The Study And Application Of Pretreatment Technology For Complex Matrix Samples

With the development of medicine and life sciences,the samples encountered in the exploration of the world are becoming more and more complex,due to the diversity of samples,especially for analytical analysis in complex substrates,sample pretreatment technology is still an important initial step in sample analysis,and becomes the key to our ability to obtain accurate and reliable analysis results.Based on the increasingly important role of sample pretreatment technology in analytical chemistry today,the development and application of complex matrix sample pre-analysis techniques in pharmaceutical,food and complex biological samples are studied.Part one:Determination of Indomethacin in Indomethacin Gel byObjective:The modification of hollow fiber was studied to eliminate the adsorption of indomethacin by ultrafiltration membrane,and an accurate and simple pretreatment method was established to remove the polymeric excipients in the gel,and then the main drug content was determined.Methods:After the modification of the PVDF-HF by three kinds of surfactants,1g Gel sample was dissolved by 25 m L methanol and then test solution was transferred to the modified hollow fiber centrifugal ultrafiltration device(HFCF-UF)with 4000 rpm centrifuging for 10 min,and the cavity filtrate was diluted and injected directly into HPLC.Results:After ultrafiltration treatment of samples with PVDF hollow fiber membrane treated with 2%Tween-80,there was no non-specific adsorption of indomethacin and the interference of polymer gel materials was effectively eliminated.The indomethacin showed a good linearity in the range of 5.05-30.3?g/m L with an average recovery of 99.6%and the RSD was less than 1.5%.Conclusions:The established analytical method provides reference for the characterization of indomethacin in gels.Part two:Rapid detection of illegal addition of malachite green and mobility spectrometryObjective:A rapid and simple eddy assisted dispersive liquid-liquid microextraction-ion mobility spectrometry was developed for the rapid detection of crystal violet and malachite green in aquaculture water.Methods:Chloroform was used as the extractant,acetonitrile as the dispersant,and was added to the aquaculture water sample with borax-Na OH solution to adjust the p H of aquaculture water to 12,vortex assisted to form a mixed opaque system,and then centrifugation,the chloroform layer was dried by nitrogen,the dissolved solvent,methanol:0.5%acetic acid(V/V,90/10),was added,volume was half of the volume of the extraction layer,and the mixture was used for IMS analysis.Results:MG was in the range of 5.12-102.3 ng/m L,and R~2 was0.98.CV was in the range of 5.65-113 ng/m L,and R~2 was 0.99.The LOD of MG and CV was up to 0.33 ng/m L and 0.30 ng/m L.No matrix interference was found in the analysis of real water samples.Conclusions:The method is easy to operate,environmentally friendly,high extraction recovery and rapid detection.It is suitable for the rapid detection of trace malachite green and crystal violet in aquaculture water to ensure food safety at the source.Part three:Rapid determination of ephedrine in urine by solid-phaseObjective:A new type of poly-vinylidene fluoride microporous membrane-polydopamine-graphene oxide solid phase extraction pretreatment method combined with portable high-resolution ion mobility spectrometry was established to rapidly detect ephedrine in urine.Methods:The extraction membrane was rolled into a tube and placed in a centrifugal tube.The urine sample solution was added for vortex adsorption and the sample solution was discarded.The extraction membrane and centrifugal tube were cleaned with ultrapure water,discard the washing water,and repeat 3 times.The target substance on the extraction membrane was added with methanol vortex elution for 10 min,and the eluent was detected with IMS.Results:The results showed that the good linearity was found from0.124 to 6.129?g/m L for ephedrine.The limits of detection ephedrine was9.60 ng/m L.The recovery was 91.0%-113%.Conclusions:The established method can quickly complete the entire sample processing and detection process,and is suitable for small sample analysis.The method is simple to operate,high sensitivity and reproducibility,which meets the DUID detection requirements,and is expected to provide an effective means for rapid detection and field monitoring of drug driving.