Solid-phase microextraction advantages

Table 3.45 Characteristics of solid-phase microextraction Advantages...

Solid-phase microextraction (SPME), a new solvent-free sample preparation technique, was invented by C. Arthur and J. Pawliszyn in 1990. This method was mainly applied for the extraction of volatile and semivolatile organic pollutants in water samples. However, since 1995, SPME has been developed to various biological samples, such as whole blood, plasma, urine, hair, and breath, in order to extract drags and poisons in forensic field. The main advantages of SPME are high sensitivity, solventless, small sample volume, simplicity, and rapidity (Liu et al., 1998). 

SBSE takes advantage of the high enrichment factors of sorptive beds, but with the application range and simplicity of solid-phase microextraction (SPME)... 

MEPS has so far been applied mainly to the analysis of drugs in biological samples only one application for the extraction of PAHs in water has been published.26 One of the major advantages of the MEPS design is that the packed syringe can be used many times over, for example, more than 400 times for water samples. Moreover, the technique permits a fast handling time in the analysis of PAHs in water, the speed enhancement being 15 and 100 times compared to the literature procedures of solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE), respectively see Sections 4.2.3 and 4.2.4. 

Similar biomimetic methods have been developed for assessing the (bio)avail-ability of organic chemicals in water, sediments, and soil (Mayer et al. 2003 Ter Laak et al. 2006). The main advantage of these nondepletion techniques, such as the solid-phase microextraction methods (SPMEs), is that they may be used without disturbing the chemical distribution in surface water or soils or sediments. 

The third alternative is the use of a Solid Phase Microextraction fibre (SPME) to collect the volatiles in the headspace. The technique is clean, very easy to use and provides a good concentration of many volatiles on the headspaces of wine. Because of this, it has been the technique of choice in some recent works (Marti et al. 2003 Fan and Qian 2005 Gurbuz et al. 2006 Tat et al. 2007). Nevertheless, the use of this technique is not exempt from problems either. On the one hand the technique does not provide an extract, and on the other hand it is quite difficult to optimize and validate and therefore to assess the reliability of the results. It should be concluded that, although the technique is appealing, more research is needed in order to establish its advantages and drawbacks. 

Solid Phase Microextraction Out of the many sample preparation methods, solid phase microextraction (SPME) is one of the most frequently used. SPME is used for the determination of VOCs in liquid, gas, and solid samples. The great advantage of the method is that it combines, in one stage, the isolation and enrichment of compounds, and completely eliminates the need for organic solvents. 

Solid-phase microextraction, first reported by Belardi and Pawliszyn in 1989, is an alternative sampling technique. The method has the advantages of convenience and simplicity, and it does not release environmentally polluting organic solvents into the atmosphere. The method is based on the extraction of analytes directly from liquid samples or from headspace of the samples onto a polymer- or adsorbent-coated fused silica fiber. After equilibration, the fiber is then removed and injected onto the gas chromatograph. ... 

The low concentration levels of the compounds in environmental samples impose specific requirements in terms of sample injection for GC analysis. In addition to the common injection techniques of capillary GC (split, splitless, on-column, and programmed temperature vaporized (PTV) injection), some other sample introduction methods coupled to GC such as solid-phase microextraction (SPME), headspace, etc., have favored the versatility of GC and reduced the time required for sample preparation. These techniques have an advantage over the conventional injection methods, which is that a preconcentration step prior to GC... 

While open tubular (OT) columns are the most popular type, both open tubular and packed columns are treated throughout, and their advantages, disadvantages, and applications are contrasted. In addition, special chapters are devoted to each type of column. Chapter 2 introduces the basic instrumentation and Chapter 7 elaborates on detectors. Other chapters cover stationary phases (Chapter 4), qualitative and quantitative analysis (Chapter 8), programmed temperature (Chapter 9), and troubleshooting (Chapter 11). Chapter 10 briefly covers the important special topics of GC-MS, derivatization, chiral analysis, headspace sampling, and solid phase microextraction (SPME) for GC analysis. 

SPME (Solid-phase microextraction) has recently been developed as a rapid, inexpensive, and solvent-free technique. This technique uses a fine fused silica fiber with a polymeric coating to extract organic compounds from their matrix. The main advantages of SPME are simplicity, high sensitivity, small sample volume, and lower cost per analysis. SPME techniques can be successfully applied for polar and nonpolar compounds in gas, liquid, and solid samples and can be easily coupled with various analytical instruments such as GC, GC-MS, HPLC, and LC-MS [22, 56]. 

As described earlier (4,5), we have studied nestmate recognition by examining the differences of cuticular hydrocarbons between species, colonies, and castes. Briefly, we developed a methodology for the extraction of termite cuticular hydrocarbons by solid phase microextraction (SPME). Both headspace SPME, where the termites were heated in a vial to 120 °C with the fiber 1 cm above the termites, and direct contact SPME, where live termites walked on the SPME fiber for a certain time period, were studied. As shown in Figure 1, both methods were comparable to the normal hexane extraction method in the types of cuticular hydrocarbons that were extracted. Since SPME requires less manipulation of the sample and may use living termites, it may have advantages. 

Solid-phase microextraction (SPME), first described by Pawliszyn and coworkers [157-161], is a recent upcoming sample preparation method for phenolic and other organic compounds from water and air samples. It is a novel solvent-free sample preparation technique. SPME has advantage of simplicity, low cost, and rapid extraction. It has been successfully coupled with various techniques such as GC, HPLC, CE, and MS. 

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