中空纤维碳纳米管/正辛醇固-液协同微萃取机理及其应用

Mechanism and Application of Hollow Fiber Carbon Nanotubes/Octanol Solid-Liquid Synergistic Microextraction

讨论了以中空纤维为载体的碳纳米管/正辛醇固-液协同微萃取机理,建立了中空纤维碳纳米管/正辛醇固-液协同微萃取-高效液相色谱法同时测定复杂样品中微量咖啡酸、阿魏酸和肉桂酸含量的方法。以2.5cm长的聚偏氟乙烯中空纤维为碳纳米管正辛醇分散液载体,供相为分析物的HCl(pH 2.1)溶液,接受相为pH 12.7的NaOH溶液,在35℃下,搅拌萃取60min,萃取液进行高效液相色谱紫外检测。在优化的实验条件下,分析物的线性范围均在0.05～50!g/L,r>0.9990(n=5);检出限均为0.015!g/L;日内与日间精密度均小于9.8%(n=9),平均回收率为93.8%～115.2%;富集倍数分别为514,942和1084倍。在以中空纤维为支持体的碳纳米管/正辛醇微萃取中,碳纳米管/正辛醇分散液嵌入中空纤维管壁上的微孔中形成了碳纳米管/正辛醇固-液微萃取单元束,对苯丙烯酸类化合物起到协同萃取作用。

The mechanism of hollow fiber carbon nanotubes （CNTs）/octanol solid-liquid synergistic microextraction was investigated. A novel method was developed for the separation and determination of three cinnamic acid derivatives, coffee acid, ferulic acid and cinnamon acid, in pollen , honey and coffee by the solid-liquid synergistic microextraction combined with high performance liquid chromatography. The optimal experimental conditions were as follows：L a 2. 5-cm polyvinylidene fluoride hollow fiber was used as the carrier of the dispersed solution consisting of CNTs and n-octanol; the donor was HC1 solution（pH 2. 1） and the acceptor was NaOH solution（pH 12. 7）; the extract was stirred for 60 min at 35 ℃. Under the abovementioned conditions, the linear ranges of eaffeie acid, ferulic acid and cinnamic acid were 0.05- 50 gg/L, r〉0. 9990 （n= 5）, the detection limits were 0. 015 μg/L, the RSDs of inter-day and intra-day were less than 9.8 % （n=9）, the average recoveries ranged from 93.8%to 115.2%. The enrichment factors for caffeic acid, ferulic acid and cinnamic acid were 514, 942 and 1084, respectively. The extraction mechanism suggested that because the CNTs and octanol were scattered into the pores of hollow fiber, in every fiber pore, there was a component unit beam of solid-liquid microextraction, which played the role of synergistic microextraction, so as to greatly improved the enrichment factors and mieroextraction efficiency for cinnamic acid derivatives.