50 Years of Image Analysis

Hydrogels for biomedical applications.

Sustainable solvents are a topic of growing interest in both the research community and the chemical industry due to a growing awareness of the impact of solvents on pollution, energy usage, and contributions to air quality and climate change. Solvent losses represent a major portion of organic pollution, and solvent removal represents a large proportion of process energy consumption. To counter these issues, a range of greener or more sustainable solvents have been proposed and developed over the past three decades. Much of the focus has been on the environmental credentials of the solvent itself, although how a substance is deployed is as important to sustainability as what it is made from. In this Review, we consider several aspects of the most prominent sustainable organic solvents in use today, ionic liquids, deep eutectic solvents, supercritical fluids, switchable solvents, liquid polymers, and renewable solvents. We examine not only the performance of each class of solvent within the context of the...

Green and Sustainable Solvents in Chemical Processes

https://mostwiedzy.pl/pl/publication/download/1/a-new-tool-for-the-evaluation-of-the-analytical-procedure-green-analytical-procedure-index_24146.pdf

A new tool for the evaluation of the analytical procedure: Green Analytical Procedure Index.

There is great need for stand-alone luminescence-based chemosensors that exemplify selectivity, sensitivity, and applicability and that overcome the challenges that arise from complex, real-world media. Discussed herein are recent developments toward these goals in the field of supramolecular luminescent chemosensors, including macrocycles, polymers, and nanomaterials. Specific focus is placed on the development of new macrocycle hosts since 2010, coupled with considerations of the underlying principles of supramolecular chemistry as well as analytes of interest and common luminophores. State-of-the-art developments in the fields of polymer and nanomaterial sensors are also examined, and some remaining unsolved challenges in the area of chemosensors are discussed.

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Supramolecular Luminescent Sensors

Captopril (CAP) is an orally active angiotensin-converting enzyme (ACE) inhibitor and has been widely used for management of hypertension and congestive heart failure. CAP lacks an aromatic chromophore required for facile direct UV detection and also has two chiral centers. These factors can render the determination of CAP in complex matrices challenging. This review covers more than 20 years of analytical research on this drug, focusing mainly on pharmaceutical and biological applications. The primary separation techniques discussed are gas chromatography, liquid chromatography, and capillary electrophoresis. The structures of the CAP derivatizing agents as well as a table summarizing various HPLC methods are provided. A discussion of key recent chromatographic and electrophoretic methods for other ACE inhibitors is also present.

Separation methods for captopril in pharmaceuticals and biological fluids.

In this study, a novel and simple fluorescent carbon quantum dots (CQDs) based nano-sensor for colchicine determination has been prepared. The nitrogen doped CQDs probe was prepared using uric acid as a carbon/nitrogen source via a one-step pyrolysis. The sensor is based on inner filter effect (IFE) where colchicine acts as a powerful absorber that affects the excitation of the fluorescer (CQDs). This overlap results in a quantitative attenuation of the fluorescence of CQDs with increasing colchicine concentration in the range of 2–25 μM. The developed sensor has the advantages of simplicity, less time-consuming, convenience and satisfactory selectivity for colchicine determination in pharmaceutical dosage forms.

N-Doped Carbon Dots as a Fluorescent Nanosensor for Determination of Colchicine Based on Inner Filter Effect

Sodium alendronate is the first in a pharmacological class known as bisphosphonates, used for treatment of various bone diseases. Assay of bisphosphonates by a spectroscopic technique is very challenging due to the fact that they lack chromophores and none of them are fluorescent. In this work, a simple method is presented for determination of alendronate in bulk and in pharmaceutical tablets using spectrofluorometry by exploiting the ability of alendronate to displace salicylate from the iron(III)-salicylate chelate, forming a non-fluorescent colorless iron(III)-alendronate complex. The liberated salicylate is fluorescent and is equivalent to the mount of alendronate added. The response was linear over the concentration range 20-90 μM and the proposed method was validated according to the guidelines of the International Conference on Harmonization. The correlation coefficient was found to be 0.995 and the limit of detection was 7.5 μM. The method was successfully applied for determination of alendronate in the commercially available Osteonate® tablets. The average percent recovery ± percent relative standard deviation was found to be 102.118 ± 2.033 which is congruent with the label claim of the dosage form. The results were also compared to a reported method using t-test and F-test at 95% confidence level; no significant differences were observed. The presented method is simple, fast, easy, cost-effective and suitable for routine pharmaceutical analysis.

A simple innovative spectrofluorometric method for the determination of alendronate in bulk and in pharmaceutical tablets

Ion exclusion chromatography (IELC) of short chain aliphatic carboxylic acids is normally done using a cation exchange column under standard HPLC conditions but not in the ultra-HPLC (UHPLC) mode. A novel IELC method for the separation of this class of carboxylic acids by either HPLC or UHPLC utilizing a C18 column dynamically modified with sodium dodecyl sulfate has been developed. The sample capacity is estimated to be near 10 mM for a 20 µL injection or 0.2 µmol using a 150 × 4.6 mm column. The optimum mobile phase determined for three standard mixtures of organic acids is 1.84 mM sulfuric acid at pH 2.43 and a flow rate of 0.6 mL/min. Under optimized conditions, a HPLC separation of four aliphatic carboxylic acids such as tartaric, malonic, lactic and acetic can be achieved in under 4 min and in <2 min in the UHPLC mode at 2.1 mL/min. A variety of fruit juice and soft drink samples are analyzed. Stability of the column as measured by the retention order of maleic and fumaric acid is estimated to be ∼4,000 column volumes using HPLC and 600 by UHPLC. Reproducible chromatograms are achieved over at least a 2-month period. This study shows that the utility of a C18 column can be easily extended when needed to IELC under either standard or UHPLC conditions.

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Fotouh R. Mansour

Papers

Separation methods for captopril in pharmaceuticals and biological fluids.

N-Doped Carbon Dots as a Fluorescent Nanosensor for Determination of Colchicine Based on Inner Filter Effect

A simple innovative spectrofluorometric method for the determination of alendronate in bulk and in pharmaceutical tablets

Ion-Exclusion High-Performance Liquid Chromatography of Aliphatic Organic Acids Using a Surfactant-Modified C18 Column

Liquid chromatography with alkylammonium formate ionic liquid mobile phases and fluorescence detection.