Determination And Remove Method Of The Main Disease And Insert Pesticide In Grapes

This paper firstly studied the determination of chlorothalonil standard by SPME-GC/MS. Key researched using the orthogonal experiment method to optimize the determination of chlorothalonil residue in grapes by SPME-GC/MS. Then studied the remove rule of chlorothalonil and triazolone in different parts of grapes at room temperature and refrigerated condition. Finally find more efficient, practical and non toxic remove by comparing removal efficiency of several non-toxic cleaning methods on organophosphorus pesticide residues and organochlorine pesticide residues in grapes.First, research the method of measuring chlorothalonil standard by SPME-GC/MS, and discussed the test conditions of SPME: extraction temperature, extraction time, stirring speed, and preliminary analysis the effect factor of each factor.Second, quest for using the method of orthogonal test design optimization SPME conditions, and establish the SPME–GC/MS combination detection chlorothalonil in grapes. In the experiment of SPME process factors: extraction time, temperature, stirring speed, are orthogonal experiment design, through the intuitive analysis and variance analysis between the primary and secondary factors to determine the optimal operating conditions: the extracting temperature 40°c, extraction time 30min, stirring speed 600rpm, analytical time 2min, temperature analytical 220°c, Washing time 1s. In the best condition of chlorothalonil determination of linear range for 5-200μg/kg, detection limit for 0.12μg/kg, recovery is between 71.2-116.9%, precision is between 4.3-10.7%. This test method is simple, convenient operation, meet chlorothalonil samples were grapes practical needs.Then, select chlorothalonil and triazolone this two organochlorine pesticides as representative. Study the remove rule of this two pesticides in the whole fruit, peel and pulp grape samples at room temperature and refrigeration conditions.Finally, select tap water, acetic acid, sodium carbonate, sodium chloride this non-toxicity dissolvent and control group (commercial detergent of pesticide residues) to clean drug-loading grape and small tomato samples which contained chlorothalonil, alpha-endosulfan, beta-endosulfan, fenthion, diazinon, malathion, chlorpyrifos, quintiofos this 8 organophosphorus and organochlorine pesticide residues by the above methods. Compare and analysis the remove effect, then find one non-toxic, effective, economical remove pesticide residues method.The result shows: the remove of chlorothalonil in whole grape is faster than triazolone in them. At beginning the remove speed of pesticide residues is grow fast when the temperature go up, then gradually the remove speed go down when the temperature go up. And the remove rate decrease as the temperature decrease. The remove of chlorothalonil and triazolone in grape followed the first-order dynamics, the half-life period of are 2.68 and 2.83 days at room temperature. In this remove method, the remove of sodium carbonate is the most effective way which removed 80% of pesticides residues. Second is acetate with the removal rate for 70.8%, but for some kind of organophosphorus pesticide residues, acetate removal efficiency is better than sodium carbonate's. Considering acetic acid is averaged household stocked, so choose acetic acid.