Immobilization of controlled Pu:Am ratio on actinide-specific affinity monolith support developed in capillary and coupled to inductively coupled plasma mass spectrometry.

The objective of this work was to develop an actinide-specific monolithic support in capillary designed to immobilize precise Pu:Am ratios and its coupling to inductively coupled plasma mass spectrometry (ICP-MS) for immobilized metal affinity chromatography applications. This format offers many advantages, such as reducing the sample amount and waste production, which are of prime importance when dealing with highly active radioelements. Four organic phosphorylated-based monoliths were synthesized in situ through UV photo-polymerization in capillary and characterized. The capillary coupling to ICP-MS was set up in conventional laboratory using Th and Sm as chemical analogues of Pu and Am. A dedicated method was developed to quantify online Th and Sm amounts immobilized on the monolithic capillaries, allowing to select the best monolith candidate poly(BMEP-co-EDMA)adp. By precisely adjusting the elemental composition in the loading solutions and applying the developed quantification method, the controlled immobilization of several Th:Sm molar ratios onto the monolith was successful. Finally, the capillary ICP-MS coupling was transposed in a glove box and by applying the strategy developed to design the monolithic support using Th and Sm, the immobilization of a 10.5 ± 0.2 (RSD = 2.3%, n = 3) Pu:Am molar ratio reflecting Pu ageing over 48 years was achieved in a controlled manner on poly(BMEP-co-EDMA)adp. Hence, the new affinity capillary monolithic support was validated, with only hundred nanograms or less of engaged radioelements and can be further exploited to precisely determine differential interactions of Pu and Am with targeted biomolecules in order to better anticipate the effect of Am on Pu biodistribution.

Sustainable and reusable probe-encapsulated porous poly(AMST-co-TRIM) monolithic sensor for the selective and ultra-sensitive detection of toxic cadmium(II) from industrial/environmental wastewater.

This study focuses on a new type of fast responsive solid-state visual colorimetric sensor, custom engineered with dual-entwined porous polymer imbued with chromoionophoric 4-(sec-butyl)- 2-((5-mercapto-1,3,4-thiadiazol-2-yl)diazenyl)phenol (SMDP) probe for selective and ultra-sensitive colorimetric sensing of Cd(II). The polymer monolith, i.e., poly(aminostyrene-co-trimethylolpropanetrimethacrylate) denoted as poly(AMST-co-TRIM), is designed through a stoichiometric blending of monomer, crosslinker, and porogens leading to superior surface area, pore and adsorption properties for the voluminous incorporation of SMDP probe for target specific ion sensing. The porosity, surface and structural characteristics of the poly(AMST-co-TRIM)monolith and poly(AMST-co-TRIM)SMDP sensor are investigated using p-XRD, XPS, TG-DTA, FT-IR, BET/BJH, FE-SEM, HR-TEM, EDAX, and SAED techniques. The poly(AMST-co-TRIM)SMDP sensor reveals a frozen geometrical orientation of SMDP molecules to bind selectively with Cd(II), forming stable charge-transfer complexes by exhibiting transitional visible color shifts from light yellow to dark green (λmax 608 nm). The sensor imposes a linear response from 0-200 ppb, with quantification and detection limits of 0.95 and 0.28 ppb. The fabricated sensor material is cost-effective and versatile in its solid-state naked-eye sensing, with excellent reusability. The sensor performance has been verified using various environmentally contaminated water and commercial cigarette samples, with a recovery of ≥ 99.12% and an RSD of ≤ 1.95%, thus reflecting exceptional data reproducibility/reliability.

Cryogels and Monoliths: Promising Tools for Chromatographic Purification of Nucleic Acids.

The increasing demand for highly pure biopharmaceuticals has put significant pressure on the biotechnological industry to innovate in production and purification processes. Nucleic acid purification, crucial for gene therapy and vaccine production, presents challenges due to the unique physical and chemical properties of these molecules. Meeting regulatory standards necessitates large quantities of biotherapeutic agents of high purity. While conventional chromatography offers versatility and efficiency, it suffers from drawbacks like low flow rates and binding capacity, as well as high mass transfer resistance. Recent advancements in continuous beds, including monoliths and cryogel-based systems, have emerged as promising solutions to overcome these limitations. This review explores and evaluates the latest progress in chromatography utilizing monolithic and cryogenic supports for nucleic acid purification.

New trends in modelling of breakthrough curves to remove pollutants using adsorption on advanced monoliths geometries.

This work proposes a rigorous mathematical model capable of reproducing the adsorption process in dynamic regime on advanced monoliths geometries. For this, four bed geometries with axisymmetric distribution of channels and similar solid mass were proposed. In each geometry a different distribution of channels was suggested, maintaining constant the bed dimensions of 15 cm high and 5 cm radius. The mathematical modeling includes mass and momentum transfer phenomena, and it was solved with the COMSOL Multiphysics software using mass transfer parameters published in the literature. The overall performance of the column was evaluated in terms of breakthrough (CA/CA0 = 0.1) and saturation times (CA/CA0 = 0.9). The mass and velocity distributions obtained from the proposed model show good physical consistency with what is expected in real systems. In addition, the model proved to be easy to solve given the short convergence times required (2-4 h). Modifications were made to the bed geometry to achieve a better use of the adsorbent material which reached up to 80%. The proposed bed geometries allow obtaining different mixing distributions, in such a way that inside the bed a thinning of the boundary layer is caused, thus reducing diffusive effects at the adsorbent solid-fluid interface, given dissipation rates of about 323 × 10-11 m2/s3. The bed geometry composed of intersecting rings deployed the best performance in terms of usage of the material adsorbent, and acceptable hydrodynamical behavior inside the channels (maximum fluid velocity = 35.4 × 10-5 m/s and drop pressure = 0.19 Pa). Based on these results, it was found that it is possible to reduce diffusional effects and delimit the mass transfer zone inside the monoliths, thus increasing the efficiency of adsorbent fixed beds.

Selective immunoglobulin aggregates removal in antivenoms by a simple chromatographic step based on a monolithic stationary phase.

Antivenom therapy is a critical intervention for treating the more than 5.000.000 envenomation accidents that occur each year around the world. These immunotherapeutic drugs are mostly produced following techniques developed more than fifty years ago with minor changes. Aggregate content has been described as one of the main causes of early adverse effects after intravenous administration of antivenoms. In this work we propose the introduction of a final polishing step to traditional antivenom manufacturing processes aimed at lowering the aggregate content in the final product. The refinement step proposed in this work is based on the selective capture of immunoglobulin aggregates by a cation exchange monolithic stationary phase. We show that this media can effectively remove aggregates in the final product under isotonic ion-strength and mildly acidic conditions following a negative chromatography strategy, thus making it a useful technique for producing higher quality products.

CO2 adsorption on carbonaceous materials obtained from forestry and urban waste materials: a comparative study.

The increasing emissions of gaseous pollutants of anthropogenic origin, such as carbon dioxide (CO2), which causes global warming, have raised great interest in developing and improving processes that allow their mitigation. Among them, adsorption on porous materials has been proposed as a sustainable alternative. This work presents a study of CO2 equilibrium adsorption at low temperatures (0, 10, and 20 °C) over a wide range of low pressures, on activated carbon derived from Eucalyptus (ES) and Patula pine (PP) forest waste, and carbonaceous material derived from waste tires (WT). The precursors of these materials were previously prepared, and their physicochemical properties were characterized. ES and PP were thermochemically treated with phosphoric acid, and WT was oxidized with nitric acid. Additionally, these materials were used to obtain monoliths using uniaxial compaction techniques and different binding agents, with better results obtained with montmorillonite. A total of six adsorbent solids had their textural and chemical properties characterized and were tested for CO2 adsorption. The highest specific surface area (1405 m2 g-1), and micropore properties were found for activated carbon derived from Eucalyptus whose highest adsorption capacity ranged from 2.27 mmol g-1 (at 0 °C and 100 kPa) to 1.60 mmol g-1 (at 20 °C and 100 kPa). The activated carbon monoliths presented the lowest CO2 adsorption capacities; however, the studied materials showed high potential for CO2 capture and storage applications at high pressures. The isosteric heats of adsorption were also estimated for all the materials and ranged from 16 to 45 kJ mol-1 at very low coverage explained by the energetic heterogeneity and weak repulsive interactions among adsorbed CO2 molecules.

Direct Synthesis of Metal-Organic Framework Sols: Advances and Perspectives.

The intrinsic lack of processability in the conventional nano/microcrystalline powder form of metal-organic frameworks (MOFs) greatly limits their application in various fields. Synthesis of MOFs with certain flowability make them promising for multitudinous applications. The direct synthesis strategy represents one of the simplest and efficient method for synthesizing solution processable MOF sols/suspensions, compared with other approaches, for instance, the post-synthesis surface modification, the direct dispersion of MOFs in hindered ionic liquids, as well as the calcination method toward a few MOFs with melting behavior. This article reviews the recent direct synthesis strategies of solution processable MOF sols and their typical applications in different fields. The direct synthesis strategies of MOF sols can be classified into two categories: particle size reduction strategy, and selective coordination strategy. The synthesis mechanism of different strategies and the factors affecting the formation of sols are summarized. The application of solution processable MOF sols in different fields are introduced, showing great application potentials. Furthermore, the challenges faced by the direct synthesis of MOF sols and the main methods to deal with the challenges are emphasized, and the future development trend is prospected.

Characterization of hybrid organo-silica monoliths for possible application in the gradient elution of peptides.

We characterized thermally polymerized organo-silica hybrid monolithic capillaries to test their applicability in the gradient elution of peptides. We have used a single-pot approach utilizing 3-(methacryloyloxy)propyltrimethoxysilane (MPTMS), ethylene dimethacrylate (EDMA), and n-octadecyl methacrylate (ODM) as functional monomers. The organo-silica monolith containing MPTMS and EDMA was compared with the stationary phase prepared by adding ODM to the original polymerization mixture. Column prepared using a three-monomer system provided a lower accessible volume of flow-through pores, a higher proportion of mesopores, and higher efficiency. We utilized isocratic and gradient elution data to predict peak widths in gradient elution. Both protocols provided comparable results and can be used for peptide peak width prediction. However, applying gradient elution data for peak width prediction seems simpler. Finally, we tested the effect of gradient time on achievable peak capacity in the gradient elution of peptides with a column prepared with a three-monomer system providing a higher peak capacity. However, the performance of hybrid organo-silica monolithic stationary phases in gradient elution of peptides must be improved compared to other monolithic stationary phases. The limiting factor is column efficiency in highly aqueous mobile phases, which needs to be focused on.

High Recovery Chromatographic Purification of mRNA at Room Temperature and Neutral pH.

Messenger RNA (mRNA) is becoming an increasingly important therapeutic modality due to its potential for fast development and platform production. New emerging RNA modalities, such as circular RNA, drive the need for the development of non-affinity purification approaches. Recently, the highly efficient chromatographic purification of mRNA was demonstrated with multimodal monolithic chromatography media (CIM® PrimaS), where efficient mRNA elution was achieved with an ascending pH gradient approach at pH 10.5. Here, we report that a newly developed chromatographic material enables the elution of mRNA at neutral pH and room temperature. This material demonstrates weak anion-exchanging properties and an isoelectric point of 5.3. It enables the baseline separation of mRNA (at least up to 10,000 nucleotides (nt) in size) from parental plasmid DNA (regardless of isoform composition) with both a NaCl gradient and ascending pH gradient approach, while mRNA elution is achieved in a pH range of 5-7. In addition, the basic structure of the novel material is a chromatographic monolith, enabling convection-assisted mass transfer of large RNA molecules to and from the active surface. This facilitates the elution of mRNA in 3-7 column volumes with more than 80% elution recovery and uncompromised integrity. This is demonstrated by the purification of a model mRNA (size 995 nt) from an in vitro transcription reaction mixture. The purified mRNA is stable for at least 34 days, stored in purified H2O at room temperature.

Construction of chiral capillary electrochromatography microsystems based on Aspergillus sp. CM96.

Novel chiral capillary electrochromatography (CEC) microsystems were constructed based on Aspergillus sp. CM96. As a newly discovered intrinsic characteristic of the cell, cell chirality occupies an essential position in life evolution. Aspergillus sp. CM96 spore (CM96s) was chosen as a proof of concept to develop chiral capillary columns. Interestingly, various types of amino acid (AA) enantiomers were baseline separated under the optimized conditions. Furthermore, the time-dependent chiral interactions between AAs and CM96s were explored in a wider space. Pectinases generated from Aspergillus sp. CM96 fermentation were immobilized onto graphene oxide-functionalized capillary silica monoliths for separating AA enantiomers. Molecular docking simulations were performed to explore chiral separation mechanisms of pectinase for AA enantiomers. These results indicated that Aspergillus sp. CM96-based CEC microsystems have a significant advantage for chiral separation.

Sponge-nested polymer monoliths: Versatile materials for the solid-phase extraction of bisphenols.

Polymer monoliths are promising materials for sample preparation due to their high porosity, pH stability, and simple preparation. The use of melamine formaldehyde foams has been reported as an effective support to prepare highly robust silica and polymer monoliths. Herein, divinylbenzene monoliths based on a 50:50 (%, w/w) crosslinker/porogen ratio have been nested within a melamine-formaldehyde sponge, resulting in monoliths with a surface area higher than 400 m2 /g. The extraction performance of these monoliths was evaluated for the extraction of endocrine-disrupting bisphenols from aqueous solutions. We evaluated for the first time the versatility of sponge-nested polymer monoliths by comparing three different extraction modes (vortex mixing, magnetic stirring, and orbital shaking). Vortex mixing showed a comparable recovery of bisphenols (39%-81%) in a shorter extraction time (30 min, instead of 2 h). In addition, the robustness of the sponge-nested polymer monoliths was demonstrated for the first time by reshaping a larger monolithic cube (0.125 cm3 ) into four smaller pieces (4 × 0.03125 cm3 ) leading to a 16%-21% increase in extraction efficiency. This effect was attributed to an increase in the effective contact area with the sample, obtaining a higher analyte extraction capacity.

Reducing pressure and increasing peak capacity by incorporating an adaptable flow stream splitting platform to high-performance liquid chromatography columns: A study on C18 silica-based monoliths.

In this study, an adaptable end-column platform was fitted to a commercially available monolith, which enabled the column to be fitted with a flow-splitting device. A variety of flow-splitting adapters could be incorporated into the platform, and in this study, a radial flow stream splitter was utilized. The advantage of the radial flow stream spitter was that it overcame issues relating bed density variations that could cause bands to distort in the radial cross-section of the column. Using propylbenzene as a test standard in isocratic elution mode, height equivalent to a theoretical plate curves were constructed across ten flow rates, and it was found that the column efficiency improved by as much as 73%. Furthermore, the dual outlet flow splitter enabled a very substantial reduction in column back pressure, with the decrease being consistently between 20 to 30% depending on the column length. Additionally, sensitivity increased by 45%, consistent with the observed increase in efficiency. The adaptable end-column platform could be retrofitted to almost any commercial column with the expectation of gaining efficiency, sensitivity, and reducing back pressure.

Segmented two-dimensional liquid chromatography. Proof of concept study.

The separation in liquid chromatography is defined either by the space domain where it proceeds until the least retained analyte reaches the outlet of the column or by the time when individual analytes elute out of the column. These two approaches lead to the four possible combinations of two-dimensional liquid chromatography with online space x time coupling being the least experimentally feasible. Here, we show the development of a novel two-dimensional liquid chromatography method combining separation defined by space and the conventional elution-based separation. First-dimension column consisted of four capillary segments coupled serially via two-position six-port valves allowing an online and comprehensive transfer of analytes from the first to the second dimension. After initial experiments using homemade monolithic capillary columns, we tested commercially available columns in both dimensions. We ended with the combination of packed capillary columns in the first dimension and monolithic capillary column in the second dimension. We used a reversed-phase retention mechanism in the first spatial dimension, while HILIC was in the second, time-based dimension. We also developed a theoretical model to describe the proposed two-dimensional separation that was further confirmed by utilizing both an isocratic and gradient elution in the second dimension. Finally, we applied our experimental setup to separate neurotransmitters contained in human urine.

Trends in monoliths: Packings, stationary phases and nanoparticles.

Monoliths media are gaining interest as excellent substitutes to conventional particle-packed columns. Monolithic columns show higher permeability and lower flow resistance than conventional liquid chromatography columns, providing high-throughput performance, resolution and separation in short run times. Monolithic columns with longer length, smaller inner diameter and specific selectivity to peptides or enantiomers have been played important role in hyphenated system. Monolithic stationary phases possess great efficiency, resolution, selectivity and sensitivity in the separation of complex biological samples, such as the complex mixtures of peptides for proteome analysis. The development of monolithic stationary phases has opened the new avenue in chromatographic separation science and is in turn playing much more important roles in the wide application area. Monolithic stationary phases have been widely used in fast and high efficiency one- and multi-dimensional separation systems, miniaturized devices, and hyphenated system coupled with mass spectrometers. The developing technology for preparation of monolithic stationary phases is revolutionizing the column technology for the separation of complex biological samples. These techniques using porous monoliths offer several advantages, including miniaturization and on-line coupling with analytical instruments. Additionally, monoliths are ideal support media for imprinting template-specific sites, resulting in the so-called molecularly-imprinted monoliths, with ultra-high selectivity. In this review, the origin of the concept, the differences between their characteristics and those of traditional packings, their advantages and drawbacks, theory of separations, the methods for the monoliths preparation of different forms, nanoparticle monoliths and metal-organic framework are discussed. Two application areas of monolithic metal-organic framework and nanoparticle monoliths are provided. The review article discusses the results reported in a total of 218 references. Other older references were included to illustrate the historical development of monoliths, both in preparation and types, as well as separation mechanism.

A Continuous-Flow Microreactor for Knoevenagel Condensation of Ethyl Cyanoacetate with Benzaldehyde: The Effect of Grafted Amino Groups on Catalytic Activity.

Ethyl α-cyanocinnamate was synthesized in the Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate in flow monolithic microreactor of 0.63 cm3 volume. The catalytically active core was made of silica monolith modified with various amine group precursors. Structural properties of the support, surface density of NHx groups, and catalytic activity were investigated. It was found that the poly- or di-amine groups attached to the silica surface appeared to be more effective than the aminopropyl groups. Microreactors grafted with diamine functional groups, accompanied by hydrophobic methyl groups, showed the highest activity and stability. It was proved that the decisive role on the activity of catalysts was exerted by the presence of primary amines in diamine chain. The reaction conditions were optimized and it was found that almost full substrate conversion could be achieved in 6 min at 50 °C in the microreactor with low concentration of diamine groups equal to 0.33 mmol g-1 .

Room temperature synthesis of monolithic MIL-100(Fe) in aqueous solution for energy-efficient removal and recovery of aromatic volatile organic compounds.

The removal and recovery of volatile organic compounds (VOCs) are widely used in many industrials. Unfortunately, most conventional porous materials not only have low VOCs uptake, but also need to be regenerated at relatively high temperature. Metal-organic frameworks (MOFs) have great potential for the removal and recovery of VOCs as their record-breaking gas adsorption capacity, easy regeneration, tunable pore structure and functional groups. Whereas, powdered MOFs are hardly implemented in industrial fields owing to their low bulk density and high pressure drop. Exploring a green method to prepare granular MOFs for the removal and recovery of VOCs is still a challenge. Herein, we report the room temperature green synthesis of a stable Fe-based MOF monolith by using water as the solvent without applying high pressure and chemical binders. The static and dynamic experiments show that the optimized centimeter-scale monolith has high porosity and mechanical strength, and exhibits much better adsorption performance for representative aromatic VOCs (benzene, toluene and p-xylene), than commercial activated carbon and activated carbon fiber under the same conditions. Remarkably, as-synthesized monolith can be rapidly regenerated at lower temperature. These results clearly demonstrate the advantages of MOF monoliths in removing and recovering VOCs, and also provide new insight into the effects of drying temperature, washing and centrifugation procedures on MOF shaping.

Influence of ion-pairing reagents on the separation of intact glycoproteins using hydrophilic-interaction liquid chromatography - high-resolution mass spectrometry.

Hydrophilic-interaction liquid chromatography (HILIC) of intact proteins offers high-resolution separations of glycoforms of glycoproteins differing in the number of (neutral) glycans. However, to obtain efficient separations it is essential that the positively charged sites of the proteins are shielded by acidic (negative) ion-pair reagents (IPRs), so as to enhance the contribution of the hydroxyl groups of the (neutral) sugars in the glycoprotein. Here, we studied the influence of various IPRs that differ in physico-chemical properties, such as hydrophobicity and acidity, on the capillary-scale HILIC separation of intact (glyco)proteins. We evaluated the use of fluoroacetic acid (MFA), difluoroacetic acid (DFA), trifluoroacetic acid (TFA), and heptafluorobutyric acid (HFBA) as diluents for sample preparation, as solvents for sample loading on a reversed-phase trap prior to the HILIC separation, and as mobile-phase components for HILIC and HILIC-MS. To reduce the contribution of ion-exchange interaction with the (silica-based) stationary phase, we used an acrylamide-based monolithic column. We studied the influence of the different IPRs on each step of the separation of a mixture of proteins of different size and hydrophilicity and on the separation of the five glycoforms of ribonuclease B. The content of IPR in the sample was shown not to affect the separation and the MS detection. However, a low content of TFA and DFA in the mobile phase is favourable, as it reduces adduct formation and leads to higher signal intensity. The optimized HILIC conditions successfully resolved nine major glycoforms groups of a ∼40 kDa glycoprotein horseradish peroxidase (HRP), as an example of a complex glycoprotein.

High-throughput immunoaffinity enrichment and N-glycan analysis of human plasma haptoglobin.

Haptoglobin (Hp) is a positive acute phase protein, synthesized in the liver, with four N-glycosylation sites carrying mainly complex type N-glycans. Its glycosylation is altered in different types of diseases but still has not been extensively studied mainly due to analytical challenges, especially the lack of a fast, efficient, and robust high-throughput Hp isolation procedure. Here, we describe the development of a high-throughput method for Hp enrichment from human plasma, based on monolithic chromatographic support in immunoaffinity mode and downstream Hp N-glycome analysis by hydrophilic interaction ultrahigh-performance liquid chromatography with fluorescent detection (HILIC-UHPLC-FLR). Chromatographic monolithic supports in a 96-well format enable fast, efficient, and robust Hp enrichment directly from diluted plasma samples. The N-glycome analysis demonstrated that a degree of Hp deglycosylation differs depending on the conditions used for N-glycan release and on the specific glycosylation site, with Asn 241 being the most resistant to deglycosylation under tested conditions. HILIC-UHPLC-FLR analysis enables robust quantification of 28 individual chromatographic peaks, in which N-glycan compositions were determined by UHPLC coupled to electrospray ionization quadrupole time of flight mass spectrometry. The developed analytical approach enables fast evaluation of total Hp N-glycosylation and is applicable in large-scale studies.

Enabling Solution Processable COFs through Suppression of Precipitation during Solvothermal Synthesis.

Covalent organic frameworks (COFs) are crystalline, nanoporous materials of interest for various applications, but current COF synthetic routes lead to insoluble aggregates which precludes processing for practical implementation. Here, we report a COF synthesis method that produces a stable, homogeneous suspension of crystalline COF nanoparticles that enables the preparation of COF monoliths, membranes, and films using conventional solution-processing techniques. Our approach involves the use of a polar solvent, diacid catalyst, and slow reagent mixing procedure at elevated temperatures which altogether enable access to crystalline COF nanoparticle suspension that does not aggregate or precipitate when kept at elevated temperatures. On cooling, the suspension undergoes a thermoreversible gelation transition to produce crystalline and highly porous COF materials. We further show that the modified synthesis approach is compatible with various COF chemistries, including both large- and small-pore imine COFs, hydrazone-linked COFs, and COFs with rhombic and hexagonal topologies, and in each case, we demonstrate that the final product has excellent crystallinity and porosity. The final materials contain both micro- and macropores, and the total porosity can be tuned through variation of sample annealing. Dynamic light scattering measurements reveal the presence of COF nanoparticles that grow with time at room temperature, transitioning from a homogeneous suspension to a gel. Finally, we prepare imine COF membranes and measure their rejection of polyethylene glycol (PEG) polymers and oligomers, and these measurements exhibit size-dependent rejection and adsorption of PEG solutes. This work demonstrates a versatile processing strategy to create crystalline and porous COF materials using solution-processing techniques and will greatly advance the development of COFs for various applications.

Chromatographic supports for enantioselective liquid chromatography: Evolution and innovative trends.

Diverse approaches have been explored as chromatographic supports for chiral stationary phases (CSPs) in liquid chromatography (LC), such as the introduction of nanoparticles, superficially porous particles, and new materials including monoliths, metal-organic frameworks, covalent-organic frameworks as well as hybrid chromatographic supports. Nevertheless, silica-based CSPs are still nowadays the most successfully and widely applied. In this review, the most relevant achievements related with chromatographic supports used for development of CSPs for LC are described. The advantages and drawbacks of the different materials used as chromatographic supports are critically discussed. Some recent examples of applications are also presented, emphasizing innovative trends in LC.