Dissertation > Excellent graduate degree dissertation topics show

Residual Degradation Dynamics and Residue of Deltamethrin in Yali Pear Fruit

Author: YinLiLi
Tutor: ZhangYuXing
School: Agricultural University of Hebei
Course: Pomology
Keywords: Pear Degradation Dynamics Residues Deltamethrin
CLC: X592
Type: Master's thesis
Year: 2006
Downloads: 112
Quote: 1
Read: Download Dissertation

Abstract

With China's accession to WTO, the export of fruit growing number of countries in Europe and the United States have the export of agricultural products in China to establish a \therefore great efforts to develop pollution-free food pear production, improve pear food safety and market competitiveness, pollution-free production and consumption of pears has become inevitable. Pear is one of the world's top five fruits of the advantages of traditional fruit trees. Of pear cultivation area and production rank first in the world. But the pear psylla, Rhubarb aphid, borer and other pests are widely distributed in various pear-producing areas in China, is the most important pest of pear, seriously affect the yield and quality of pome fruit. Production pyrethroid pesticide used more and more the pear pest prevention and control of the production. Deltamethrin as pyrethroid insecticides, pear-producing areas are widely used, has a very good effect on the pear pests. Little research has been reported on the analysis of deltamethrin residues in pear fruit dynamics and distribution. Therefore, this thesis to the deltamethrin as the research object, using the method of gas chromatography (GC), research in pear fruit Degradation Dynamics of distribution and different factors, and the correlation of the residue levels. The results are as follows: 1 in accordance with a pesticide multiple sampling method, in late April, late May and mid-August, spraying 2.5% deltamethrin, study its Degradation Dynamics of pear fruit. The results showed that in different spraying periods, deltamethrin residues digestion dynamic equation was as follows: C = 0.3201e ^{The 0.0808t C = 0.2226e ^{-0.0862t , C = 0.3092e (-0.0983t), the correlation coefficient R were 0.9690,0.9131,0.9865 the degradation half T _1/2 8.58d, 8.04d, 7.05d. Deltamethrin in three different periods in the Degradation Dynamics of pear fruit are in line with first-order kinetics model, have a high correlation to faster digestion pear fruit being readily biodegradable insecticide agent. 2 deltamethrin in late May and mid-August after spraying pear fruit Degradation dynamic equations for C = for 1.0435e ^{-0.0577t C = the 0.9300e ^{- 0.0868t , the correlation coefficient R 0.9901,0.9917. The deltamethrin pear peel Degradation Dynamics of the first-order kinetics model, and has a higher correlation. Deltamethrin residues in pear pulp first increased and then a downward trend, the highest in the first days after spraying. Deltamethrin in pear fruit residues are mainly concentrated in the pear peel, penetrate into the flesh few deltamethrin residues were not detected in the hearts of the fruit, showed significant residual contact . 2.5% and deltamethrin 2000 times spraying, 3 times, pear residues is of 0.020mg/kg 0.031mg/kg. The results show that: the frequency of spraying deltamethrin residues in pear, but spraying once or three times, the final residue of deltamethrin did not exceed the national maximum residue limits standards. 5 2.5% deltamethrin 2000 times, spraying 1 and 3, in the non-bagging pear residues of 0.020 to 0.031mg/kg bagging pear deltamethrin residues below the check the limit (LOD). The results show that the: fruit growth pear bagging can significantly reduce the amount of deltamethrin residues in fruit.}}}}

Related Dissertations

CLC: > Environmental science, safety science > Environmental pollution and its prevention > Agricultural chemicals,toxic chemicals, pollution and its prevention
© 2012 www.DissertationTopic.Net Mobile