Solid-phase extraction

A typical solid phase extraction manifold. The cartridges drip into the chamber below, where tubes collect the effluent. A vacuum port with gauge is used to control the vacuum applied to the chamber.

Solid-phase extraction (SPE)[1] is a solid-liquid extractive technique, by which compounds that are dissolved or suspended in a liquid mixture are separated, isolated or purified, from other compounds in this mixture, according to their physical and chemical properties. Analytical laboratories use solid phase extraction to concentrate and purify samples for analysis. Solid phase extraction can be used to isolate analytes of interest from a wide variety of matrices, including urine, blood, water, beverages, soil, and animal tissue.[2][3][4]

SPE uses the affinity of solutes, dissolved or suspended in a liquid (known as the mobile phase), to a solid packing inside a small column, through which the sample is passed (known as the stationary phase), to separate a mixture into desired and undesired components. The result is that either the desired analytes of interest or undesired impurities in the sample are retained on the stationary phase. The portion that passes through the stationary phase is collected or discarded, depending on whether it contains the desired analytes or undesired impurities. If the portion retained on the stationary phase includes the desired analytes, they can then be removed from the stationary phase for collection in an additional step, in which the stationary phase is rinsed with an appropriate eluent.[5]

It is possible to have an incomplete recovery of the analytes by SPE caused by incomplete extraction or elution. In the case of an incomplete extraction, the analytes do not have enough affinity for the stationary phase and part of them will remain in the permeate. In an incomplete elution, part of the analytes remain in the sorbent because the eluent used does not have a strong enough affinity.[6]

Many of the adsorbents/materials are the same as in chromatographic methods, but SPE is distinctive, with aims separate from chromatography, and so has a unique niche in modern chemical science.

  1. ^ Buszewski, Boguslaw; Szultka, Malgorzata (2012). "Past, Present, and Future of Solid Phase Extraction: A Review". Critical Reviews in Analytical Chemistry. 42 (3): 198–213. doi:10.1080/07373937.2011.645413. ISSN 1040-8347.
  2. ^ Hennion, Marie-Claire (1999). "Solid-phase extraction: method development, sorbents, and coupling with liquid chromatography". Journal of Chromatography A. 856 (1–2): 3–54. doi:10.1016/S0021-9673(99)00832-8. ISSN 0021-9673. PMID 10526783.
  3. ^ Augusto, Fabio; Hantao, Leandro W.; Mogollón, Noroska G.S.; Braga, Soraia C.G.N. (2013). "New materials and trends in sorbents for solid-phase extraction". TrAC Trends in Analytical Chemistry. 43: 14–23. doi:10.1016/j.trac.2012.08.012. ISSN 0165-9936. S2CID 96825406.
  4. ^ Supelco (1998), Guide to Solid Phase Extraction (PDF), archived from the original (PDF) on 13 January 2012
  5. ^ Buszewski, Boguslaw; Szultka, Malgorzata (July 2012). "Past, Present, and Future of Solid Phase Extraction: A Review". Critical Reviews in Analytical Chemistry. 42 (3): 198–213. doi:10.1080/07373937.2011.645413. ISSN 1040-8347. S2CID 98381163.
  6. ^ Raeke, Julia; Lechtenfeld, Oliver J.; Wagner, Martin; Herzsprung, Peter; Reemtsma, Thorsten (2016). "Selectivity of solid phase extraction of freshwater dissolved organic matter and its effect on ultrahigh resolution mass spectra". Environmental Science: Processes & Impacts. 18 (7): 918–927. doi:10.1039/C6EM00200E. ISSN 2050-7887. PMID 27363664.