science

Solid-phase microextraction

Solid-phase microextraction is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Solid-phase microextraction rather than just read about it. In short: Solid phase microextraction, or SPME, is a solid-phase extraction sampling technique that involves the use of a fiber coated with an extracting phase, that can be a liquid (polymer) or a solid (sorbent), which extracts different kinds of analytes (including both volatile and non-volatile) from different kinds of media, that can be in liquid or gas phase. The quantity of analyte extracted by the fibre is proportional…

Key takeaways

Solid-phase microextraction belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Solid-phase microextraction to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Solid-phase microextraction from memory before moving on to harder problems.

Reference excerpt

Solid phase microextraction, or SPME, is a solid-phase extraction sampling technique that involves the use of a fiber coated with an extracting phase, that can be a liquid (polymer) or a solid (sorbent), which extracts different kinds of analytes (including both volatile and non-volatile) from different kinds of media, that can be in liquid or gas phase. The quantity of analyte extracted by the fibre is proportional to its concentration in the sample as long as equilibrium is reached or, in case of short time pre-equilibrium, with help of convection or agitation.

Analysis After extraction, the SPME fiber is transferred to the injection port of separating instruments, such as a gas chromatography and mass spectrometry, where desorption of the analyte takes place and analysis is carried out.

Advantages The attraction of SPME is that the extraction is fast, simple, can be done usually without solvents, and detection limits can reach parts per trillion (ppt) levels for certain compounds. SPME also has great potential for field applications; on-site sampling can be done even by nonscientists without the need to have gas chromatography-mass spectrometry equipment at each location. When properly stored, samples can be analyzed days later in the laboratory without significant loss of volatiles.

Fiber coatings The coating on the SPME fiber can be selected to improve sensitivity for specific analytes of interest; ideally the sorbent layer will have a high affinity for the target analytes. There are many commercially available SPME fiber coatings that are combinations of polydimethylsiloxane, divinylbenzene, Carboxen, polyacrylate, and polyethylene glycol. However, one downside to many of the commercially available SPME fibers is that they tend to be physically brittle due to their composition. Depending on the characteristics of the target analytes, certain properties of the coating improve extraction such as polarity, thickness, and surface area. The sample matrix can also influence the fiber coating selection. Based on the sample and analytes of interest, the fiber may need to tolerate direct immersion as opposed to a headspace extraction. In one of the study the fiber coating method significantly enhances the performance of SPME by ensuring a high binding capacity and improved mass transfer efficiency. By preventing the ingress of the polymeric adhesive matrix into the pores of the sorbent particles, the method allows for faster adsorption and desorption times, which is crucial for high-throughput applications. Metal–organic frameworks (MOFs) have been investigated as sorbent materials for SPME coatings because their pore dimensions and surface functional groups can be modified to alter extraction affinity and selectivity. Zirconium-based MOFs, including members of the UiO family, have been incorporated into polymeric coatings on SPME Arrow devices for the extraction of phenolic contaminants from food samples. For example, an amino-functionalized UiO-67 material was dispersed in polyacrylonitrile and deposited on a stainless-steel SPME Arrow by electrospinning. The coating was used with high-performance liquid chromatography and ultraviolet detection to determine bisphenol A, p-tert-butylphenol, 4-pentylphenol, nonylphenol, and hexestrol in milk and pork. The reported limits of detection were 0.003–0.01 μg L−1, and the coating retained stable extraction performance over 200 extraction–desorption cycles.

Application of SPME in forensic science SPME has become an essential technique in forensic science, particularly for analyzing complex matrices such as blood, urine, and environmental samples. Its advantages include the ability to perform rapid and sensitive extractions without the need for extensive sample preparation, which is crucial in forensic investigations where sample integrity is paramount. For instance, SPME has been successfully employed to detect drugs of abuse, explosives, and other volatile compounds from various samples, allowing for the efficient identification of substances relevant to criminal cases. The automation and miniaturization of SPME techniques further enhance their applicability in forensic settings, enabling high-throughput analysis and reducing the risk of contamination.

Green sample preparation SPME is recognized as a green analytical method for sample preparation, particularly in forensic drug analysis. This technique offers several advantages over traditional methods like liquid–liquid extraction (LLE) and solid-phase extraction (SPE), including automation, rapid sample processing, and reduced solvent usage. SPME allows for the extraction of analytes directly from complex matrices, such as biological and environmental samples, while minimizing the environmental impact associated with conventional extraction techniques.

References

Further reading Green Analytical Methods and Miniaturized Sample Preparation techniques for Forensic Drug Analysis. 2025. doi:10.1016/C2022-0-02711-2. ISBN 978-0-443-13907-9. Janusz Pawliszyn: Handbook of Solid Phase Microextraction, Chemical Industry Press, 2009. Pawliszyn J.: Solid Phase Microextraction: Theory and Practice, Wiley-VCH, 1997. Pawliszyn J.: Applications of Solid Phase Microextraction, Royal Society of Chemistry, 1999.

Interactive lectures Introduction to Solid Phase Microextraction Quantification using Solid Phase Microextraction

Illustrations

Worked examples

Example 1 — a first encounter with Solid-phase microextraction

Start with the simplest possible case. Write down what Solid-phase microextraction claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Solid-phase microextraction before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Solid-phase microextraction ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Solid-phase microextraction

In research: Solid-phase microextraction appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Solid-phase microextraction in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Solid-phase microextraction is common in secondary-school and first-year university syllabi. It links to neighbouring topics Laboratory techniques, so understanding it makes those chapters shorter.
In everyday life: Look for Solid-phase microextraction outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Solid-phase microextraction in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Solid-phase microextraction means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Solid-phase microextraction out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Solid-phase microextraction in simple terms?

Why does Solid-phase microextraction matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Solid-phase microextraction?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Solid-phase microextraction.