Solid-phase extraction applications

P.D. McDonald and E.S.P. Bouvier, Solid Phase Extraction Applications Guide and Bibliography, A Resource for Sample Preparation Methods Development, Waters, Milford, MA... 

Solid phase extraction applicable to extracts of carrot, orange juice, peach, tomato, vegetable soup. Load hexane extracts onto alumina N Sep-Pak cartridge. Elute a- and /3-carotene with hexane/acetone, 96.5 3.5 and /3-cryp-toxanthin with acetone... 

McDonald, P. D. and Bouvier, E. S. P. 1995. Solid Phase Extraction Applications... 

There are three general adsorbent classes used most often in solid phase extraction applications polar, ion-exchange, and nonpolar. Each class exhibits unique properties of retention and selectivity based on interactive properties of the products and the adsorbent surface. If the chemical structure and functional groups of desired products are known, this information can be used in choos-... 

Note 6. The Soxhlet extraction gives a material which is sufficiently free from residual template and suitable for chromatographic applications, considering that subsequent column washing will further reduce the amount of residual template. Do not use this material for solid-phase extraction applications, because this technique requires more exhaustive template extraction methods. 

Marzolini, C. Beguin, A. Telenti, A. Schreyer, A. Buclin, T. Biollaz, J. Decosterd, L.A. Determination of lopinavir and nevirapine by high-performance liquid chromatography after solid-phase extraction Application for the assessment of their transplacental passage at delivery. J. Chromatogr. B, 2002, 774 (2), 127-140. 

A method which uses supercritical fluid/solid phase extraction/supercritical fluid chromatography (SE/SPE/SEC) has been developed for the analysis of trace constituents in complex matrices (67). By using this technique, extraction and clean-up are accomplished in one step using unmodified SC CO2. This step is monitored by a photodiode-array detector which allows fractionation. Eigure 10.14 shows a schematic representation of the SE/SPE/SEC set-up. This system allowed selective retention of the sample matrices while eluting and depositing the analytes of interest in the cryogenic trap. Application to the analysis of pesticides from lipid sample matrices have been reported. In this case, the lipids were completely separated from the pesticides. 

The first bioanalytical application of LC-GC was presented by Grob et al. (119). These authors proposed this coupled system for the determination of diethylstilbe-strol in urine as a replacement for GC-MS. After hydrolysis, clean-up by solid-phase extraction and derivatization by pentafluorobenzyl bromide, the extract was separated with normal-phase LC by using cyclohexane/1 % tetrahydrofuran (THE) at a flow-rate of 260 p.l/min as the mobile phase. The result of LC-UV analysis of a urine sample and GC with electron-capture detection (ECD) of the LC fraction are shown in Ligures 11.8(a) and (b), respectively. The practical detection limits varied between about 0.1 and 0.3 ppb, depending on the urine being analysed. By use of... 

Solid phase extraction systems have a wide range of application whether operated manually or automatically. Wherever materials are present in solution at very low concentrations they offer a means of extraction and concentration that is simple, efficient and fast. 

Pimbley, D. and Patel, P.D., Agrifood applications of solid-phase extraction a review, Leatherhead Food RA Sci. Tech. Notes, 197, 2000. 

Kennedy et al. developed a lasalocid immunoassay for application to residues in chicken meat and liver samples. The antibody was specific and did not cross-react with salinomycin, maduramicin, or monensin. Sample preparation consisted of homogenization in aqueous acetonitrile, removal of fat from an aliquot of the aqueous acetonitrile by hexane extraction, and evaporation of acetonitrile. The sample was then reconstituted with assay buffer. Liver required an additional solid phase extraction step. The LOQ was 0.02 xgkg for muscle and 0.15 agkg for liver. These workers were able to use the system to determine the half-life of lasalocid in the tissues. 

W. Simpson, Solid Phase Extraction Principles, Strategies and Applications. M. Dekker, New York, NY (1997). 

Solid Phase Extraction Principles and Practice. By E. M. Thurman Commercial Biosensors Applications to Clinical, Bioprocess and Environmental Samples. Edited by Graham Ramsay... 

Solid Phase Sorbents. Solid Phase Extraction Formats. Automated Solid Phase Extraction. Solid Phase Microextraction. Applications of SPE and SPME. 

Application of SPE to sample clean-up started in 1977 with the introduction of disposable cartridges packed with silica-based bonded phase sorbents. The solid phase extraction term was devised in 1982. The most commonly cited advantages of SPE over liquid-liquid extraction (LLE) as practiced on a macroscale include the reduced time and labor requirements, use of much lower volumes of solvents, minimal risk of emulsion formation, selectivity achievable when desired, wide choices of sorbents, and amenability to automation. The principle of operation consists of four steps (1) conditioning of the sorbent with a solvent and water or buffer, (2) loading of the sample in an aqueous or aqueous low organic medium, (3) washing away unwanted components with a suitable combination of solvents, and (4) elution of the desired compound with an appropriate organic solvent. 

Online Solid Phase Extraction as Tool for High-Throughput Applications... 

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