Study On Separation Technology Based On Nanomaterials And Its Application

With the rapid development of life science, biological engineering and environmental science, the analytes are becoming more and more complex, therefore the separation and detection of trace components in complex matrix has become a prominent problem. Although the detection limit of modern instrumental analysis methods is getting lower and lower, it is difficult to directly analyze the content of these components. On one hand, the physical and chemical state of the sample is not suitable for direct determination, or the analysis method is not sensitive enough for the low content of the component. On the other hand, matrix interferes the determination, or the analysis method is lack of appropriate calibration standards and reagents. So it is necessary to use a variety of separation and enrichment techniques to improve the sensitivity and selectivity of analytical methods.In recent years, solid phase extraction as a sample pretreatment method is developing rapidly. Solid phase extraction technology uses solid adsorption agent to adsorb target compounds in liquid samples, and separate them from the sample matrix and interfering compounds. Then solvent desorption or thermal desorption is used to achieve the separation and preconcentration of the target compounds. Solid phase extraction technology greatly enhance the detection of analytes, and improve the recovery of the sample.Nanomaterial is a new functional material received extensive attention in recent years, and has a series of novel physical and chemical properties. Its specific surface area is large, the surface atoms are lack of neighboring atoms, and due to its unsaturation, it is easy to combine with other atoms to be stable, with great chemical activity. Nanomaterial is an ideal adsorption material.The pretreatment of biological samples by electrospinning nanofibers was studied. The solid phase extraction column was filled with nano fiber as adsorbent, and we called it packed-fiber solid phase extraction. Compared with the existing extraction materials, the electrospinning nanofiber has large specific surface area, fast adsorption and desorption, high enrichment efficiency; The packed-fiber solid phase extraction greatly reduce the amount of organic solvent to reduce the harm to the human body; The extraction has the advantages of easy operation, easy automation. Solid phase extraction technology based on nanofiber can be combined with other techniques to achieve better detection results.This research combined solid phase extraction device based on electrospinning nanofiber with flow injection and liquid chromatograph/mass spectrometer to establish two analytic methods and applied to the determination and evaluation of biological samples. The main aspects of this paper were summarized as follows:(1) Establishment of a detection method based on packed-fiber solid phase extraction combined with liquid chromatography-mass spectrometryThe packed-fiber solid phase extraction technology was combined with the high precision HPLC-MS. The samples were pretreated by PFSPE array devices to purify and separate the target compounds, and reduce the matrix effect, and make HPLC-MS get a better selectivity and higher sensitivity. In this chapter, the urinary cortisol and cortisone were determined by this method. The detection limit is 0.2ng/mL for cortisol and 0.5ng/mL for cortisone, the recovery is 92.1%?103.2%, and the intra-day and inter-day precision is lower than 4%.(2) Application of packed-fiber solid phase extraction combined with HPLC-MS in the evaluation of autistic children's morning urinary cortisol and cortisoneThe method was used to determine the the autistic children's morning urinary cortisol and cortisone from Bo Ai School in Suzhou. In this research, we intended to find the relationship between the concentration of the urinary cortisol and cortisone of autistic children with normal ones. There was no significant difference with absolute value of cortisol and cortisone, but the ratio of them in autistic children's morning urinary was significantly lower than that in normal children.(3) Establishment of a detection method based on packed-fiber solid phase extraction combined with flow injection analysis.The packed-fiber solid phase extraction technology was combined with the rapid and convenient flow injection technology. The saliva samples were pretreated by packed-fiber solid phase extraction, and it could purify the samples quickly and effectively and reduce the viscosity of saliva. Independent design and set up a set of flow injection pipeline, simple and efficient, trial in the determination of large quantities of samples.The detection limit is 0.5(g/mL, the recovery is 95.5%?109.6%, and the intra-day and inter-day precision is lower than 10%. Application of packed-fiber solid phase extraction combined with flow injection in the evaluation of children's salivary imidazole compounds(4) The method was used to determine the the salivary imidazole compounds of primary school students in Nanchang and the diurnal variation of salivary imidazole compounds. In this research, we intended to find the relationship between the concentration of the compound in saliva of children with different ages and genders. There was a significant difference with age, but no significant difference was observed with gender.