Journal of separation science最新文献

In this work, we investigated the possibility of using response surface methodology to optimize the conditions for the synthesis of molecularly imprinted polyaniline specific to quercetin and horseradish peroxidase simultaneously. The work also discusses the role of horseradish peroxidase during aniline polymerization. As far as we know, a methodology for the synthesis of dual-template imprinted polyaniline selective to low and high molecular weight compounds simultaneously has not been described previously. The imprinted polyaniline layer was obtained on the surface of a microtitration plate, and response surface methodology was used to predict the optimal synthesis conditions to achieve the highest possible selectivity of polyaniline to quercetin (imprinting factor 2.4). We used the predicted optimal conditions to produce a polyaniline-modified microtitration plate and successfully used it for solid-phase extraction of quercetin and horseradish peroxidase with high selectivity (imprinting factors 2.3 and 24.6, respectively) in model solutions. Sorption capacity was 0.7 and 1.2 mg g⁻¹ for quercetin and horseradish peroxidase, respectively. As we can see, the results of response surface methodology prediction were in good agreement with the experimental values of the quercetin imprinting factor.

The heat generated by the Joule effect during capillary electrophoresis (CE) runs creates radial temperature gradients in the separation medium. These temperature gradients cause zone dispersion in addition to molecular diffusion. This severely limits the field strengths that can be applied during the runs, especially when solutions with high ionic conductivity are used. This greatly increases run times, especially when high separation efficiencies are sought. In this work, the author proposes tying cooling capillaries (fused silica microtubes) along the external surface of the analytical capillary, allowing the circulation of coolants to efficiently and symmetrically control temperature in CE. The author deduced, step-by-step, the three master equations that serve as guidelines to produce a good match and tightly secure cooling capillaries along the outer surface of analytical capillaries. Additionally, an automated capillary tying machine was developed and demonstrated. Sets were produced with: four, five, and six cooling capillaries tied around one analytical capillary. The outer diameters of the capillaries used (one analytical and $�n$ cooling) and the values of the remaining voids left between the first and last cooling capillary are in good agreement with the predictions of the three master equations deduced in this work. To the author's knowledge, this is the first time that cooling capillaries were tied around analytical capillaries to produce an efficient and symmetric cooling system for CE and toroidal capillary electrophoresis.

In this work, we investigated the possibility of using response surface methodology to optimize the conditions for the synthesis of molecularly imprinted polyaniline specific to quercetin and horseradish peroxidase simultaneously. The work also discusses the role of horseradish peroxidase during aniline polymerization. As far as we know, a methodology for the synthesis of dual-template imprinted polyaniline selective to low and high molecular weight compounds simultaneously has not been described previously. The imprinted polyaniline layer was obtained on the surface of a microtitration plate, and response surface methodology was used to predict the optimal synthesis conditions to achieve the highest possible selectivity of polyaniline to quercetin (imprinting factor 2.4). We used the predicted optimal conditions to produce a polyaniline-modified microtitration plate and successfully used it for solid-phase extraction of quercetin and horseradish peroxidase with high selectivity (imprinting factors 2.3 and 24.6, respectively) in model solutions. Sorption capacity was 0.7 and 1.2 mg g⁻¹ for quercetin and horseradish peroxidase, respectively. As we can see, the results of response surface methodology prediction were in good agreement with the experimental values of the quercetin imprinting factor.

The heat generated by the Joule effect during capillary electrophoresis (CE) runs creates radial temperature gradients in the separation medium. These temperature gradients cause zone dispersion in addition to molecular diffusion. This severely limits the field strengths that can be applied during the runs, especially when solutions with high ionic conductivity are used. This greatly increases run times, especially when high separation efficiencies are sought. In this work, the author proposes tying cooling capillaries (fused silica microtubes) along the external surface of the analytical capillary, allowing the circulation of coolants to efficiently and symmetrically control temperature in CE. The author deduced, step-by-step, the three master equations that serve as guidelines to produce a good match and tightly secure cooling capillaries along the outer surface of analytical capillaries. Additionally, an automated capillary tying machine was developed and demonstrated. Sets were produced with: four, five, and six cooling capillaries tied around one analytical capillary. The outer diameters of the capillaries used (one analytical and $�n$ cooling) and the values of the remaining voids left between the first and last cooling capillary are in good agreement with the predictions of the three master equations deduced in this work. To the author's knowledge, this is the first time that cooling capillaries were tied around analytical capillaries to produce an efficient and symmetric cooling system for CE and toroidal capillary electrophoresis.

A novel light-controlled adsorption system for direct targeting of antibody Fab fragments was developed by utilizing indole-3-butyric acid functionalized magnetic microspheres. Indole-3-butyric acid, serving as a specific small molecule ligand, was successfully conjugated to amine-functionalized magnetic microspheres via a 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide activation strategy. Under illumination at a particular wavelength, the indole-3-butyric acid ligand generated reactive radicals that interacted with the nucleotide-binding sites of antibody Fab fragments, enabling effective affinity adsorption. Static adsorption experiments demonstrated that the system's adsorption behavior obeys the Langmuir model (K_F = 0.122, R² = 0.996), indicating a homogeneous adsorption process. Kinetic studies further revealed that the adsorption process follows a second-order kinetic model (k₂ = 0.0257, R² = 0.989). When compared with conventional antibody adsorption systems, this new system exhibited specific targeting of Fab fragments, enhanced selectivity, and adjustable properties. In particular, at pH 7.0, effective elution was achieved by increasing the salt concentration, with the eluted product retaining antigen-binding activity. The purification recovery rate exceeded 98%, and the system maintained effective adsorption and elution of Fab fragments across various pH conditions. Besides, even after 10 reuse cycles, the system retained more than 96% of its efficiency, thus presenting excellent regenerability and reusability. In summary, the developed light-controlled antibody Fab region adsorption system offers a highly efficient, stable, and cost-effective approach. It is also expected to become one of the most effective methods for antibody Fab purification in the future.

Study aimed to isolate and purify compounds from the stems and leaves of Panax quinquefolius. By employing a highly innovative separation technique that combined multistage countercurrent chromatography (MRCC), high-speed countercurrent chromatography (HSCCC), and an advanced online-storage inner-recycling countercurrent chromatography (OS-IRCCC) mode for the first time, 12 compounds were successfully isolated, including 10 ginsenosides and 2 flavonoids. First, the crude extract was fractionated into five parts using D101 MRCC, with HPLC analysis revealing that 40% and 60% ethanol eluate contained the highest compound diversity. Overall, 40% ethanol eluate was separated using the solvent system of EtOAc/n-BuOH/H₂O (2:1:3, v/v), whereas 60% ethanol eluate underwent traditional countercurrent chromatography coupled with OS-IRCCC separation using the solvent system of methyl tert-butyl ether (MTBE)/n-BuOH/ACN/H₂O (4:2:3:8, v/v). Ultimately, various compounds were obtained, including kaempferol 3-O-β-d-glucopyranosyl-(1 → 2)-β-d-galactopyranosyl-7-O-α-l-rhamnopyranoside (13.2 mg), ginsenoside Rc (7.4 mg), 20(R)-ginsenoside Rh₁ (7.2 mg), ginsenoside Re (12.3 mg), kaempferol 3-O-β-d-glucopyranosyl-(1 → 2)-β-d-galactopyranoside (14.1 mg), ginsenoside Rb₁ (8.2 mg), ginsenoside Rb₂ (17.5 mg), ginsenoside Rb₃ (27.3 mg), ginsenoside Rg₁ (13.3 mg), ginsenoside Rg₂ (9.7 mg), ginsenoside Rd (11.4 mg), and pseudo-ginsenoside F₁₁ (16.7 mg). This research highlights the efficacy of the novel separation technique in isolating and purifying valuable compounds from P. quinquefolius stems and leaves.

This study investigates the consistency of quality between the traditional decoction (TD) of Pheretima aspergillum and its dispensing granule decoction (DGD) by examining their chemical composition and antithrombotic efficacy. We first determined the nucleoside components, protein content, and volatile compounds in 10 batches of TD and 9 batches of DGD sourced from three manufacturers using high-performance liquid chromatography (HPLC), UV–vis spectrophotometry, and gas chromatography ion mobility spectrometry (GC-IMS). Next, we assessed antithrombotic efficacy by measuring the relative length of tail thrombosis and calculating the thrombus inhibition rates at 24 and 48 h. Our comprehensive analysis revealed that the concentrations of hypoxanthine, uridine, inosine, adenosine, and proteins in TD were significantly higher than those in DGD. Moreover, the types and concentrations of volatile compounds in TD and DGD exhibited substantial differences, with 19 volatile compounds identified as differentially present between the two decoctions. Despite these compositional differences, both decoction types demonstrated equivalent antithrombotic efficacy. Overall, the quality of DGD from manufacturers A and B aligned closely with that of TD. However, TD exhibited a higher overall quality compared to DGD, while both decoctions maintained consistent antithrombotic efficacy.

A novel light-controlled adsorption system for direct targeting of antibody Fab fragments was developed by utilizing indole-3-butyric acid functionalized magnetic microspheres. Indole-3-butyric acid, serving as a specific small molecule ligand, was successfully conjugated to amine-functionalized magnetic microspheres via a 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide activation strategy. Under illumination at a particular wavelength, the indole-3-butyric acid ligand generated reactive radicals that interacted with the nucleotide-binding sites of antibody Fab fragments, enabling effective affinity adsorption. Static adsorption experiments demonstrated that the system's adsorption behavior obeys the Langmuir model (K_F = 0.122, R² = 0.996), indicating a homogeneous adsorption process. Kinetic studies further revealed that the adsorption process follows a second-order kinetic model (k₂ = 0.0257, R² = 0.989). When compared with conventional antibody adsorption systems, this new system exhibited specific targeting of Fab fragments, enhanced selectivity, and adjustable properties. In particular, at pH 7.0, effective elution was achieved by increasing the salt concentration, with the eluted product retaining antigen-binding activity. The purification recovery rate exceeded 98%, and the system maintained effective adsorption and elution of Fab fragments across various pH conditions. Besides, even after 10 reuse cycles, the system retained more than 96% of its efficiency, thus presenting excellent regenerability and reusability. In summary, the developed light-controlled antibody Fab region adsorption system offers a highly efficient, stable, and cost-effective approach. It is also expected to become one of the most effective methods for antibody Fab purification in the future.