Rapid fabrication of zwitterionic sulfobetaine vinylimidazole-based monoliths via photoinitiated copolymerization for hydrophilic interaction chromatography

Zwitterionic sulfobetaine-based monolithic stationary phases have attracted increasing attention for their use in hydrophilic interaction chromatography.In this study,a novel hydrophilic polymeric monolith was fabricated through photo-initiated copolymerization of 3-(3-vinyl-1-imidazolio)-1-propanesulfonate(SBVI)with pentaerythritol triacrylate using methanol and tetrahydrofuran as the porogenic system.Notably,the duration for the preparation of this novel monolith was as little as 5 min,which was significantly shorter than that required for previously reported sulfobetaine-based monoliths prepared via conventional thermally initiated copolymerization.Moreover,these monoliths showed good morphology,permeability,porosity(62.4%),mechanical strength(over 15 MPa),column efficiency(51,230 plates/m),and reproducibility(relative standard deviations for all analytes were lower than 4.6%).Mechanistic studies indicated that strong hydrophilic and negative electrostatic interactions might be responsible for the retention of polar analytes on the zwitterionic SBVI-based monolith.In particular,the resulting monolith exhibited good anti-protein adhesion ability and low nonspecific protein adsorption.These excellent features seem to favor its application in bioanalysis.Therefore,the novel zwitterionic sulfobetaine-based monolith was successfully employed for the highly selective separation of small bioactive compounds and the efficient enrichment of N-glycopeptides from complex samples.In this study,we prepared a novel zwitterionic sulfobetaine-based monolith with good performance and developed a simpler and faster method for preparation of zwitterionic monoliths.

A novel hydrophilic polystyrene-based beads for hydrophilic interaction chromatography by surface-initiated atom transfer radical polymerization

A one-step procedure to hydrophilize monodisperse poly（chloromethyl-styrene-co-divinylbenzene） beads has been presented with 2-hydroxy-3-[4-（hydroxymethyl）-1H-1,2,3-triazol-1-yl]propy1 2-methylacrylate（HTMA） as monomer by surface-initiated atom transfer radical polymerization（SI-ATRP）.The length of the grafted poly（HTMA） chain was varied via controlling the ratio of HTMA to initiator on the surface of the beads.Using these grafted beads as the stationary phase in hydrophilic interaction chromatography,good separation was obtained for nucleosides in the mobile phase of acetonitrile-water.It was also found that the retention time and selectivity of solutes showed a positive relationship with the length of the grafted poly（HTMA） chain.

Hydrophilic interaction liquid chromatography with indirect ultraviolet detection for the separation and quantification of pyrrolidinium ionic liquid cations

A method of hydrophilic interaction liquid chromatography with indirect ultraviolet detection was developed to determine three pyrrolidinium ionic liquid cations, i.e. N-methyl-N-ethyl pyrrolidinium cation （[MEPy]＋）, N-methyl-N-propyl pyrrolidinium cation （[MPPy]＋） and N-methyl-N-butyl pyrrolidi- nium cation （[MBPy]＋）. Chromatographic separation was achieved on a hydrophilic column using imidazolium ionic liquids and organic solvents as the mobile phase. The effects of the background ultraviolet absorption reagents, the imidazolium ionic liquids, detection wavelength, organic solvents, column temperature and the pH value of the mobile phase on the separation and determination of pyrrolidinium cations were investigated and the retention behaviors in hydrophilic interaction chromatography were discussed. The optimized chromatographic conditions were selected. Under the optimal conditions, the detection limits （SIN = 3） for [MEPy]＋, [MPPy]＋ and [MBPy]＋ were 0.59, 0.53 and 0.46 mg/L, respectively. The method has been successfully applied to the determination of the three ionic liquids synthesized in our chemistry laboratory. This research results may improve the analytical method of ionic liauid cations.

A Metal-organic Framework with Alternately Hydrophilic and Hydrophobic Layers Based on Tetrazole Derivative:Synthesis,Structure and Luminescent Property

A new metal-organic framework based on ethyl 1H-tetrazole-5-acetate （Hetza）, [Ag4（etza）4] （1）, has been synthesized and characterized by elemental analysis, IR, thermal gravimetric and X-ray structural analysis. Crystal data for the title complex are as follows： triclinic system, space group P1 with a = 11.0771（6）, b = 11.6636（6）, c = 13.2925（8）, a = 102.3710（10）, β =103.3810（10）, γ = 90.0890（10）°, V = 1629.60（16） A3, Mr = 1052.06, Z = 2, F（000） = 1024, Dc = 2.144 g/cm3, μ（MoKa） = 2.438 mm^-1, the final R = 0.0538 and wR = 0.1475 （I 〉 2σ（I））. Complex 1 adopts the （4.82） topological network and the alternately hydrophilic-hydrophilic and hydropho- bic-hydrophobic arrangements. The luminescent properties of complex 1 and the free Hetza ligand have been studied in the solid states.

可去除染料--N-聚糖多方法深入分析中的缺失环节

As the roles of glycans in health and disease continue to be unraveled,it is becoming apparent that glycans’immense complexity cannot be ignored.To fully delineate glycan structures,we developed an integrative approach combining a set of cost-effective,widespread,and easy-to-handle analytical methods.The key feature of our workflow is the exploitation of a removable fluorescent label—exemplified by 9-fluorenylmethyl chloroformate(Fmoc)—to bridge the gap between diverse glycoanalytical methods,especially multiplexed capillary gel electrophoresis with laser-induced fluorescence detection(xCGELIF)and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOFMS).Through the detailed structural analysis of selected,dauntingly complex N-glycans from chicken ovalbumin,horse serum,and bovine transferrin,we illustrate the capabilities of the presented strategy.Moreover,this approach“visualizes”N-glycans that have been difficult to identify thus far—such as the sulfated glycans on human immunoglobulin A—including minute changes in glycan structures,potentially providing useful new targets for biomarker discovery.

Quantitative analysis of 3-isopropylamino-1,2-propanediol as a degradation product of metoprolol in pharmaceutical dosage forms by HILIC-CAD

Aryloxypropanolamine is an essential structural scaffold for a variety of b-adrenergic receptor antagonists such as metoprolol.Molecules with such a structural motif tend to degrade into α,β ehydroxypropanolamine impurities via a radicaleinitiated oxidation pathway.These impurities are typically polar and nonchromophoric,and are thus often overlooked using traditional reversed phase chromatography and UV detection.In this work,stress testing of metoprolol confirmed the generation of 3-isopropylamino-1,2-propanediol as a degradation product,which is a specified impurity of metoprolol in the European Pharmacopoeia(impurity N).To ensure the safety and quality of metoprolol drug products,hydrophilic interaction chromatography(HILIC)methods using Halo Penta HILIC column(150mm×4.6 mm,5 μm)coupled with charged aerosol detection(CAD)were developed and optimized for the separation and quantitation of metoprolol impurity N in metoprolol drug products including metoprolol tartrate injection,metoprolol tartrate tablets,and metoprolol succinate extended-release tablets.These HILIC-CAD methods were validated per USP validation guidelines with respect to specificity,linearity,accuracy,and precision,and have been successfully applied to determine impurity N in metoprolol drug products.

Separation of Peptides by Pressurized Capillary Electrochromatography

A novel gradient pressurized capillary electrochromatography (pCEC) instrument was developed to separate peptides. Two gradient elution modes, hydrophobic and hydrophilic interaction mode in pCEC, were performed on this instrument. Baseline separation of six peptides was obtained on two gradient modes with C18 column and strong cationic exchange column respectively. The effects of mixer volume and total flow rate of pumps on resolution were also discussed.

亲水作用色谱柱与阳离子交换树脂柱结合分离无机离子(英文)

A combination of hydrophilic interaction chromatographic(HILIC) column and a weakly acidic cation-exchange resin(WCX) column was used for simultaneous separation of inorganic anions and cations by ion chromatography(IC).Firstly,the capability of HILIC column for the separation of analyte ions was evaluated under acidic eluent conditions.The columns used were SeQuant ZIC-HILIC(ZIC-HILIC) with a sulfobetaine-zwitterion stationary phase(ZIC-HILIC) and Acclaim HILIC-10 with a diol stationary phase(HILIC-10).When using tartaric acid as the eluent,the HILIC columns indicated strong retentions for anions,based on ion-pair interaction.Especially,HILIC-10 could strongly retain anions compared with ZIC-HILIC.The selectivity for analyte anions of HILIC-10 with 5 mmol/L tartaric acid eluent was in the order of I-> NO-3 > Br-> Cl-> H2PO-4.However,since HILIC-10 could not separate analyte cations,a WCX column(TSKgel Super IC-A/C) was connected after the HILIC column in series.The combination column system of HILIC and WCX columns could successfully separate ten ions(Na+,NH+4,K+,Mg2+,Ca2+,H2PO-4,Cl-,Br-,NO-3 and I-) with elution of 4 mmol/L tartaric acid plus 8 mmol/L 18-crown-6.The relative standard deviations(RSDs) of analyte ions by the system were in the ranges of 0.02%-0.05% in retention times and 0.18%-5.3% in peak areas through three-time successive injections.The limits of detection at signal-to-noise ratio of 3 were 0.24-0.30 μmol/L for the cations and 0.31-1.2 μmol/L for the anions.This system was applied for the simultaneous determination of the cations and the anions in a vegetable juice sample with satisfactory results.

Effect of hydrophilic or hydrophobic interactions on the self-assembly behavior and micro-morphology of a collagen mimetic peptide

Peptide self-assembles with bionic properties have been widely utilized for bioactive drugs and biomedical materials.Collagen mimetic peptide(CMP)gains more attention due to its unique advantages in biosecurity and function.Unfortunately,the self-assembly mechanism of CMP,particularly the effect of intermolecular forces on its self-assembly behavior and morphology,is still unrecognized.Herein,the hydrophilic glycidol(GCD)and hydrophobic Y-glycidyl ether oxypropyl trimethoxysilane(GLH)were grafted onto the side chains of CMP through the ring-opening reaction(GCD/CMP,GLH/CMP).Subsequently,the effects of hydrophilic and hydrophobic interactions on the self-assembly behavior and morphology of CMP were further studied.The results substantiated that the GCD/CMP and GLH/CMP self-assembly followed“nucleation-growth”mechanism,and the supererogatory hydrophilic and hydrophobic groups prolonged the nucleation and growth time of CMP self-assembly.Noted that the hydrophilic interaction had stronger driving effects than hydrophobic interaction on the self-assembly of CMP.The GCD/CMP and GLH/CMP self-assembles exhibited fibrous 3D network and microsphere morphology,respectively.Furthermore,the GLH/CMP self-assembles had better resistance to degradation.Consequently,the microtopography and degradation properties of CMP self-assembles could be controlled by the hydrophilic and hydrophobic interactions between CMP,which would further provide a way for subsequent purposeful design of biomedical materials.

Challenges in Analysis of Hydrophilic Metabolites Using Chromatography Coupled with Mass Spectrometry

Hydrophilic metabolites play important roles in cellular energy metabolism,signal transduction,immunity.However,there are challenges in both identification and quantification of the hydrophilic metabolites due to their weak interactions with C18-reversed-phase liquid chromatography(RPLC),leading to poor retention of hydrophilic metabolites on the columns.Many strategies have been put forward to increase the retention behavior of hydrophilic metabolites in the RPLC system.Non-derivatization methods are mainly focused on the development of new chromatographic techniques with different separation mechanisms,such as capillary electrophoresis,ion-pairing RPLC etc.Derivatization methods improve the hydrophobicity of metabolites and can enhance the MS response.This review mainly focused on the illustration of challenges of LCMS in the analysis of hydrophilic metabolomics field,and summarized the non-derivatization and derivatization strategies,with the intention of providing multiple choices for analysis of hydrophilic metabolites.

Inherently hydrophilic mesoporous channel coupled with metal oxide for fishing endogenous salivary glycopeptides and phosphopeptides

Both glycosylation and phosphorylation exert crucial rule in multitudinous biological processes.For in-depth profiling of glycosylation and phosphorylation,a magnetic metal oxide is effectively coupled with inherently hydrophilic mesoporous channels(denoted as Fe_(3)O_(4)@TiO_(2)@mSiO_(2)-TSG).Based on the mechanism of hydrophilic interaction liquid chromatography(HILIC)and metal oxide affinity chromatography(MOAC),the Fe_(3)O_(4)@TiO_(2)@mSiO_(2)-TSG nanomaterial shows high capacity for simultaneously enriching glycopeptides and phosphopeptides.With human saliva collected in successive four days as practical biological sample,endogenous glycopeptides and phosphopeptides are efficiently enriched.Further gene ontology analysis reveals that the identified endogenous glycopeptides and phosphopeptides participate in diverse molecular functions and biological processes.This strategy is anticipated to promote variation analysis of salivary post-translational modifications.

Determination of L-ergothioneine in food by UPLC-MS/MS method

L-Ergothioneine(L-EGT)possesses excellent antioxidant activity and has been used in the food,pharmaceuticals and cosmetics industries.In this study,a new efficient and sensitive ultra-performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)method was established for the quantitative determination of L-EGT in food.The sample was extracted with methanol-water(70:30,V/V),separated by hydrophilic interaction liquid chromatography(HILIC)and detected by triple-quadrupole mass spectrometry.Validation studies were carried out on different product and the limit of quantitation was 20μg/kg(milk,alcohol-free beverages,dairy products)and 40µg/kg(cereal bars,chocolate).Excellent linearity(correlation coefficient(R2)≥0.999)was achieved for L-EGT quantification in the range of 5–200 ng/mL.The recoveries of the method(83.7%−107.5%)and the relative standard deviation(RSD,0.88%−6.84%(n=6))meet the performance criteria required for the determination of L-EGT in food.Finally,the applicability of the method was tested by analysing actual samples.In general,the method developed is simple,reliable,accurate,and stable and could be useful for routine analyses of L-EGT in food.

Recent progress in polar metabolite quantification in plants using liquid chromatography-mass spectrometry

Metabolite analysis or metabolomics is an important component of systems biology in the post-genomic era.Although separate liquid chromatography（LC） methods for quantification of the major classes of polar metabolites of plants have been available for decades,a single method that enables simultaneous determination of hundreds of polar metabolites is possible only with gas chromatography-mass spectrometry（GC-MS） techniques.The rapid expansion of new LC stationary phases in the market and the ready access of mass spectrometry in many laboratories provides an excellent opportunity for developing LC-MS based methods for multitarget quantification of polar metabolites.Although various LC-MS methods have been developed over the last 10 years with the aim to quantify one or more classes of polar compounds in different matrices,currently there is no consensus LC-MS method that is widely used in plant metabolomics studies.The most promising methods applicable to plant metabolite analysis will be reviewed in this paper and the major problems encountered highlighted.The aim of this review is to provide plant scientists,with limited to moderate experience in analytical chemistry,with up-to-date and simplified information regarding the current status of polar metabolite analysis using LC-MS techniques.

Evaluation and optimization of analytical procedure and sample preparation for polar Streptomyces albus J1074 metabolome profiling

Metabolomics is an essential discipline in omics technology that promotes research on the biology of microbial systems.Streptomyces albus J1074 is a model organism used in fundamental research and industrial microbiology.Nevertheless,a comprehensive and standardized method for analyzing the metabolome of S.albus J1074 is yet to be developed.Thus,we comprehensively evaluated and optimized the analytical procedure and sample preparation for profiling polar metabolites using hydrophilic interaction liquid chromatography(HILIC)coupled with high-resolution mass spectrometry(HRMS).We systematically examined the HILIC columns,quenching solutions,sample-to-quenching ratios,and extraction methods.Then,the optimal protocol was used to investigate the dynamic intracellular polar metabolite profile of the engineered S.albus J1074 strains during spinosad(spinosyn A and spinosyn D)fermentation.A total of 3648 compounds were detected,and 83 metabolites were matched to the standards.The intracellular metabolomic profiles of engineered S.albus J1074 strains(ADE-AP and OE3)were detected;furthermore,their metabolomes in different stages were analyzed to reveal the reasons for their differences in their spinosad production,as well as the current metabolic limitation of heterologous spinosad production in S.albus J1074.The HILIC-HRMS method is a valuable tool for investigating polar metabolomes,and provides a reference methodology to study other Streptomyces metabolomes.