Study On The Biomarkers In Non-invasive Body Fluids By HF-LPME/CE Technology

1.PrefaceCapillary electrophoresis(CE)has developed rapidly since the 1980 s because of its diverse separation modes and its ability to be used with a variety of detectors.Among them,the amperometric detector(AD)can selectively and sensitively detect eletroactive substances,and the combined technology of CE and AD(CE-AD)has become a commonly used technology in the fields of biomedicine and other fields.However,sample pretreatment has gradually become an essential part of analysis and determination for complicated samples with trace analytes.Hollow-fiber liquid-phase microextraction(HF-LPME)stands out from many other microextraction technologies due to its high efficiency,ease of operation,both purification and enrichment efficiency and environmental friendliness.Based on a brief overview of the principle and application scope of CE-AD technology,this chapter focuses on the development,category and applications of liquid-phase microextraction,and the new progress of the application of nanoparticles in various hollow fiber-based microextraction technologies.In this thesis,combining HF-LPME with CE-AD technology,trace analyses of potential biomarkers in non-invasive body fluids were realized by optimizing extraction mode to improve purification and enrichment selectivity.2.Determination of the thiol biomarker in human saliva by salt-effect enhanced HF-LPME/mini-CE-ADA HF-LPME method was established for purification and enrichment of glutathione(GSH)in human saliva followed by a miniaturized capillary electrophoresis with amperometric detection system(mini-CE-AD).Based on regulating isoelectric point and increasing salt effect to modify donor phase,HF-LPME could provide high enrichment efficiency for GSH up to 471 times,and the extract was directly injected for CE analysis.The salt-effect enhanced HF-LPME/mini-CE-AD method has been successfully applied to saliva analysis,and acceptable LOD(0.46 ng/m L,S/N=3)and recovery(92.7~101.3%)could be obtained in saliva matrix.The sample pretreatment of this developed method was simple and required no derivatization,providing a potential alternative for non-invasive fluid analysis using portable instrument.3.Determination of free urinary metabolite biomarkers of whole grain intake based on ZIF-8-HF-LPME/CE-ADThe whole grain intake is closely associated with human health.In this work,HF-LPME reinforced with zeolitic imidazolate framework-8(ZIF-8)nanoparticles was introduced for purification and enrichment of free urinary metabolite biomarkers of whole grain intake,and the resultant extract was directly analyzed by CE–AD system.Based on the synergistic effect of three-phase dynamic HF-LPME reinforced with ZIF-8 and the online stacking of the transient moving chemical reaction boundary,the enrichment factors of 3,5-dihydroxybenzoic acid(DHBA)and 3-(3,5-dihydroxyphenyl)-1-propionic acid(DHPPA)reached 1018-1034 times,and their LODs achieved 0.33~0.67 ng/m L(S/N=3)in urine matrix.The developed method has been successfully used for urine analysis,and the sample recovery data were in the range of 97.0~103.5 %.This developed method provided an attractive alternative for the determination of urinary metabolite biomarkers of whole grain intake due to its sensitive,fast,low-cost and environmental-friendly features.