Investigation Of Pesticide Residues In Some Fruits And Vegetables In Shanghai Suburb And Study On Effective Cleaning Methods

The pesticides residues of the daily consumption of fruits and vegetables in some fruits and vegetables in Shanghai were investigated firstly in our present study. On the basis of the investigation, fruits and vegetables(strawberry, green vegetables, amaranthus tricolor, swamp morningglory, celery, cucumber, pepper, eggplant) with high detection rate of pesticides(chlorothalonil, procymidone, cyhalothrin) were selected as the detection targets. And then the effective leaning methods were studied, and the main results were as follows:Gas chromatography(GC) and high performance liquid chromatography(HPLC) were employed to determine 45 pesticide residues in 8 categories of fruits and vegetables(berry and kernel fruits, leaf, root, fruit, flower, gourd and bud seedling vegetables) from 2011 to 2013. The results showed that the food safety level of fruits and vegetables from this suburban district were acceptable because all of the forbidden pesticides were not detected. Organochlorine and pyrethroid pesticides, which has high efficacy and low or medium toxicity, were mainly used in this area, and all of these pesticide residues were under the limitation of National Maximum Residue Limits for Pesticides in Food. The detected rate of pesticide residues in berries fruits, leaf vegetables and fruit vegetables were relatively higher than other samples, which were 86.43%, 19.05% and 17.65%, respectively.The results of cleaning methods showed that if farmers use pesticides strictly in accordance with instructions, pesticide residues level of most of samples(selected from experiment) were less than the national standard prescribed maximum residues after the safe interval period. As for cleaning methods, water immersion, rice-rinsing water immersion, detergent immersion, ozone machine could effectively remove pesticide residues in fruits and vegetables. Taking into account the economic benefits, convenient operation and removal efficiency, the best cleaning method is immersion with rice-rinsing water for 5-10 minutes. In addition, the best way to remove pesticide residues of peel fruits and vegetables, such as cucumber, was peeling.