Studies And Applications On Dispersive Liquid-liquid Microextraction Technologies

Dispersive Liquid-liquid Microextraction(DLLME)is a novel sample pretreatment technique,which incorporates sampling,extraction and enrichment into one step.And DLLME had some advantages such as simplity,rapidness,low consumption of organic solvent,low cost,high sensitivity,recovery and stability.The aim of this study was to compare four new modes of DLLME,and then ultrasound-assisted emulsification microextraction(USA-EME)were used for the analysis of volatile compounds in aromatic water from cardamoms and phthalic acid esters(PAEs)in dipping water of food packaging films.A brief description was given as follows:1.An overview about the development process,theoretical basis,factors affecting the extraction efficiency and the application of DLLME was summarized,as well as a detail review of the research of the aromatic water and phthalic acid esters.2.The volatile constituents from aromatic water of Amomum kravanh Pierre ex Gagnep were successfully extracted by microwave-assisted extraction(MAE)coupled with four modes of DLLME and identified by GC/MS.Compound species identified by USA-EME method was more than the other three methods of DLLME.The main compounds are 4-terpineol(2.25%),camphor(2.36%),a-terpineol(4.52%),fenchone(6.06%),4-Isopropyl-l-methyl-2-cycloh exen-l-ol(9.93%),eucalyptol(13.54%),6,6-Dimethylbicyclo[3.1.1]hept-2-ene-2-carbaldehyde(42.85%)and so on.The results showed that these methods were all simple and feasible for plants analysis.3.The volatile constituents from aromatic water of three kinds of cardamoms were successfully extracted by microwave-assisted extraction(MAE)coupled with ultrasound-assisted emulsification microextraction(USA-EME)and identified by GC/MS.The results showed that 56 compouds were identified in Alpinia katsum adai Hayata,50 and 66 compouds were identified in Mgristica fragrans Houtt and Alpinia galanga Willd respectively,the same compounds they have are eucalyptol and terpineol.The proposed method provided a rapid,effective process for determining volatile constituents in aromatic water,thus we can get more comprehensive information.4.A coupled technique,ultrasound-assisted emulsification microextraction(USA-EME)was studied for the extraction of 3 phthalic acid esters(PAEs)in dipping water of food packaging films prior to gas chromatography-mass spectrometry(GC-MS).It was found that the method provided a good linearity of calibration curve,RSD values varied from 3.08%to 7.09%(n=5)and the detection limits(S/N=3)were in the range of 0.19?4.17 ng/mL for each PAE.It can be concluded that the USAEME method is an efficient,rapid,simple,environmentally friendly,and cheap microextraction techniques for the determination of PAEs in water samples.