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The New Detection Methods Of Chlorpyrifos And Aflatoxin M1in Foods By The Chromatographia

Posted on:2015-10-07Degree:MasterType:Thesis
Country:ChinaCandidate:Q SunFull Text:PDF
GTID:2181330434455242Subject:Occupational and Environmental Health
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Chlorpyrifos and aflatoxin M1(AFM1) are all poison and harmful substances infoods, which is harm to human health. It is very important significance to study ontheir new detection methods of Chlorpyrifos and aflatoxin M1(AFM1) in foods. Inthe chapter1, the pretreat ment methods of food samples for the agriculturalchemicals were introduced, and the research progress of detection for chlorpyrifos andAFM1in foods has also presented. Beyond that, we have also summarized the maincontents and innovations of this thesis.In the chapter2, the quantity of aflatoxin M1residues of toxins for the detectionof High Performance Liquid Chromatography in butter was studied, and made themethod validation. What we have done showed that the linearity, precision andrecovery of the detection have reached the testing requirements. HPLC detectionmethods for monitoring conditions: samples will be purified by immunoaffinitycolumn, separated by C18column, mobile phase requirements: acetonitrile+water(25:75), flow rate:1.0ml/min, excitation wavelength:361nm, emission wavelength:433nm. The concentration of Aflatoxin M1is0.01~11.00μg/kg, H=2.25ρ-0.28(r=0.9992), the detection limit is0.008μg/kg, recovery is82.06%~106.50%. Thetreatment procedures are simple and the analysis results is much ideal here.In the chapter3, we aim to improve the speed and accuracy of detection ofchlorpyrifos residues in Wuchang fish by applying GC-PFPD detector and integratingthe liquid-liquid extraction into solid phase extraction. Acetone-water-petroleumether extract samples with anhydrous sodium sulfate and the organic phase istransferred to the evaporation flask, rotary evaporated to near dryness, add dissolvedin eluent, CARB/NH2column purification, and finally we use GC-PFPD detection toconduct quantitative analysis. According to the dictation of experimental condition ofchlorpyrifos residues in Wuchang fish through GC-PFPD detection, we found that,when the concentration of chlorpyrifos is0.013mg/kg~30.00mg/kg, A=138848ρ+126.3(r=0.9991), the detection limit is0.008mg/kg and the recovery rate is90.30%~103.80%. This method avoids the insufficient of separate liquid-liquid extraction or solid phase extraction when use it separately, based on a combination oftwo pre-treatment methods and the use of advanced flame pulse detector, so that themethod sensitivity and high recovery is improved, and is equipped with the advantageof low detection limit and good repeatability. This method good applies to thedetection of chlorpyrifos of fish, which is worthy of promotion.In the chapter4, we use three pre-treatment methods to detect theorganophosphorus of cabbage so as to analysis the extraction difference comparedwith the different methods. At present, there are three pre-treatment methods forsample cabbages including solid support liquid-liquid extraction, QuEChERS andliquid-liquid extraction. After the pre-treatment, the organophosphorus pesticideresidues of the three samples will be detected and analyzed by capillary gaschromatography with pulsed flame photometric detector in a quantitative way. Finally,the recovery of measured value, measured values of positive samples of the detectionresults of all samples will be compared and analyzed here. The results showed thatthere is no difference for the recovery of measured value and measured values ofpositive samples based on the chi-square test and T test. However, the method ofQuEChERS is much more ideal with simple operation, less solvent consumption andthis method is worth of promotion.
Keywords/Search Tags:Chlorpyrifos, Aflatoxins (AFT) M1, Pulsed flame photometric detector(PFPD), Gas chromatography, High performance liquid chromatography, Pretreat ment
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