Study On The Whole Monitoring Teachnology Of Quality Safety In Pear's Producation

Pear is a favorite fruit by consumers.It is also one of the world's most important fruits. China is the world's largest producer of pears.As to increase the appearance quality and control of diseases and pests,pesticides were used in the pears,which were growing.Pear's quality safety has become a major issue to consumers.This article analysed the principle of dynamics of pesticide residues in pear,and then primarily explored technology of safety monitoring system,medicine and storage stage in pear production.The results were list below.1.Established the detection method of triadimefon,imidacloprid + abamectin, diniconazole,acetamiprid,carbendazim,thiophanate-methyl,cypermethrin,beta-cypermethrin, abamectin in pear.The recovery was in 78.6%-106.9%.The relative standard deviation was more than 4.489%.When S/N was three,the quantitative restrictions can be reached 0.1 mg/kg excpt abamectin.Abamectin,diniconazole and acetamiprid can be reached 0.01 mg/kg.They can meet the country or requirements of the residue.The establishments of the pre-treatment and detection techniques were conducived to large quantities of samples.And the operation was esay.2.Residual dynamics of triadimefon,imidacloprid + abamectin,diniconazole,acetamiprid, carbendazim,thiophanate-methyl,cypermethrin,beta- cypermethfin,abamectin in pear were studied.The results indicated the half-lives of triadimefon,imidacloprid + abamectin,carbendazim,thiophanate-methyl,cypermethrin,beta- cypermethrin, abamectin were 1.93,1.51,1.93,1.85,3.47,36.59,2.50 days respectively.But pesticide residues had little changes from the dynamic curves of diniconazole and acetamiprid. They were not original(diniconazole 0.0887mg/kg;acetamiprid 0.026mg/kg) exceeding the Maximum Residue Limit.3.In the field we designed five modes(general,added time,added dosage,safty, comparison mode).Through detecting,the results were that the ultimate tests of pesticide residues in general and safty mode were zero.The dose and frequency of using were safe in accordance with the above types of medication.The added time mode can be detected pesticides,which residues of carbendazim and cypermethrin were 3.280 mg / kg,9.272 mg / kg in not bagged pear respectively.They were exceeded the national MRL standards.In the added dosage mode,the detected residue of carbendazim and cypermethrin were 1.421 mg / kg,3.774 mg / kg in not bagged pear respectively.Carbendazim did not exceed the national standards.But cypermethrin did. Therefore,the attention should be on the pear production in the application of the times and doses.4.The field experiments were designed on different processing of bagged and not bagged in pear samples.and the harvest samples were washed and not wsahed.Through detecting,pesticide residue of bagged pears was lower than not bagged.The washed pericarp of not bagged pear had a certain residual in the elimination.But the pesticides were transformed to the flesh with time.The elimination of the pesticides not obviously at last.5.By carbendazim,cypermethrin,thiophanate-methyl,beta- cypermethrin,abamectin in the distribution of pears was researched.Detect results were that,carbendazim primarily existed in the flesh.In the final residue of the flesh was about seven times than the pericarp.Cypermethrin primarily existed inthe pericarp.In the final residue of the flesh was about five times than the pericarp.Thiophanate-methyl,beta- cypermethrin and abamectin primarily existed in the pericarp.They did not detect residual in the pericarp and flesh at last.6.Research was contraposed the postpartum of not bagged pear which carbendazim and cypermethrin had a relatively high content.The results were that carbendazim was firstly increased and then reeducated with time in the Storage.But the pesticide residues in pericarp were cleared up slowly than the flesh.The pericarp was about 3-10 times more than the flesh.The storage temperature recommended 25℃.It can beconsumed after five davs.Cypermethrin was also irstly inereased and then reeducated with time in the Storage.The pericarp was about 5-7 times more than the flesh.Pericarp and flesh were always occupation proposed during storage.