| Oil is a kind of essential food in people's life and an important source of nutritionfor human body. Oil can improve the flavor, texture and taste of food and can providehuman body with the essential fatty acids to maintain the body function properly. Thequality of oil directly is related to human body health. Edible oils include vegetableoils, animal fats and butterfats. During production, processing, storage andtransportation of edible oil, the poisonous and harmful materials maybe introduced.The edible oils maybe adulterated with other oils. The safety problem of edible oil hascaused wide attention. To develop proper methods to detect the compounds in edibleoils are necessary.In the introduction, the composition and characteristics of fatty acids in oils, andsort, source, property, and processing technology of oil were reviewed. The toxicsubstances in edible oil, and the source and harmfulness of the substances wereintroduced. And the common analysis methods for detection these compounds inedible oils were summarized.In chapter2, a spectrophotometry for analyzing peanut oil adulterated withother edible oils was developed. The method for determining adulterants in peanutoil was based on monitoring the change of absorbance when the sample wasrefrigerated.10kinds of refined peanut oils (RPOs) from different suppliers werechosen and adulterated with other seed oils at the concentration levels ranging from5%to30%. A total of210samples were analyzed. The qualitative analysis ofadulterated samples can be done according to common characteristics ofabsorbance-time curve of the sample. The absorbance difference (ΔA) between pure peanut oil sample and adulterated sample at refrigeration time of13.1min canindicate the concentration of adulterants. Compared with GC method, the detectioncapability is higher,instrument used is simpler and the results are more satisfactory.In chapter3, real-time refrigeration turbidimetry and common chemometricmethods, including principal component analysis (PCA) and partial least squares(PLS), were applied to the discrimination and purity assessment of some RPOsadulterated with other seed oils. A special turbidimeter was developed and theworking temperature fluctuation could be lower than±0.25℃. The curves ofturbidance vs. refrigeration time of RPO samples were constructed and analyzed byPCA and PLS-1. Discrimination of pure RPO and adulterated samples wassuccessfully achieved by calculating and comparing the Euclidean or Manhattandistances of their first two principal components (PCs) obtained by PCA. The PLS-1was applied to the purity assessment of RPO samples. The correlation coefficient androot-mean-square error of prediction (RMSEP) were0.94and2.75%, respectively.Forty-six RPO samples were analyzed by the proposed method and gaschromatography, respectively. The analytical results obtained show that only oneadulterated sample confirmed by PCA was misjudged. The absolute errors of thepurity assessment results obtained by PLS-1relative to those obtained by GC wereless than4%.In chapter4, the mixture of MWCNTs and neutral alumina was used asadsorbent of dSPE for the extraction of the9organophosphorus pesticides frompeanut oil. The extract was analyzed by gas chromatography-mass spectrometry. Theeffects of some experimental conditions, such as types of multi-walled carbonnanotubes, amount of adsorbents and extraction time were examined. The optimalconditions were obtained as follows: MWCNTs-1was selected as the adsorbent; theamount of MWCNTs and neutral alumina was100mg and1.00g, respectively;clean-up time was3.5min. Under the optimal conditions, the obtained recoveries ofthe analytes in7samples were between85.9and114.3%and relative standarddeviations were lower than8.48%. The limits of detection and quantification for theanalytes were0.7–1.6μg kg-1and2.2–5.4μg kg-1, respectively. The proposed methodwas compared with SPE, MSPD, GPC and dSPE. The methods were applied for theextraction of pesticides from edible oil samples, and the Student's t test was applied.The statistical analysis indicates that there are no significant differences amongrecoveris obtained by the method and LLE–SPE (p＜0.001) and there are no significant differences among recoverise of the analytes obtained by the proposedmehod and LLE–dSPE (p＜0.001). And this method has the advantage of strongerpurifying ability and higher sensitivity.In chapter5, the multiwall carbon nanotubes-based matrix solid phase dispersionwas applied for the extraction of hormones, including estrogen (E2,EE2,E3,CEE,E1) and progesterone (MPG,PG,NEA) in butter samples. The method includesMSPD extraction of the8hormone from butter samples, derivatization of hormoneswith heptafluorobutyric acid anhydride-acetonitrile mixture, and determination by gaschromatography-mass spectrometry. The effects of some experimental conditions,such as types of multi-walled carbon nanotubes, types of elution solvents, amount ofadsorbent, volume of elution solvent and flow rate of elution solvent were examined.The optimal conditions were obtained as follows: the mixture containing0.30ggraphitized MWCNTs and0.10g MWCNTs was selected as absorbent,12mL ethylacetate was used as elution solvent, the elution solvent flow rate was0.9mL min-1.Under these conditions, the8hormones were completely separated within14.5min.The stability of derivatives and matrix effect were also studied. The recoveries ofhormones obtained by analyzing the five spiked butter samples were from84.5to111.2%and relative standard deviations from1.9to8.9%. Limits of detection andquantification for determining the analytes were in the range of0.2to1.3and0.8to4.5μg kg1, respectively.In chapter6, a method useing ionic liquid as the solvent of liquid-liquidmicroextraction, assisted with microwave extraction and coupled with highperformance liquid chromatographic separation for determination of6sulfonamides(SAs) in animal oils was developed. The experimental parameters affected peak aresof target compounds, including the types of ILs, volume of IL, amount of ion-pairingagent (NH4PF6), pH values of sample solution, and extraction temperature and timewere evaluated. The optimal conditions were obtained as follows:[C4MIM][BF4] wasselected as micro-extractant, volume of [C4MIM][BF4] was200μL, amount ofNH4PF6was0.8710g, pH values of extractant was11.0, and the extractiontemperature and time were80℃and5min, respectively. The6SAs werecompletely separated from each other within12min. The limits of detection andquantification obtained are in the range of0.4-0.5μg kg1and1.2-1.8μg kg1,respectively. The accuracy of the method was evaluated by analyzing five spikedanimal oil samples at two fortified levels (5and50μg kg1), and the recoveries of SAs varied from81.4to114.5%with relative standard deviations ranging from0.8to9.0%. The effect of standing time of6spiked animal oil samples on the SAsrecoveries was also examined, and the results were satisfactory.
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