Study On Trace Analytical Mehtods Of Typical Alkaline Compounds By Combing Novel Electromembrane Extraction With CE-C~4D Technology

1.PrefaceCapillary electrophoresis(CE)has the merit of high separation efficiency and little sovent consumption and etc.,which has been widely used in various analytical fields.As a universal detector,capacitive coupled contactless conductance detection(C~4D)is suitable for various substances,but its limit of detection is relatively high.Electromembrane extraction(EME)is anew kind of sample preconcentration technology driven by direct current electric field,and possesses good purification and high enrichment efficiency,which has a potential application prospect in trace analyses of complex systems.Based on a brief introduction of the analytical principle and research progress of CE-C~4D technology,this chapter mainly reviews the enrichment principle,device and application research progress of EME,and summarizes the current research status and development prospect of CE in the field of food safety and environmental analysis.2.Study on DS-EME/CE-C~4D analysis method of cypromazine and its degradation product melamine in food and environmental samplesIn this work,based on the combination technology of double surfactants reinfored EME(DS-EME)with CE-C~4D,a DS-EME/CE-C~4D trace analysis method was developed for simultaneous separation and detection of cypromazine and its degradation product melamine.Under conditions,the target analytes and the main potential interferers(aliphatic amines and main co-existing inorganic cations)could be completely separated within 14 mins.Taking water,soil and cucumber as analytical samples,DS-EME based on trioctyl phosphate and diethyl hexyl phosphatecould provide good enrichment and purification effects.The limits of detection achieved 0.2-1.5 ng/mL(S/N=3),and the enrichment factores is 115-123times.This method did not require derivatization,had good reproducibility and recovery,and the required reagents were simple and eco-friendly,which provides an alternative for trace analysis of cypromazine and its degradation product melamine in complex samples.3.Study on QDs@TEHP-EME/CE-C~4D analysis method of typical prohibited dye additives in aquatic productsIn this work,based on EME modified by quantum dots(QDs)and trioctyl phosphate(TEHP)and CE-C~4D analytical system,a QDs@TEHP-EME/CE-C~4D method was developed for sensitive detection of food banned dye additives(malachite green and crystal violet).Under the optimum electrophoretic conditions,the target analytes and the potential co-existing interferences(common amino acids and inorganic cations)could be baseline separated in 17 min.This work focused on the effects of different nanomaterials,such as QDs,GO and carbon nanotubes,on the selective enrichment efficiency of EME.Combining the excellent characteristics of nanoparticles and surfactants,this developed QDs@TEHP-EME/CE-C~4D combined system realized the above target substances in aquaculture products.The limits of detection of the target analytes was 5.6-14.6 ng/mL(S/N=3),the enrichment factor was up to 206 times(malachite green),and the recovery data were 97.0-118%.This method was easy to operate,reproducible and eco-friendly,providing a novel method for food safety analysis.