聚酰亚胺/SiO2杂化材料固相微萃取涂层的制备及其应用

本文采用溶胶-凝胶技术制备了PI/SiO2固相微萃取涂层。由均苯四甲酸酐(PMDA)和4,4-二氨基二苯醚(ODA)共聚得到的聚酰胺酸,与四乙氧基硅烷水解产生的羟基进行缩合反应,通过γ-氨丙基三乙氧基硅烷偶联剂键合在石英纤维表面,经过高温脱水环化生成聚酰亚胺/二氧化硅复合固相微萃取涂层。通过红外光谱、热重分析、扫描电子显微镜对涂层的结构、热稳定性、表面形貌进行了分析。采用顶空固相微萃取-气相色谱联用法测定了水中的一氯代苯、邻二氯苯、间二氯苯,色谱峰面积与浓度呈良好的线性关系,线性相关系数(r)分别为0.9977、0.9988、0.9985,最低检测限分别为0.08mg/L、0.03mg/L、0.05mg/L,相对标准偏差(n=6)分别为6.34%、4.39%、4.76%。

Preparation and application of polyimide/silica hybrid coating for solid phase microextraction

The PI/SiO2 coating of solid-phase microextraction was prepared by the sol-gel technology.The polyamic acid was synthesized from pyromellitic acid dianhydride(PMDA)and 4,4’-diaminodiphenylether(ODA).Tetraethoxysilane was hydrolyzed to generate the silicon alcohol.After dehydration cyclization at high temperature,the PI/SiO2 were formed by the condensation reaction between the polyamic acid and the silicon alcohol.PI/SiO2 were bonded on the quartz fiber surface with coupling agent.The surface morphology of the coating was observated by scanning electron microscope.The structure of the coating was studied by IR.The thermostability of the coating was examined by thermal analysis.Monochlorobenzene,o-dichlorobenzene and m-dichlorobenzene in aqueous phase were detected by head space-solid phase microextraction-gas chromatography.In the range from 2-12mg/L,the relationship between the peakarea and concentration of monochlorobenzene,o-dichlorobenzene and m-dichlorobenzene were linear.The correlation coefficients(r)were 0.9977,0.9988 and 0.9985 respectively.The limits of detection of the monochlorobenzene,o-dichlorobenzene and m-dichlorobenzene were 0.081mg/L,0.03mg/Land 0.05mg/L.The relative standard deviations were 6.34%,4.39%and 4.76%(n=5)repectively.