ASE-UPLC For The Determination Of Pesticide Residues And Active Anthraquinones

In recent years, increasing attention has been paid to the quality and safety (QS) offoodstuffs and products. In the determination of analytes in agricultural products samples,sample preparation is very important.Especially some target concentration is very low. It isimportant to develop efficient,fast, simple and green sample preparation method in order toobtain repeatable,reliable analytical result.Accelerated solvent extraction (ASE) is a green extraction technique. ASE can extractdifferent classes of pesticides residues and active ingredient which exist in numerous kinds ofplant origin matrix. Compared with other traditional extraction methods, it has manyadvantages such as easy to operate, less pollution to the environment by the organic solvent,automatic in the extraction procedures. But, ASE also has some drawbacks.Extract needfurther purification.The purifying methods have gained great development. Forexample, solid phase extraction, molecular imprinting technique. The selectivity of complexsamples pretreatment was increased greatly when the ASE technology and purifyingtechnology were applied together. The pesticide residues and active ingredient in complexbiological samples can be separated and detection quickly and effectively.First of all, it is described that the history and development of the ASE technology.For, Abrief overview of the ultra-performance liquid chromatographyIn chapter2, A Highly Sensitive Method for the Determination of Thiophanate Methyl,Cyromazine, and Their Metabolites in Edible Fungi by Ultra-Performance LiquidChromatography Using Accelerated Solvent Extraction and Cleanup with Solid-PhaseExtraction. The conditions of separation and detection were investigated and optimized.Under optimized conditions, good linearity was achieved with a correlation coefficient (r2) of≥0.9998. The method limit of quantification (LOQ) was0.36,0.24,0.4, and0.5μg kg–1forMEL, CYR, MBC, and TM, The recoveries at three spiked concentrations for TM, MBC,CYR, and MEL in four edible fungi samples at the three spiked levels were in the range of82–105%with RSDs of1.9–5.6%.The proposed method can be used for the routine determination of CYR and MEL in ediblefungi with the characteristic of speediness, high sensitivity and accuracy as well as lowconsumption of reagents.In chapter3, A novel analytical method was developed for effective separation and rapidsimultaneous determination of anthraquinones in Tartary Buckwheat by ultra-performanceliquid chromatography coupled to a diode array detector (UPLC DAD). A selectiveaccelerated solvent extraction (SASE) procedure combines an accelerated solventextraction (ASE) and clean-up in situ. SASE conditions were investigated and optimized inthe details.Methanol/acetone (50:50,v/v) was selected as solvent for the extraction and silicagel was selected as sorbents for clean-up. The SASE procedure simplified further the entiresample-preparation chain and achieved satisfactory results in the analyses of anthraquinonescompared with traditional extraction methods. The effective separation of six anthraquinonesfrom an extract of Tartary Buckwheat on a Acquity BEH C18(2.1mm×50mm,1.7μm)column using gradient elution was achieved within7min. Good linearity was achieved, witha correlation coefficient (r2) of≥0.9998. The limit of detection and the limit of quantificationwere in the range of0.033–0.067μg/mL and0.1–0.2μg/mL, respectively. Under theoptimized conditions, good recovery (98.3–109%) of the anthraquinones was achieved. Thevalidated method is successfully applied to quantify the anthraquinones in Tartary Buckwheatand its products.In chapter4, A highly selective molecularly imprinted polymer solid-phase extraction(MIPs-SPE) combined with accelerated solvent extraction and ultra-performance liquidchromatography-DAD detection was developed for the simultaneous isolation anddetermination of six anthraquinones in slimming tea samples. The new molecularlyimprinted polymers (MIPs) was synthesized by using danthron as dummy template withprecipitation polymerization and successfully were applied as a special sorbent of SPE for theselective extraction of six anthraquinones from slimming tea. The MIPs was applied as aspecial sorbent for the solid-phase extraction (SPE) of six anthraquinones from slimming teasamples, showing high selectivity and affinity. Using the MIPs as SPE sorbents couldeffectively eliminate the interferences of the matrix. The proposed method could be applied for the selectiveextraction, separation and determination of six anthraquinones in slimming tea samples. Theproposed method could be applied for the selective extraction, separation and determinationof six anthraquinones in slimming tea samples.