The Preparation Of A Novel Solid-phase Microextraction Coating Material And Its Application In The Determination Of Volatile Metabolites In The Cell Headspace

As a kind of pulmonary primary malignant tumors,lung cancer has become the main cause for human death due to cancers.Atmosphere particle with the size less than 2.5 ?m?PM2.5?is easy to reach distal regions of lung and could lead to the exacerbation of allergic and respiratory diseases.The exposure to high concentration of PM2.5 is related to the occurrence of lung cancer.The morbidity and mortality of lung cancer have increased steadily in the recent years,owing to extremely low early diagnostic rate.So it is important to improve the early diagnostic rate in order to help those patients live longer.Volatile organic compounds?VOCs?in exhaled air are regarded as biomarkers of lung cancer,and the coupling of solid phase microextraction?SPME?with gas chromatography-mass spectrometry?GC-MS?can provide a safe and promising method for the detection of VOCs biomarkers.However,the VOCs analysis still faces challenges such as the trace-level concentration of VOCs and complex matrix of exhaled air.A suitable sample preconcentration method is required for the separation and enrichment of VOCs from complex gas matrix.SPME is a powerful sample preparation technique that was put forward by Pawliszyn in the 1990s.It has been widely used in many fields due to its excellent merits of simple operation,time-saving,solvent-free and efficient combination with instruments.Fiber SPME only needs small amounts of coating to enrich the analytes,and fibers can be introduced directly in injection port after extraction,thus the method gains a wide application in gas analysis.In this paper,two novel SPME fiber coatings were successfully prepared,and the coupling of SPME with GC-MS was applied for the extraction of VOCs in headspace gas of MRC-5 and PM2.5-induced MRC-5 cell lines.The main study contents are listed as follows:1.The composite material of graphene oxide/polyaniline/polypyrrole?GO/PANI/PPy?was prepared on the outer surface of stainless steel wire by an in-siut electrochemical polymerization strategy.Based on the coating,a simple and sensitive solid phase microextraction-gas chromatography-mass spectrometry?SPME-GC-MS?method was developed for the detection of VOCs in the headspace of MRC-5.The surface character,thermal stability,lifespan and extraction efficiency of coating were investigated,and the extraction efficiency was better than commercial fibers.The parameters affecting the extraction and desorption efficiency were studied.Under the optimal conditions,good linear correlation was obtained in the range of 0.002-40 ?g L^-1.The limits of detection was as low as 1.0 ng·L^-1.Relative standard deviations were ranged from 1.2%to 13.6%for single fiber and from 1.9%to 18.0%for fiber-to-fiber.The method was successfully applied for the detection of VOCs in the headspace of MRC-5.And it provides a potential tool for the detection of VOCs in cell lines.2.The Graphene oxide/Polyaniline?GO/PANI?was firstly deposited on a stainless steel wire through an electrodeposition technology.Then,polydopamine was coated on GO/PANI fiber by self-polymerization of dopamine and the fiber coating of graphene oxide/polyaniline/polydopamine?GO/PANI/PDA?was prepared.Based on the composite,a rapid,lowcost and sensitive SPME-GC-MS method was proposed for the analysis of VOCs in the headspace of Particulate Matters 2.5?PM2.5?-induced MRC-5 cell lines.The coating exhibited large specific surface area,good thermal stability,long lifespan and excellent extraction efficiency.Some parameters affecting extraction and desorption efficiency were evaluated.Under the optimal conditions,the linear correlation,accuracy,sensitivity and recoveries were studied.The method obtained good linear relationship in the range of 0.001-40 ?g L^-1,with the correlation coefficients above 0.9922.Relative standard deviations were ranged from 1.1%to 8.4%for single fiber and from 0.2%to 1 1.2%for fiber-to-fiber.The limits of detection was as low as 0.3 ng·L^-1.The recoveries were ranged from 84%to 109%.The method was used for the quantitative analysis of VOCs in PM2.5-induced MRC-5 cell lines.And it is expected to provide a theoretical basis for the study of cytotoxicology of atmospheric particulates.