Water microextraction

Takao Y, Chul Lee H, Ishibashi Y, Kohra S. Tominag screening method for bisphenol A in environmental water microextraction (SPME). J Health Sci 1999 45 (39). 

A recent method, still in development, for determining total 4-nitrophenol in the urine of persons exposed to methyl parathion is based on solid phase microextraction (SPME) and GC/MS previously, the method has been used in the analysis of food and environmental samples (Guidotti et al. 1999). The method uses a solid phase microextraction fiber, is inserted into the urine sample that has been hydrolyzed with HCl at 50° C prior to mixing with distilled water and NaCl and then stirred (1,000 rpm). The fiber is left in the liquid for 30 minutes until a partitioning equilibrium is achieved, and then placed into the GC injector port to desorb. The method shows promise for use in determining exposures at low doses, as it is very sensitive. There is a need for additional development of this method, as the measurement of acetylcholinesterase, the enzyme inhibited by exposure to organophosphates such as methyl parathion, is not an effective indicator of low-dose exposures. 

Several extraction methods for water samples are applicable, such as solvent extraction, SPE using a cartridge and disk and solid-phase microextraction (SPME). 

The most widely employed techniques for the extraction of water samples for triazine compounds include liquid-liquid extraction (LLE), solid-phase extraction (SPE), and liquid-solid extraction (LSE). Although most reports involving SPE are off-line procedures, there is increasing interest and subsequently increasing numbers of reports regarding on-line SPE, the goal of which is to improve overall productivity and safety. To a lesser extent, solid-phase microextraction (SPME), supercritical fluid extraction (SEE), semi-permeable membrane device (SPMD), and molecularly imprinted polymer (MIP) techniques have been reported. 

Saldana MDA, Zetzl C, Mohamed RS and Brunner G. 2002a. Decaffeination of guarana seeds in a microextraction column using water-saturated CO2. J Supercrit Fluids 22 119-127. 

Diaz A, Ventura F, Galceran MT (2002) Development of a solid-phase microextraction method for the determination of short-ethoxy-chain nonylphenols and their brominated analogs in raw and treated water. J Chromatogr A 963 159-167... 

Penalver A, Pocurull E, Borrull F, Marce RM (2000) Determination of phthalate esters in water samples by solid-phase microextraction and gas chromatography with mass spectro-metric detection. J Chromatogr A 872(1-2) 191-201... 

Liu W, Gan JJ (2004) Determination of enantiomers of synthetic pyrethroids in water by solid phase microextraction - enantioselective gas chromatography. J Agric Food Chem 52 736-741... 

Hawthorne SB, Grabanski CB, Hageman KJ, Miller DJ. Simple method for estimating polychlorinated biphenyl concentrations on soils and sediments using subcriti-cal water extraction coupled with solid-phase microextraction. J. Chromatogr. A 1998 814 151-160. 

In the 1990s, Pawliszyn [3] developed a rapid, simple, and solvent-free extraction technique termed solid-phase microextraction. In this technique, a fused-silica fiber is coated with a polymer that allows for fast mass transfer—both in the adsorption and desorption of analytes. SPME coupled with GC/MS has been used to detect explosive residues in seawater and sediments from Hawaii [33]. Various fibers coated with carbowax/divinylbenzene, polydimethylsiloxane/divinylbenzene, and polyacrylate are used. The SPME devices are simply immersed into the water samples. The sediment samples are first sonicated with acetonitrile, evaporated, and reconstituted in water, and then sampled by SPME. The device is then inserted into the injection port of the GC/MS system and the analytes thermally desorbed from the fiber. Various... 

Arthur CL, Pratt K, Motlach S, et al. 1992. Environmental analysis of organic compounds in water using solid-phase microextraction. J High Resolut Chromatogr 15(11) 741 -744. 

Nitrobenzene, 2,4-dinitrotoluene and 2,6-dinitrotoluene were determined in water by GC-EC or GC-CLD thermal energy analyzer (TEA) and by EI-MS, CI-MS and NICI-MS455, after solid-phase microextraction (SPME) with polydimethylsiloxane coated fiber. SPME is a technique to concentrate organic compounds dissolved in an aqueous matrix by adsorption on a solid stationary phase immobilized on a fused silica fiber. The analytes were thermally desorbed directly into the GC injector LOD was 9 pg/L for nitrobenzene and 15 pg/L for the dinitrotoluenes456. 

Bourgeois D, Gaudet J, Deveau P, et al. 1993. Microextraction of organophosphorous pesticides from environmental water and analysis by gas chromatography. Bull Environ Contam Toxicol 50(3) 433 440. 

Analysis of y-hexachlorocyclohexane in lake water using disposable solid-phase microextraction fibers and GC Chromatography (YU Hongxia, China)... 

For the determination of 1,2-dibromoethane (EDB) and l,2-dibromo-3-chloropro-pane (DBCP) in water by hexane microextraction and GC... 

Eisert R, Karsten L. 1996. Solid-phase microextraction coupled to gas chromatography A new method for the analysis of organics in water. J Chromatogr 733 143-157. 

Paschke, A. and Popp, P. 2003, Solid-phase microextraction fibre-water distribution constants of more hydrophobic organic compounds and dieir correlations widi octanol-water partition coefficients. J. Chromatogr. A 999 35-42. 

Air, water Solid phase microextraction (from air, water, or headspace over water) GC/ECD 0.9 ppb (v/v) gas phase 30 ng/L (30 ppt, w/v) liquid phase No data Chai et al. 1993... 

Chai M, Arthur CL, Pawliszyn J, et al. 1993. Determination of volatile chlorinated hydrocarbons in air and water with solid-phase microextraction. Analyst (Cambridge, U. K.) 118(12) 1501-1505. 

Determination of Chlorinated Acids in Drinking Water by Liquid-Liquid Microextraction, Derivatization, and Fast... 

Saraullo, A., Martos, P.A., and Pawliszyn, J. Water analysis by solid phase microextraction based on physical chemical properties of the coating, Anai. Chem., 69(11) 1992-1998, 1997. 

Figure l Photograph of diver collecting water samples during early studies on dissolved explosives in simulated ordnance in waters off San Clemente Island. Water is drawn by a pump over a solid phase microextraction fiber (not seen in photo) where explosives are retained and enriched. The SPME fiber was then presented to an IMS analyzer for the determination of explosives. Full application of these methods was made in Halifax Harbor. Source [72]... 

Microextraction with decanoic acid, tetrahydrofuran, water... 

Experiments to identify disinfection by-products (DBFs) have been carried out using two different procedures. In the first, natural waters (e.g., river, lake) are reacted with the disinfectant, either in a pilot plant, an actual treatment plant, or in a controlled laboratory smdy. fii the second type of procedure, aquatic humic material is isolated and reacted with the disinfectant in purified water in a controlled laboratory study. This latter type of study is relevant because humic material is an important precursor of THMs and other DBFs. Aquatic humic material is present in nearly all natural waters, and isolated humic material reacts with disinfectants to produce most of the same DBFs found from natural waters. Because DBFs are typically formed at low levels (ng/L-pg/L), samples are usually concentrated to allow for DBF detection. Concentration methods that are commonly used include solid phase extraction (SFE), solid phase microextraction (SFME), liquid-liquid extraction, and XAD resin extraction (for larger quantities of water) [9]. 

Domino MM, Pepich BV, Munch DJ, Fair PS, Xie Y (2003) EPA Method 552.3. Determination of haloacetic acids and dalapon in drinking water by liquid-liquid microextraction, derivatization, and gas chromatography with electron capture detection. EPA 815-B-03-002. U.S. EPA, Cincinnati, OH. Available at http //www.epa.gov/ogwdw/methods/pdfs/ methods/met552 3. pdf... 

Polo M, Llompart M, Garcia-Jares C, Cela R (2005) Multivariate optimization of a solid-phase microextraction method for the analysis of phthalate esters in environmental waters. J Chromatogr A 1072 63-72... 

P. Kotianova and E. Matisova, Liquid-phase microextraction and its utilization for trace analysis of organic compounds in water matrix. Chemicke Listy, 2000,94(4), 220-225. Liu Jf, Chi Yg, Jiang Gb, C. Tai, Peng Jf and JT. Hu, Ionic liquid-based liquid-phase microextraction, a new sample enrichment procedure for liquid chromatography. Journal of Chromatography A, 2004,1026(1-2), 143-147. 

E. Psillakis and N. Kalogerakis, Hollow-fibre liquid-phase microextraction of phthalate esters from water. Journal of Chromatography A, 2003, 999(1-2), 145-153. 

Arthur and Pawliszyn introduced solid-phase microextraction (SPME) in 1990 as a solvent-free sampling technique that reduces the steps of extraction, cleanup, and concentration to a unique step. SPME utilizes a small segment of fused-silica fiber coated with a polymeric phase to extract the analytes from the sample and to introduce them into a chromatographic system. Initially, SPME was used to analyze pollutants in water - via direct extraction. Subsequently, SPME was applied to more complex matrixes, such as solid samples or biological fluids. With these types of samples, direct SPME is not recommended nevertheless, the headspace mode (HSSPME) is an effective alternative to extracting volatile and semivolatile compounds from complex matrixes. (Adapted from Llompart et ah, 2001)... 

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