Dynamic liquid-phase microextraction

S. Myung, S. Yoon and M. Kim, Analysis of benzene ethylamine derivatives in urine using the programmable dynamic liquid-phase microextraction (LPME) device. Analyst, 2003,128(12), 1443-1446. 

L. Hou, G. Shen and H. K. Lee, Automated hollow fiber-protected dynamic liquid-phase microextraction of pesticides for gas chromatography-mass spectrometric analysis. Journal of Chromatography A, 2003, 985(1-2), 107-116. 

Hou, L. and H.K. Lee. 2002. Application of static and dynamic liquid-phase microextraction in the determination of polycyclic aromatic hydrocarbons. J. Chromatogr. A 976 377-385. 

Wang, Y., Y.C. Kwok, Y. He, and H.K. Lee. 1998. Application of dynamic liquid-phase microextraction to the analysis of chlorobenzenes in water by using a conventional microsyringe. Anal. Chem. 70 46104614. 

Saraji, M. 2005. Dynamic headspace liquid-phase microextraction of alcohols. J. Chromatogr. A 1062 15-21. 

Fig.l Headspace analysis and microextraction methods (here only the headspace mode is shown) used for the determination of fuel oxygenates, (a) Headspace analysis, (b) headspace solid-phase microextraction (HS-SPME) redrawn after [60], (c) solid-phase dynamic extraction (SPDE) redrawn after [61] and (d) liquid-phase microextraction (LPME) redrawn after [62]... 

Chen P-S, Huang S-D. Determination of ethoprop, diazinon, disulfoton and fenthion using dynamic hollow fiber-protected liquid-phase microextraction coupled with gas chromatogra-phy-mass spectrometry. Talanta 2006 69 669-675. 

Pezo, D. Salafranca, J. Nerin, C. Development of an automatic multiple dynamic hollow fibre liquid-phase microextraction procedure for specific migration analysis of new active food packaging containing essential oils. J. Chromatogr. A, 2007,1174, 85-94. 

LLE, liquid-liquid extraction MAE, microwave-assisted extraction SEE, solid-phase extraction SPME, solid-phase microextraction LPME, liquid-phase microextraction SOME, single-drop microextraction D-LLLME, dynamic liquid-liquid-liquid microextraction SEE, supercritical fluid extraction MIP, molecularly imprinted polymers sorbent SPMD, device for semipermeable membrane extraction PDMS, polydimethylsiloxane coated fiber PA, polyacrylate coated fiber CW-DMS, Carbowax-divinylbenzene fiber PDMS-DVB, polydimethylsiloxane divinylbenzene fiber CAR-PDMS, Carboxen-polydimethylsiloxane coated fiber DVB-CAR-PDMS, divinylbenzene Carboxen-polydimethylsiloxane coated fiber CW-TPR, Carbowax-template resin HS-SPME, headspace solid-phase microextraction MA-HS-SPME, microwave-assisted headspace-solid-phase microextraction HEM, porous hollow fiber membrane PEl-PPP, polydydroxylated polyparaphenylene. 

Chiang, J.S. Huang, S.D. Determination of haloethers in water with dynamic hollow fiber liquid-phase microextraction using GC-FID and GC-ECD. Talanta 2007, 71 (2), 882-886. 

Chia, K.J. and Huang, S.D. Simultaneous derivatization and extraction of primary amines in river water with dynamic hollow fiber liquid-phase microextraction followed by gas chromatography-mass spectrometric detection. Journal of Chromatography A 2006,1103 (1), 158-161. 

The techniques discussed in this chapter vary in automatability and frequency of use. Thus, while automatic hydride and cold mercury vapour generation are implemented in laboratory-constructed or commercially available dynamic equipment that is straightforward, easy to operate and inexpensive, automating laboratory headspace modes and solid-phase microextraction is rather complicated and commercially available automated equipment for their implementation is sophisticated and expensive. Because of its fairly recent inception, analytical pervaporation lacks commercially available equipment for any type of sample however, its high potential and the interest it has aroused among manufacturers is bound to result in fast development of instrumentation for both solid and liquid samples. This technique, which is always applied under dynamic conditions, has invariably been implemented in a semi-automatic manner to date also, its complete automatization is very simple. 

Enrichment techniques described in the literature for organic sulfur compounds include liquid/liquid extraction, static and dynamic gas extraction methods, trapping, solid-phase microextraction (SPME), and solid-phase extraction. 

It has been coupled with enzyme immunoassay for efficient and fast polyaromatic hydrocarbon (PAH) screening in soil [21]. In a number of studies both static and dynamic superheated water extraction has been coupled to solid-phase microextraction [15, 25, 28, 30, 35, 38], sometimes with other analytical methods also coupled. It has been coupled with gas chromatography-mass spectrometry [31], capillary electrophoresis [31], liquid chromatography-mass spectrometry [32] and liquid chromatography-gas chromatography [41]. Sometimes other chemicals are added to the water used, such as acid [42] or phosphate buffer [43]. Different trapping methods for analytical extraction have been examined [44]. 

The search of adequate extraction techniques allowing the identification and quantification of wine volatile compounds has attracted the attention of many scientists. This has resulted in the availability of a wide range of analytical tools for the extraction of these compounds from wine. These methodologies are mainly based on the solubility of the compounds in organic solvents (liquid-liquid extraction LLE, simultaneous distillation liquid extraction SDE), on their volatility (static and dynamic headspace techniques), or based on their sorptive/adsorptive capacity on polymeric phases (solid phase extraction SPE, solid phase microextraction SPME, stir bar sorptive extraction SBSE). In addition, volatile compounds can be extracted by methods based on combinations of some of these properties (headspace solid phase microextraction HS-SPME, solid phase dynamic extraction SPDE). 

Dynamic PFE usually requires implementing a concentration step prior to the determinative step, and because the extracted analytes are dissolved in a liquid (usually aqueous) phase, SPE is a highly useful tool for avoiding the dilution effect. For this purpose, SPE cartridges and columns packed with appropriate sorbents and coupled online to the extractor outlet can be employed in the same way as commented on for static PEE. Miniaturized retention has also been developed by using solid-phase microextraction (SPME). 

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