通过固相微萃取与紫外可见光谱联用,以壳聚糖为固化溶剂,实现了对蔬菜叶片中叶绿素a和叶绿素b含量的快速测定.壳聚糖膜对叶绿素具有足够高的富集倍数,并且该膜均匀、透明、机械强度好.实验考察了萃取时间、离子强度、pH及能量供给方式对萃取效率的影响.在优化的实验条件下,叶绿素a和叶绿素b的重现性(RSD)分别为7.1%和8.4%,检出限(3σ)分别为0.155 mg/L和0.099 mg/L,回收率为92.3%~97.9%.同时,与传统叶绿素分析方法比较,结果令人满意.A rapid and simple method using solid-phase microextraction coupled with ultraviolet-visible absorption spectroscopy for the analysis of chlorophyll a and chlorophyll b in plant leaves is presented.It was simply in-expensive and free solvent.Chitosan,a kind of natural polymers containing plenty of amido and hydroxyl,was used as solidified organic solvent to extract chlorophyll for the first time.After a chip of chitosan was immersed in an aqueous sample,chlorophyll a began to partition into the polymer.The system may reach a complete equilibrium in 80 min.Since the chitosan membrane is enough tough and uniformity that it may be detected by ultraviolet-visible absorption spectroscopy.Several factors affecting the extraction efficiency such as extract time,ion intensity and pH were investigated.Under optimum condition,the reproducibility of the method was 7.1% for chlorophyll a and 8.4% for chlorophyll b,respectively.The detection limit(3σ) was 0.155 mg/L for chlorophyll a and 0.099 mg/L for chlorophyll b,respectively.The recovery was within the range of 92.3%～97.9%.Meanwhile,the performance of the method was compared with the traditional method and excellent agreements were observed between the methods.“863”计划(2002AA639390);; 福建省自然科学基金(D0410001)资
