4,141 Results Found

During the synthesis of the bulk drug Raloxifene hydrochloride, eight impurities were observed, four of which were found to be new. All of the impurities were detected using the gradient high performance liquid chromatographic (HPLC) method, whose ar...

The transformation of organochlorine and organic impurities such as CCl4, C2H2Cl2, C2HCl3, C2Cl4, C2H2Cl4, CH4, C3H8, C4H10, and C6H6 in the content range of 10−2–10−6 wt.%, as well as BCl3 impurities at the level of 3 × 10&mi...

This article deals with the identification and characterization of process-related impurities of trans-resveratrol (3,5,4'-trihydroxystilbene), which exhibits several health benefits, including cancer prevention. During the synthesis of the bulk drug...

A thorough, systematic study into the effect that structurally related impurities have on both the process and product quality during the crystallization of an active pharmaceutical ingredient is presented. The presence of acetanilide and metacetamol...

Brass alloys are critical for numerous modern applications. However, a significant knowledge gap exists regarding the impact of impurities on their processability, particularly regarding hot cracking susceptibility. This issue is exacerbated by incre...

Iron is one of the most stubborn impurities in quartz minerals, and the iron content partly determines the various applications of quartz. Iron can exist in quartz in the forms of iron minerals, fluid inclusions, and lattice impurities. The removal o...

We employ Green’s function method for describing multiband models with magnetic impurities and apply the formalism to the problem of chromium impurities adsorbed onto a carbon nanotube. Density functional theory is used to determine the bandstr...

An improved gradient, reversed-phase liquid chromatographic (RP-LC) method was developed and subsequently validated for the determination of Loratadine and its impurities/degradation products in pharmaceutical drug substance. Separation was achieved...

The safety of a medicinal product is determined by its pharmacological and toxicological profile, which depends not only on the active substance’s toxicological properties, but also on the impurities it contains. Because impurities are a proble...

Chemical synthesis is a science and an art. Rooted in laboratory or large-scale manufacture, it results in certain side products, eventually compromising the integrity of the final products. Such “impurities” occur in small amounts and, w...

An impurity immersed in a medium constitutes a canonical scenario applicable in a wide range of fields in physics. Though our understanding has advanced significantly in the past decades, quantum impurities in a bosonic environment are still of consi...

Aiming at the problem of high impurity rate in the recycled residual film, combined with the existing installation (4JMLE-210 agricultural residual film recycling machine), the removal mechanism of light impurities on the film surface was analyzed. T...

Two unknown impurities were detected in the cefazolin sodium bulk drug substance using gradient reversed-phase high-performance liquid chromate-graphy (HPLC). These impurities were isolated by preparative HPLC and characterized by using spectroscopic...

In many materials, impurities and imperfections play a critical role on the physical and chemical properties. In the present review, some examples of such materials are discussed. A bulk nanobubble (an ultrafine bubble) is stabilized against dissolut...

The removal of impurities in molybdenum concentrate has become a new challenge for enterprises due to the cancellation of pickling. Whether impurity minerals can be converted into soluble ions during roasting is important for the impurity removal by...

This paper reviews the effects of Pb and Zn impurities and their removal in the ironmaking process. The phase changes during ironmaking were investigated, along with the removal techniques of such impurities and their environmental impact. Results sh...

A physicochemical characterization of the process-related impurities associated with the synthesis of pemetrexed disodium was performed. The possibility of pemetrexed impurities forming has been mentioned in literature, but no study on their structur...

Barnidipine hydrochloride is a long term dihydropyridine calcium channel blocker used for the treatment of hypertension. During the process development of barnidipine hydrochloride, four barnidipine impurities were detected by high-performance liquid...

Linagliptin, a xanthine derivative, is a highly potent, selective, long-acting and orally bioavailable DPP-4 inhibitor for the treatment of type 2 diabetes. During the process development of linagliptin, five new process-related impurities were detec...

One of the most intriguing questions of modern volcanology is the inception of an eruption. Despite efforts to detect premonitory signals, numerous unpredicted eruptions have occurred recently. It has been suggested that these unpredicted eruptions m...

Baijiu, China’s traditional distilled spirit, is produced through solid-state fermentation and distillation of grains, resulting in a highly complex chemical and sensory profile. However, exogenous impurities introduced via raw materials, water...

Sono-crystallisation has been used to enhance crystalline product quality particularly in terms of purity, particle size and size distribution. In this work, the effect of impurities and ultrasound on crystallisation processes (nucleation temperature...

The traditional blast furnace ironmaking process is the most widely used ironmaking process globally, yet it is associated with significant drawbacks, including high energy consumption and carbon emissions. To achieve low-carbon ironmaking, researche...

Two unknown impurities were observed during the process development for multigram-scale synthesis of eplerenone (Inspra®). The new process-related impurities were identified and fully characterized as the corresponding (7β,11α,17α)-11-hydroxy- and (7...

Impurity detection is an important link in the chain of food processing. Taking walnut kernels as an example, it is difficult to accurately detect impurities mixed in walnut kernels before the packaging process. In order to accurately identify the sm...

This work was aimed at the definition of a chromatographic method able to separate and quantify impurities present in sapropterin-containing drugs during an accelerated stability study. The chromatographic method was applied to the orphan drug Kuvan&...

Two unknown impurities were detected in verapamil hydrochloride bulk drug using isocratic reversed-phase high performance liquid chromatography (HPLC). These impurities were isolated by preparative HPLC. Spectral data for the isolated impurities were...

A profile of impurities in bortezomib anhydride, produced by a recently developed convergent technology, has been characterized. HPLC-MS analysis of the drug essence revealed three impurities: an epimer of bortezomib, resulting from partial racemizat...

Graphene has immense potential as a material for electronic devices owing to its unique electrical properties. However, large-area graphene produced by chemical vapor deposition (CVD) must be transferred from the as-grown copper substrate to an arbit...

Currently, a global attention has been paid to the development and exploitation of shallow depth heavy oil reservoirs. Such oilfields are rationally developed via a network of horizontal wells. However, the weakly cemented reservoir rock beds lead to...

FT-IR spectroscopy is the basic finger-print method for qualitative and quantitative analysis of nitrogen, boron, and hydrogen impurities in natural and synthetic diamonds. In quantitative measurements of impurity concentrations, external standard sa...

The recycled methanol solvent of the HPPO (liquid-phase epoxidation of propylene and hydrogen peroxide to propylene oxide) process usually contains many kinds of trace impurities, such as fusel alcohol, aldehyde, ketone, ester, acetal, and amine. In...

Selective catalytic reduction (SCR) is still the most widely used process for controlling NOx gas pollution. Specifically, commercial vanadium-based catalysts have problems such as narrow operating temperature range and environmental pollution. Resea...

Fluorite (CaF2), a halogen elemental mineral, always co-exists with other minerals. The Ca element in fluorite is often replaced by rare earth elements (REEs), such as cerium (Ce) and yttrium (Y). In this work, the electronic structures of fluorite c...

We describe the synthesis of two positional isomers and a desfluoro impurity of Voriconazole starting with Friedel–Crafts acylation of mono- and difluoro-benzene. These isomers are the crucial components in determining the quality of Voriconazole dur...

Impurities in paint layers executed with green and blue copper pigments, although relatively common, have been studied only little to date. Yet, their proper identification is a powerful tool for classification of paintings, and, potentially, for fut...

This study investigates the influence of specific surface area (SSA) and aluminum hydroxide particle size on sodium aluminate’s purification efficiency in the Bayer process. This research examines how variations in SSA affect the adsorption and...

Carbon dioxide capture, utilization, and storage for enhanced oil recovery (CCUS-EOR) represents an effective strategy for reducing CO2 emissions while improving oil recovery efficiency. However, harsh environmental conditions during the process can...

In this communication, we report surface state, with Rashba impurities, of a generic topological Kondo insulator (TKI) system by performing a mean-field theoretic (MFT) calculation within the framework of slave-boson protocol. The surface metallicity...

Background: The supply chains of food raw materials have recently been heavily influenced by geopolitical events. Products that came from, or transited through, areas currently in conflict are now preferentially supplied from alternative areas. These...

During the harvesting and preparation of tea, it is common for tea to become mixed with some impurities. Eliminating these impurities is essential to improve the quality of famous green tea. At present, this sorting procedure heavily depends on manua...

Online detection of impurities content in the corn deep-bed drying process is the key technology to ensure stable operation and to provide data support for self-adapting control of drying equipment. In this study, an automatic approach to corn image...

In this study, we examined the effect of CO2 injection into deep saline aquifers, considering impurities present in blue hydrogen production. A fluid model was designed for reservoir conditions with impurity concentrations of 3.5 and 20%. The results...

The polymer-derived SiC fibers are mainly used as reinforcing materials for ceramic matrix composites (CMCs) because of their excellent mechanical properties at high temperature. However, decomposition reactions such as release of SiO and CO gases an...

Phosphogypsum is an industrial byproduct that is limited in its high-value application due to the presence of dyeing impurities (such as organic matter and carbon black). The flotation method has been verified to be effective in separating these dyei...

Power transformers are critical components of power grids, and their operational status characterization and fault diagnosis are crucial for power system reliability. Oil quality assessment is a crucial method for determining transformer status, and...

Both yellow luminescence (YL) and blue luminescence (BL) bands of GaN films have been investigated for decades, but few works report the relationship between them. In this study, two sets of GaN samples grown via metalorganic chemical vapor depositio...

Adeno-associated virus (AAV)-based vectors expressing therapeutic genes continue to demonstrate great promise for the treatment of a wide variety of diseases and together with other gene transfer vectors represent an emerging new therapeutic paradigm...

In order to reflect possible issues in future sole e-waste processing, an electrolyte of complex chemical composition reflecting system of sole e-waste processing was obtained by following a specially designed pyro-electrometallurgical method. The ob...

The conversion of lignocellulosic biomass to valuable chemicals such as levulinic acid and γ-valerolactone is a promising approach for achieving a sustainable circular economy. However, the presence of impurities during the stepwise chemical processi...