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Monitoring of over-expressed nucleolin in the cytoplasm facilitates early cancer diagnosis. Herein, we present a novel biosensing nanoscaffold based on anti-nucleolin aptamers and polymer-grafted graphene oxides for the fluorescent imaging of nucleolin in the cell cytoplasm, which can distinguish cancer cells from normal cells. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) has been extensively explored as a promising nanomaterial for applications in biology because of its unique properties. Therefore, systematic investigation of GO toxicity is essential to determine its fate in the environment and potential adverse effects. In this study, acute toxicity, oxidative stress and immunotoxicity of GO were investigated in zebrafish. No obvious acute toxicity was observed when zebrafish were exposed to 1, 5, 10 or 50 mg/L GO for 14 days. However, a number of cellular alterations were detected by histological analysis of the liver and intestine, including vacuolation, loose arrangement of cells, histolysis and disintegration of cell boundaries. As evidence for oxidative stress, malondialdehyde levels and superoxide dismutase and catalase activities were increased and glutathione content was decreased in the liver after treatment with GO. GO treatment induced an immune response in zebrafish, as demonstrated by increased expression of tumor necrosis factor α, interleukin-1 β, and interleukin-6 in the spleen. Our findings demonstrated that GO administration in an aquatic system can cause oxidative stress and immune toxicity in adult zebrafish. To our knowledge, this is the first report of immune toxicity of GO in zebrafish. [ABSTRACT FROM AUTHOR]

Exogenous and endogenous genotoxic carcinogens and their in vivo metabolites may result in DNA damage and cause adverse health effects. It is very difficult to specifically detect trace DNA damage in the presence of a large excess of unmodified nucleosides. Here we report a molecularly imprinted polymer (MIP) nanocomposite, namely nanoMIP, which can be used as a “plastic antibody” for specific recognition of benzo[a]pyrene diol epoxide (BPDE)–DNA adduct. Enhanced binding affinity (880 nM) of nanoMIPs was achieved by using two tailor-made functional monomers. The property of binding kinetics was greatly improved in virtue of the well-defined nanostructure, which was fabricated by initiators for continuous activator regeneration-atom transfer radical polymerization (ICAR-ATRP). The BPDE-adducted DNA can be specifically captured by synthetic nanoMIP. By taking advantage of this antibody-mimicking behavior, we further developed a fluorescently imaged particle counting immunoassay (FIPCIA) method for ultrasensitive detection of BPDE–ssDNA adducts using a laser scanning confocal microscope (LSCM). The number of countable fluorescent dots is proportional to the content of BPDE–ssDNA adducts in the DNA sample. The proposed plastic antibody-based FIPCIA method can detect traces of BPDE–DNA adducts as low as 18 pM in human lung carcinoma A549 cells. This highly-sensitive detection of DNA lesions offers a promising alternative to immunogenic antibody-based immunoassays for genomics and DNA modification analysis. [ABSTRACT FROM AUTHOR]

Abstract: To assess the potential risks associated with the environmental exposure of β-lactam antibiotics (BLAs), the monitoring of the occurrence, distribution, and fate of these emerging contaminants in the environment is required. Herein, we demonstrate a molecularly imprinted solid-phase extraction (MISPE) method for selective and reliable screening of trace BLAs in river and tap water. By developing a low-temperature photopolymerization, highly selective molecularly imprinted polymers (MIPs) for five BLAs (penicillin G, amoxicillin, ampicillin, nafcillin and mezlocillin) were synthesized. Nafcillin was chosen as a pseudo template to make the MIP sorbent (Nafc-MIP), which was used in pseudo-template MISPE for preconcentration of the other four BLAs from river and tap water. The application of pseudo-template MISPE overcomes the template bleeding, which significantly elevates the sample background and restricts the application of MIP for detection of the target BLA below 2μg/L. The average recoveries of BLAs are in the range of 60–90% when Nafc-MIP was adopted as the selective MISPE sorbent. The developed method was validated, and applied to the screening of trace β-lactam antibiotics in river and tap water. The linearity of the calibration curve for each BLA was observed over the range of 0.1–20μg/L (r >0.998). The β-lactam antibiotics were found within the range of 0–9.56μg/L in river water at the downstream of antibiotics manufacturers, and none were detected in the tap water. [Copyright &y& Elsevier]

Abstract: Monolithic silica columns have inspired considerable research interests in the separation science because of their unique properties in permeability, mass transfer, efficiency and throughput. In this paper, a chemically p-tert-butylcalix[8]arene-bonded silica monolith was prepared as the promising candidate for versatile LC separations. Micrometer-sized macropores and nanometer-sized mesopores in this derivatized silica monolith reduce the diffusion path length and provide both low backpressure and high column efficiencies, leading to high-speed and high-throughput separations. Since p-tert-butylcalix[8]arene possesses a π-donors cavity composed of benzene rings while polycyclic aromatic hydrocarbons, anthraquinones, phenol regio isomers and fullerenes are π-systems with appreciable electron affinity, they may have a chance to get involved in forming host–guest inclusion complexes through non-covalent interactions, e.g. hydrophobic and π–π interactions. Compared with RP-18e, the prepared calixarene-bonded monolith exhibited better selectivity to molecules which contains more π-electrons and more condensed cyclic moieties. The column efficiency was about 22000plates/m. The calixarene-bonded monolith also showed its good performances in separation of fullerenes and dihydropyridines, indicating a promising approach for purification of fullerenes with high purity from the carbon soot. [Copyright &y& Elsevier]

Abstract: Benzo[a]pyrene, a common environmental pollutant, can be metabolized into reactive anti-benzo[a]pyrene diol epoxide (anti-BPDE), which predominantly binds to deoxyguanine in DNA and forms four stereoisomeric adducts. To characterize the stereochemistry of these adduct isomers, preparation of single adducted deoxyguanosine (dG) is required for efficient enantiomeric analysis. Here, we demonstrate an improved method for preparation, identification, and analysis of four BPDE-adducted dGs, including (+)-trans-, (−)-trans-, (+)-cis-, and (−)-cis-anti-BPDE-N 2 -dG. These stereoisomerically adducted nucleosides were first synthesized by a direct reaction of (±)-anti-BPDE with dG, followed by optimized solid-phase extraction (SPE) and HPLC purification. The reaction of (±)-anti-BPDE and dG displayed a yield as high as 45%. The developed preparation method does not require any enzymatic digestion. Based on highly efficient separation achieved by optimization of stationary phase and mobile phase, LC-UV–MS/MS and LC-diode array detection (DAD)-fluorescence detection (FL) methods were established for characterization and analysis of the four stereoisomeric anti-BPDE-dGs. The established LC-DAD-FL method may provide characterization and analysis of four stereoisomeric anti-BPDE-dGs and two interfering anti-BPDE tetrols by taking advantage of their distinct fluorescence quenching. [Copyright &y& Elsevier]

Abstract: A molecularly imprinted solid-phase extraction coupled with high performance liquid chromatography (MISPE–HPLC) method was developed for rapid screening of mycophenolic acid (MPA) in human plasma. MPA imprinted polymers (MPA-MIP) were synthesized and then tested for their performance both in organic and in aqueous solution. MPA was selectively trapped and preconcentrated on the MPA-MIP sorbent using different loading and washing conditions. The good selectivity of MPA-MIP enabled further clean-up of the interfering components in human plasma. For the proposed MISPE–HPLC method, the linearity between responses (peak area) and concentration was found over the range of 1–100μg/ml with a linear regression coefficient (R 2) of 0.9989. The limit of detection (LOD) and theoretical limit of quantification (LOQ) for MPA in plasma were 0.10 and 0.32μg/ml, respectively. The precisions were 7.3, 3.5 and 4.7% RSD for intra-day assay and 9.2, 4.1 and 5.5% RSD for inter-day reproducibility, respectively, at three concentration levels of MPA in spiked plasma (1, 10 and 100μg/ml). Both recoveries for the extraction (more than 74%) and for the analytical method (more than 87%) were acceptable for screening MPA in plasma samples. Twelve-hour pharmacokinetic profile of MPA for a renal transplant recipient receiving chronic oral dosing of 500mg mycophenolate mofetil (MMF) was investigated. Results indicated that this method could be applied for therapeutic drug monitoring of mycophenolic acid in patient plasma. [Copyright &y& Elsevier]

Abstract: A high-performance liquid chromatography (HPLC) method with evaporative light scattering detection (ELSD) was applied for simultaneous determination of stachyose, sucrose and raffinose in Chinese artichoke (Stachys Sieboldii Miq.). Carbohydrates were separated on a Bondapak NH2 column using a ternary solvent mixture of methanol–acetonitrile–water (55:25:20, v/v/v) as mobile phase. Two different crafts (method 1 and method 2) for extraction and purification of stachyose in Chinese artichoke tubers were detailed and evaluated. Method 1 can meet the purpose of quantification and method 2 is appropriate for the purpose of purification. The content of stachyose in dry tubers was determined to be 236.0mg/g (from method 1) and the purity of the extracted stachyose flour was calculated to be 87.34% (from method 2), respectively. The analytical method fulfills all the standard requirements of linearity, accuracy and precision. Therefore, it is suitable for purification and routine quantification of stachyose in Chinese artichoke. [Copyright &y& Elsevier]

Abstract: A monolithic molecularly imprinted polymer (monolithic MIP) was designed and prepared for chiral separation of nateglinide and its l-enantiomer. The enantiomers were rapidly separated on this novel monolithic MIP based chiral stationary phase (MIP-CSP), whereas the enantioseparation was not obtained on the non-imprinted polymer (NIP). Chiral recognition was found to be dependent on the stereo structures and the arrangement of functional groups of the imprinted molecule and the cavities on MIP. Thermodynamic data (ΔΔH and ΔΔS) obtained by Van’t Hoff plots revealed an enthalpy-controlled enantioseparation. The binding capacity was evaluated by frontal analysis. Monolithic nateglinide-MIP had an effective number of binding sites B t =41.15μmolg−1 with a dissociation constant of K d =7.40mM. The morphological characteristics of the monolithic MIP were investigated by pore analysis and scanning electron microscope (SEM). Results showed that both mesopores and macropores were formed in the monolith. Over all, this study presents a new and practical possibility for providing high rates of mass transfer, fast separations and high efficiencies without the pressure constraints of the traditional bulk molecularly imprinted polymers, through the monolithic MIPs. [Copyright &y& Elsevier]

Molecularly imprinted nanotubes for enantioselective drug delivery and controlled release are fabricated by the combination of template synthesis and ATRP grafting. The release of R-propranolol from the imprinted nanotubes in rats is restricted while the release of pharmacologically active S-enantiomer is greatly promoted. [ABSTRACT FROM AUTHOR]

Long-term exposures to environmental toxicants are causative factors for human health effects. DNA damages are of great interest in that they can serve as the potential biomarkers of environmental exposure and mutations. Qualitative and quantitative detection of their level in genomic DNA, are helpful for the understanding of the generation, transformation, repair and fate of DNA damages and for elucidating the mechanism underlying carcinogenesis. Methodologies based on liquid chromatography-mass spectrometry (LC-MS) have shown unique advantages in accurate and highly sensitive analysis of these structurally modified DNA damages. The present review summarizes our current knowledge on LC-MS analysis of genetic DNA damages, with special emphasis on structurally chemical DNA modifications induced by environmental exposure. Advances in LC-MS analysis and monitoring of oxidative DNA lesion, DNA adducts induced by heavy metals, persistent organic pollutants, bisphenols, fine particulate matters, aldehydes and halobenzoquinones are comprehensively summarized. • Highly sensitive LC-MS methods for DNA damages analysis. • Oxidative DNA damages, DNA adducts induced by environmental exposure. • DNA modifications caused by new emerging contaminants including PM2.5 and BPA. • Advances in DNA damage monitoring and adductomics benefited from LC-MS/MS. [ABSTRACT FROM AUTHOR]

• New porous polydopamine/graphene oxide composite adsorbents were prepared. • Polydopamine acts as a synergistic adsorbent rather than just a modification layer. • Pipette-tip solid-phase extraction using the composite adsorbent was developed. • Simultaneous determination of alectinib and its metabolite in plasma was achieved. • The PDAG can be as a new adsorbent to extract weakly polar anticancer drugs. Alectinib is known as an effective targeted drug, which has excellent therapeutic effect on non-small cell lung cancer and can significantly prolong the survival of patients. Therapeutic drug monitoring is necessary due to the photo-instability of alectinib and the individual differences in patients. In this work, a porous polydopamine graphene oxide composite (PDAG) was prepared by a simple surface modification method. A PDAG-based pipette-tip solid-phase extraction (PT-SPE) coupled with HPLC-UV detection was proposed for the separation and detection of alectinib and its active metabolite M4 in plasma. The method was methodologically validated and showed good linearity in the range of 50–5000 ng mL−1 (R 2 > 0.9995). The limit of detection (LOD) was 4.8 ng mL−1 and 3.9 ng mL−1 for alectinib and M4, respectively, and the limit of quantitation (LOQ) was 16.1 ng mL−1 and 13.1 ng mL−1, respectively. The intra-day and inter-day precision expressed by coefficient of variation was less than 4.8 %. The recovery of this method ranged from 84.9 % to 103.5 % with a standard deviation of less than 4.3 %. In conclusion, the established method is accurate, stable and inexpensive, and can be used to monitor the levels of alectinib and M4 in plasma, which provide technical and data support for exploring optimal individualized remedial dosing regimens. [ABSTRACT FROM AUTHOR]

Abstract Four DNA bases are essential biochemical elements for coding heritable life blueprint. Meanwhile, organisms utilize modifying enzymes to post chemical groups on DNA bases to regulate gene expression, chromosome structures, and transposase activity, and to defense pathogens. The researches on the biochemical modifications of DNA bases are at the cutting edge of life sciences and chemical biology. Up to date, along with fantastic progresses, liquid chromatography hyphenated with mass spectrometry (LC-MS)-based technologies become popular and powerful tools for chemical structure-dependent identification and quantification of diverse DNA modifications. Here we provided comprehensive review on LC-MS-based technologies and related pretreatment technologies for profiling of epigenetic DNA modifications, mainly focusing on innovative technologies developed for desalting, DNA digestion, and ionization for mass spectrometry detection. We also summarized the epigenetic progresses, which benefited from the development of the LC-MS methodologies and technologies, on the studies of specific DNA modifications, in particular, 5-hydroxymethylcytosine and 5-formylcytosine. Highlights • LC-MS/MS methods for detection of epigenetic DNA modifications. • DNA hydrolysis for generation of LC-MS detectable mononucleosides. • Chemical approaches for enhancing LC-MS signal. • Progresses on epigenetic DNA modifications benefited from LC-MS/MS analysis. [ABSTRACT FROM AUTHOR]

8-Hydroxydeoxyguanosine (8-OHdG) is a widely-used biomarker of oxidative DNA damages. 8-OHdG in peripheral blood leukocyte is associated with mutation and cancer risk. The level of 8-OHdG in peripheral blood leukocytes can indicate a long-term response to oxidative stress rather than that in urine. Accurate identification and quantification of leukocyte 8-OHdG are essential for understanding its mechanism of formation, repair, and biological consequences. In this study, a fast and accurate ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC–MS/MS) method was developed and validated to detect 8-OHdG in human peripheral leukocyte. DNA in blood samples were extracted and digested, then subjected onto UHPLC–MS/MS using an isocratic elution on a Zorbax Eclipse Plus C18 column (2.1 × 100 mm, 1.8 μm). Multiple reaction monitoring (MRM) mode was adopted by using [ 15 N 5 ]-8-OHdG as an internal standard. The assay was linear over the concentration range of 1.0–100 nM with R 2 = 0.999. The accuracy for spiked samples was 90.9%–94.8%, and the intra-day precision was within 3.7%. The limit of detection (LOD) is 0.30 nM and limit of quantification (LOQ) is 1.0 nM with 5 μl of sample injection. By the analysis of human leukocyte 8-OHdG (n = 121) using the developed UHPLC–MS/MS method, it demonstrates that the level of leukocyte 8-OHdG of the cancer patients group (n = 46) is significantly higher than that of the health control (n = 75). [ABSTRACT FROM AUTHOR]

• A recyclable and reusable multi-enzymes cascade (SNSC-MNPs) for enzymatic digestion of genomic DNA was constructed. • SNSC-MNPs cascade enable fast digestion of genomic DNA into mono-nucleosides within 30 min. • Coupling SNSC-MNPs with HPLC-MS/MS, a sensitive and accurate method for quantitation of 5-hydroxymethylcytosine (5hmC) was developed. • TCBQ exposure induces elevated 5hmC levels in the genome of T24 cells. Long-term exposure to halobenzoquinones (HBQs) can induce genomic damages and abnormal epigenetic modifications. High-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) has shown unique advantages in identification and sensitive analysis of these structurally modified DNA lesions. Prior to MS analysis, genomic DNA needs to be fully digested into mono-nucleosides. Here, we prepared Supernuclease (SN)-, snake venom phosphodiesterase (SVP)- and calf intestinal alkaline phosphatase (CIP)- individually immobilized magnetic nanoparticles (MNPs), and combined them according to certain formula to construct a recyclable SN-SVP-CIP magnetic nanoparticles (SNSC-MNPs) cascade for rapid and efficient DNA digestion. The SNSC-MNPs cascade can fully digest genomic DNA into mono-nucleosides within 30 min. The SNSC-MNPs cascade coupled with HPLC-MS/MS method can accurately and sensitively detect 5-hydroxymethylcytosine (5hmC) changes in genome of human bladder cancer T24 cells induced by tetrachlorobenzoquinone. The immobilization of enzymes on MNPs can enhance the stability and enzymatic activity of the three enzymes, which guarantees the reusability and longtime preservation of the cascades. The relative digestive efficiencies are among 86% -106% up to ten times of reuse. The newly synthesized SNSC-MNPs cascade coupled with HPLC-MS/MS method is promising for fast identification and analysis of structural modifications in genomic DNA. [ABSTRACT FROM AUTHOR]

Abstract: A DNA aptamer based high-performance affinity chromatography is developed for selective extraction and screening of a basic protein lysozyme. First, a poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolithic column was synthesized in situ by thermally initiated radical polymerization, and then an anti-lysozyme DNA aptamer was covalently immobilized on the surface of the monolith through a 16-atom spacer arm. The target protein lysozyme but non-target proteins can be trapped by the immobilized anti-lysozyme DNA aptamer. In contrast, lysozyme cannot be trapped by the immobilized oligodeoxynucleotide that does not contain the sequence of the anti-lysozyme DNA aptamer. The study clearly demonstrates the trapping of lysozyme by the immobilized anti-lysozyme DNA aptamer is mainly due to specific recognition rather than simple electrostatic interaction of positively charged protein and the negatively charged DNA. The inter-day precision was determined as 0.8% for migration time and 4.2% for peak area, respectively. By the use of aptamer affinity monolith, a screening strategy is developed to selectively extract lysozyme from chicken egg white, showing the advantages of high efficiency, low cost and ease-of-operation. [Copyright &y& Elsevier]

• PDESs-MIP/GO with rich adsorption interactions and high selectivity was prepared. • A rapid and low-cost method was developed by PDESs-MIP/GO, CPT-MSPD, and HPLC. • The method is used to detect anti-adipogenesis markers in Solidago decurrens Lour. Overweight and obesity are the causes of many diseases and have become global "epidemics". Research on natural active components with anti-adipogenesis effects in plants has aroused the interest of researchers. One of the most critical problems is establishing sample preparation and analytical techniques for quickly and selectively extracting and determining the active anti-adipogenesis components in complex plant matrices for developing new anti-adipogenic drugs. In this study, a new poly(deep eutectic solvents) surface imprinted graphene oxide composite (PDESs-MIP/GO) with high selectivity for phenolic acids was prepared using deep eutectic solvents as monomers and crosslinkers. A miniaturized centrifugation-accelerated pipette-tip matrix solid-phase dispersion method (CPT-MSPD) with PDESs-MIP/GO as adsorbent, coupled with high-performance liquid chromatography, was further developed for the rapid determination of anti-adipogenesis markers in Solidago decurrens Lour. (SDL). The established method was successfully used to determination anti-adipogenesis markers in SDL from different regions, with the advantages of accuracy (recoveries: 94.4 − 115.9 %, RSDs ≤ 9.8 %), speed (CPT-MSPD time: 11 min), selectivity (imprinting factor: ∼2.0), and economy (2 mg of adsorbent and 1 mL of solvents), which is in line with the current advanced principle of "3S+2A" in analytical chemistry. [ABSTRACT FROM AUTHOR]

• A new molecular imprinting graphene nanocomposite (PIL-MIP/GO) was synthesized. • PIL-MIP/GO has fast mass transfer, rich adsorption mechanism, and high selectivity. • A HPLC-UV method for β-agonists was designed based on PIL-MIP/GO as PT-SPE sorbent. • The method was successfully applied to detect β-agonist in swine urine. • The analytical method was sensitive, selective, accurate, nonfatal, and economical. The illegal use of β-agonists often endangers animal-derived food safety. In this study, a selective detection method for β-agonists in swine urine was established via the combination of polymeric ionic liquid-molecularly imprinted graphene oxide-miniaturized pipette tip solid-phase extraction and high-performance liquid chromatography. It is worth noting that this method relied mainly on the designed adsorbent, which presented a rich adsorption mechanism, fast mass transfer rate, and high selectivity, and was successfully utilized in the selective extraction of β-agonists from swine urine samples. The proposed method has low LOD (0.20–0.56 ng/mL), high recovery (94.9–107.9%), and high reusability (4 times, 91.9–108.8%), which indicates its high potential as a selective, sensitive, accurate, and nonfatal method for monitoring the illegal use of β-agonists in the livestock breeding stage. [ABSTRACT FROM AUTHOR]

[Display omitted] • The citrate-functionalized osmium nanoparticles (Os-citrate NPs) have been prepared. • Os-citrate NPs exhibit excellent peroxidase-like specific activity and efficient hydroxyl radicals (•OH) production. • Doping small amount of OsO 2 in the surface composition of Os-based NPs could greatly improve the production of •OH. • Os-based nanozyme can comletely degrade phenolic pollutants within 30 min. Platinum group metals-based nanomaterials have shown promise as enzyme mimics, and attracted much attention in the fields of chemical catalysis, biosensor, therapy and pollutants degradation. Surprisingly, only a few works exist on the exploration of osmium-based nanozymes, and the catalytic activities and applicable potentials thereof have not been comprehensively understood. Herein, we prepared a kind of citrate-functionalized osmium nanoparticles (Os-citrate NPs) by one-pot synthesis strategy. The obtained Os-citrate NPs can boost hydrogen peroxide (H 2 O 2) to produce hydroxyl radical (•OH), enabling it to serve as a peroxidase mimic. Steady-state kinetics revealed that Os-citrate NPs is rather potent and peroxidase-like specific nanozyme. Doping a certain amount of osmium oxides (OsO 2) in the surface of Os-citrate NPs can greatly improve the production of •OH from H 2 O 2 , enhancing the peroxidase-like specific activity. We applied this Os-citrate catalyst in advanced oxidative degradation of phenolic pollutants. In a wide pH range of 2.0–10, 4-nitrophenol could be fast degraded by the combination of H 2 O 2 with Os-citrate NPs. As a proof-of-concept, the Os-citrate nanozyme was successfully employed in highly efficient degradation of phenolic pollutants. To the best of our knowledge, this is the first report on the application of Os-based peroxidase-like nanozymes in highly efficient degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

Highlights: [•] Different functionalized chemical groups affect the dispersibility of f-SWCNTs. [•] Insignificant effects on mitochondrial activity and ROS production in MCF7 cells by f-SWCNTs. [•] Exposure induced cell membrane damage and cell apoptosis, decreased cell adhesion. [Copyright &y& Elsevier]

Abstract: The detection and quantification of disease-related proteins play critical roles in clinical practice and diagnostic assays. We present an affinity probe capillary electrophoresis/laser-induced fluorescence polarization (APCE/LIFP) assay for detection of human thrombin using a specific aptamer as probe. In the APCE/LIFP assay, the mobility and fluorescence polarization of complex are measured simultaneously during CE analysis. The affinity complex of human thrombin can be well separated from unbound aptamer on CE and clearly identified on the basis of its fluorescence polarization and migration. Because of the binding favorable G-quartet conformation potentially involved in the specific aptamer, it was assumed that monovalent and bivalent cations promoting the formation of a stable G quadruplex conformation in the aptamer may enhance the binding of the aptamer and thrombin. Therefore, we investigated the effects of various metal cations on the binding of human thrombin and the aptamer. Our results show that cations like K+ and Mg2+ could not stabilize the affinity complex. Without the use of typical cations, a highly sensitive assay of human thrombin was developed with the corresponding detection limits of 4.38×10−19 and 2.94×10−19 mol in mass for standard solution and human serum, respectively. [Copyright &y& Elsevier]

Abstract: A weak ion exchange monolithic column prepared by modifying the GMA–MAA–EDMA (glycidyl methacrylate–methacrylic acid–ethylene glycol dimethacrylate) monoliths with ethylenediamine was applied to remove matrix compounds in biological fluid. Using this monolithic column, on-line clean-up and screening of oxacillin and cloxacillin in human urine and plasma samples had been investigated. Chromatography was performed by reversed-phase HPLC on a C18 column with ultraviolet detection at 225nm. Results showed that the ion exchange monolithic column could be used for deproteinization and retaining oxacillin and cloxacillin in human urine and plasma, which provided a simple and fast method for assaying drugs in human urine and plasma. [Copyright &y& Elsevier]

Abstract: A weak cation-exchange monolithic column was prepared by modifying the GMA-EDMA (glycidyl methacrylate-co-ethylene glycol dimethacrylate) monoliths with ethylenediamine and monochloracetic acid. The properties of the column were investigated; the column exhibited the ability of low backpressure and fast analysis. Using this monolithic column, trace doxazosin in human serum albumin (HSA) solution and plasma samples has been on-line tested, the extraction efficiency and the maximum loading capacity of the monolithic column were obtained. The results showed that the monolithic column could realize deproteinization and trace drug enrichment simultaneously in the HSA solution and human plasma, which provided a simple, cheap, effective and friendly to environment method for assaying drugs in the blood. [Copyright &y& Elsevier]