A review of micro-solid-phase extraction techniques and devices applied in sample pretreatment coupled with chromatographic analysis

ELECTROSPINNING APPLIED TO THE DEVELOPMENT OF ADSORBENT NANOFIBERS AIMING AT IMPROVING SOLID PHASE (MICRO)EXTRACTION TECHNIQUES. The limitations and challenges associated with the complex analyte-matrixinterfering interactions make the development of new sorbent materials an attractive line in several research areas, ranging from the synthesis and characterization to the application of these materials. Among the different strategies for manufacturing sorbent nanomaterials, the electrospinning of nanofibers based on polymeric solutions incorporated into Metal-Organic Frameworks (MOFs), Molecularly Imprinted Polymers (MIPs) and Nanoparticles (NPs) have represented in recent years, one of the methods more versatile and promising with regard to obtaining materials with large surface area and potential for functionalization and chemical modification. In this sense, the objective of this contribution is to highlight recent work aimed at the synthesis of electrospun nanofibers applied in adsorption and sample preparation processes, highlighting the synthetic nanofiber strategies based on MOFs, MIPs and NPs and the main challenges and perspectives of the applications, although little explored, of these materials in solid phase extraction and microextraction techniques.

Despite the advances in analytical instrumentation, separation, enrichment and sample clean-up procedures continue to be essential analytical steps prior to the determination stage itself. Numerous potential interferents and low concentrations of analytes make a preliminary extraction procedure necessary. The development of new extraction techniques and the improvement of existing techniques using novel extraction materials are the main trends in this research area. Nanomaterials, materials with sizes or features ranging from 1 to 100 nm in one or more dimensions, have drawn extensive attention from scientists in recent years mainly owing to their unique and attractive thermal, mechanical, electronic and biological properties. Their high surface-to-volume ratio, the possibility for surface functionalization and favorable thermal features provide the flexibility needed in a broad range of analytical application. Their properties have been extensively exploited in different extraction techniques, such as solid-phase extraction and microextraction. Nanomaterials can be used as single particles, aggregates, powders or dispersed in a matrix, and their physicochemical properties can be controlled through structural design, incorporation of suitable components or modification of the surfaces. Whereas monofunctional nanomaterials provide a single function, the preparation of core/shell nanoparticles allows different properties to be combined in one material. In the preparation of these multifunctional nanomaterials, various strategies are used to attain a combination of targeting specificity, magnetic properties and analysis capability. The surface modification of nanomaterials by functional molecules, particles or polymers can improve the separation and preconcentration efficiency, analytical selectivity and method reliability. The aim of this chapter is to provide an updated and critical review of the most important features and applications of nanomaterials (metallic, silica and carbon-based) for solid-phase extraction and microextraction techniques. Emphasis will be placed on description of work that has provided interesting results for use in this analytical field.

Tyramine detection using PEDOT:PSS/AuNPs/1-methyl-4-mercaptopyridine modified screen-printed carbon electrode with molecularly imprinted polymer solid phase extraction

Quercetin molecularly imprinted polymers: Preparation, recognition characteristics and properties as sorbent for solid-phase extraction

Pesticide residue analysis enables researchers to detect the minute quantity of residual pesticides by applying sensitive analytical techniques which include gas chromatography with mass spectrometry and liquid chromatography with mass spectrometry. However, the sample preparation step prior to utilizing these sophisticated techniques is key to achieving the required sensitivity. The present article reviews the significant methods available for sample preparation for pesticide residue analysis in edible oil. Present sample extraction and cleanup section, most common extraction and cleanup techniques such as liquid‐liquid extraction, solid phase extraction/dispersive solid phase extraction and quick, easy, cheap, effective, rugged and safe method are discussed. Since selection of sorbent affects the recovery, matrix effect and rate of false positive and false negatives, hence, special attention has been paid to sorbents required for sample cleanup. Many sorbents are commercially available however their possible interactions with fatty acids and impurities have not been highlighted in literature. The present review not only highlights the role of commonly used sorbents such as florisil, graphitized carbon black, primary secondary amine and octadecyl bonded silicas but also discusses the pros and cons of newly developed sorbents.

Effects of pendant-like hydrophilic monomers on the adsorption properties of reversed-phase-type sorbents for solid-phase extraction

Silicalite as a sorbent for solid-phase extraction

(Re) thinking towards a sustainable analytical chemistry: Part I: Inorganic elemental sample treatment, and Part II: Alternative solvents and extraction techniques

Recent progress of graphene aerogel as sorbent in solid-phase extraction: A review

A new dilution-enrichment sample preparation strategy for expanded metabolome monitoring of human breast milk that overcomes the simultaneous presence of low- and high-abundance lipid species

Chapter 7 - Solid-phase extraction

Determination of trace selenium in high purity tellurium by hydride generation atomic fluorescence spectrometry after solid phase extraction of a diaminobenzidine-selenium chelate

Computational design of molecularly imprinted polymer for solid phase extraction of moxifloxacin hydrochloride from Avalox® tablets and spiked human urine samples

Flavonoids are a large group of plant secondary metabolites that are present in most plants, and are vital for plant growth, development and protection. Among the many functions of these compounds is their contribution to stress amelioration. The accurate identification and quantification of total or individual flavonoids in plants exposed to stressful conditions (e.g. ultraviolet radiation) is challenging due to their structural diversity. The present review provides the up to date knowledge and highlights trends in plant flavonoid analysis. The review covers all steps from the field to the laboratory, focussing on UV-B effects on flavonoids, and identifying critical issues concerning sample collection, pre-treatment, extraction techniques and quantitative or qualitative analysis. A well-planned sampling and sample prehandling strategy is vital when capturing organ, tissue and developmental-stage dependent changes in flavonoids, as well as the dynamic changes due to time of UV-exposure and diurnal or seasonal parameters. A range of advanced extraction and purification techniques can facilitate the quantitative transfer of flavonoids to solvents. The advantages and disadvantages of analytical methods, including chromogenic assays, liquid and thin-layer chromatography, mass spectrometry, nuclear magnetic resonance detection, and non-destructive in situ fluorescent analysis need to be consciously evaluated in the context of the specific biological question posed. Thus, no one method can be applied to every single study of flavonoid. The message of this review is that researchers will need to carefully consider the biological process that they intend to study, and select an analytical method that optimally matches their specific objectives.

Preparation and evaluation of dummy-template molecularly imprinted polymer as a potential sorbent for solid phase extraction of imidazole fungicides from river water