High-performance Liquid Chromatographic Determination Research Articles

A novel HPLC method for analysis of atosiban and its five related substances in atosiban acetate injection

Consulting the national pharmacopoeia, no official quality standard was found for estimation of related substances and assay of atosiban acetate injection, of which main active component is atosiban. To solve this problem, herein, a novel high performance liquid chromatographic (HPLC) method was developed and validated in this study. A chromatographic system comprising an Inertsil ODS-2 analytical column, mobile phase-A of water (pH adjusted to 3.2 with trifluoroacetic acid)-acetonitrile-methanol (77:14:9, v/v/v), mobile phase-B of acetonitrile-methanol (65:35, v/v), a flow rate of 1.0 mL min-1 and a UV detector set at 220 nm with column temperature at 35 °C has shown simple, reproducible and specific determination for atosiban and its five related substances. Also, we combined with mass spectrometry to characterize the molecular weight and tentative structure of the impurities. Using HPLC verified methodology, results of the validation study showed that the precision, specificity and accuracy of the five impurities, good linear equation R squared was greater than 0.9993, and as such, the limit of detection and the limit of quantification have been determined. The proposed method in this study, which, to the best of our knowledge, is the most comprehensive HPLC determination applied to the routine analysis in quality control of this injection.

Validation of High-Performance Liquid Chromatography for Determination of Bromelain in Pineapple (Ananas comosus (L) Merr) Water

Objective: The aim of the present study was to validate HPLC method for analysis bromelain levels in pineapple water and application that method to determine the storage time of pineapple water. Methods: The reversed phase of HPLC method was tested and optimized before it is validated. The composition and the flow rate of the mobile phase is the optimized parameter. The analytical parameters validated were detection limits, linearity, accuracy and precision. Pineapple water was stored for 8 h at 10ºC and bromelain was determined using the validated HPLC method. Result: The optimum mobile phase composition was methanolwater (70:30) with a flow rate of 1 ml/min. The detector concentration-response was linear with coefficient of determination of 0.993. The accuracy of HPLC method at a recovery of 1 and 2% bromelain was 106.37 ± 1.94% and 98.12 ± 1.29% (n = 5), respectively. The precision, expressed as the coefficients of variation (CV), at 1 and 2% bromelain were 1.83 and 1.32% (n = 5), respectively. Bromelain level at zero time was 81.53%. After storage for 8 h at 10ºC, bromelain levels in pineapple juice appeared to decrease not statistically significant (p > 0.05), with to mean value of 78.46 ± 2.88%. Conclusion: The HPLC method developed was valid to analyze accurately concentrations of bromelain in pineapple water and it can be used to study the shelf life of pineapple water based on bromelain content. The bromelain content in pineapple juice was not statistically significantly different after 8 h storage at 10°C.

Liquid-liquid extraction by low-temperature partition and high-performance liquid chromatography for determination of flunixin and phenylbutazone in horse hair

Liquid-liquid extraction by low-temperature partition and high-performance liquid chromatography for determination of flunixin and phenylbutazone in horse hair

Stability-Indicating HPLC Determination of Rifampicin in Bulk Drug and Dosage Form

A simple, selective, precise and stability-indicating high-performance liquid chromatography (HPLC) method for the determination of rifampicin in the parent drug substance and drug products was developed and validated as per the current ICH guidelines. The analysis was achieved isocratically on Phenomenex Luna C18 column (5 μm; 250 × 4.6 mm) utilizing a mobile phase consisting of a mixture of formic acid buffer, pH adjusted to 4.5, and acetonitrile (55:45 v/v) at a flow rate of 1.5 mL min-1 with UV detection at 235 nm. The retention time was 3.5 min. The linear regression analysis for calibration plot showed good linear relationship with r2 = 0.9999 with respect to peak area in the concentration range 5 – 250 μg mL-1. The limits of detection and quantification were 3.0 and 9.2 μg mL-1, respectively. The method was validated for precision, accuracy, selectivity, recovery, robustness and ruggedness. The intra-day and inter-day accuracy expressed as % relative error were better than 2%. The precision determined and expressed as % relative standard deviation did not exceed 0.5%. Rifampicin was subjected to acid and alkali hydrolysis, oxidation, photo degradation and dry heat treatment. The drug was found to undergo complete degradation under acid-, base-, and oxidation-induced stress conditions, but was stable under other stress conditions. The method was applied to commercial drug capsules and showed highly satisfactory results.

Three-Dimensional High-Performance Liquid Chromatographic Determination of Asn, Ser, Ala, and Pro Enantiomers in the Plasma of Patients with Chronic Kidney Disease

The concentrations of several d-amino acids have been reported to significantly increase in the plasma of patients with chronic kidney disease (CKD). However, the amounts of these d-amino acids are low (around 1% of the l-form or lower), and their analyses were complicated by various interfering compounds in many clinical samples. A highly selective analytical method is thus required to perform the accurate and precise determination of these d-amino acids in the plasma of CKD patients. In the present study, a selective 3D-HPLC system equipped with reversed-phase, anion-exchange, and enantioselective columns has been designed and developed for the determination of the asparagine, serine, alanine and proline enantiomers. For the sensitive analysis, amino acids were precolumn derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole and detected by their fluorescence. The system was validated by using human plasma in addition to the standard amino acids, and results with a sufficient linearity, precision, and accuracy were obtained. The 3D-HPLC system was applied to the plasma of patients with different stages of CKD and all of the target d-amino acids were clearly observed without interferences for all 25 tested patients. Good correlations were shown between the kidney function of the patients and the %d values of the target analytes, especially d-Asn and d-Ser, indicating that the present 3D-HPLC method is useful for the sensitive diagnosis of CKD.

Superparamagnetic core-shell dummy template molecularly imprinted polymer for magnetic solid-phase extraction of food additives prior to the determination by HPLC

A highly sensitive and selective method for the simultaneous extraction and determination of trace vanillin, ethyl vanillin, maltol and ethyl maltol in beverage samples using magnetic solid-phase extraction coupled with high-performance liquid chromatography (HPLC) was developed. The novel superparamagnetic dummy template molecularly imprinted polymers (Fe3O4@MDMIP) were prepared by adopting a sol-gel approach using 3-hydroxy-2,6-bis(hydroxymethyl) -4-pyrone, whose structure was similar to that of the vanillin and maltol, as the dummy template for selective extraction of vanillin, ethyl vanillin, maltol and ethyl maltol. The obtained Fe3O4@MDMIP exhibits high uniformity and monodispersity. Besides, Fe3O4@MDMIP has an outstanding magnetic susceptibility (56.33 emu g−1) than common obtained samples. The maximal adsorption capacity (Qmax) of the resulting Fe3O4@MDMIP for the four food additives was up to 609.99 mg g−1. The imprinting factors of the Fe3O4@MDMIP ranged from 2.07 to 2.71 for the four food additives, which indicated that the obtained adsorbents have high selectivity. Under the optimum experimental conditions, the Fe3O4@MDMIP was successfully applied to the magnetic solid-phase extraction of vanillin, ethyl vanillin, maltol and ethyl maltol followed by HPLC determination in beverage samples. Validation experiments indicated that the developed method presented good linearity (2.07–463 ng mL−1), satisfactory precision (RSD, 2.68–6.91%), and high recovery (91.2–107.1%). The limits of detection ranged from 44 to 201 ng L−1, and the enrichment factors were in the range of 432–484. The results demonstrated great potential of the optimized method for sample preparation in routine analysis of trace food additives.

Novel hydrophobic deep eutectic solvent for vortex assisted dispersive liquid-liquid micro-extraction of two auxins in water and fruit juice samples and determination by high performance liquid chromatography

A green, simple, sensitive, efficient and rapid method was developed based on application of a novel deep eutectic solvent in vortex-assisted dispersive liquid-liquid microextraction (VA-DES-DLLME) of two auxins (indole-3-acetic acid (IAA) and 1-naphthaleneacetic acid (NAA)) in water and fruit juice samples followed by high performance liquid chromatography determination. The novel hydrophobic deep eutectic solvent was readily prepared by mixing isoamyl alcohol as hydrogen bonding donor and trioctylmethylammonium chloride as hydrogen bonding acceptor at room temperature for 3 min. Affecting parameters on VA-DES-DLLME were investigated and optimized. Under the optimum conditions, good linearity (1.0–500 μg L−1, r2 ≥ 0.99) was obtained for the auxins. Limit of detection (LOD) was 0.2 and 0.3 μg L−1 for IAA and NAA, respectively. Moreover, repeatability (intra-day, n = 6) and reproducibility (inter-day, n = 3) of the method expressed as relative standard deviation (RSD) at 10 and 100 μg L−1 concentration levels were <8%. Finally, applicability of the developed method was evaluated by analyzing the auxins in water and fruit juice samples and satisfactory results were obtained (recovery ≥ 90%).

Application of response surface methodology to optimize pipette tip micro-solid phase extraction of dyes from seawater by molecularly imprinted polymer and their determination by HPLC

In this paper, a novel pipette tip micro-solid phase extraction based on molecularly imprinted polymer as a selective sorbent was developed and applied for extraction, pre-concentration and high-performance liquid chromatographic determination of trace amounts of malachite green (MG), rhodamine B (RB), methyl orange (MO) and acid red 18 (AR) dyes in seawater samples. Different parameters affecting the extraction efficiency such as type and volume of eluent solvent, sample volume, number of cycles of extraction and desorption, amount of sorbent and pH of the sample solution were evaluated using one-variable-at-a-time and response surface methodology. In order to optimize dyes extraction, seven factors in three levels were used for Box–Behnken experimental design. Under optimum extraction condition, pH of sample solution was 3.1 for MG, 3.0 for RB, 7.1 for MO and 6.1 for AR; volume of eluent solvent (HCl, 0.5 mol L−1) was 200 µL; volume of the sample solution was 10 mL (for MG) and 4 mL (for RB, MO and AR); the concentration of triton X-114 was 0.085 (MG), 0.10 (RB), 0.08 (MO) and 0.075 (AR) % v/v; the number of extraction cycles was 10 (MG), 6 (RB), 5 (MO) and 7 (AR); the number of elution cycles was 10, 6, 5 and 9, respectively, for MG, RB, MO and AR; NaCl concentration was 0.4 mol L−1; and amount of MIP was 2.0 mg for all dyes. The linear range of calibration curves was 0.5–250.0 µg L−1 for malachite green and methyl orange and 0.5–150.0 µg L−1 for both rhodamine B and acid red 18. The detection limits calculated to be 0.083, 0.10, 0.12 and 0.17 µg L−1 for MG, RB, MO and AR, respectively. The developed protocol was successfully used for determination of dyes in seawater of Chabahar Bay. The mean recoveries were ranged between 76.1 and 97.3% by mean relative standard deviations of 1.2–7.1%.

Preparation of mixed-matrix membranes from metal organic framework (MIL-53) and poly (vinylidene fluoride) for use in determination of sulfonylurea herbicides in aqueous environments by high performance liquid chromatography

Novel mixed-matrix membranes (MMM) were prepared from metal-organic frameworks (MOF) (MIL-53) and poly (vinylidene fluoride) (PVDF), viz MIL-53–PVDF MMM, for the simultaneous dispersion membrane extraction (DME) of seven sulfonylurea herbicides (SUs) in aqueous environments followed by high performance liquid chromatography (HPLC) determination. The MIL-53–PVDF MMM was well characterized and major factors influencing DME performances were systematically investigated including membrane type, MOF dosage, eluent type, solution pH, extraction/elution time and salinity, etc. Under optimal conditions, the MIL-53–PVDF MMM based DME coupled with HPLC exhibited excellent linearity within 0.03–10 μg L−1 for chlorimuronethyl and 0.01–10 μg L−1 for other six SUs individual. High enrichment factor of 250 was obtained, as well as low detection limits and quantification limits ranged from 3.75 to 10.30 ng L−1 and 12.49–34.30 ng L−1, respectively. Furthermore, the method attained high recoveries of 77.20–111.00% at three spiking levels of SUs, with relative standard deviations of 1.28–14.67% in tap water, seawater and surface water samples. Additionally, the MMM was readily separated from water and well regenerated, and could keep about 80% recovery after 25 cycles. Compared to that reported extraction materials, the MIL-53–PVDF MMM possessed the advantages of high enrichment ability, excellent reusability, good practicality and easy separation, indicating it was a promising alternative for the enrichment of SUs from aqueous environments.

Phytoplankton community structure in contrasting ecosystems of the Southern Ocean: South Georgia, South Orkneys and western Antarctic Peninsula

The relationships between taxonomy and distribution of the phytoplankton and environmental parameters were studied in four contrasting zones (North of the South Orkney Islands= NSO, Southeast of the South Orkney Islands = SSO, Northwest of South Georgia = NSG and West of Anvers = WA) of the Atlantic sector of the Southern Ocean, during the PEGASO cruise of the BIO Hespérides (January–February 2015). The structure of the phytoplankton community was determined by microscopic examination and by pigment analyses using high-performance liquid chromatography (HPLC) followed by application of the CHEMTAX algorithm. Overall, a statistically significant association was found between fluorometric and HPLC determinations of chlorophyll a, and between chemotaxonomic and microscopy-derived estimates of the contribution of diatoms, dinoflagellates and cryptophytes, although cryptophytes appeared to be underestimated by the microscopic observations. The highest average levels of fluorometric chlorophyll a (517 mg m−2) were found at NSG, followed by WA (132 mg m−2), NSO (120 mg m−2) and SSO (34 mg m−2). The phytoplankton community at NSG was dominated by diatoms like Eucampia antarctica and Thalassiosira spp. Cryptophytes and diatoms (mainly Corethron pennatum, small Thalassiosira spp. and Fragilariopsis spp.) were the most abundant chemotaxonomic groups at NSO, followed by haptophytes types 6 + 7, Phaeocystis-like (haptophytes type 8) and, especially in the deeper levels of the euphotic zone, pelagophytes. At SSO, the most important groups were haptophytes types 6 + 7, followed by diatoms (with a combination of taxa similar to that of NSO), Phaeocystis-like and pelagophytes. The main CHEMTAX groups at WA were cryptophytes (between surface and about 40 m depth), haptophytes types 6 + 7 and diatoms. The ratio between the photoprotective pigment diadinoxanthin and the sum of the light harvesting pigments of diadinoxanthin-containing phytoplankton (sum of 19′-butanoyloxyfucoxanthin, 19′-hexanoyloxyfucoxanthin, fucoxanthin and peridinin) was highest at SSO, indicating exposure to a high irradiance environment, and presented a significant positive correlation with the euphotic zone depth. The ratios of the algal osmolyte dimethylsulfoniopropionate and the trace gas dimethylsulfide to chlorophyll a showed the same pattern across zones, highlighting the role of light-related ecophysiology in combination with taxonomy in regulating the production of dimethylated sulfur by plankton communities.

Dissolvable layered double hydroxide as a sorbent in dispersive micro‐solid phase extraction for the determination of acidic quinolones in honey by HPLC

This study presents a simple and green dispersive micro-solid phase extraction method for preconcentration of acidic quinolones from honey prior to high performance liquid chromatography determination. A two-dimensional nanostructured zinc-aluminum layered double hydroxide was synthesized and used as the sorbent for dispersive micro-solid phase extraction. Its different characteristics from conventional sorbents is that it is dissolvable in acidic solution (pH<4). After the extraction, the analyte elution step was omitted and thus the use of organic solvents was avoided. The key parameters influencing the extraction efficiency such as the amount of sorbent, pH of sample solution, vortex time, type and volume of acidic solution were investigated and optimized. The method exhibited low limits of detection (3.0-5.0ng/g), good linearity (10-2000ng/g) with coefficients of determinations higher than 0.9991, acceptable precision (RSD<9.1%) and accuracy (RE<5.8%). The proposed method is fast, efficient, eco-friendly, and suitable for the determination of acidic quinolones in honey samples.

Application of zinc/aluminum layered double hydroxide nanosorbent in a fixed-bed column for SPE-preconcentration followed by HPLC determination of diclofenac in biological and hospital wastewater samples

A zinc/aluminum layered double hydroxide (Zn/Al LDH) with carbonate interlayer anions was synthesized by the co-precipitation method. The prepared sorbent was examined for the solid phase extraction (SPE) and high performance liquid chromatography (HPLC) determination of the trace amounts of diclofenac (DCF) in human serum, as a complex matrix, and hospital wastewater samples. The first step of the procedure was the extraction of DCF by the synthesized Zn/Al LDH via an anion exchange mechanism, in which the interlayer carbonate anions were involved. A univariate sequential optimization procedure was conducted to find the optimal value of the parameters affecting the extraction process. The second step was the elution of the adsorbed DCF by a sodium hydroxide solution (2 mol L−1), followed by HPLC analysis of DCF. Under the optimal experimental conditions, the calibration plots for the determination of DCF in hospital wastewater and human serum samples were linear in the ranges of 3–415 (R2 = 0.999) and 9–300 (R2 = 0.997) μg L−1, respectively. The corresponding limits of detection were found to be as 0.16, 1.5 μg L−1, and the evaluated preconcentration factors were 41 and 37. The stability of the studied LDH allowed using a column packed with this adsorbent for 185 adsorption-desorption cycles. The results demonstrated the potentials of the developed method for efficient preconcentration and thus precise trace analysis of DCF in real samples.

Development and application of microwave-assisted extraction and advanced low density microextraction technique coupled with high-performance liquid chromatography for the successful determination of heterocyclic aromatic amines in barbecued meat sample and method optimization using response surface methodology

Heterocyclic aromatic amines (HAAs) produced during heat processing in meat samples are introduced as chemical toxicants with hazardous effect on human body. In this study, we applied an advanced, simple, efficient and sensitive analytical procedure based on microwave-assisted extraction and low density solvent/dispersive liquid–liquid microextraction coupled with high-performance liquid chromatography for the determination of four kinds of HAAs (2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)) in barbecued meat samples for the first time. The parameters affected on microextraction method including type and volume of extraction and disperser solvents, salt percent and PH were optimized using response surface design. The dynamic linear range was 1–1000 ng g−1. The coefficient of determination was higher than 0.982, relative standard deviations were between 3.7 and 8.1%. The recoveries in tree levels (10, 50 and 100 ng g−1) were obtained 89–101.5%. Detection limits were between 0.25 and 0.71 ng g−1. Offered technique is sensitive, selective‚ quick and precise. The most concentration of HAAs determined in barbecued meat samples was for IQ 1250 ng g−1 and the lowest amount is also related to IQ type 25 ng g−1. This proposed method presents proper concentration factors and detection limits for determination of HAAs in different barbecued meat samples.

High performance liquid chromatographic determination of triclosan, triclocarban and methyl-triclosan in wastewater using mini-bar micro-solid phase extraction

An analytical method for the determination of the antibacterial agents (triclosan, triclocarban and methyl-triclosan) in wastewater is described. Attention was paid to sample pre-treatment where a new device, the mini-bar micro-solid phase extraction (mini-bar μ-SPE) was introduced. As in conventional micro-solid phase extraction (μ-SPE) device, sorbent (graphene, 20 mg) was introduced into a porous polypropylene (PP) bag (1.5 cm × 0.8 cm). It was next inserted into another slightly bigger PP bag (2.0 cm × 0.8 cm) together with a small metal rod (diameter, 1 mm; length, 1.5 cm). The open end of the outer bag was heat-sealed to secure the contents. After the extraction, the extracts were analysed by liquid chromatography on a pentafluorophenyl column (250 mm × 4.6 mm × 5 μm) with ultraviolet detection. Various experimental conditions influencing the mini-bar μ-SPE such as the effects of membrane type, preconditioning solvent, stirring speed, sorbent type and amount, sample volume and pH on the extraction were optimized. The desorption parameters (sonication time, solvent type and volume) were also studied. The method was validated, and calibration curves were linear with r2 > 0.99 over the range of 0.2–1000 μg L−1. The limits of detection were in the range 0.04–0.07 μg L−1. Recoveries were in the range between 80.8 and 103% for the target analytes. The relative standard deviation for inter- and intra -day precision was in the range of 3.6–27% for all analytes. The validated method was applied to the determination of the antibacterial agents in a campus wastewater treatment plant. Advantages of the mini- bar μ-SPE over the conventional μ-SPE are also highlighted.

High Performance Liquid Chromatography Determination and Optimization of the Extraction Process for the Total Alkaloids from Traditional Herb Stephania cepharantha Hayata.

Stephania cepharantha Hayata is a traditional Chinese herbal medicine used to treat lung cancer, and its alkaloids, especially cepharanthine (CEP), were reported to be its effective ingredients. Therefore, the extraction of potential antitumor ingredients from the plant was of interest. We first explored the optimized solvent extraction of antitumor agents from S. cepharantha Hayata guided by an in vitro antitumor activity assay. The solvent for extraction and its concentration, the liquid to material ratio, extraction duration, particle size, macerating time, and the frequency of extraction were investigated using a single-factor experiment. An orthogonal design (L9, 34) was constructed to determine the suitable extraction conditions. The crude extract was then purified sequentially by macroporous adsorption resins (MR) for the enrichment of CEP. Under these optimal conditions, the yield of total alkaloids in the herbs was 3.4%, whereas the CEP content was 2.9%. Total alkaloids exhibited significant anti-proliferative activities in the A549 cell line. Our study provides means for the further development and use of the antitumor components from S. cepharantha, which has potential for application in the pharmaceutical industry.

Dual-template molecularly imprinted polymers for dispersive solid-phase extraction of fluoroquinolones in water samples coupled with high performance liquid chromatography.

Novel dual-template molecularly imprinted polymers (dt-MIPs) were prepared by simple and facile precipitation polymerization using norfloxacin (NOR) and enrofloxacin (ENR) as templates for simultaneous selective recognition and extraction of the two fluoroquinolones (FQs). The as-prepared dt-MIPs exhibited high adsorption capacity and excellent selectivity towards NOR and ENR. Several main parameters affecting the efficiency of dt-MIP based dispersive solid-phase extraction (DSPE) were systematically investigated, coupled with high performance liquid chromatography determination. Consequently, high enrichment factors of 71 and 61 were obtained for NOR and ENR respectively, and good linearity in the range of 1-200 μg L-1 was observed, with correlation coefficients (r) above 0.9977. The limits of detection and quantification for NOR were 0.22 and 0.67 μg L-1, respectively, and 0.36 and 0.98 μg L-1 for ENR. Satisfactory recoveries of the two FQs from spiked lake, sea and tap water samples at three concentration levels were attained in the range of 80.9-101.0% with relative standard deviations of 0.9-6.9%. The present study not only has great potential for applications in FQ determination, but will also enrich research into dual/multi-template imprinting.

Solvent pulse desorption on-line solid-phase extraction combined with high-performance liquid chromatographic determination of 14 sulfonamides in environmental water samples

We developed a new method for detecting sulfonamides using a manual injection valve, octyl (C8) as the sorbent in a solid-phase extraction column. Use of gradient flow for a solvent pulse can prevent the use of a second pump and a switch valve.

Qualitative and quantitative analysis of Porana sinensis Hemsl by UHPLC-Q-Exactive MS, TLC autographic method and DART-MS.

Erycibe obtusifolia and E. schmidtii are widely used in traditional Chinese medicine (TCM) to treat joint pain and rheumatoid arthritis. With the reduction of wild E. obtusifolia and E. schmidtii resources, Porana sinensis has been widely used as a substitute. However, few studies have been conducted on the chemical composition and quality control of P. sinensis. To clarify the chemical composition and improve the quality control of P. sinensis. We developed an ultra-high performance liquid chromatography electrospray ionisation Q-Exactive Focus tandem mass spectrometry (UHPLC-ESI-Q-Exactive Focus-MS/MS) method to characterise the chemical constituents of P. sinensis. A strategy based on a combination of high-performance thin-layer chromatography (HPTLC) and direct analysis in real-time (DART) ion source was proposed for the identification of alkaloid components in P. sinensis. Thin-layer chromatography (TLC) autography for 2,2'-diphenyl-1-picrylhydrazyl free radical (DPPH˙) and TLC bioautography for xanthine oxidase were used to rapidly screen marker compounds for high-performance liquid chromatography (HPLC) determination of P. sinensis. Based on the selected marker compounds, a HPLC method for the quantitative determination of eight marker compounds in P. sinensis was developed. Eighteen compounds in P. sinensis were identified by UHPLC-Q-Exactive MS. Taken together with the results of TLC autography and TLC bioautography, eight compounds were chosen as marker compounds for HPLC determination of P. sinensis. The alkaloid components in P. sinensis were identified as Baogongteng A and Baogongteng C by DART-MS. We systematically clarified the chemical composition of P. sinensis for the first time, and potentially improved its quality control. These results should promote the application of P. sinensis as a new resource for Caulis Erycibes.

Spectrophotometric and liquid chromatographic determination of Zn(II), Ni(II), Fe(II), Co(II), and Cu(II) as metal chelates from vegetable and pharmaceutical samples using 3-hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridine carboxaldehyde-4-phenyl-3-thiosemicarbazone as derivatizing reagent

A novel Schiff base chelating ligand 3-hydroxy-5-(hydroxymethyl)-2-methyl-4-Pyridine carboxaldehyde-4-phenyl-3-thiosemicarbazone (Pyridoxal-4-phenyl-3-thiosemicarbazone-PDPTSC) was synthetized and investigated for spectrophotometric and high performance liquid chromatographic (HPLC) separation and determination of Zn(II), Ni(II), Fe(II), Co(II), and Cu(II) as metal chelates on Microsorb C-18 (150 × 4.6 mm i.d, 5 µm) column. A good separation and elution of complexes was achieved isocratically with a mixture of methanol: water: acetonitrile: sodium acetate (1 mM) (65: 30: 4: 1 v/v/v/v) with a flow rate of 1 mL/min and UV detection was at 320 nm. The solvent extraction method was developed for simultaneous determination of metals with detection limits within 9.20–88.0 ng/mL. The developed method was applied for the quantitative determination of metal ions Fe(II), Zn(II) from pharmaceutical preparations, Surbex-Z, Polybion-Z, Fefol, and Fefolvit capsules with percentage recovery within (96.4–98.8%) (RSD% 1.86–4.28) and Co(II) and Cu(II) from vegetable samples carrot, potato, cucumber, and green peas with (RSD% 2.44–3.16) respectively.

Adipose Tissue-Derived Biomarkers of Intestinal Barrier Functions for the Characterization of Diarrhoea-Predominant IBS.

Background Alterations of the small-intestinal permeability (s-IP) might play an essential role in a subgroup of diarrhoea-predominant IBS (D-IBS) patients. Goals (a) To analyse in D-IBS patients the symptom profile in relation to the altered (+) or not (−) s-IP using the Gastrointestinal Symptom Rating Scale (GSRS). (b) To assess the circulating levels of the adipokines IL-6, IL-8, TNF-α, leptin, and adiponectin, along with LPS, TLR-4, neurotensin, and brain-derived neurotrophic factor (BDNF). The frequency distribution of SNPs at the loci for the investigated molecules and leptin receptor was evaluated. Study The study included 34 D-IBS patients and 17 healthy controls (HC). s-IP permeability was assayed by high-performance liquid chromatography determination in the urine of the lactulose to mannitol ratio. Concentrations of IL-6, IL-8, TNF-α, LPS, TLR-4, leptin, adiponectin, neurotensin, and BDNF were assayed by ELISA. Screening of genetic variants was done employing the restriction fragment length polymorphism-polymerase chain reaction method. Results D-IBS(−) patients had a significantly higher GSRS cluster pain and diarrhoea profile than D-IBS(+) ones. Significant correlations were found between the symptoms clusters and immune activation and inflammation markers. The levels of adipo(cyto)kines in D-IBS(+) patients were higher than those of controls, and IL-6 levels correlated with those of LPS. Leptin and BDNF were significantly higher, and neurotensin levels were significantly lower in D-IBS(+) than in controls. No differences were found in the frequency distribution of genotypes among the study groups. Conclusions Results from this study could be of some help in the characterization of the D-IBS and highlight the contribution of an altered intestinal barrier in the pathogenesis of this syndrome. Besides, a role could be ascribed to molecules secreted by the visceral adipose tissue that can impact on barrier functions.