Impact of iron supplementation on gestational diabetes mellitus: A literature review.

Gestational diabetes mellitus (GDM) is a common complication of pregnancy, affecting 14% of pregnancies worldwide, and the prevention of pathological hyperglycaemia during pregnancy is meaningful for global public health. The role of iron supplementation in the progression of GDM has been of significant interest in recent years. Iron is a micronutrient that is vital during pregnancy; however, given the toxic properties of excess iron, it is probable that prophylactic iron supplementation will increase the risk of adverse pregnancy outcomes, including GDM. It is critical to clarify the effect of iron supplementation on the risk of GDM. Therefore, in this review, we comprehensively assess the role of iron in pregnancy. This review aimed to analyse the necessity of iron supplementation and maintenance of iron homeostasis during pregnancy, particularly reviewing the role and function of iron in beta cells and examining the mechanisms of excess iron contributing to the pathogenesis of GDM. Moreover, we aimed to discuss the association of haemoglobin and ferritin with GDM and identify priority areas for research.

[Analysis and evaluation of paddy-upland rotation of Gastrodia elata- Oryza sativa in Dabie Mountains].

Gastrodia elata, as the valuable Chinese medicinal material, has been used for more than 2 000 years in China. With the increasing market demand for G. elata, the traditional wild resources have been unable to transform into commodities. At present, local authorities give full play to the advantages of natural resources and vigorously cultivate G. elata to form the cultivation mode and technical system with local characteristics. Huanggang Comprehensive Experimental Station of National Technical System of Chinese Medicinal Materials Industry has optimized and summarized the paddy-upland rotation of G. elata-Oryza sativa in Dabie Mountains of Hubei province through field visits and guidance for four consecutive years. Based on the ecological adaptability and planting characteristics of G. elata and O. sativa, and the actual production experience of farmers, analyzed the principle of paddy-upland rotation from production environment selection and fungus treatment, and evaluated the paddy-upland rotation of G. elata-O. sativa from production status, ecological benefits, and economic benefits. The paddy-upland rotation of G. elata-O. sativa has achieved efficient cultivation of G. elata and produced considerable economic benefits. Through the summary, analysis, and evaluation of the paddy-upland rotation mode of G. elata-O. sativa in Dabie Mountains, the present study put forward the optimization strategy of cultivation technology for G. elata in low-altitude areas, i.e., to use artificial Armillaria sticks instead of traditional cut-log for substitute cultivation of G. elata, which can effectively alleviate the "bacteria-forest contradiction" arising from the cultivation of G. elata. It can also improve the ecological environment and production status of the Dabie Mountains and even the G. elata producing areas at the same altitude.

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.

[Analysis and evaluation of mineral elements of Chrysanthemum morifolium for medicinal and tea use of different germplasm resources].

In this study, 23 germplasm resources of Chrysanthemum morifolium used in medicine and tea were collected from Dabie Mountains and its surrounding producing areas, and the contents of 13 mineral elements were determined and compared. The thermal maps of correlation analysis, principal component analysis and cluster analysis were used for comprehensive evaluation. The results showed that the average content of each element in Ch. morifolium of different germplasm resources was: K>N>P>Mg>Ca>Fe>Mn>Zn>Cu>Ni>Cr>Pb>Cd, and the leaves were: K>N>Ca>Mg>P>Fe>Mn>Zn>Cr>Cu>Ni>Pb>Cd. There are rich contents of N, P, K, Ca, Mg and Fe in Ch. morifolium flowers and their leaves, among them, K element has the largest change range, while N, Ca, Fe, Mg and Zn elements have a larger change range. The absorption and accumulation of each element in the leaves of different germplasm resources varied greatly. The correlation analysis shows that there is a strong positive correlation between Ca element, Mg, Mn and Cd element.Principal component analysis in Ch. morifolium flowers characteristic elements for Mn, Cr, Cu, P, K, can be used as a Ch. morifolium resources to identify the characteristics of the elements, choose top five principal component(F1-F5) comprehensive evalua-tion of medicinal Ch. morifolium, scored in the top five varieties for Hangiu-Fuhuangju, Hangju-Xiaoyangju, Hangju-Sheyangju, Hangju-Dayanghua, Hangju-Subeiju,indicates that in terms of mineral elements, the five medicinal Ch. morifolium resources quality is better. The PCA score chart can divide 23 Ch. morifolium resources into 4 groups, and the cluster analysis heat map divides 23 Ch. morifolium resources into 5 groups. All the Ch. morifolium resources of the same type can be well clustered together, indicating that the difference in mineral element content of Ch. morifolium germplasm resources is closely related to genetic factors.

Fabrication of a cycloalkyl-monolith for on-line solid-phase extraction and determination of four polyphyllins in plasma.

A cycloalkyl-based polymer monolithic column for solid-phase extraction was prepared via radical polymerization using cyclohexyl methacrylate as the monomer. The preparative conditions such as crosslinker/monomer ratio and the amount of the porogens were optimized and the resulting monoliths were characterized by scanning electron microscopy and nitrogen adsorption-desorption method. On-line solid-phase extraction-high-performance liquid chromatography was performed to quantitatively analyse polyphyllin I, II, VI and VII contained in herbal medicine of paridis rhizome in mouse plasma using the homemade optimized monolithic SPE column combined with a C18 column, in which water was used to remove the plasma matrix while the polyphyllins in the mouse plasma were eluted by acetonitrile-water (42:58, V/V). Results obtained from the method validation show that the present method is feasible for the quantitative analysis of the four polyphyllins in plasma. The developed method was further applied for the real mouse plasma sample. These results show that the homemade cycloalkyl-based polymer monolithic SPE column has good ability for clean-up of the interfering bio-matrix and simultaneously extracting the four polyphyllins from mouse plasma. Furthermore, the present method is a promising method for quantitative determination of saponins compounds from complex bio-samples with the advantages of simple and efficient.

Molybdenum disulfide-hypercrosslinked polymer composite as an adsorbent for determination of polycyclic aromatic hydrocarbons in environmental water coupled with HPLC-FLD.

A composite was synthesized from two-dimensional molybdenum disulfide (MoS2) nanosheets and hypercrosslinked polymers (HCP), and the composite was characterized by infrared spectroscopy, scanning electron microscopy, and specific surface area. The fluffy and porous structure and multiple adsorption sites (π-interaction, static electricity, hydrogen bonding) make it ideal for use as an adsorbent. A pipette tip solid-phase extraction with the composite as the adsorbent combined with HPLC-FLD was developed to determine trace amounts of polycyclic aromatic hydrocarbons (phenanthrene, anthracene, fluoranthene, pyrene, benzo(α)anthracene) in environmental water. Under optimal extraction conditions, the method has a wide linear range (0.5-100 ng mL-1) and low limit of detection (0.024-0.099 ng mL-1), and the recoveries of PAHs from spiked environmental water were 73.8% to 123.6% (relative standard deviation ≤ 6.7%, n = 3). Graphical abstract Schematic representation of a three-dimensional molybdenum disulfide-ethylenediamine-hypercrosslinked polymer composite (MoS2-EDA-HCP) using pipette tip solid-phase extraction adsorbent for extracting trace levels of polycyclic aromatic hydrocarbons (PAHs) prior to HPLC-FLD. HCP, hypercrosslinked polymer; MoS2, molybdenum disulfide; EDA, ethylenediamine.

Deep eutectic solvent functionalized graphene oxide composite adsorbent for miniaturized pipette-tip solid-phase extraction of toluene and xylene exposure biomarkers in urine prior to their determination with HPLC-UV.

A deep eutectic solvent functionalized graphene oxide composite adsorbent (DFG) was synthesized through reversible-addition fragmentation chain-transfer polymerization. The synthesized DFG had multiple adsorption interactions after covalent modification with a deep eutectic solvent (allyltriethylammonium bromide/ethylene glycol). Adsorption isotherms and kinetics studies of DFG indicate that the adsorption of hippuric acid (HA) and methylhippuric acid (MHA) was monolayer chemical adsorption. The comparison of DFG with commercial adsorbents demonstrates that the adsorption ability of DFG was superior. This was due to the multiple adsorption interactions of DFG for the three analytes (mainly π-interaction, hydrogen bonding, electrostatic adsorption, and hydrophobic interaction). The DFG adsorbent was applied to miniaturized pipette-tip solid-phase extraction (MPT-SPE), followed by high-performance liquid chromatography (HPLC) to determine biomarkers in urine for toluene and xylene exposure. The DFG-MPT-SPE-HPLC method required only 2.00 mg of DFG as adsorbent, 0.50 mL of washing solvent, and 0.40 mL of elution solvent to achieve a wide linear range (0.200-200 µg mL-1), high recoveries (90.9-99.1%), and high precision (RSD ≤ 6.3%). The proposed method was applied to determine HA and MHA in urine samples from occupational workers. Graphical abstract Deep eutectic solvent functionalized graphene oxide composite adsorbent for miniaturized pipette-tip solid-phase extraction of toluene and xylene exposure biomarkers in urine prior to their determination with HPLC-UV.

Screening and Isolating Major Aldose Reductase Inhibitors from the Seeds of Evening Primrose (Oenothera biennis).

Aldose reductase (AR) is a drug target for therapies to treat complications caused by diabetes mellitus, and the development of effective AR inhibitors (ARIs) of natural origin is considered to be an attractive option for reducing these complications. In this research, the rat lens AR (RLAR) inhibitory activity of evening primrose (Oenothera biennis) seeds was investigated for the first time. In our results, the 50% (v/v) methanol extract of evening primrose seeds exhibits excellent RLAR inhibitory activity (IC50 value of 7.53 µg/mL). Moreover, after enrichment of its bioactive components, the ARIs are more likely to be present in the ethyl acetate fraction of 50% (v/v) methanol extract (EME) of evening primrose seeds, which exhibits superior RLAR inhibitory activity (IC50 value of 3.08 µg/mL). Finally, gallic acid (1), procyanidin B3 (2), catechin (3), and methyl gallate (4) were identified as the major ARIs from the EME by affinity-based ultrafiltration-high-performance liquid chromatography and were isolated by high speed countercurrent chromatography, with gallic acid (11.46 µmol/L) and catechin (14.78 µmol/L) being the more potent inhibitors of the four ARIs identified. The results demonstrated that evening primrose seeds may be a potent ingredient of ARIs.

[Quality assessment of soil fertility of planting Chrysanthemum morifolium areas of Macheng city based on minimum data set].

A minimal data set( MDS) for soil fertility evaluation of Chrysanthemum plantation areas of Macheng city was established by principal component analysis( PCA) combined with Norm values of soil fertility indices and correlation coefficients among indices. A radar map was used to visually reflect the fertility level of individual indicators. Then,the comprehensive index model was used to calculate the soil fertility quality index( SFQI),and the values of SFQI was used to cluster,and the results showed that MDS was composed of five indicators: organic matter( OM),total phosphate( TP),available phosphorus( Av P),available magnesium( Av Mg) and available ferrum( Av Fe). Radar maps showed that the fertility of available phosphorus( Av P) and available copper( Av Cu) was mostly different in the two town,and the fertility of available ferrum( Av Fe) is smallest different. Except for the effective manganese( Av Mn) fertility level of Huangtugang town was higher than that of Futianhe town,the rest were lower than that of Futianhe town. Through analysis,the sensitivity of SFQI value calculated by taking the contribution rate of MDS index in the principal component of the whole data set( TDS) as the weight was the highest,MDS could better replace TDS. The value of SFQI-MDS ranged from 0. 353 to 0. 833,with an average value of 0. 604 and a coefficient of variation of 22%. The results of SFQI-MDS clustering showed that soil fertility could be divided into four categories: grade Ⅰ( 0. 727-0. 833) was superior,accounting for 25. 0%,grade Ⅱ( 0. 615-0. 681)was good,accounting for 29. 2%,mainly distributed in Futianhe Town,grade Ⅲ( 0. 494-0. 589) was medium,accounting for29. 1%,and grade Ⅳ( 0. 353-0. 419) was poor,accounting for 16. 7%,mainly distributed in Huangtugang town. Soil fertility of Futianhe town was better than that of Huangtugang town. It is suggested that boron fertilizer and potassium fertilizer should be supplemented to Chrysanthemum morifolium in production practice,and the amount of phosphate fertilizer,magnesium fertilizer and nitrogen fertilizer should be increased appropriately. At the same time,the amount of organic fertilizer should be increased to enhance soil fertility and improve soil physical and chemical properties.

Fabrication of an ionic-liquid-based polymer monolithic column and its application in the fractionation of proteins from complex biosamples.

An ionic-liquid-based polymer monolithic column was synthesized by free radical polymerization within the confines of a stainless-steel column (50 mm × 4.6 mm id). In the processes, ionic liquid and stearyl methacrylate were used as dual monomers, ethylene glycol dimethacrylate as the cross-linking agent, and polyethylene glycol 200 and isopropanol as co-porogens. Effects of the prepolymerization solution components on the properties of the resulting monoliths were studied in detail. Scanning electron microscopy, nitrogen adsorption-desorption measurements, and mercury intrusion porosimetry were used to investigate the morphology and pore size distribution of the prepared monoliths, which showed that the homemade ionic-liquid-based monolith column possessed a relatively uniform macropore structure with a total macropore specific surface area of 44.72 m2 /g. Compared to a non-ionic-liquid-based monolith prepared under the same conditions, the ionic-liquid-based monolith exhibited excellent selectivity and high performance for separating proteins from complex biosamples, such as egg white, snailase, bovine serum albumin digest solution, human plasma, etc., indicating promising applications in the fractionation and analysis of proteins from the complex biosamples in proteomics research.

Separation of proteins from complex bio-matrix samples using a double-functionalized polymer monolithic column.

A double-functionalized polymer monolithic column was fabricated within the confines of a stainless-steel column (50 mm × 4.6 mm i.d.) via a facile method using iron porphyrin, ionic liquid (1-allyl-3-methylimidazolium chloride) and 1,10-decanediol dimethacrylate as tri-monomers; ethylene dimethacrylate as a crosslinker; polyethylene glycol 400 and N,N-dimethylformamide as co-porogens; benzoyl peroxide and N,N-dimethyl aniline as the redox initiation system. Results obtained from scanning electron microscopy, nitrogen adsorption-desorption, and mercury intrusion porosimetry confirmed the uniform pore structure and the pore size distribution of macro-pores. The home-made monolith was further characterized by elemental analysis to investigate the elemental composition of Fe supplied by iron porphyrin, confirming the synthetic process. The resulting optimized monolithic column was used as the stationary phase in high performance liquid chromatography for separating proteins, such as mixture of standard proteins, egg white, and human plasma, exhibiting good selectivity and high performance. It is worth noting that the home-made double-functionalized polymer monolithic column shows excellent selectivity for fractionation separation of human plasma proteins, and it is a promising separation tool for complex bio-samples in proteomic research.

An ionic liquid-magnetic graphene composite for magnet dispersive solid-phase extraction of triazine herbicides in surface water followed by high performance liquid chromatography.

A new ionic liquid-magnetic graphene (IL-MG) composite was used as the adsorbent in magnetic dispersive solid-phase extraction to rapidly extract and isolate triazine herbicides from surface water. IL-MG was synthesized by a simple and time-saving one-pot strategy where the synthesis of magnetic Fe3O4, the modification with an IL, and the reduction of graphene oxide to graphene were conducted at the same time. An IL was applied to enrich the interaction mechanism between IL-MG and analytes (π-π, hydrophobic interaction, and electrostatic interaction). Moreover, the IL and Fe3O4 nanoparticles acted as spacers, inserting between the layers of graphene to prevent the aggregation of graphene, which improved the adsorption ability because of the large specific surface area of IL-MG. The resultant IL-MG had hierarchical flake structures and showed a high adsorption capacity (8266.0-12 324.1 µg g-1) toward triazine herbicides. Under suitable conditions, the linearity for triazine herbicides was achieved in the range of 0.55-500 ng mL-1 with a detection limit of 0.09-0.15 ng mL-1 and a quantitation limit of 0.31-0.51 ng mL-1, and the enrichment factor was 83-fold, which indicated that the proposed method could be successfully applied for the determination of triazine herbicides in surface water.

Molecularly imprinted ionic liquid magnetic microspheres for the rapid isolation of organochlorine pesticides in environmental water.

A new type of molecularly imprinted ionic liquid magnetic microspheres was synthesized by aqueous suspension polymerization, using 4,4'-dichlorobenzhydrol as a dummy template, and 1-allyl-3-ethylimidazolium hexafluorophosphate and methacrylic acid as co-functional monomers. The results of morphology and magnetic property evaluation of the obtained microspheres demonstrated that it was monodispersed spherical, possessed a rough surface, and an outstanding magnetic properties. Binding experiments revealed that it had a substantial adsorption capacity and strong recognition ability to organochlorine pesticides (OCPs) in aqueous solution. Then the microspheres were applied as an adsorbent of magnetic dispersive solid-phase extraction for the selective recognition and rapid determination of OCPs in environmental water. Under the optimum conditions, good linearity of the three types of OCPs (dicofol, tetradifon, and p,p'-dichlorodiphenyldichloroethane) was achieved in the range of 1.0-100 ng/mL (r ≥ 0.9994). The recoveries at three spiking levels ranged from 82.6 to 100.4% with the RSDs less than 6.9%.

Hydrophilic Molecularly Imprinted Resorcinol-Formaldehyde-Melamine Resin Prepared in Water with Excellent Molecular Recognition in Aqueous Matrices.

Hydrophilic molecularly imprinted resorcinol-formaldehyde-melamine resin (MIRFM) is synthesized in water and shows excellent molecular recognition in aqueous matrices. The double functional monomers resorcinol and melamine, and the cross-linker formaldehyde, are all hydrophilic, and then the hydrophilic groups (such as hydroxyls, imino groups, and ether linkages) can be introduced into MIRFM, which make the material compatible with aqueous samples. The general principle is demonstrated by the synthesis of MIRFM using sulfanilamide as a dummy template for the selective recognition to sulfonamides (SAs) in milk samples. Resorcinol and melamine can interact with the template mainly by hydrogen bonding and π-π interaction, which makes MIRFM and the analytes have strong affinity. Besides, melamine can improve the rigidity of MIRFM and accelerate the polymerization process, so there is no need to add base or acid as a catalyst, which guarantees the success of molecular imprinting. MIRFM shows higher recovery and improved purification effect for SAs, in comparison to silica, HLB, C18, and SCX. Because of its excellent hydrophilicity and specificity, MIRFM is promising to be applied in biological, environmental, and clinical fields.

Novel pyridinium-based tags: synthesis and characterization for highly efficient analysis of thiol-containing peptides by mass spectrometry.

In this study, a novel type of pyridinium-based tags, 1-[3-[(2-iodo-1-oxoethyl)amino]propyl]-4-methylpyridinium bromide (IMP) and 1-[3-[(2-iodo-1-oxoethyl)amino]propyl]-4-propylpyridinium bromide (IPP), were designed, synthesized, and applied to the derivatization of thiol-containing peptides. With model peptides as the sample, the labeling efficiency and the stability of the peptide derivatives were investigated. The results indicate that nearly 100% derivatization yield was achieved with the developed tags and the peptide derivatives were stable at room temperature for at least one week. Furthermore, improved ionization efficiency and increased charge states were achieved via both matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MS) and electrospray ionization (ESI) MS, of which IPP exhibited the more obvious improvement of ionization efficiency. Further analysis of tryptic digests of bovine serum albumin (BSA) and α-transferrin, showed that increased identification efficiency of the thiol-containing peptides was achieved by combination with IMP or IPP derivatization. For example, the identification efficiency of the thiol-containing peptides of α-transferrin increased more than 42% upon combination with the IMP or IPP derivatives. We anticipate the novel tags are promising for highly efficient thiol-containing peptide identification in proteome research, especially for low concentrations.

Pipette-tip solid-phase extraction by use of a sol-gel hybrid adsorbent: a new pretreatment strategy for rapid screening of cucumbers for cyanazine and atrazine.

A pipette-tip solid-phase extraction (PT-SPE) method using a sol-gel hybrid adsorbent has been developed. The method could be used for rapid screening of vegetable matrices for cyanazine and atrazine; assay of cucumbers is reported as an example. The sol-gel hybrid adsorbent was synthesized from tetraethyl orthosilicate (TEOS) as the precursor and γ-(methacryloyloxy)propyltrimethoxysilane (KH570) as both surface modifying agent and monomer for the polymerization. Under the optimized conditions, good calibration linearity was obtained in the range 0.022-1.65 µg g(-1) with correlation coefficients (r) ≥0.9996. Recovery at three spike levels ranged from 87.6 to 93.8 % with relative standard deviations ≤7.8 %. This extraction strategy has several advantages, for example ease of assembly, low cost, and high extraction efficiency, and is a potential pretreatment strategy for rapid screening of cyanazine and atrazine in vegetables.

Novel imidazolium-embedded N,N-dimethylaminopropyl-functionalized silica-based stationary phase for hydrophilic interaction/reversed-phase mixed-mode chromatography.

A novel imidazolium-embedded N,N-dimethylaminopropyl-functionalized silica-based stationary phase (Sil-ImCl) was prepared and further used for hydrophilic interaction/reversed-phase mixed-mode chromatography. The Sil-ImCl stationary phase was respectively characterized by Fourier transform infrared spectrometry, thermogravimetric analysis, and element analysis. A variety of hydrophilic or hydrophobic compounds were used to evaluate the retention mechanisms of the developed stationary phase, and the effects of buffer salt concentration and pH of mobile phase on the retention of these compounds were also investigated. The developed stationary phase was successfully applied for separation of nucleosides and nucleic acid bases, water-soluble vitamins, phenols, and positional isomers. Moreover, simultaneous separation of polar and nonpolar compounds was also achieved with high resolution, outperforming the commercially available C8 column and amino column. Furthermore, the Sil-ImCl stationary phase has been successfully applied for separation of secondary metabolites of Hansfordia sinuosae. All these results demonstrate that the Sil-ImCl stationary phase might be promising for separation of complex polar and nonpolar compounds with high efficiency, especially in biological industry.

Development of a novel imidazolium-based aromatic quaternary ammonium tag: synthesis and application to the efficient analysis of cysteinyl-peptides by mass spectrometry.

RATIONALE: Chemical derivatization is a very promising technique for improving analysis of peptides by mass spectrometry (MS). In this study, a novel kind of imidazolium-based aromatic quaternary ammonium tag, 1-[3-[(2-iodo-1-oxoethyl)amino]propyl]-3-butylimidazolium bromide (IPBI), designed with strong gas-phase basicity and a permanent positive charge, was firstly synthesized and further used for derivatization of cysteinyl-peptides with improved ionization efficiency and higher charge states. METHODS: Both the model peptides and tryptic digests of proteins were used to evaluate the effect of IPBI derivatization on the MS performance of the derivatized peptides, and the results were further compared with the commonly used iodoacetamide (IAA) tag. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)-MS and electrospray ionization (ESI)-MS were used to evaluate the ionization efficiency and charge states of the derivatized peptides. RESULTS: With model peptides as samples, a nearly 100% derivatization efficiency and superior stability were achieved via IPBI derivatization. By further analysis of both standard peptides and tryptic protein digests, the ionization efficiency and charge states of IPBI-derivatized peptides could be remarkably improved. For example, for protein bovine serum albumin, compared with the commercial available IAA tag, the identification efficiency of cysteinyl-peptides was increased about 67% by combining with IPBI derivatization. CONCLUSIONS: The results indicated that the novel tag is an effective derivatization reagent for cysteinyl-peptide identification. We hope it could be further used for high-efficiency cysteinyl-peptide identification in proteome research, especially those with low abundance and poor ionization efficiency.

Imidazolium-based iodoacetamide functional tags: design, synthesis, and property study for cysteinyl-peptide analysis by mass spectrometry.

New types of imidazolium-based iodoacetamide tags were designed, synthesized and further exploited for cysteinyl-peptide analysis with superior labeling efficiency, high stability, improved ionization efficiency, and increased charge states by mass spectrometry. For the first time, the effects of these kinds of tags on the mass spectrometry performance of the derivatized peptides were investigated, which is of great importance to help us design more efficient tags for the analysis of peptides or proteins, especially for those with low abundance.

Ionic liquid-modified magnetic polymeric microspheres as dispersive solid phase extraction adsorbent: a separation strategy applied to the screening of sulfamonomethoxine and sulfachloropyrazine from urine.

Ionic liquid-modified magnetic polymeric microspheres (ILMPM) were prepared based on Fe3O4 magnetic nanoparticles (MNPs) and ionic liquids (ILs) incorporated into a polymer. The composites were characterized using scanning electron microscopy, Fourier transform infrared analysis, thermogravimetric analysis, X-ray diffraction, and vibrating magnetometer, which indicated that ILMPM had a regularly spherical shape and strong magnetic property. The obtained ILMPM were successfully applied as a special adsorbent of magnetic dispersive solid phase extraction (MDSPE) for the rapid extraction and isolation of sulfamonomethoxine sodium and sulfachloropyrazine sodium in urine. The factors that affected extraction efficiency, such as adsorption conditions, desorption conditions, washing and elution solvents, and pH of the sample solution, were optimized. Under the optimum condition, good linearity in the range of 0.005-2.0 µg g(-1) (r ≥ 0.9996) was obtained for the two sulfonamides (SAs); the average recoveries at three spiked levels ranged from 86.9 to 102.1 %, with relative standard deviations of ≤4.3 %. The presented ILMPM-MDSPE method combined the advantages of ILs, MNPs, and MDSPE and therefore could be potentially applied for rapid screening of SAs in urine.