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Research On Rapid Determination Of Chlorpyrifos And Neomycin Residues In Food By Resonance Light Scattering Method

Posted on:2013-03-21Degree:MasterType:Thesis
Country:ChinaCandidate:Y L XuFull Text:PDF
GTID:2231330395468724Subject:Food Science
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In recent years, with the development of agriculture and animalhusbandry, A large number of fertilizers、pesticides, veterinary drugs and feedadditives were used in plant and animal in order to improve production and preventpest and animal disease.Due to use the banned pesticides and veterinary medicinesand improper use of them, the pollutional problems were prominent day by day suchas in agricultural、livestock and other food whereas the drugs can increase productionand cure many diseases, consequently threating to human health seriously and theproblems not only brought tremendous pollution in our natural environment, but alsothreated humanity’s health and hindered the development of food in internationaltrade.Therefore, it’s important practical significance to build and complete a moreeasy and rapid test method of agricultural and veterinary drug residue.In1990s, the resonance light scattering (RLS) technique was found by Pasternacket al using the common fluorescence spectrophotometer.Nearly more than twodecades, thanks to merits of simplicity, rapidity, higher sensitivity, this method werefavoured by researchers in the field of chemistry. Currently, the RLS technique hasbeen rapid development and become a powerful analytical technique in the field ofanalytical chemistry.The thesis selects vegetables and milk as samples and organophosphoruspesticides-chlorpyrifos and Aminoglycoside antibiotics-Neomycin as research objectsrespectively, building a new quick and easy method of their residues in food by RLStechnique with970CRT fluorescence spectrophotometer. Details are as follows:1. Take the leek、amaranth、sweet potatoes and black and white dishes as samples,after a series of operations that pulverization, ultrasonic extraction with acetone, high-speed centrifugation and filtration and so on, this method is based on the reaction ofchlorpyrifos with crystal violet-potassium iodide in Britton-Robinson butter solutionat pH11.00, and was determined by resonance light scattering(RLS) technology. Itwas showed that the maximum RLS peak was at650nm. A good liner relationship(r=0.9981) was exhibited for chlorpyrifos concentration in the range of0.016~0.877μg/mL and the relative scattered light intensity and the detection limit of 0.016μg/mL; The relative standard deviations(RSDs) of precision for5replicatedeterminations of all the samples were below2.5%.The recoveries were range of91.4%to100.3%. Because of merits of simplicity, rapidity, higher sensitivity, thismethod was well for the determination of chlorpyrifos residue of vegetables.2. Take the Ultrahigh Temperature (UHT)-sterilizated pure milk from supermarket assample, after a series of pre-treatments that blending, ultrasonic extraction andprotein precipitation, high-speed centrifugation, purified by solid phase extraction,this experiment is based on the reaction of neomycin with acid fuchsin inBritton-Robinson butter solution at pH5.50, and was determined by resonance lightscattering(RLS) technology. It was showed that the maximum RLS peak was at625nm. A good liner relationship (r=0.9978) was exhibited for chlorpyrifosconcentration in the range of0.012~2.50μg/mL and the relative scattered lightintensity and the detection limit of0.012μg/mL; The relative standard deviations(RSD)of precision for5replicate determinations of all the samples were below2.5%Therecoveries were range of89.1%~94.4%. Because of merits of simplicity, rapidity,higher sensitivity, this method were well for the determination of neomycin residue ofmilk.This study aimed to expand the application of resonance light scattering method inchemical analysis by above experiment. The paper established a new method fordetection of pesticides, veterinary drugs residues in food using RLS technologythrough a large number of works, which can provide the basis for the relevantdepartments to develop faster, more practical pesticide and veterinary drug residuestesting standards in vegetables,milk and other food.The method was easy to universalexpansion and application becaues of its advantages such as simpler operation andcheaper costs of the experimental apparatus.
Keywords/Search Tags:resonance light scattering, vegetable, milk, chlorpyrifos, neomycin, crystal violet-potassium iodide, acid fuchsin
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