The Effect of the Stationary Phase on Resolution in the HPLC-Based Separation of Racemic Mixtures Using Vancomycin as a Chiral Selector: A Case Study with Profen Nonsteroidal Anti-Inflammatory Drugs

\ua9 2023 by the authors.Chiral resolution is a technique of choice, making it possible to obtain asymmetric and enantiomerically pure compounds from a racemic mixture. This study investigated the behavior of vancomycin when used as a chiral additive in high-performance liquid chromatography (HPLC) to separate enantiomers of nonsteroidal anti-inflammatory drugs (NSAIDs), including ketoprofen, ibuprofen, flurbiprofen, and naproxen enantiomeric impurities. We compared two achiral stationary phases (C18 and NH2) to assess the impact of mobile phase composition and stationary phase on the vancomycin retention time in the racemic resolution of drug enantiomers. Our results demonstrated the successful enantioseparation of all drugs using vancomycin in the mobile phase (phosphate buffer 0.05 M/2-propanol, 50/50) with an NH2 column. This enhanced separation on the NH2 column resulted from the chromatography system’s efficiency and vancomycin dimers’ stereoselective interaction on the NH2 surface. This study underscores the importance of stationary phase selection in the chiral resolution of NSAIDs with vancomycin as a chiral additive. It offers valuable insights for future research and development of NSAID chiral separation methods, highlighting potential vancomycin applications in this context

The fate and behaviour of gunshot residue: recreational shooter distribution

Despite continued improvements in gunshot residue (GSR) detection and analysis, there are still challenges in the interpretation of GSR evidence. The level and distribution of GSR present on an individual can be influenced by many factors, dependent upon the context of any given case. Due and diligent attention must therefore be placed upon fate and behaviour processes in relation to GSR when assessing and interpreting any case findings. The distribution of GSR upon the body of a recreational shooter was assessed. Samples were taken from 17 positions across a shooter’s body immediately after the discharge of one round of ammunition. The shooting hand prevailed as the most GSR-contaminated area, with as many as 351 characteristic GSR particles identified. The face and supporting hand also exhibited high levels of GSR contamination. This level of contamination raises questions concerning the fate and behaviour of GSR particles within the general environment, specifically with regard to transfer processes

Etude de l’action du phosphate dipotassique sur la Dolomite: formation et évaluation des phosphates doubles de Potassium et Magnésium

Ce travail consiste en l'étude de l’interaction entre le phosphate dipotassique et la dolomite des sols calcaires et en la préparation d'un phosphate double de potassium et magnésium. Nous montrons que le phosphate bipotassique peut réagir sur la dolomite et donc donner: (1) un phosphate double de potassium et calcium[K3CaH(PO4)2], (2) le phosphate bicalcique (CaHPO4), (3) le carbonate de potassium (K2CO3) et (4) un composé amorphe contenant du magnésium dont l’évolution en présence d’eau libère le phosphate trimagnésien [Mg3(PO4)2]. Nous avons essayé de préparer un phosphate double de potassium et magnésium par voie aqueuse. Nous avons obtenu, selon le mode opératoire, des cristaux d’un hydrate ou un gel amorphe susceptible de cristalliser en donnant ce même sel. Les analyses chimique et thermogravimétrique ont permis de le caractériser et d’obtenir le produit anhydre. Les phases ont été caractérisées par leur diagramme Debye-Scherrer. Il s’agit du phosphate (KMgPO4.6H2O) et sa phase anhydre (KMgPO4). La bibliographie contient plusieurs travaux sur le phosphate (KMgPO4). Cependant, cette étude présente une nouvelle méthode de préparation de ce composé.Mots clés: minerai du phosphate; phosphate double de potassium et calcium; voie humide. Through this work, the present study looks into the reactions between phosphate bipotassic and dolomite calcaired sol. So we have prepared the phosphate bipotassic and magnesium. It has noticed that the phosphate bipotassic can react with dolomite and gave v5 the hollowing findings: - Phosphate bipotassic and calcium [K3CaH(PO4)2], -Phosphate double calcium (CaHPO4), -Potassium carbonite (K2CO3) and q soft compound contain the magnesium, this one will develop with water into phosphate third magnesium [Mg3(PO4)2]. We have prepared the phosphate double potassium and magnesium by "watered method". So that we have obtained crystal hydrate, or soft gel which can be crystallized and give the same salt. The heat equilibrium chemical study was able to give no watered result which can be easily noticed. The phases evolution was distinguished by Debye-Scherrer diagramms. This result is illustrated in phosphate (KMgPO4.6H2O) and its anhydrous compound (KMgPO4). In spite of the fact that this anhydrous compound is found in several works, we don't find the watered compound in bibliography. So, it has prepared with a new method.Keywords: phosphate minerals; phosphate bipotassium and calcium; watered method.

Study of gunshot residue by NAA and ESEM/EDX using several kinds of weapon and ammunition

This work is realized in view to determine appropriate techniques for the revelation of mineral gun shoot residues. Picked up from the crime scene, these indicial traces are used as material proofs for helping and guiding judicial investigations. As achievement of this process, two (02) technics were employed for mineral gun shoot residues, namely; Neutron Activation Analysis, and scanning electron microscopy/EDX. Samples of metallic powder residue were realized after several shoots by different kind of weapons with local and foreign ammunitions. So, this study was undertaken to develop chemical ballistic specialty in order to improve forensic investigations and drive benefit to Technical and Scientific Police of Algeria to be use for judicial investigation. It turns out that the SEM/EDX method is more adequate to this type of investigation, despite the high sensitivity of the NAA. This is stated; NAA remains a complementary methods