Capillary Chromatography Research Articles

Preparation of core‐shell microporous organic polymer‐coated silica microspheres for chromatographic separation and N‐glycopeptides enrichment

Through a "one-pot" strategy, a layer of microporous organic polymer was coated onto the surface of monodisperse amino-functionalized silica microsphere via amino-aldehyde condensation reaction with core-shell structure. The change in chemical structure of material before and after modification was determined by Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Due to existence of a large number of amino and aldehyde groups in microporous organic polymer shell, the water contact angle decreased from 56.8° (silica microspheres) to 34.7° (microporous organic polymer-coated silica microspheres). Based on these properties, microporous organic polymer-coated silica microspheres were employed as the stationary phase for capillary liquid chromatography and successfully offered baseline separation of polar small molecules. Additionally, the material could also be served as the sorbent of hydrophilic interaction chromatography to enrich glycopeptides from human serum digest. A total of 470 unique N-glycopeptides and 342 N-glycosylation sites mapped to 112 N-glycosylated proteins were unambiguously identified from 2μL of human serum, exhibiting a promising application prospect of microporous organic polymer-coated silica microspheres in the pretreatment of proteomics samples.

Long-term intake of Lactobacillus paracasei KW3110 prevents age-related circadian locomotor activity and changes in gut metabolism in physiologically aged mice.

Aging involves age-progressive loss of physiological functions in organs and tissues. We previously showed that Lactobacillus paracasei KW3110 suppressed age-related inflammation and prevented age-related retinal ganglion cell (RGC) loss. As RGCs mediate biological behaviors associated with responses to ambient light, we assessed whether L. paracasei KW3110 affects circadian locomotor activities in physiologically aged mice. The ratio of locomotor activity during the nighttime (active phase) to daytime (inactive phase) significantly decreased in physiologically aged mice compared with young mice: intake of L. paracasei KW3110 prevented this decrease. We also performed metabolomics analysis of cecal contents using both capillary electrophoresis and liquid chromatography time-of-flight mass spectrometry to better understand the benefical effects for aging of L. paracasei KW3110 through a gut retina axis, since our previous study showed that L. paracasei KW3110 mitigated not only age-related expansions of intestinal inflammatory immune cells but age-related alternation of gut microbiome composition. Principal component analysis showed clear changes in metabolites between physiologically aged mice fed a diet containing L. paracasei KW3110 and age-matched control mice. Furthermore, we found that intake of L. paracasei KW3110 mitigated age-related changes in some fatty acids compared with age-matched control mice. Taken together, L. paracasei KW3110 might regulate age-related alternation of metabolites in cecal contents, potentially leading to suppression of age-related decline in physiological functions, including impairment of circadian locomotor activities.

The role of α-tocopherol and ɷ-3 polyunsaturated fatty acids in miscarriage at early stages of pregnancy with cytomegalovirus infection

Introduction. It is now generally acknowledged that cytomegalovirus infection (CMVI) is one of the main causes of miscarriage. However, the mechanism of this effect has not been sufficiently studied. At the same time, the influence of acids of the ɷ-3 family and α-tocopherol (αTP) on the placentation process through a pro-angiogenic action is shown.Aim. To study the concentration of αTP and ɷ-3 family acids in the peripheral blood and establish their role in miscarriage in CMV-seropositive women with CMVI reactivation.Materials and methods. A case-control study included 64 women in the first trimester of pregnancy (7-10 weeks), of which 36 were CMV-seropositive with CMVI reactivation (main group) and 28 were CMV-seronegative (control group). CMVI was diagnosed by the determination of class M and G antibodies by ELISA, as well as CMV DNA detected by PCR. The concentration of ɷ-3 acids of the family (eicosapentaenoic – EPA, docosahexaenoic – DHA) in blood serum was studied by capillary gas-liquid chromatography (J.P.Carreau, J.P.Dubacq). The αTP concentration was determined by the fluorometric method (L.G.Hansen, W.I.Warwich).Results. In women of the main group, a significant (p<0.001) decrease in the concentration of αTP to 1.32±0.025 μg/mL was observed in the peripheral blood compared to the same indicator in the control group (1.49±0.029 μg/mL). At the same time, the levels of EPA and DHA were also statistically significant (p<0.001) lower than the same indicator in the control group and amounted to 1.09±0.012 and 6.09±0.015%, respectively (in the control, 1.29±0.071 and 8.80±0.071%, respectively). Conclusion. The obtained results of the study allow us to establish the important role of disorders in the content of α-TF, EPA and DHA in the pathogenesis of miscarriage during reactivation of CMVI in the early periods of gestation, which can serve as a basis for expanding diagnostic and therapeutic measures in this pathology of pregnant women.

Swine plasma peptides obtained using pepsin: In silico and in vitro properties and biological activities

The objective of this study was to perform prediction in silico of bioactivity, toxicity, allergenicity, and cell penetration potentials and evaluate, in vitro, the biological activities of swine plasma hydrolysates obtained using pepsin. The size of the peptides was determined through SDS-PAGE electrophoresis and the presence of functional groups through Fourier transform infrared spectroscopy (FTIR). Proteins and peptides were separated by online nanoscale capillary liquid chromatography and analyzed by tandem mass spectrometry with nanoelectrospray (nanoESI MS/MS). In silico potentials were obtained using digital platforms. Antioxidant activity, inhibition of α-amylase and α-glucosidase digestive enzymes, and inhibition of angiotensin-I converting enzyme were determined in vitro. The maximum degree of hydrolysis (28.44%) was obtained at 42 °C, pH 2, and 125 rpm. Peptides with sizes inferior to 10 kDa were obtained, and the FTIR spectra showed the efficiency of the enzyme. A total of 129 proteins and 376 peptides were identified, of which 72 presented bioactive potential. No bioactive peptide presented toxicity potential. However, 79.17% are possible allergens. Six bioactive peptides are cellular penetrants. The need for further in vitro evaluation is evident. The antioxidant activity values were considered satisfactory, with DPPH radical scavenging and iron-reducing power, more than 80%. All hydrolysates tested inhibited α-amylase and α-glucosidase, however, a low inhibition. The maximum inhibition of the angiotensin-converting enzyme was 15.41%. For these enzymes, the values of inhibition can be increased with the purification of peptides that have bioactivity, identified in the in silico study. Swine plasma can be a protein source with the potential to provide compounds with biological activities for functional/nutraceutical application.

A stationary pseudophase semi-permanent coating for open-tubular capillary liquid chromatography and electrochromatography

We describe the chromatographic and electrochromatographic separation of small neutral and charged analytes using a fused silica capillary with a stationary pseudophase semi-permanent coating of didodecyldimethyl ammonium bromide (DDAB) aggregates. The coating was prepared by flushing the capillary with a DDAB solution that was rinsed out with the mobile phase. Our studies (i.e., electroosmotic flow measurements by capillary electrophoresis, chromatographic retention of a neutral probe and atomic force microscopy) suggested the formation of DDAB patchy admicelle, complete admicelle, or larger aggregates at the solid surface - liquid interface inside the capillary, depending on the concentration of DDAB used in coating the capillary. The analytical figures of merit for open tubular liquid chromatography (OT-LC, pressure driven) and open tubular capillary electrochromatography (OT-CEC, voltage driven) using a capillary coated with 0.5 mM DDAB and mobile phase/background solution of 25 mM borate buffer at pH 9.5 with 10% MeOH were the following: LOD = 3.0–5.0 µg/mL (OT-LC) and 2.5–5.0 µg/mL (OT-CEC); linearity R2 > 0.99 (peak area (OT-LC) and corrected peak area (OT-CEC)), intraday and interday repeatability%RSD < 5% (n = 12) for retention/migration time, peak area (OT-LC) and corrected peak area (OT-CEC). The reversed-phase and anion-exchange property of the stationary pseudophase was studied by the addition of organic solvents and sodium chloride to the mobile phase, respectively. We also demonstrate the increase in the ks of the tested analytes by implementing successive multiple ionic layer (SMIL) coating strategies with DDAB in combination with a cationic and/or anionic polyelectrolyte. The use of a stationary pseudophase coating is potentially an easy alternative way to conduct open-tubular liquid chromatography and electrochromatography.

Antioxidant activity of a polysaccharide from Dictyophora indusiata volva and MECC analysis of its monosaccharide composition

In this paper, a crude polysaccharide (PDI) was extracted from D. indusiata volva. The antioxidant activities of PDI were examined by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical, hydroxyl radical and ABTS radicals scavenge assay. The results showed that PDI had antioxidant activities in all these assays, indicating that it could be used as an antioxidant. Then a rapid and highly efficient micellar electrokinetic capillary chromatography (MECC) method coupled with diode array detector was developed to determine the monosaccharides composition of the polysaccharide sample. The optimum conditions were as follows: 20 ​mM borate (pH ​= ​9.3) and 15 ​mM SDS as the electrophoresis medium, the separation temperature was 20 ​°C. Under these conditions, monosaccharides could be separated within 8 ​min. The polysaccharide of the volva was mainly composed of glucose, mannose, galactose and arabinose.

Analysis of arsenic binding proteins in HepG2 cells based on a biotinylated phenylarsenite probe

For a deep understanding of arsenic's mutagenicity, carcinogenicity and teratogenicity, the elucidation of arsenic binding proteins in organisms is a necessary prerequisite. Herein, a biotinylated phenylarsenite (Bio-PAO(III)) probe was synthesized for in situ binding to arsenic binding proteins in HepG2 cells. The Bio-PAO(III)-arsenic binding proteins complexes were captured by the prepared streptavidin-magnetic beads (SA-MBs) by specific interaction of biotin-SA. After magnetic separation, the arsenic binding proteins in the eluent was separated by sodium dodecyl sulfate-polyacrylamide - gel electrophoresis, and the in-gel tryptic digested protein bands were subjected to capillary high performance liquid chromatography coupled with electrospray ionization mass spectrometry analysis. 32 kinds of arsenic binding proteins were identified in HepG2 cells, which could be divided into three groups, structure proteins, enzymes related with tricarboxylic acid cycle and fatty synthesis and transcriptional regulator. Poly [ADP-ribose] polymerase 1 and general transcription factor IIH subunit 1 were identified to bind with arsenicals, which may affect the process of nucleotide excision repair in HepG2 cells.

Small-Footprint, Field-Deployable LC/MS System for On-Site Analysis of Per- and Polyfluoroalkyl Substances in Soil

Per- and polyfluoroalkyl substances (PFASs) are emerging environmental pollutants of global concern. For rapid field site evaluation, there are very few sensitive, field-deployable analytical techniques. In this work, a portable lightweight capillary liquid chromatography (capLC) system was coupled with a small footprint portable mass spectrometer and configured for field-based applications. Further, an at-site ultrasound-assisted extraction (pUAE) methodology was developed and applied with a portable capLC/mass spectrometry (MS) system for on-site analysis of PFASs in real soil samples. The influential variables on the integration of capLC with MS and on the resolution and signal intensity of the capLC/MS setup were investigated. The important parameters affecting the efficiency of the pUAE method were also studied and optimized using the response surface methodology based on a central composite design. The mean recovery for 11 PFASs ranged between 70 and 110%, with relative standard deviations ranging from 3 to 12%. In-field method sensitivity for 12 PFASs ranged from 0.6 to 0.1 ng/g, with wide dynamic ranges (1-600 ng/g) and excellent linearities (R2 > 0.991). The in-field portable system was benchmarked against a commercial lab-based LC-tandem MS (MS/MS) system for the analysis of PFASs in real soil samples, with the results showing good agreement. When deployed to a field site, 12 PFASs were detected and identified in real soil samples at concentrations ranging from 8.1 ng/g (for perfluorooctanesulfonic acid) to 2935.0 ng/g (perfluorohexanesulfonic acid).

P–368 Dynamic metabolomic profiling during early implantation period

Abstract Study question To investigate the different metabolomic profiling in serum between pregnant and non-pregnant women during early implantation period. Summary answer Metabolomics of progesterone-related hormones enhances from ET day3 for pregnancy women compared with non-pregnancy women. What is known already Metabolomics is based on high-throughput analytical methods to identify and quantify metabolites. Compared to other omics study, metabolomics is the closest one to the phenotype, allowing the observation of dynamic changes in phenotype at specific timepoints. So far there is no published work about the metabolomics profile in human early implantation period. Study design, size, duration: Study design: comparative study. Size: 14 pregnancy women and 14 non-pregnancy women. duration: time-course. Participants/materials, setting, methods Participants: pregnancy women and unpregnancy women after embryo transfer (ET). Setting: university-based study. Methods: Peripheral blood were collected at ET day0, 3, 6 and 9. metabolomic profiling in serum by platforms of capillary electrophoresis-mass spectrometry (CE-MS) and liquid chromatography–mass spectrometry (LC-MS). Main results and the role of chance There were no statistical difference of the age, BMI, basal FSH level, endometrium thickness on the day of embryo transfer, distribution of primary and secondary fertility, embryo transfer cycle as well as the infertile types between the two groups. After deleting those with over 50% missing data, we finally have 310 metabolites into statistical analysis. Among the 310 metabolite, lipid metabolites account the largest percentage, nearly half of all metabolites. The second biggest class of metabolites in our data was organic acids. Combined results in repeated measurement ANOVA (RM-ANOVA) and ANOVA-simultaneous component analysis (ASCA) as well as multivariate empirical Bayes time-series analysis (MEBA), we finally found that progesterone-related hormones were the most important metabolites for the whole time-series data. Those significant metabolites showed a significant down regulation from ET day0 to ET day3 and up regulation from ET day3 to ET day9. Limitations, reasons for caution we have limited sample size for this study and further validation is necessary for confirmation. Wider implications of the findings: The phenomenon of upregulation of progesterone-related hormones from day3 in pregnancy group might be related to the embryo-originated hcg. Because the embryo has entered into endometrium at day3 and produced cytokines, hcg and other interaction with endometrium. Trial registration number NA

Analysis of δ-globin gene alleles in Tunisians: description of three new delta-thalassemia mutations.

Thalassemia is one of the most prevalent worldwide autosomal recessive disorders characterized by a great molecular and clinical expression heterogeneity. Alpha and beta-thalassemia are the main two types observed in case of mutations affecting alpha and beta-globin genes respectively. Delta-thalassemia is noted when mutations occur on the delta-globin gene. In Tunisia, β-thalassemia prevalence isestimated at 2.21% of carriers. However, few reports investigated the delta-globin gene. In this work, we aimed to perform a molecular study to help define the molecular spectrum of δ-thalassemia mutations in Tunisia. The study involved 7558 patients among whom we selected 179 individuals with abnormal HbA2 values or fractions. Hemoglobin analysis was performed using Capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC). DNA sequencing was performed on ABI prism 310 Genetic Analyzer Applied Biosystems. CUPSAT (Cologne University Protein Stability Analysis Tool) was used for the prediction of protein stability changes upon missense mutations and mutants were modeled via DeepView-SwissPdbViewer and POV-Ray softwares for molecular dynamics simulation studies. We identified four mutations: HbA2-Yialousa described for the first time in Tunisia ( in 72.72% of cases) and 3 mutations reported for the first time in the world: (i) c.442T > C Stop147Arg ext 15aa-stop observed in 18.18% of cases, (ii) c.187 G > C (Ala62Pro) noted in 4.54% of casesand (iii) c.93-1G > C found in 4.54% of cases. Our data provide genetic basis that would be especially useful in screening for beta-thalassemia trait during delta-beta thalassemia associations.

Characterization of Organic Polymer Monolith Columns Containing Ammonium Quarternary As Initial Study For Capillary Chromatography

Abstract: The polymerization process with a simple step has become the centre of attention of several researchers. Various polymers have been developed, although in general, they use polymerization with a post-modification method. A quaternary ammonium monolith organic polymer has been prepared using a simple single thermal method in this research. 2-(Methacryloyloxy)-N,N,N-trimethylethanaminium chloride was as the monomer, and ethylene dimethacrylate was as crosslinker. The polymerization proceeded in fused-silica capillary (100 mm, 0.32 mm i.d. x 0.45 mm o.d.) using a one-pot approach method. To achieve the perfect macropores, isopropyl alcohol, PEG 400, and ethanol were used as porogen. Characterization of the surface morphology was carried out using a Scanning Electron Microscope (SEM), and the existence of an amine group was characterized by Fourier Transform Infrared Spectroscopy (FTIR). The distribution size of pores in the polymer was in the range of 1.29 to 3.33 µm.Abstrak: Polimerisasi dengan proses yang sederhana dan simpel menjadi pusat perhatian beberapa peneliti. Berbagai macam polimer telah dikembangkan, akan tetapi pada umumnya menggunakan polimerisasi dengan metode post-modification. Pada penelitian ini, polimer organik yang mengandung amonium kuartener dalam bentuk monolit dengan polimerisasi yang menggunakan suhu tunggal dan sederhana telah dilakukan. 2-(Methacryloyloxy)-N,N,N-trimethylethanaminium chloride digunakan sebagai monomer dan ethylene dimethacrylate sebagai crosslinker. Polimerisasi dilakukan dengan metode one-pot aaproach di dalam kapiler silika (100 mm, 0,32 mm i.d. x 0,45 mm o.d.). Untuk mendapatkan makropori yang sempurna, isopropil alkohol, PEG 400 dan etanol digunakan sebagai porogen. Karakterisasi morfologi permukaan dilakukan dengan menggunakan Scanning Electron Microscope (SEM), dan Fourier Transform Infrared Spectroscopy (FTIR) untuk mengidentifikasi gugus fungsi gugus amina yang terdapat pada polimer. Ukuran distribusi pori pada polimer berkisar antara 1,29 sampai 3,33 µm.

Simple and efficient method for the determination of fipronil and two main metabolites in eggs by capillary liquid chromatography

Capillary liquid chromatography (CLC) with UV-diode array detection has been proposed for the first time to determine fipronil and two metabolites, fipronil-sulfide and fipronil-sulfone in hen egg samples. Under optimum conditions, analytes eluted in less than 12 min. Despite the complexity of egg samples, a simple and fast sample preparation method based on salting-out assisted liquid–liquid extraction (SALLE) was developed using acetonitrile as extraction solvent and ammonium sulfate as salting out reagent. To obtain satisfactory extraction efficiencies for the target compounds, several parameters affecting the procedure were optimized, including the nature and amount of the extraction solvent and the type and amount of salting-out reagent, among others. Validation parameters of the proposed SALLE-CLC-UV method yielded satisfactory results with repeatability and intermediate precision, expressed as relative standard deviation (RSD), below 9% and 11%, respectively and recoveries above 80%. Good linearity was obtained (R2 > 0.990) with limits of detection (LOD) below 5 μg·kg−1. The advantages of a miniaturized technique such as CLC in terms of reduced sample and solvent consumption, combined with simplicity of the SALLE procedure, make this method an attractive green alternative to traditional LC for the monitoring of these residues in egg samples.

Explanation of the Formation of Complexes between Representatives of Oxazolidinones and HDAS-β-CD Using Molecular Modeling as a Complementary Technique to cEKC and NMR.

Molecular modeling (MM) results for tedizolid and radezolid with heptakis-(2,3-diacetyl-6-sulfo)-β-cyclodextrin (HDAS-β-CD) are presented and compared with the results previously obtained for linezolid and sutezolid. The mechanism of interaction of chiral oxazolidinone ligands belonging to a new class of antibacterial agents, such as linezolid, tedizolid, radezolid, and sutezolid, with HDAS-β-CD based on capillary electrokinetic chromatography (cEKC), nuclear magnetic resonance (NMR) spectroscopy, and MM methods was described. Principles of chiral separation of oxazolidinone analogues using charged single isomer derivatives of cyclodextrin by the cEKC method were presented, including the selection of the optimal chiral selector and separation conditions, complex stoichiometry, and binding constants, which provided a comprehensive basis for MM studies. In turn, NMR provided, where possible, direct information on the geometry of the inclusion complexes and also provided the necessary structural information to validate the MM calculations. Consequently, MM contributed to the understanding of the structure of diastereomeric complexes, the thermodynamics of complexation, and the visualization of their structures. The most probable mean geometries of the studied supramolecular complexes and their dynamics (geometry changes over time) were determined by molecular dynamics methods. Oxazolidinone ligands have been shown to complex mainly the inner part of cyclodextrin, while the external binding is less privileged, which is consistent with the conclusions of the NMR studies. Enthalpy values of binding of complexes were calculated using long-term molecular dynamics in explicit water as well as using molecular mechanics, the Poisson–Boltzmann or generalized Born, and surface area continuum solvation (MM/PBSA and MM/GBSA) methods. Computational methods predicted the effect of changes in pH and composition of the solution on the strength and complexation process, and it adapted the conditions selected as optimal during the cEKC study. By changing the dielectric constant in the MM/PBSA and MM/GBSA calculations, the effect of changing the solution to methanol/acetonitrile was investigated. A fairly successful attempt was made to predict the chiral separation of the oxazolidinones using the modified cyclodextrin by computational methods.

Use of Portable Capillary Liquid Chromatography for Common Educational Demonstrations Involving Separations

High-performance liquid chromatography is one of the primary techniques covered in the undergraduate analytical chemistry curriculum. This technology report describes the use of a portable capillary-scale instrument that can provide similar performance to a benchtop instrument but generates less solvent waste and enables operation in nonlaboratory settings. Comparisons between the two instrument types were made for single-standard calibration analysis of caffeine in diet soda and aspirin content in over-the-counter tablets, with relative percent differences between the standards and samples under 5% for both instrument types and both samples. The capability to use the instrument in lecture and outreach demonstration activities was also explored. Portable instruments can serve similar pedagogical purposes to traditional instruments as well as provide a platform to introduce discussions on green analytical chemistry based on differences in solvent waste generation and power consumption.

Capillary Liquid Chromatography for the Determination of Terpenes in Botanical Dietary Supplements.

Dietary supplements of botanical origin are increasingly consumed due to their content of plant constituents with potential benefits on health and wellness. Among those constituents, terpenes are gaining attention because of their diverse biological activities (anti-inflammatory, antibacterial, geroprotective, and others). While most of the existing analytical methods have focused on establishing the terpenic fingerprint of some plants, typically by gas chromatography, methods capable of quantifying representative terpenes in herbal preparations and dietary supplements with combined high sensitivity and precision, simplicity, and high throughput are still necessary. In this study, we have explored the utility of capillary liquid chromatography (CapLC) with diode array detection (DAD) for the determination of different terpenes, namely limonene, linalool, farnesene, α-pinene, and myrcene. An innovative method is proposed that can be applied to quantify the targets at concentration levels as low as 0.006 mg per gram of sample with satisfactory precision, and a total analysis time <30 min per sample. The reliability of the proposed method has been tested by analyzing different dietary supplements of botanical origin, namely three green coffee extract-based products, two fat burnings containing Citrus aurantium (bitter orange), and an herbal preparation containing lime and leaves of orange trees.

Residual amounts of pesticides in citrus fruits: analytical control

Introduction. Thanks to possessing beneficial properties and vitamin content, citrus fruits occupy a prominent place in the ubiquitous nutrition of all ages due to various crops. On the other hand, due to climatic conditions, they cannot be cultivated in our country and are classified as imported products, which justifies the importance of controlling their safety. Purpose of the work. The creation of a multicomponent method for determining the residual amounts of pesticides and their metabolites in citrus fruits. Materials and methods. HPLC with triple quadrupole mass detector in multiple reaction monitoring (MRM) mode and capillary gas-liquid chromatography with mass selective detector (GC-MC) in selected ion monitoring mode (SIM) together were used to perform the identification and quantitative determination of the active substances of pesticides of various classes (amino pyrimidines, imidazoles, carbamates, strobilurins, triazoles, organophosphorus compounds, etc.) As a sample preparation method, there was used the QuEChERS technology, based on the extraction of pesticides with an organic solvent from a homogenized sample in the presence of salts containing citrate buffer and the purification of the extracts by dispersive solid-phase extraction. Results. To control the safety of citrus fruits (lemons, grapefruits, oranges, tangerines) imported from Egypt, Turkey and Abkhazia, purchased on the food market, a multi-method was used for determining the residual amounts of a wide range of pesticide compounds (50 names of active ingredients of pesticides and their toxic metabolites) in citrus fruits. The identified levels of active pesticide ingredients did not exceed the established MRLs. Conclusion. The modern development of the analytical chemistry of pesticides, the use of a tandem of gas and liquid chromatography with mass spectrometric detection made it possible to implement a group method for the quantitative determination of the active substances of pesticides and their toxic metabolites in citrus fruits. Modern development makes it possible to detect the contamination of their residual amounts in the processed products.

Stationary phases based on the nanoparticles for pharmaceutical and biomolecule separations

Because of impossibility to achieve a general column for separation purposes, columns must be amended in order to acquire specific chemical characteristics such as hydrophobic, hydrophilic or ionic interactions. In this regard, particular properties of nanoparticles such as large specific surface, high pore volume, narrow particle size- and pore size distribution, and excellent stability introduce them as perfect supports for electrochromatography and chromatographic applications, which enhance the retention and separation efficiency. On the other hand, because of disadvantages of silica stationary phases, it is noteworthy to design new stationary phases for the separation process. Apart from that, the applications of nanoparticles in separation process give rise to reach a suitable mass transfer, which is significant in chromatographic science. Hence, the present report studies various stationary phases based on the nanoparticles for the analysis of biomolecules and chiral drugs using capillary electrochromatography and liquid chromatography techniques, which provide rapid and efficient separations, short run time, high enantioseparation, and less consumption of expensive stationary phases.

Lipase-produced omega-3 acylglycerols for the fortification and stabilization of extra virgin olive oil using hydroxytyrosyl palmitate

Pure concentrates of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids were used to produce monoacylglycerol and diacylglycerol (MDG) oils via enzymatic glycerolysis in a solvent-free system. Immobilized lipase from Candida antarctica B (Novozym 435) was employed for the glycerolysis reaction with up to 90% product formation in one hour. This lipase also favoured diacylglycerol (DAG) over monoacylglycerol (MAG) production. Products were purified using silica gel chromatography and characterised by capillary chromatography with flame ionization detection (Iatroscan-FID). Purified products were added to extra virgin olive oil (EVOO) at a concentration of 20% w/w. The fortified olive oil was stabilized using hydroxytyrosyl palmitate, an antioxidant prepared by conjugating hydroxytyrosol with palmitic acid using Novozym 435 lipase. In vitro hydrolysis of the fortified oil was also carried out using porcine pancreatic lipase to investigate the mechanism of action of this enzyme on the oil mixtures.

Determination of artemisinin and its analogs in Artemisia annua extracts by capillary electrophoresis – Mass spectrometry

The applicability of micellar electrokinetic capillary chromatography (MEKC) with mass spectrometric detection for the determination of artemisinin and its analogs (e.g. ascaridole, artemisia ketone, casticin, deoxyartemisinin, arteannuic acid, artemetin, dihydroartemisinic acid) was studied. 40 mM ammonium perfluorooctanoate (pH 9.5) with 2% isopropanol (IPA) was used as background electrolyte (BGE) and the sheath liquid was 50 % (v/v) IPA:water containing 0.1 % formic acid. Separation was performed in a bare fused silica capillary. Artemisinin was detected at 283.1545 m/z as [M+H]+ ion. For artemisinin the linear range was found to be 0.6 μg/mL - 60 μg/mL and the limit of detection was 0.18 μg/mL. The RSD% values were 2.6 % for migration times and 4.8 % for peak areas (N = 6). In the ethanolic extracts of Artemisia annua leaves, in addition to artemisinin, a large number of other organic components could be separated and determined. MEKC-MS revealed the existence of diastereomers of several compounds (artemisinin, deoxyartemisinin, dihydroartemisinic acid) in the plant extracts.

Chiral Capillary Electrokinetic Chromatography: Principle and Applications, Detection and Identification, Design of Experiment, and Exploration of Chiral Recognition Using Molecular Modeling.

This work reviews the literature of chiral capillary electrokinetic chromatography from January 2016 to March 2021. This is done to explore the state-of-the-art approach and recent developments carried out in this field. The separation principle of the technique is described and supported with simple graphical illustrations, showing migration under normal and reversed polarity modes of the separation voltage. The most relevant applications of the technique for enantioseparation of drugs and other enantiomeric molecules in different fields using chiral selectors in single, dual, or multiple systems are highlighted. Measures to improve the detection sensitivity of chiral capillary electrokinetic chromatography with UV detector are discussed, and the alternative aspects are explored, besides special emphases to hyphenation compatibility to mass spectrometry. Partial filling and counter migration techniques are described. Indirect identification of the separated enantiomers and the determination of enantiomeric migration order are mentioned. The application of Quality by Design principles to facilitate method development, optimization, and validation is presented. The elucidation and explanation of chiral recognition in molecular bases are discussed with special focus on the role of molecular modeling.