双氨基硅烷偶联剂用于聚酰亚胺固相微萃取涂层改性的研究

Bis-amino silane coupling agent modified polyimide solid phase micro extraction coating

以3,3′,4,4′-二苯甲酮四羧酸二酐,4,4′-二氨基二苯醚为原料,用1,3-双(3-氨基丙基)-1,1,3,3-四甲基二硅氧烷作偶联剂,N,N-二甲基甲酰胺为溶剂,共聚得到含硅聚酰胺酸。把共聚物涂渍到石英纤维上,经过梯度升温、高温脱水环化生成有机硅改性聚酰亚胺固相微萃取涂层。采用顶空固相微萃取-气相色谱联用法分别测定了水中的苯、氯苯、硝基苯,确定了最佳萃取温度和时间,考察了样品分析方法的精密度和最低检测限,色谱峰高与浓度呈良好的线性关系,双氨基硅烷偶联剂改性涂层的R2分别为0.9947,0.991 0,0.996 7;最低检测限较低,双氨基硅烷偶联剂改性涂层分别为0.017,0.021,0.030mg/L;相对标准偏差RSD(n=6)较小,双氨基硅烷偶联剂改性涂层分别为4.62,3.58和2.92%。

The polyamic acid with silicon was synthesized from 3,3＇,4,4＇-benzophenonetetracarboxylic dianhydride and 4,4＇-diaminodiphenylether in the N,N-dimethylformamide with the 1,3-bis （3-aminopropyl） -1,1,3,3- tetramethyl-disiloxane as the coupling agent. The quartz fiber was coated by the copolymer. The silicone modified polyimide solid phase microextraction coating was formed after high-temperature dehydration cyclization under gradient heating.The benzene,chlorobenzene and nitrobenzene were detected by head space-solid phase microextraction-gas chromatography to determine the optimum extraction temperature and time,to investigate the precision of the method, the lowest detection llmit.The relationship between the peaks and concentration of benzene, chlorobenzene and nitrobenzene were linear.The correlation coefficients（R2） of benzene,chlorobenzene and nitrobenzene were 0.9947, 0.991 0and 0.9967respectively; The minimum detection limit is lower. The lowest detectionlimits of the benzene,chlorobenzene and nitrobenzene were 0.017, 0.021and 0.030 mg/L; The relative standard deviation is smaller.The relative standard deviations were 0.017, 0.021and 0.030 mg/L （n=6） repectively.