Current trends in affinity-based monoliths in microextraction approaches: A review

Chromatography media and purification processes for complex and super-large biomolecules: A review

The biopharmaceutical industry has been one of the most dynamic industries in the world. New biopharmaceuticals are constantly developed, especially for complex and super-large biomolecules including antibodies, virus-like particles (VLPs), viral vectors, DNA, mRNA, and are very promising in drugs, vaccines, cell and gene therapy. Due to complex and unstable structures, as well as low concentration, it is very difficult to purify these complex and super-large biomolecules. Chromatography is the most widely used purification technique in bioseparation, and chromatography media is the key material. This review gives a comprehensive analysis of chromatography media and purification processes for complex and super-large biomolecules. A detailed summary of tailor-made chromatography media is first provided, including particle size and its uniformity, pore structure, spacer arm and polymer grafting, and new ligands and special separation mechanisms. Then the current choices and trends of purification processes for vaccines, VLPs, DNA, mRNA, antibodies and modified therapeutic proteins are reviewed. Finally, a brief overview of continuous biochromatography and computer-assisted chromatographic method development is provided. We hope this review will provide some useful guidance for design of chromatography media and purification of complex biopharmaceuticals.

Aptamer based hybrid monolithic pipette tips supported by melamine sponge for enrichment of proteins

BACKGROUND

The convenient preparation and application of functionalized organic-inorganic hybrid monolithic materials have obtained substantial interest in the pretreatment of complex samples by solid-phase extraction (SPE). Compared to the in-tube solid-phase microextraction in fused-silica capillaries, micro SPE in plastic pipette tips have fascinating merits for the easily operated enrichment of trace target analytes from biological samples. However, the poor compatibility of organic-inorganic hybrid monoliths with plastics leads to the rare appearance of commercial hybrid monolithic pipette tips (HMPTs). Therefore, how to synthesize the organic-inorganic hybrid monolithic materials with better extraction performance in plastic pipette tips becomes a challenge.

RESULTS

We develop a facile and cheap strategy to immobilize organic-inorganic hybrid monoliths in pipette tips. Melamine sponge was employed as the supporting skeleton to in situ assemble amine- and thiol-bifunctionalized hybrid monolithic material via "one pot" in a pipette tip, and gold nanoparticles (GNPs) and thiol-modified aptamer against human α-thrombin were sequentially attached to the hybrid monolith within the HMPTs. The average coverage density of the aptamer with GNPs as an intermediary reached as high as 818.5 pmol μL-1. The enriched thrombin concentration was determined by a sensitive enzymatic chromogenic assay with the limit of detection of 2 nM. The extraction recovery of thrombin at 10 nM in human serum was 86.1 % with a relative standard deviation of 6.1 %. This proposed protocol has been applied to the enrichment and determination of thrombin in real serum sample with strong anti-interference ability, low limit of detection and high recovery.

SIGNIFICANCE

The amine- and thiol-bifunctionalized HMPTs prepared with sponge as the skeleton frame provided a novel substrate material to decorate aptamers for efficient enrichment of proteins. This enlightens us that we can take advantage of the tunability of sponge assisted HMPTs to produce and tailor a variety of micro SPE pipette tips for broader applications on the analysis of trace targets in complex biological, clinic and environmental samples.

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.

Itaconic Acid-Based Organic-Polymer Monolithic Column for Hydrophilic Capillary Electrochromatography and Its Application in Pharmaceutical Analysis

Itaconic acid is an excellent hydrophilic monomer owing to the dicarboxylic group possessing strong polarity. This study reports on the preparation of a new organic-polymer monolithic column poly(itaconic acid-co-3-(acryloyloxy)-2-hydroxypropyl methacrylate) (poly(IA-co-AHM)) featuring excellent hydrophilic chromatography ability and its application in pharmaceutical analysis. The monolithic column was successfully synthesized by using the monomer itaconic acid and the cross-linker AHM through an in situ copolymerization method. Optical microscopy, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were employed for the characterization of the poly(IA-co-AHM) monolithic column, and all of these demonstrated that the prepared itaconic acid-based monolithic column exhibited satisfactory permeability and a homogeneous porous structure. Owing to the carboxylic groups of itaconic acid, a cathodic electroosmotic flow (EOF) was generated on the itaconic acid-based monolithic column among the pH ranges of the mobile phase from 4.0 to 9.0. Depending on the powerful hydrophilic interactions, different kinds of polar substances, including thioureas, nucleoside drugs, sulfonamides, and polypeptides, were separated efficiently by the itaconic acid-based monoliths poly(IA-co-AHM). The separations of polar compounds were successfully realized, even at a lower level of 50% acetonitrile content on this monolithic column. The highest column efficiencies corresponding to N,N'-dimethylthiourea and idoxuridine were 102 720 and 124 267 N/m, respectively. The poly(IA-co-AHM) monolithic column displayed excellent repeatability, whose relative standard deviations (RSDs) of the retention time and peak area were both lower than 5.0%. All experimental results demonstrated that the new itaconic acid-functionalized monolithic column was greatly appropriate to separate the polar compounds under the HILIC mode.

Preparation of miniaturized hydrophilic affinity monoliths: Towards a reduction of non-specific interactions and an increased target protein density

In affinity chromatography, non-specific interactions between the ligands and the affinity column may affect the results, leading to misinterpretations during the investigation of protein-ligand interactions (detection of false positives in ligand screening, lack of specificity in purification). Such non-specific interactions may arise both from the underlying support or from the target protein itself. If the second ones are protein-dependent (and cannot be studied in a general framework), the first ones occur in the same way regardless of the immobilized target. We propose a methodology to identify the origin of such non-specific interactions with the underlying material of the affinity column. This methodology relies on the systematic investigation of the retention behavior of a set of 41 low-molecular weight compounds covering a wide chemical space (net charge, log D, functionality). We first demonstrate that the main source of non-specific interactions on the most commonly used GMA-co-EDMA monolith comes from hydrophobic effects. To reduce such non-specific interactions, we developed a new hydrophilic glycidyl methacrylate-based monolith by replacing the EDMA crosslinker by the more hydrophilic NN' Methylenebisacrylamide (MBA). Optimization of the synthesis parameters (monomer content, initiation type, temperature) has focused on the reduction of non-specific interaction with the monolithic support while maximizing the amount of protein that can be grafted onto the monolith at the issue of its synthesis. The retention data of the 41 test solutes on the new poly(GMA-co-MBA) monolith shows a drastic reduction of non-specific interactions except for cationic compounds. The particular behavior of cationic compounds is due to their electrostatic interactions with carboxylic groups resulting from the partial acidic hydrolysis of amide groups of MBA during the epoxide ring opening step. So, the ring opening step in acidic media was replaced by a hot water treatment to avoid side reaction on MBA. The new monolith poly(GMA-co-MBA) not only has improved hydrophilic surface properties but also a higher protein density (16 ± 0.8 pmol cm^-1 instead of 8 ± 0.3 pmol cm^-1). To highlight the benefits of this new hydrophilic monolith for affinity chromatographic studies, frontal affinity chromatography experiments were conducted on these monoliths grafted with con A.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2019-2020

This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2020. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. The review is basically divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of arrays. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other areas such as medicine, industrial processes and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. The reported work shows increasing use of incorporation of new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented nearly 40 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show little sign of diminishing.

Matrices and Affinity Ligands for Antibody Purification and Corresponding Applications in Radiotherapy

Antibodies have become an important class of biological products in cancer treatments such as radiotherapy. The growing therapeutic applications have driven a demand for high-purity antibodies. Affinity chromatography with a high affinity and specificity has always been utilized to separate antibodies from complex mixtures. Quality chromatographic components (matrices and affinity ligands) have either been found or generated to increase the purity and yield of antibodies. More importantly, some matrices (mainly particles) and affinity ligands (including design protocols) for antibody purification can act as radiosensitizers or carriers for therapeutic radionuclides (or for radiosensitizers) either directly or indirectly to improve the therapeutic efficiency of radiotherapy. This paper provides a brief overview on the matrices and ligands used in affinity chromatography that are involved in antibody purification and emphasizes their applications in radiotherapy to enrich potential approaches for improving the efficacy of radiotherapy.

Current development of bioanalytical sample preparation techniques in pharmaceuticals

Sample preparation is considered as the bottleneck step in bioanalysis because each biological matrix has its own unique challenges and complexity. Competent sample preparation to extract the desired analytes and remove redundant components is a crucial step in each bioanalytical approach. The matrix effect is a key hurdle in bioanalytical sample preparation, which has gained extensive consideration. Novel sample preparation techniques have advantages over classical techniques in terms of accuracy, automation, ease of sample preparation, storage, and shipment and have become increasingly popular over the past decade. Our objective is to provide a broad outline of current developments in various bioanalytical sample preparation techniques in chromatographic and spectroscopic examinations. In addition, how these techniques have gained considerable attention over the past decade in bioanalytical research is mentioned with preferred examples. Modern trends in bioanalytical sample preparation techniques, including sorbent-based microextraction techniques, are primarily emphasized.

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Bioanalytical sampling techniques are described with suitable applications in pharmaceuticals.

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The pros and cons of each bioanalytical sampling techniques are described.

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Relevant biological matrices are outlined.

Selection and characterization of DNA aptamers for highly selective recognition of the major allergen of olive pollen Ole e 1

In this study, single-stranded DNA aptamers with binding affinity to Ole e 1, the major allergen of olive pollen, were selected using systematic evolution of ligands by exponential enrichment (SELEX) method. Binding of the aptamers was firstly established by enzyme-linked oligonucleotide assay (ELONA) and aptaprecipitation assays. Additionally, aptamer-modified monolithic capillary chromatography was used in order to evaluate the recognition of this allergenic protein against other non-target proteins. The results indicated that AptOle1#6 was the aptamer that provided the highest affinity for Ole e 1. The selected aptamer showed good selective recognition of this protein, being not able to retain other non-target proteins (HSA, cyt c, and other pollen protein such as Ole e 9). The feasibility of the affinity monolithic column was demonstrated by selective recognition of Ole e 1 in an allergy skin test. The stability and reproducibility of this monolithic column was suitable, with relative standard deviations (RSDs) in retention times and peak area values of 7.8 and 9.3%, respectively (column-to-column reproducibility). This is the first study that describes the design of an efficient DNA aptamer for this relevant allergen.

Preparation of Affinity Chromatography Monolith in Miniaturized Format and Application for Protein Separation

Affinity chromatography is one of the versatile technique to selectively separate target biomolecules from complex biological sources (plasma, saliva, urine, etc.). Conventional chromatography resins possess technical limitations at mini-analytical scale, which was overcome with the use of alternative material known as monoliths. This chapter discusses on the how to modify the fused silica capillary inner surface, prepare polymer monoliths within the capillary confinements, chelation of metal-ions on monoliths and protein separation from diluted human plasma using metal-ion monolith microcolumn.

Affinity monolith chromatography: A review of general principles and recent developments

Affinity monolith chromatography (AMC) is a liquid chromatographic technique that utilizes a monolithic support with a biological ligand or related binding agent to isolate, enrich, or detect a target analyte in a complex matrix. The target-specific interaction exhibited by the binding agents makes AMC attractive for the separation or detection of a wide range of compounds. This article will review the basic principles of AMC and recent developments in this field. The supports used in AMC will be discussed, including organic, inorganic, hybrid, carbohydrate, and cryogel monoliths. Schemes for attaching binding agents to these monoliths will be examined as well, such as covalent immobilization, biospecific adsorption, entrapment, molecular imprinting, and coordination methods. An overview will then be given of binding agents that have recently been used in AMC, along with their applications. These applications will include bioaffinity chromatography, immunoaffinity chromatography, immobilized metal-ion affinity chromatography, and dye-ligand or biomimetic affinity chromatography. The use of AMC in chiral separations and biointeraction studies will also be discussed.

Facile DNA adsorption enabling ammonium-based hydrophilic affinity monolithic column for high-performance online selective microextraction of ochratoxin A

Herein, a facile protocol of simple DNA adsorption on UV-initiated polymerization supports was proposed for effectively fabricating aptamer-based affinity monolithic column. Hydrophilic cationic monolith with an excellent mechanical stability was achieved within 7 min and then massive aptamers were directly bound by DNA charge-dependent adsorption. Strong cationic quaternary ammonium-based monomer was employed to provide effective and stable positive charge surface for aptamer immobilization in a wide range of pH. An ultra-high aptamer coverage density of 6813 pmol/μL was achieved to gain a highly specific online recognition performance. Limitations such as low aptamer capacity, tedious modification and time-consuming reactions in the traditional biological or covalent modification strategies were avoided. By using ochratoxin A (OTA) as the given analyte, the selective recognition and high recoveries were successfully achieved, and little cross-reactivity towards OTB analogue was only 0.5% even if the content of OTB got up to 125 folds of OTA. Applied to sample analysis, the satisfactory discriminations of trace OTA were obtained at 93.9 ± 1.9% - 96.5 ± 1.7%（n = 3）in beer, wheat and chicken liver samples. It might light a cost-effective access to efficiently preparing high-performance affinity monoliths towards the selective in-tube microextraction of OTA.

Extraction and determination of tussilagone from Farfarae Flos with online solid-phase extraction-high-performance liquid chromatography using a homemade monolithic cartridge doped with porous organic cage material

A solid-phase extraction cartridge was fabricated using diallyl isophthalate as the monomer with the addition of porous organic cage material via in situ free-radical polymerization in a stainless-steel column. The resulting monolithic adsorbent exhibited a relatively uniform porous structure, a high specific surface area of 113.98 m² /g, and multiple functional chemical groups according to the characterization results. An online solid-phase extraction-high-performance liquid chromatography procedure was fabricated to extract and determine tussilagone from Farfarae Flos. The results show that the complex sample matrices can be removed in the solid-phase extraction procedure. Simultaneously, tussilagone can remain, which can be subsequently switched to an octadecylsilane bonded analytical column. The methodological validation showed that the correlation coefficient was 0.9999 with a linear range of 0.6-200.0 µg/mL, the limit of detection was 0.2 µg/mL, the limit of quantification was 0.6 µg/mL, accuracy was 100.3-100.6%, and relative standard deviation of precision was ≤1.9%. The present monolithic cartridge exhibits good reusability of not more than 100 times. The real sample of Farfarae Flos was determined with a tussilagone content of 0.74 mg/g.

In situ photo-initiated polymerized oligonucleotide-functionalized hydrophilic capillary affinity monolith for highly selective in-tube microextraction of ochratoxin A mycotoxin

A photo-initiated polymerized oligonucleotide-grafted hydrophilic affinity monolithic column was synthesized in situ, and exploited for selective in-tube solid phase micro-extraction (IT-SPME) protocol towards the sensitive detection of ochratoxin A (OTA). Only 7 min was required for the rapid polymerization of aptamer-based affinity monolith, which was much less than the reaction time of most thermal polymerization (12-16 h) and sol-gel chemistry methods (up to 52 h). Characterizations such as polymerization recipes, structure morphology, FTIR spectrum, elemental mapping, mechanical stability, and specific recognition performance were evaluated. A significantly hydrophilic nature with a low contact angle of 15° was observed, and a mixed-mode mechanism including aptamer affinity recognition and hydrophilic interaction (HI) was employed. By coupling with HPLC-fluorescence detection, the highly specific online recognition performance was achieved with an extremely low nonspecific adsorption of the analogues. The calibration curve of OTA was obtained in the concentration range 0.05-50.00 ng·mL^-1 with a limit of detection (LOD, S/N = 3) of 0.012 ng·mL^-1. Applied to sample analysis, acceptable recovery yields of 95.1 ± 1.4% - 99.5 ± 2.2% (n = 3) were obtained in beer and red wine. The proposed method lighted a promising way to efficiently preparing a hydrophilic aptamer-affinity monolith for highly specific recognition of trace mycotoxin by IT-SPME coupled with HPLC. A hydrophilic oligonucleotide-based affinity capillary monolith was explored via in situ photopolymerization for overcoming low preparation efficiency and achieving high-performance online IT-SPME of OTA mycotoxin.

Macroporous Polymer Monoliths in Thin Layer Format

Nowadays, macroporous polymer monoliths represent widely used stationary phases for a number of dynamic interphase mass exchange processes such as high-performance liquid chromatography, gas chromatography, electrochromatography, solid-phase extraction, and flow-through solid-state biocatalysis. This review represents the first summary in the field of current achievements on the preparation of macroporous polymer monolithic layers, as well as their application as solid phases for thin-layer chromatography and different kinds of microarray.

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

Sample pretreatment is one of the most crucial and error-prone steps of an analytical procedure; it consents to improve selectivity and sensitivity by sample clean-up and pre-concentration. Nowadays, the arousing interest in greener and sustainable analytical chemistry has increased the development of microextraction techniques as alternative sample preparation procedures. In this review, we aimed to show two different categorizations of the most used micro-solid-phase extraction (μSPE) techniques. In essence, the first one concerns the solid-phase extraction (SPE) sorbent selection and structure: normal-phase, reversed-phase, ion-exchange, mixed-mode, molecular imprinted polymer, and special techniques (e.g., doped cartridges for specific analytes). The second is a grouping of the commercially available μSPE products in categories and sub-categories. We present every device and technology into the classifications paying attention to their historical development and the actual state of the art. So, this study aims to provide the state-of-the-art of μSPE techniques, highlighting their advantages, disadvantages, and possible future developments in sample pretreatment.

Advances and applications of in-tube solid-phase microextraction for analysis of proteins

In-tube solid-phase microextraction (IT-SPME) with capillary column as extraction device is a well-established green extraction technique with a lot of applications in the fields of biomedicine, food and environment. This article reviews the research contributions of IT-SPME for analysis of proteins. The paper first briefly describes the history of IT-SPME. Then, the development and principle of IT-SPME for analysis of proteins are introduced, in which capillary column configurations of IT-SPME and instruments for quantitative analysis of proteins are summarized. Subsequently, the synthesis strategy and recognition principle of different recognition units, including antibodies, aptamers, molecularly imprinted polymers, and boronate affinity materials, are discussed in detail. This part also introduces several rare recognition units, including lectins, restricted access materials, lysine modified with β-cyclodextrin and cell membrane. The development trend and possible future direction of IT-SPME for analysis of proteins are mentioned.

Recent trends in sorbents for bioaffinity chromatography

Isolation or enrichment of biological molecules from complex biological samples is mostly a prerequisite in proteomics, genomics, and glycomics. Different techniques have been used to advance the efficiency of the purification of biological molecules. Bioaffinity chromatography is one of the most powerful technique that plays an important role in the isolation of target biological molecules by the specific interactions with ligands that are immobilized on different support materials. This review examines the recent developments in bioaffinity chromatography particularly over the past 5 years in the literature. Also properties of supports, immobilization techniques, types of binding agents, and methods used in bioaffinity chromatography applications are summarized.

A poly(N,N-dimethylaminoethyl methacrylate-co-ethylene glycol dimethacrylate) monolith for direct solid-phase extraction of benzodiazepines from undiluted human urine

A novel polymeric monolith using N,N-dimethylaminoethyl methacrylate as the monomer and ethylene glycol dimethacrylate as the crosslinker was successfully synthesized in a syringe and applied for direct solid-phase extraction of four benzodiazepines (bromazepam, triazolam, midazolam and diazepam) from undiluted urine samples prior to high performance liquid chromatography. The monolith was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption-desorption experiments. Moreover, extraction parameters, including loading, washing and eluting conditions were optimized. Under the optimized conditions, the proposed method obtained linear ranges of 2.0-500 ng mL^-1 with correlation coefficients (r) higher than 0.9997. The limits of detection (S/N = 3) and limits of quantification (S/N = 10) were 0.4-0.6 ng mL^-1 and 1.4-2.0 ng mL^-1, respectively. The recoveries at three spiked levels ranged from 83.7% to 103% with the intra- and inter-day precisions from 0.6-7.6% to 2.7-9.8%. The present monolith allowed direct loading of crude urine samples without any filtration or dilution step. Besides, the sorbent offered an enhancement factor of 16.7-20.6 and was stable enough for ten replicate cycles of extraction/desorption of urine samples. The developed method presented an alternative strategy for the accurate and convenient determination of benzodiazepines in urine samples.

Extraction of β-blockers from urine with a polymeric monolith modified with 1-allyl-3-methylimidazolium chloride in spin column format

A glycidyl methacrylate-based monolith was modified with imidazolium-based ionic liquid (IL) to be used as stationary phase for solid-phase extraction (SPE). The host monolithic support was prepared by in-situ UV polymerization in spin column format. Two approaches were developed to incorporate the IL into the polymeric monolithic matrix: generation of IL onto the surface monolith, and copolymerization by addition of the IL to the polymerization mixture, which gave the best results. The resulting sorbent materials were morphologically characterized and used for the isolation of five β-blockers from human urine samples. All SPE steps were accomplished by centrifugation, which reduces significantly costs and time in sample treatment. Under optimal conditions, β-blockers were quantitatively retained in the modified monolith at pH 12, and desorbed with a water-methanol mixture, to be subsequently determined via HPLC with UV detection. The limits of detection ranged between 1.4 and 40 μg L^-1, and the reproducibility among extraction units (expressed as relative standard deviation) was below 8.2%. The novel phase was successfully applied to the extraction of propranolol in urine samples with recoveries above 90%.

Facile fabrication of functional groups-rich sorbent for the efficient enrichment of aromatic N- and S-containing compounds in environmental waters

Extraction strategy is designed for the pretreatment of low contents of aromatic N- and S-containing compounds (ANSCs) in environmental waters prior to chromatographic analysis. To enrich studied ANSCs effectively, poly (9-vinylanthracene/4-vinylphenylboronic acid-co-ethylene dimethacrylate/divinylbenzene) polymeric monolithic sorbent were facilely fabricated using the one-step free radical polymerization. Various technologies were employed to investigate the structure and morphology of the resultant monolith. Combining with solid-phase microextraction format, the sorbent exhibited satisfying concentrated performance for ANSCs through multiply interactions under the optimized conditions. After desorption with eluent, the retained analytes were analyzed by HPLC. Results showed that the extraction efficiencies ranged from 51.6 to 93.2%. The linear ranges and limits of detection were 0.01-150 μg/L and 0.63-2.64 ng/L, respectively. Furthermore, the precisions were all below 10%. The introduced approach was productively practiced on three real water samples for simultaneous quantification of studied ANSCs, and the fortified recoveries ranged from 81.5 to 118%. All the results well evidenced that prepared sorbent can enrich ANSCs effectively and the introduced method is reliable alternative for routine analysis of ANSCs in environmental waters.

Highly Permeable Monolith-based Multichannel In-Tip Microextraction Apparatus for Simultaneous Field Sample Preparation of Pesticides and Heavy Metal Ions in Environmental Waters

A portable multichannel in-tip microextraction-based field sample preparation (FSP) apparatus was developed using polymer-based monoliths as an extraction phase. The construction of the FSP device is quite facile and convenient. More specifically, according to the chemical properties of studied analytes, functional-rich and high-permeability monoliths were in situ synthesized in pipet tips. After that, three tips containing the sorbents were mounted to three syringes, which were connected to a screw motor employed to drive the syringes and accurately regulate the flow rates in the adsorption and desorption stages. Because of the multifunction groups in the monoliths, the sorbents displayed satisfactory coextraction performance for pesticides (carbamates and triazoles) and heavy metal ions (Cd²⁺, Pb²⁺, and Cu²⁺) under the optimized conditions. The practicability of the proposed apparatus was demonstrated by the quick and simultaneous FSP of studied analytes in various environmental waters and combined with high-performance liquid chromatography/diode-array detection (for pesticides) and atomic absorption spectrometry (for metal ion) analysis. The results indicated that the limits of detection for the pesticides and metal ions were in the range of 0.36 to 1.2 ng/L and 0.061 to 0.40 ng/L, respectively, with ideal coefficients of determination. Furthermore, the results obtained with the constructed device were quite comparable to those obtained with the traditional laboratory extraction process, which demonstrated that the newly developed apparatus possesses the expected application in the high-throughput FSP of pesticides and heavy metal ions in water samples.

Redefining the chemistry of super-macroporous materials: when dendritic molecules meet polymer cryogels

Dendritic cryogels modify the functionality and properties against conventional cryogels and improve the Immunoglobulin G (IgG) adsorption.