR Hamidullah Shah, M. Nauman Ahamd, Saleemullah, M. Suleman and A.U.R. Saljoqi ABSTRACT The study was undertaken in 2004, at the Department of Agricultural Chemistry, NWFP Agricultural University, Peshawar Pakistan, to access the residues of commonly used pesticides viz Cypermethrin, Methamedophos, Monocrotophos, Cyfluthrin, Dialdrin and Methyl Parathian, respectively in three varieties of Mango being collected from the local markets in Peshawar. The samples were treated with organic solvent Cyclohexane and ethylacetate (1:1), cleaned on Gel Permeation Chromatograph (GPC) and analyzed on auto system Gas Chromatograph (GC) with electron capture detector (ECD). All the samples were found to be contaminated with a degree of variation of pesticides residue studied. However, all the samples were within permissible limits, set by FAO/WHO with reference to public health. INTRODUCTION Mango ( Mangifera indica ), a member of family noxious insects, fungi, weeds etc, various Anacardiaceae, is known as king of fruits. Its insecticides, fungicides and herbicides are used over popularity is mainly due to its excellent flavour, this fruit on a massive scale. When applied delicious taste and high nutritive value. It is the improperly, residues of some of these pesticides can choicest fruit of the sub-continent. Its original home remain on foods and as such can pose a significant is believed to be South Asia where it has been hazard to human health. cultivated for the last four thousand years (Salunkhe and Desai, 1984). It is now an important fruit of the There is great demand for Pakistani mangoes in the tropic and mild sub-tropical parts of the world like country as well as abroad. This delicious fruit is Pakistan, India, South China and Malaya. It is a rich highly appreciated in many of the European, Middle source of vitamin A and vitamin C. Ripe pulp of Eastern and Far-Eastern countries, thus opening mangoes provides 74 k Cal of energy per 100 grams tremendous opportunities for its exports and fetch of edible portion. premium prices in the world markets. Today’s market demands for not only the quality of agricultural Its general composition is, moisture (79.2 - 82%) produce but also the safety and environment friendly total soluble solids (12.9 - 20.8%) total sugars (10- production practices. Now in 2005 when the rules 17.3%), non-reducing sugars (7.27 - 12.35%), ash and regulations of WTO are promulgated and content (0.49 - 0.58%) and crude protein (0.38 - implemented, the FAO/WHO Codex Alimentarus 0.62%) on fresh weight basis. Agriculture sector Commission standards for pesticide residues will act contributes 25% to GDP in which the share of fruits as reference points for Sanitary and Phytosanitary and vegetables is up to Rs. 5353.6 millions (SPS) measures. Thus certification with regard to (Himayatullah, 1999). For more quantity and residue limits, good agriculture practices (GAP) and cosmetic quality of these commodities our farmers environment friendly production processing will be a rely on pesticides. About 27% of the pesticides being prerequisite for agricultural produce. To cope with consumed in the country are used on fruits and the contemporary international market there is a dire vegetables. Mango is planted over an area of about need to carry out systematic research for 83300 hectares producing about 883700 tones of determination of pesticide residues in different fruits. fruits (Ijaz and Inayat, 1997). Its cultivation is on the increase and vast tracts of land in Multan, Keeping in view of this subject, this study was Bahawalpur, Khairpur and Hyderabad divisions have designed to determine pesticide residues in different been planted with Mangoes. Here about 250 varieties varieties of mango fruits collected from local markets are known. A few important varieties of mango are of Peshawar city, with special reference to public Dusehri, Aphanso, Chaunsa, Anwar Ratol and health significance according to FAO/WHO Codex Sindhri. About 86 species of mango insect pests have Alimentarius Commission. been recorded in the country (Giani, 1968). Of these, fruit flies, mango mealy bug, scale insects, and mango hoppers cause more damage to this crop. To minimize the economic losses caused by these Department of Agricultural Chemistry, NWFP Agricultural University, Peshawar - Pakistan Hamidullah Shah et al. Determination of pesticides… 772 MATERIALS AND METHODS essential to modern agriculture. Pesticides are Collection of Sample chemicals developed and produced for use in the The study was conducted during 2004, at the control of agricultural and public health pests. Department of Agricultural Chemistry, NWFP Agricultural University, Peshawar Pakistan The Contamination of fruits and vegetables may results samples were collected from the local markets of from treatment as well as from conditions such as Peshawar city. Samples were taken from randomly improper use of pesticide from preceding treatments selected fruit shops. After collecting samples, about 1 in the soil and cross contamination. Prevention of kg composite sample was separated and sealed in health risks, including toxicological risks, due to food polythene bag. intake is central in food safety policy (Miller, 1987). In the present research work an attempt has been Extraction and clean-up made to determine the pesticide residues in mango The extraction of the samples was performed by the samples collected from the local markets of Peshawar method of Saqib et al (2002) with slight city. In this, study three varieties of mango samples, modification. One kg of mango were chopped and sample-I (Dusehri), sample II (Chaunsa) and sample mixed thoroughly. A sub-sample of 25 gm was taken III (Sindhri) were analyzed for 6 pesticides namely out and blended with 50 ml of acetone, 50 gm of Cypermethrin, Methamedophos, Monocrotophos, anhydrous sodium sulphate and 50 ml of a mixture of Cyfluthrin, Dialdrin and Methyl Parathian. It was cyclohexane and ethylacetate (1:1). The mixture was observed that all the samples were contaminated with allowed to stand for some time till a clear supernatant pesticides. MRLs (Maximum Residual Limits) of was formed. Thirty ml of the supernatant was taken different pesticides are presented in Table-1. Since out into a round bottom flask. A few drops of 10% the residual levels of all pesticides in the samples propandiol in ethylacetate and about 4-6 glass beads were within the permissible limits set by FAO/WHO were added. The solvent was evaporated to dryness at Codex Alimentarius Commission, (1993) hence are 40°C under vacuum and nitrogen stream in rotavapor. harmless and can safely be used for human The contents were reconstituted in 6 ml of consumption. cychlohexane and ethylacetate (1:1) and then passed through high flow super cells. Two ml of this sample The results further revealed that concentration of was applied on Gel Permeation Chromatographic Cypermethin and Methamedophos in Sample II (GPC) column for further cleanup. After passing (Chaunsa) was comparatively higher as compared to through GPC column, the samples were dried under other two samples. Whereas concentration of vacuum and reconstituted in 1ml ethylacetate for Monocrotophos and Cyfluthrin were higher in analysis on Gas Chromatograph (GC). Sample III (Sindhri) as compared to other tested samples. Dialdrin and Methyl Parathian are the only Instrumental Analysis detected in sample III (Sindhri) and sample I All the extraction steps mentioned above and the (Dusehri) respectively. The variation of pesticides clean up on Gel permeation chromatography (GPC) residues among the different varieties of mango is were standardized and checked for optimum mainly due to use of different pesticide in different behaviour and quantitative recoveries. Perkin Elmer concentrations in different localities depending upon Autosystem Gas Chromatograph equipped with the pest attack. These observations are in accordance electron capture detector (ECD friendly Ni) and with the findings of (Rup and Dhanaraj 1989). capillary column was used throughout the study under specific operational conditions (temperature The result of present investigation further supports programming). the findings of the previous surveys conducted in Pakistan by Masud and Hassan (1992). They reported Residues of insecticides in the samples were the residues of organochlorine, organophosphate and identified on the basis of their respective retention pyrethroid insecticides in fruit and vegetable samples, times, quantified on the basis of respective peak collected from retail markets of Karachi. Moreover areas, reported on the basis of sample weight and are these results negate the findings of Masud and Akhtar expressed as mg/kg. Since percent recoveries were (1997) that monitored samples for fruit, vegetable, optimum, therefore no corrections were made while oil, milk and water brought from Gadoon Amazai. calculating the concentrations in the samples. All the samples were free from pesticides residues. The possible reason for this difference may be that RESULTS AND DISCUSSION pesticides in Pakistan are being used in accordance A number of chemicals are in use today in the with good agricultural practice. production of agricultural commodities. They are Sarhad J. Agric. Vol. 23, No. 3, 2007 773 CONCLUSION Based on these observations it may be assumed that pesticide. However this situation is particularly all the