论文部分内容阅读
A novel approach for three-phase single drop microextraction with organic-aqueous compound pendant drop(CPD)is presented.A simple microextraction device consisting of a microsyringe,a quartz capillary and a PMMA coupling device was designed.The organic-aqueous CPDs were conveniently produced in different sizes and shapes.Good operability and droplet stability were observed during extraction under the vigorous stirring conditions.The CPD microextraction method integrates the advantages of single drop microextraction(SDME)and membrane microextraction.It includes one step of matrix isolation,solvent extraction and enrichment,direct sample introduction,and high sensitivity in a short period of time due to thin film phenomena.The analytical performance of the CPD microextraction was demonstrated by using river water and human serum samples spiked with statins as model compounds.By using a 1.2 μL toluene-aqueous CPD(volume ratio 0.2:1),a 272 to 1460-fold enrichment of statins was obtained within 8 minutes.In addition,the CPD microextraction was performed with an iterative CPD formation method to obtain much faster extraction speed(4 min)and higher enrichment factors.The possible reasons for high extraction efficiency of CPD microextraction were discussed.The results indicate that CPD microextraction is a very rapid and efficient sample pretreatment method,and is promising for automated and high-throughput applications.