With the rise of live streaming on social media, platforms like Facebook, Instagram, and YouTube have become powerful business tools. They enable users to share live videos, fostering direct connections between busine...With the rise of live streaming on social media, platforms like Facebook, Instagram, and YouTube have become powerful business tools. They enable users to share live videos, fostering direct connections between businesses and their customers. This critical literature review paper explores the impact of live streaming on businesses, focusing on its role in attracting and satisfying consumers by promoting products tailored to their needs and wants. It emphasizes live streaming’s crucial role in engaging customers, a key to business growth. The study also provides viable strategies for businesses to leverage live streaming for growth and customer engagement, underscoring its importance in the business landscape.展开更多
Cannabis is increasingly used for both medicinal and recreational purposes with an estimate of over 180 million users annually.Canada has recently legalized cannabis use in October 2018,joining several states,in the U...Cannabis is increasingly used for both medicinal and recreational purposes with an estimate of over 180 million users annually.Canada has recently legalized cannabis use in October 2018,joining several states,in the United States of America (e.g.,Colorado,California,and Oregon) and a few other countries.A variety of cannabis products including dry flowers,edibles,and oil products are widely consumed.With high demand for cannabis products worldwide,the quality of cannabis and its related products has become a major concern for consumer safety.Various guidelines have been set by different countries to ensure the quality,safety,and efficacy of cannabis products.In general,these guidelines require control of contaminants including pesticides,toxic elements,mycotoxins,and pathogens,as well as residual solvents in regard to cannabis oil.Accordingly,appropriate analytical methods are required to determine these contaminants in cannabis products for quality control.In this review,we focus on the current analytical challenges and method development for detection of pesticides and toxic elements in cannabis to meet various guidelines.展开更多
Research into long-chain polyunsaturated fatty acids (LC-PUFA), such as docosahexaenoic acid (DHA C22:6 n-3), has shown that their inclusion in the human diet is linked with many health benefits. This has led to an in...Research into long-chain polyunsaturated fatty acids (LC-PUFA), such as docosahexaenoic acid (DHA C22:6 n-3), has shown that their inclusion in the human diet is linked with many health benefits. This has led to an increased interest in the enrichment of certain foodstuffs with DHA by supplementing animal fed with DHA-rich ingredients which can lead to an increased uptake in the meat, milk and eggs animal by-products. The microalgae Aurantiochytrium limacinum has been found to be especially useful in this pursuit. It is subsequently desirable to availably have a simple and robust method for the routine analysis of DHA and other fatty acids in the algal biomass. The AOAC method 996.06 is often followed for the analysis of fatty acids in foods and demonstrating that its fitness for purpose in the analysis of DHA and additional fatty acids in Aurantiochytrium limacinum is therefore the objective of this paper. A validation of the method for the determination of DHA and three other fatty acids in Aurantiochytrium limacinum is presented. The method was found to be linear over the following ranges for each fatty acid methyl ester (FAME) analyte;50 to 15,000 μg/ml (C14:0), 300 to 95,000 (C16:0), 25 to 15,000 (C18:0) and 300 to 59,375 (C22:6). The accuracy, precision and LOD and LOQ of the method were confirmed and its robustness tested. The application of the method to assess the stability of Aurantiochytrium limacinum containing two alternative antioxidants was further examined. The investigation showed that DHA was stable over six months with the inclusion of either Duralox? or ethoxyquin as an antioxidant and ethoxyquin could additionally stabilize DHA in Aurantiochytrium limacinum up to 24 months.展开更多
In recent times, the overall interest over Supercritical Fluid Chromatography (SFC) is truly growing within various domains but especially for pharmaceutical analysis. However, in the best of our knowledge modern SFC ...In recent times, the overall interest over Supercritical Fluid Chromatography (SFC) is truly growing within various domains but especially for pharmaceutical analysis. However, in the best of our knowledge modern SFC is not yet applied for drug quality control in the daily routine framework. Among the numerous reported SFC methods, none of them could be found to fully satisfy to all steps of the analytical method lifecycle. Thereby, the present contribution aims to provide an overview of the current and past achievements related to SFC techniques, with a targeted attention to this lifecycle and its successive steps. The included discussions were therefore structured accordingly and emphasizing the analytical method lifecycle in accord with the International Conference on Harmonisation (ICH). Recent and important scientific outputs in the field of analytical SFC, as well as instrumental evolution, qualification strategies, method development methodologies and discussions on the topic of method validation are reviewed.展开更多
A simple, sensitive and precise green high-performance liquid chromatographic method including on-line pre-column oxidation combined by column switching with a short Hypersil ODS analytical column (100 mm × 4.0 m...A simple, sensitive and precise green high-performance liquid chromatographic method including on-line pre-column oxidation combined by column switching with a short Hypersil ODS analytical column (100 mm × 4.0 mm i.d.) for enrichment and separation was developed and validated to determine low levels of methotrexate (MTX). The method was based on oxidative cleavage of MTX into highly fluorescence products, 2,4-diaminopteridine-6-carboxaldehyde and the corresponding 2,4-diaminopteridine-6-carboxylic acid, during the flow of phosphate buffer (0.04 M, pH 3.4) containing the analyte through the packed reactor of cerium (IV) trihydroxyhydroperoxide (CTH) at a flow-rate of 0.2 mL/min and 40℃. The fluorescent products were enriched on the head of ODS analytical column for the final separation. The separation was performed at room temperature using an environmentally friendly mobile phase consisting of ethanol and phosphate buffer (0.04 M, pH 3.4) in the ratio of 10:90 (v/v). The eluent was monitored at emission and excitation wavelengths of 463 and 367 nm, respectively. The method was successfully applied, without any interference from the excipients, for the determination of drug in tablets and vials with a detection limit of 0.06 ng/mL from 500 ?L of sample MTX.展开更多
Nowadays, the circulation of poor quality medicines is becoming an alarming worldwide phenomenon with serious public health and socio-economic concerns. The situation is particularly critical in developing countries w...Nowadays, the circulation of poor quality medicines is becoming an alarming worldwide phenomenon with serious public health and socio-economic concerns. The situation is particularly critical in developing countries where drug quality assurance and regulatory systems for drug manufacturing, importation, distribution and sales are weak. A sustained vigilance on poor quality medicines that regroup counterfeit/falsified, substandard and degraded medicines is therefore required to ensure patient safety and genuine medicines integrity. A case situation is illustrated including a strategic approach and analytical tools that were found useful to detect poor quality medicines, identify unknown components, and timely alerts for appropriate measures against the spread of those harmful products. Several suspected medicines randomly sampled in several strategic Rwandan areas were firstly check-controlled by means of visual inspection and then applying several analytical techniques from simple to more complex ones. The following medicines were studied: quinine sulfate tablets, artemisinin-based combination tablets, and artesunate powders for injection. Taking into account the pharmaceutical forms and the chemical characteristics, the following tests were applied: uniformity of mass, friability, disintegration, fluorescence, identification and assay. They were followed by more complex analytical techniques that allowed more comprehension of abnormal findings among which the presence of a wrong active pharmaceutical ingredient in quinine sulfate tablets which is mainly discussed in this paper to illustrate a strategic approach and various analytical tools that can be used in detecting and identifying unknown component in poor quality medicines.展开更多
In this study,we developed a novel on-line solid phase extraction(SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illic...In this study,we developed a novel on-line solid phase extraction(SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illicit drugs and metabolites(methamphetamine,amphetamine,morphine,codeine,6-monoacetylmorphine,benzoylecgonine,3,4-methylenedioxymethamphetamine,3,4-methylenedioxyamphetamine,cocaine,ketamine,norketamine,and methcathinone)and cotinine(COT)in wastewater samples.The analysis was performed by loading 2 m L of the sample onto an Oasis hydrophilic-lipophilic balance cartridge and using a cleanup step(5%methanol)to eliminate interference with a total run time of 13 min.The isotope-labeled internal standard method was used to quantify the target substances and correct for unavoidable losses and matrix effects during the on-line SPE process.Typical analytical characteristics used for method validation were sensitivity,linearity,precision,repeatability,recovery,and matrix effects.The limit of detection(LOD)and limit of quantification(LOQ)of each target were set at 0.20 ng/L and 0.50 ng/L,respectively.The linearity was between 0.5 ng/L and250 ng/L,except for that of COT.The intra-and inter-day precisions were<10.45%and 25.64%,respectively,and the relative recovery ranged from 83.74%to 162.26%.The method was used to analyze various wastewater samples from 33 cities in China,and the results were compared with the experimental results of identical samples analyzed using off-line SPE.The difference rate was between 19.91%and-20.44%,and the error range could be considered acceptable.These findings showed that on-line SPE is a suitable alternative to off-line SPE for the analysis of illicit drugs in samples.展开更多
In addition to the canonical nucleobases, a variety of chemical modifications have been identified presence in nucleic acids. These modifications have been demonstrated to involve in regulating the spatiotemporal expr...In addition to the canonical nucleobases, a variety of chemical modifications have been identified presence in nucleic acids. These modifications have been demonstrated to involve in regulating the spatiotemporal expression of genes. Up to date, over 150 types of chemical modifications have been found existence in nucleic acids. Understanding the functional roles of modifications relies on deciphering the location information of modifications in nucleic acids. Analytical methods for studying nucleic acid modifications have greatly advanced in the last decade. To locate the modifications in nucleic acids, various mass spectrometry (MS)-based analytical strategies have been established. Recent progress in next-generation sequencing (NGS) in conjugation with immunoprecipitation, chemical reaction, enzyme-mediated mutation, or nanomaterials offer genome-wide or transcriptome-wide mapping of modifications, which greatly revolutionize the field of epigenetic modifications. Herein, we reviewed and summarized the established methods and the breakthrough of the techniques for locating modifications in nucleic acids. In addition, we discussed the principles, applications, advantages and drawbacks of these methods. We believe that with the rapid advancement of techniques and methods,the functions of nucleic acid modifications will be fully understood in the future.展开更多
Hollow-fiber liquid-phase microextraction(HF-LPME)and electromembrane extraction(EME)are miniaturized extraction techniques,and have been coupled with various analytical instruments for trace analysis of heavy metals,...Hollow-fiber liquid-phase microextraction(HF-LPME)and electromembrane extraction(EME)are miniaturized extraction techniques,and have been coupled with various analytical instruments for trace analysis of heavy metals,drugs and other organic compounds,in recent years.HF-LPME and EME provide high selectivity,efficient sample cleanup and enrichment,and reduce the consumption of organic sol-vents to a few micro-liters per sample.HF-LPME and EME are compatible with different analytical in-struments for chromatography,electrophoresis,atomic spectroscopy,mass spectrometry,and electrochemical detection.HF-LPME and EME have gained significant popularity during the recent years.This review focuses on hollow fiber based techniques(especially HF-LPME and EME)of heavy metals and pharmaceuticals(published 2017 to May 2019),and their combinations with atomic spectroscopy,UV-VIS spectrophotometry,high performance liquid chromatography,gas chromatography,capillary elec-trophoresis,and voltammetry.展开更多
COVID-19,a disease caused by the novel coronavirus SARS-Co V-2,has produced a serious emergency for global public health,placing enormous stress on national health systems in many countries.Several studies suggest tha...COVID-19,a disease caused by the novel coronavirus SARS-Co V-2,has produced a serious emergency for global public health,placing enormous stress on national health systems in many countries.Several studies suggest that cytokine storms(interleukins)may play an important role in severe cases of COVID-19.Neutralizing key inflammatory factors in cytokine release syndrome(CRS)could therefore be of great value in reducing the mortality rate.Tocilizumab(TCZ)in its intravenous(IV)form of administration-Ro Actemra?20 mg/m L(Roche)-is indicated for treatment of severe CRS patients.Preliminary investigations have concluded that inhibition of IL-6 with TCZ appears to be efficacious and safe,with several ongoing clinical trials.This has led to a huge increase in demand for IV TCZ for treating severe COVID-19 patients in hospitals,which has resulted in drug shortages.Here,we present a comparability study assessing the main critical physicochemical attributes of TCZ solutions used for infusion,at 6 mg/m L and 4 mg/m L,prepared from Ro Actemra?20 mg/m L(IV form)and from Ro Actemra?162 mg(0.9 m L solution pre-filled syringe,subcutaneous(SC)form),to evaluate the use of the latter for preparing clinical solutions required for IV administration,so that in a situation of shortage of the IV medicine,the SC form could be used to prepare the solutions for IV delivery of TCZ.It is important to remember that during the current pandemic all the medicines are used off-label,since none of them has yet been approved for the treatment of COVID-19.展开更多
An analytical expression of free induction decay has been derived for calculating the magic angle spinning sideband patterns of nuclear magnetic resonance spectra in a two-site exchange problem.The expression has been...An analytical expression of free induction decay has been derived for calculating the magic angle spinning sideband patterns of nuclear magnetic resonance spectra in a two-site exchange problem.The expression has been confirmed by comparing the calculated spinning sideband patterns for powdered crystalline dimethyl sulfone at different exchange rates with experimentally measured spectra at various temperatures.展开更多
The present study explores an electroreduced graphene oxide-bismuth nanoparticles composite（ErGOBi） as an electrochemical sensor for the determination of an anticancer drug, gemcitabine hydrochloride（GMB）. The Er-...The present study explores an electroreduced graphene oxide-bismuth nanoparticles composite（ErGOBi） as an electrochemical sensor for the determination of an anticancer drug, gemcitabine hydrochloride（GMB）. The Er-GOBi interface was prepared by drop casting of bismuth nitrate-graphene oxide suspension on a glassy carbon electrode（GCE） followed by electro-reduction in the potential range of 0.6 V to 1.7 V. SEM, FTIR, EDAX and AFM techniques were employed for the characterization of prepared materials. Cyclic voltammetric and electrochemical impedance spectroscopic methods were used to understand the charge transfer properties of stepwise modification of Er-GOBi/GCE. GMB exhibited an irreversible oxidation peak at 1.144 V on Er-GOBi/GCE in phosphate buffer of p H 3. A 100-fold enhanced oxidation peak current was observed at Er-GOBi/GCE when compared to that at bare GCE.Sensing performance of Er GO-Bi/GCE was optimized by varying peak current dependent parameters.Linear relationship between the peak current and concentration of GMB was observed in the range of 0.1–51.1 mmol/L in differential pulse voltammetric method and 2.1–61.1 mmol/L in linear sweep voltammetric method. The practical utility of the proposed sensor, Er-GOBi/GCE was demonstrated by determining GMB in pharmaceutical formulations and spiked urine samples.展开更多
Two simple and sensitive spectrofluorimetric (method Ι) and spectrophotometric (method ΙΙ) methods have been developed for the determination of some chloride containing toothpastes and panthenol-containing cosmetic...Two simple and sensitive spectrofluorimetric (method Ι) and spectrophotometric (method ΙΙ) methods have been developed for the determination of some chloride containing toothpastes and panthenol-containing cosmetic preparations respectively. Method Ι is based on quantitative fluorescence quenching of (terbium-salicylate-hexamine ternary complex) by fluoride which could be measured at λem/λex of 547 nm/322 nm. The ΔF-concentration plot was rectilinear over the concentration range of 0.5 - 20 μg/ml. Method ΙΙ depends reaction of panthenol with nitrobenzoxadiazole chloride (NBD-Cl) and measuring the absorbance of the resultant product at 480 nm. The absorbance-concentration plot was rectilinear over the concentration range of 2 - 20 μg/ml.展开更多
To attain maximum recovery of useful compounds from slaughterhouse waste (Suet, Tongue, Pancreas) of selected ruminant (cow, goat, lamb, and bull), the fat extraction efficiency of popular methods was compared along w...To attain maximum recovery of useful compounds from slaughterhouse waste (Suet, Tongue, Pancreas) of selected ruminant (cow, goat, lamb, and bull), the fat extraction efficiency of popular methods was compared along with fatty acid (FAs) composition. Four selected methods including Soxhlet (SOX), acid hydrolysis, Bligh & dyer (B&D), and Folch (FOL) were assessed. After methylation, extracted lipids were analyzed by Gas chromatography for FA composition. Data indicated that all selected methods were significantly (p < 0.05) different from each other, particularly higher differences were noticed for low lipid-containing products (Tongue, Pancreas) as well as their respective FA Composition. Based on Analysis of Variance and Principal component analysis, the effective method for lipid and FA Composition analysis was the FOL method. The Soxhlet method was only effective for samples with high-fat content i.e., suet, while the B&D method gave comparatively low lipid content in analyzed samples. Hence based on the results, excellent fat and fatty acid extraction was achieved with the FOL method.展开更多
A new fluorescence silver nanosensor assisted by surfactant has been synthesized and applied to ultra trace nickel determination. Operational variables which influence nanomaterial synthesis have been studied and opti...A new fluorescence silver nanosensor assisted by surfactant has been synthesized and applied to ultra trace nickel determination. Operational variables which influence nanomaterial synthesis have been studied and optimized. Synthesis was very fast and simple using non polluting solvents; silver chemical reduction was carried out at room temperature. Spectroscopic studies were carried out in order to assure the uniformed of nanomaterial obtained. Fluorescent signal of silver nanoparticles resulted enhanced in presence of Ni（II）. At optimal experimental conditions, a detection limit of 0.036 pg＇L1 and quantification limit 0.12 pg＇L~ were obtained. The calibration sensitivity was 2 x 1014 L.pg-l.cm1 for the new methodology, with a range of linearity of six orders of magnitude between 0.12 and 2.93 × 10^5 pg L^-1. The tolerance levels for potential interferent ions were studied with good results. The proposed methodology represents a promising approach for Ni（II） traces quantification due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents.展开更多
The concentration of mercury (Hg) was accurately determined in more than 228 drugs, cosmetics and household products manufactured in a variety of countries. Some drugs were found to contain up to 4424 ppb Hg, and some...The concentration of mercury (Hg) was accurately determined in more than 228 drugs, cosmetics and household products manufactured in a variety of countries. Some drugs were found to contain up to 4424 ppb Hg, and some skin creams contained up to 2769 ppm Hg. Hg in skin creams was found to be almost 100% elemental Hg (Hg0), a volatile species of Hg. Hg0 can enter the human body through inhalation and skin absorption, potentially resulting in the serious consequence of mercury poisoning. The mercury can also volatilize, contaminating the surrounding air. Other people, for example, infants and children, who are close to or contacting the skin of the person using the cosmetics, can also absorb the mercury. Total mercury (THg) was determined by combustion/trap/CVAFS. Methyl mercury (MeHg) and inorganic mercury (Hg2+) were determined by the ethylation based method. The emission of Hg0 was determined by evaporation/trap/CVAFS. All analyses were performed in accordance with explicit quality assurance and quality control protocols and procedures.展开更多
Biogeochemially reactive inorganic mercury (RHg) is an important fraction of Hg. Researchers have attempted to measure RHg when characterizing Hg-impacted sites, conducting research and development of remediation prac...Biogeochemially reactive inorganic mercury (RHg) is an important fraction of Hg. Researchers have attempted to measure RHg when characterizing Hg-impacted sites, conducting research and development of remediation practices, or evaluating remediation efficiency. In these uses, RHg will be the best choice for analysis in ways that total methyl, and other species of Hg cannot duplicate. The fraction has been inadequately measured using the Sn2+ reduction method and operationally defined as “Sn2+ reducible Hg2+”, but the resulting data did not reflect well the nature of the fraction and caused researchers to lose interest, thus limiting the use of RHg in past years. In this work, the problems of using the Sn2+ reduction method were discovered to be generating irreproducible and negatively biased results. Negative bias from 20% to 99% was found in different types of waters. To obtain reliable results, an ethylation-based GC-CVAFS method was used to determine RHg. The performance of the method was evaluated by comparing it to the Sn2+ reduction method. Biogeochemically meaningful results have been obtained in the application of the method to determine RHg in mercury mine-impacted waters from the Idrijca River in Slovenia.展开更多
The World Health Organisation reported that over 20 % of the global disease burden and deaths are caused by environmental factors such as air and dust pollution. Legacy organic pollutants (LOPs) and emerging organic p...The World Health Organisation reported that over 20 % of the global disease burden and deaths are caused by environmental factors such as air and dust pollution. Legacy organic pollutants (LOPs) and emerging organic pollutants (EOPs) are among the biggest contributors to this burden. Herein we reviewed literature published for the period 2000–2023 on selected LOPs and EOPs in indoor dust and outdoor air in Africa to understand the occurrence, associated human health risks and common analytical techniques used to identify and quantify these contaminants. The findings revealed generally lower contamination levels for most pollutants than that in most regions outside Africa except for PCBs in outdoor air and OCPs in indoor settled dust. Apart from a few studies for polychlorinated biphenyls (PCBs), most studies reported hazard index (HI) values less than 1 for outdoor air and indoor dust exposure, which suggested negligible non-carcinogenic risks in children and adults. Gas Chromatography and mass spectrometry were the most frequently used analytical techniques for both air and dust probably due to their sensitivity and selectivity in detecting chemical traces at the pg m^(−3) and ng g^(−1) levels. Although the current contamination levels are generally low, their synergistic and cumulative effects may in the long run affect the environment and human health. There is also a paucity of data on most contaminants, especially for PCNs, and PFASs in both outdoor air and dust. Coordinated efforts are needed to limit the trade, importation, and disposal of products containing LOPs and EOPs in Africa.展开更多
Since their discovery,aptamers have steadily gained recognition as versatile molecular probes,with their significance further underscored by their inclusion in IUPAC's Top Ten Emerging Technologies in Chemistry in...Since their discovery,aptamers have steadily gained recognition as versatile molecular probes,with their significance further underscored by their inclusion in IUPAC's Top Ten Emerging Technologies in Chemistry in 2024.Generated through the in vitro selection process,these oligonucleotides combine high specificity,synthetic versatility,and structural adaptability,enabling diverse applications in diagnostics,biosensing,and targeted therapeutics.While early expectations positioned aptamers as direct competitors to antibodies,practical challenges—such as susceptibility to nucleases and limited functionality in complex biological environments—have prompted a strategic shift toward specialized applications.Recent innovations highlight their unique strengths,including electrochemical biosensing,integration with dynamic DNA networks for signal amplification,and targeting membrane proteins or intracellular molecules.Rather than directly replacing antibodies,aptamers are increasingly being utilized in areas where their structural flexibility and programmability provide distinct advantages.This review discusses recent advancements in aptamer selection and explores emerging applications that harness their unique capabilities.By analyzing the evolving landscape of aptamer-based technologies,we highlight key opportunities for further development and translation into practical bioanalytical and biomedical solutions.展开更多
文摘With the rise of live streaming on social media, platforms like Facebook, Instagram, and YouTube have become powerful business tools. They enable users to share live videos, fostering direct connections between businesses and their customers. This critical literature review paper explores the impact of live streaming on businesses, focusing on its role in attracting and satisfying consumers by promoting products tailored to their needs and wants. It emphasizes live streaming’s crucial role in engaging customers, a key to business growth. The study also provides viable strategies for businesses to leverage live streaming for growth and customer engagement, underscoring its importance in the business landscape.
基金the Natural Sciences and Engineering Research Council of Canada(NSERC)for their ongoing funding support of the Li group through various research grants
文摘Cannabis is increasingly used for both medicinal and recreational purposes with an estimate of over 180 million users annually.Canada has recently legalized cannabis use in October 2018,joining several states,in the United States of America (e.g.,Colorado,California,and Oregon) and a few other countries.A variety of cannabis products including dry flowers,edibles,and oil products are widely consumed.With high demand for cannabis products worldwide,the quality of cannabis and its related products has become a major concern for consumer safety.Various guidelines have been set by different countries to ensure the quality,safety,and efficacy of cannabis products.In general,these guidelines require control of contaminants including pesticides,toxic elements,mycotoxins,and pathogens,as well as residual solvents in regard to cannabis oil.Accordingly,appropriate analytical methods are required to determine these contaminants in cannabis products for quality control.In this review,we focus on the current analytical challenges and method development for detection of pesticides and toxic elements in cannabis to meet various guidelines.
文摘Research into long-chain polyunsaturated fatty acids (LC-PUFA), such as docosahexaenoic acid (DHA C22:6 n-3), has shown that their inclusion in the human diet is linked with many health benefits. This has led to an increased interest in the enrichment of certain foodstuffs with DHA by supplementing animal fed with DHA-rich ingredients which can lead to an increased uptake in the meat, milk and eggs animal by-products. The microalgae Aurantiochytrium limacinum has been found to be especially useful in this pursuit. It is subsequently desirable to availably have a simple and robust method for the routine analysis of DHA and other fatty acids in the algal biomass. The AOAC method 996.06 is often followed for the analysis of fatty acids in foods and demonstrating that its fitness for purpose in the analysis of DHA and additional fatty acids in Aurantiochytrium limacinum is therefore the objective of this paper. A validation of the method for the determination of DHA and three other fatty acids in Aurantiochytrium limacinum is presented. The method was found to be linear over the following ranges for each fatty acid methyl ester (FAME) analyte;50 to 15,000 μg/ml (C14:0), 300 to 95,000 (C16:0), 25 to 15,000 (C18:0) and 300 to 59,375 (C22:6). The accuracy, precision and LOD and LOQ of the method were confirmed and its robustness tested. The application of the method to assess the stability of Aurantiochytrium limacinum containing two alternative antioxidants was further examined. The investigation showed that DHA was stable over six months with the inclusion of either Duralox? or ethoxyquin as an antioxidant and ethoxyquin could additionally stabilize DHA in Aurantiochytrium limacinum up to 24 months.
文摘In recent times, the overall interest over Supercritical Fluid Chromatography (SFC) is truly growing within various domains but especially for pharmaceutical analysis. However, in the best of our knowledge modern SFC is not yet applied for drug quality control in the daily routine framework. Among the numerous reported SFC methods, none of them could be found to fully satisfy to all steps of the analytical method lifecycle. Thereby, the present contribution aims to provide an overview of the current and past achievements related to SFC techniques, with a targeted attention to this lifecycle and its successive steps. The included discussions were therefore structured accordingly and emphasizing the analytical method lifecycle in accord with the International Conference on Harmonisation (ICH). Recent and important scientific outputs in the field of analytical SFC, as well as instrumental evolution, qualification strategies, method development methodologies and discussions on the topic of method validation are reviewed.
文摘A simple, sensitive and precise green high-performance liquid chromatographic method including on-line pre-column oxidation combined by column switching with a short Hypersil ODS analytical column (100 mm × 4.0 mm i.d.) for enrichment and separation was developed and validated to determine low levels of methotrexate (MTX). The method was based on oxidative cleavage of MTX into highly fluorescence products, 2,4-diaminopteridine-6-carboxaldehyde and the corresponding 2,4-diaminopteridine-6-carboxylic acid, during the flow of phosphate buffer (0.04 M, pH 3.4) containing the analyte through the packed reactor of cerium (IV) trihydroxyhydroperoxide (CTH) at a flow-rate of 0.2 mL/min and 40℃. The fluorescent products were enriched on the head of ODS analytical column for the final separation. The separation was performed at room temperature using an environmentally friendly mobile phase consisting of ethanol and phosphate buffer (0.04 M, pH 3.4) in the ratio of 10:90 (v/v). The eluent was monitored at emission and excitation wavelengths of 463 and 367 nm, respectively. The method was successfully applied, without any interference from the excipients, for the determination of drug in tablets and vials with a detection limit of 0.06 ng/mL from 500 ?L of sample MTX.
文摘Nowadays, the circulation of poor quality medicines is becoming an alarming worldwide phenomenon with serious public health and socio-economic concerns. The situation is particularly critical in developing countries where drug quality assurance and regulatory systems for drug manufacturing, importation, distribution and sales are weak. A sustained vigilance on poor quality medicines that regroup counterfeit/falsified, substandard and degraded medicines is therefore required to ensure patient safety and genuine medicines integrity. A case situation is illustrated including a strategic approach and analytical tools that were found useful to detect poor quality medicines, identify unknown components, and timely alerts for appropriate measures against the spread of those harmful products. Several suspected medicines randomly sampled in several strategic Rwandan areas were firstly check-controlled by means of visual inspection and then applying several analytical techniques from simple to more complex ones. The following medicines were studied: quinine sulfate tablets, artemisinin-based combination tablets, and artesunate powders for injection. Taking into account the pharmaceutical forms and the chemical characteristics, the following tests were applied: uniformity of mass, friability, disintegration, fluorescence, identification and assay. They were followed by more complex analytical techniques that allowed more comprehension of abnormal findings among which the presence of a wrong active pharmaceutical ingredient in quinine sulfate tablets which is mainly discussed in this paper to illustrate a strategic approach and various analytical tools that can be used in detecting and identifying unknown component in poor quality medicines.
基金supported by the National Key Research and Development Program of China(Grant No.:2018YFC0807402)the National Natural Science Foundation of China(Grant No.:82073810)。
文摘In this study,we developed a novel on-line solid phase extraction(SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illicit drugs and metabolites(methamphetamine,amphetamine,morphine,codeine,6-monoacetylmorphine,benzoylecgonine,3,4-methylenedioxymethamphetamine,3,4-methylenedioxyamphetamine,cocaine,ketamine,norketamine,and methcathinone)and cotinine(COT)in wastewater samples.The analysis was performed by loading 2 m L of the sample onto an Oasis hydrophilic-lipophilic balance cartridge and using a cleanup step(5%methanol)to eliminate interference with a total run time of 13 min.The isotope-labeled internal standard method was used to quantify the target substances and correct for unavoidable losses and matrix effects during the on-line SPE process.Typical analytical characteristics used for method validation were sensitivity,linearity,precision,repeatability,recovery,and matrix effects.The limit of detection(LOD)and limit of quantification(LOQ)of each target were set at 0.20 ng/L and 0.50 ng/L,respectively.The linearity was between 0.5 ng/L and250 ng/L,except for that of COT.The intra-and inter-day precisions were<10.45%and 25.64%,respectively,and the relative recovery ranged from 83.74%to 162.26%.The method was used to analyze various wastewater samples from 33 cities in China,and the results were compared with the experimental results of identical samples analyzed using off-line SPE.The difference rate was between 19.91%and-20.44%,and the error range could be considered acceptable.These findings showed that on-line SPE is a suitable alternative to off-line SPE for the analysis of illicit drugs in samples.
基金the National Key R&D Program of China (No. 2017YFC0906800)the National Natural Science Foundation of China (Nos. 21672166, 21635006, 21721005, 21728802) for the financial support
文摘In addition to the canonical nucleobases, a variety of chemical modifications have been identified presence in nucleic acids. These modifications have been demonstrated to involve in regulating the spatiotemporal expression of genes. Up to date, over 150 types of chemical modifications have been found existence in nucleic acids. Understanding the functional roles of modifications relies on deciphering the location information of modifications in nucleic acids. Analytical methods for studying nucleic acid modifications have greatly advanced in the last decade. To locate the modifications in nucleic acids, various mass spectrometry (MS)-based analytical strategies have been established. Recent progress in next-generation sequencing (NGS) in conjugation with immunoprecipitation, chemical reaction, enzyme-mediated mutation, or nanomaterials offer genome-wide or transcriptome-wide mapping of modifications, which greatly revolutionize the field of epigenetic modifications. Herein, we reviewed and summarized the established methods and the breakthrough of the techniques for locating modifications in nucleic acids. In addition, we discussed the principles, applications, advantages and drawbacks of these methods. We believe that with the rapid advancement of techniques and methods,the functions of nucleic acid modifications will be fully understood in the future.
基金supported by the Higher education commission of Pakistan(NRPU No.20-3925/R&D/NRPU/HEC/2014)PAK-US science and technology cooperation(Pak-US No6-4/PAK-US/HEC/2015/04)Pakistan science foundation joint research projects with MSRT,Iran(No.PSF-MSRT/Env/KP-AWKUM)。
文摘Hollow-fiber liquid-phase microextraction(HF-LPME)and electromembrane extraction(EME)are miniaturized extraction techniques,and have been coupled with various analytical instruments for trace analysis of heavy metals,drugs and other organic compounds,in recent years.HF-LPME and EME provide high selectivity,efficient sample cleanup and enrichment,and reduce the consumption of organic sol-vents to a few micro-liters per sample.HF-LPME and EME are compatible with different analytical in-struments for chromatography,electrophoresis,atomic spectroscopy,mass spectrometry,and electrochemical detection.HF-LPME and EME have gained significant popularity during the recent years.This review focuses on hollow fiber based techniques(especially HF-LPME and EME)of heavy metals and pharmaceuticals(published 2017 to May 2019),and their combinations with atomic spectroscopy,UV-VIS spectrophotometry,high performance liquid chromatography,gas chromatography,capillary elec-trophoresis,and voltammetry.
基金Project FIS PI-17/00547(Instituto CarlosⅢ,Ministerio de Economía y Competitividad,Spain),which means that it was also partially supported by European Regional Development Funds(ERDF)the University of Granada(Spain)for the support。
文摘COVID-19,a disease caused by the novel coronavirus SARS-Co V-2,has produced a serious emergency for global public health,placing enormous stress on national health systems in many countries.Several studies suggest that cytokine storms(interleukins)may play an important role in severe cases of COVID-19.Neutralizing key inflammatory factors in cytokine release syndrome(CRS)could therefore be of great value in reducing the mortality rate.Tocilizumab(TCZ)in its intravenous(IV)form of administration-Ro Actemra?20 mg/m L(Roche)-is indicated for treatment of severe CRS patients.Preliminary investigations have concluded that inhibition of IL-6 with TCZ appears to be efficacious and safe,with several ongoing clinical trials.This has led to a huge increase in demand for IV TCZ for treating severe COVID-19 patients in hospitals,which has resulted in drug shortages.Here,we present a comparability study assessing the main critical physicochemical attributes of TCZ solutions used for infusion,at 6 mg/m L and 4 mg/m L,prepared from Ro Actemra?20 mg/m L(IV form)and from Ro Actemra?162 mg(0.9 m L solution pre-filled syringe,subcutaneous(SC)form),to evaluate the use of the latter for preparing clinical solutions required for IV administration,so that in a situation of shortage of the IV medicine,the SC form could be used to prepare the solutions for IV delivery of TCZ.It is important to remember that during the current pandemic all the medicines are used off-label,since none of them has yet been approved for the treatment of COVID-19.
基金Supported in part by the National Natural Science Foundation of China under Grant No.29674006。
文摘An analytical expression of free induction decay has been derived for calculating the magic angle spinning sideband patterns of nuclear magnetic resonance spectra in a two-site exchange problem.The expression has been confirmed by comparing the calculated spinning sideband patterns for powdered crystalline dimethyl sulfone at different exchange rates with experimentally measured spectra at various temperatures.
基金the University Grant Commission, New Delhi, for providing financial support to carry out this study
文摘The present study explores an electroreduced graphene oxide-bismuth nanoparticles composite（ErGOBi） as an electrochemical sensor for the determination of an anticancer drug, gemcitabine hydrochloride（GMB）. The Er-GOBi interface was prepared by drop casting of bismuth nitrate-graphene oxide suspension on a glassy carbon electrode（GCE） followed by electro-reduction in the potential range of 0.6 V to 1.7 V. SEM, FTIR, EDAX and AFM techniques were employed for the characterization of prepared materials. Cyclic voltammetric and electrochemical impedance spectroscopic methods were used to understand the charge transfer properties of stepwise modification of Er-GOBi/GCE. GMB exhibited an irreversible oxidation peak at 1.144 V on Er-GOBi/GCE in phosphate buffer of p H 3. A 100-fold enhanced oxidation peak current was observed at Er-GOBi/GCE when compared to that at bare GCE.Sensing performance of Er GO-Bi/GCE was optimized by varying peak current dependent parameters.Linear relationship between the peak current and concentration of GMB was observed in the range of 0.1–51.1 mmol/L in differential pulse voltammetric method and 2.1–61.1 mmol/L in linear sweep voltammetric method. The practical utility of the proposed sensor, Er-GOBi/GCE was demonstrated by determining GMB in pharmaceutical formulations and spiked urine samples.
文摘Two simple and sensitive spectrofluorimetric (method Ι) and spectrophotometric (method ΙΙ) methods have been developed for the determination of some chloride containing toothpastes and panthenol-containing cosmetic preparations respectively. Method Ι is based on quantitative fluorescence quenching of (terbium-salicylate-hexamine ternary complex) by fluoride which could be measured at λem/λex of 547 nm/322 nm. The ΔF-concentration plot was rectilinear over the concentration range of 0.5 - 20 μg/ml. Method ΙΙ depends reaction of panthenol with nitrobenzoxadiazole chloride (NBD-Cl) and measuring the absorbance of the resultant product at 480 nm. The absorbance-concentration plot was rectilinear over the concentration range of 2 - 20 μg/ml.
文摘To attain maximum recovery of useful compounds from slaughterhouse waste (Suet, Tongue, Pancreas) of selected ruminant (cow, goat, lamb, and bull), the fat extraction efficiency of popular methods was compared along with fatty acid (FAs) composition. Four selected methods including Soxhlet (SOX), acid hydrolysis, Bligh & dyer (B&D), and Folch (FOL) were assessed. After methylation, extracted lipids were analyzed by Gas chromatography for FA composition. Data indicated that all selected methods were significantly (p < 0.05) different from each other, particularly higher differences were noticed for low lipid-containing products (Tongue, Pancreas) as well as their respective FA Composition. Based on Analysis of Variance and Principal component analysis, the effective method for lipid and FA Composition analysis was the FOL method. The Soxhlet method was only effective for samples with high-fat content i.e., suet, while the B&D method gave comparatively low lipid content in analyzed samples. Hence based on the results, excellent fat and fatty acid extraction was achieved with the FOL method.
文摘A new fluorescence silver nanosensor assisted by surfactant has been synthesized and applied to ultra trace nickel determination. Operational variables which influence nanomaterial synthesis have been studied and optimized. Synthesis was very fast and simple using non polluting solvents; silver chemical reduction was carried out at room temperature. Spectroscopic studies were carried out in order to assure the uniformed of nanomaterial obtained. Fluorescent signal of silver nanoparticles resulted enhanced in presence of Ni（II）. At optimal experimental conditions, a detection limit of 0.036 pg＇L1 and quantification limit 0.12 pg＇L~ were obtained. The calibration sensitivity was 2 x 1014 L.pg-l.cm1 for the new methodology, with a range of linearity of six orders of magnitude between 0.12 and 2.93 × 10^5 pg L^-1. The tolerance levels for potential interferent ions were studied with good results. The proposed methodology represents a promising approach for Ni（II） traces quantification due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents.
文摘The concentration of mercury (Hg) was accurately determined in more than 228 drugs, cosmetics and household products manufactured in a variety of countries. Some drugs were found to contain up to 4424 ppb Hg, and some skin creams contained up to 2769 ppm Hg. Hg in skin creams was found to be almost 100% elemental Hg (Hg0), a volatile species of Hg. Hg0 can enter the human body through inhalation and skin absorption, potentially resulting in the serious consequence of mercury poisoning. The mercury can also volatilize, contaminating the surrounding air. Other people, for example, infants and children, who are close to or contacting the skin of the person using the cosmetics, can also absorb the mercury. Total mercury (THg) was determined by combustion/trap/CVAFS. Methyl mercury (MeHg) and inorganic mercury (Hg2+) were determined by the ethylation based method. The emission of Hg0 was determined by evaporation/trap/CVAFS. All analyses were performed in accordance with explicit quality assurance and quality control protocols and procedures.
基金The work was partially funded by the Slovenian Re-search Agency(ARRS)through programme P1-0143 and project J1-4288and also supported by Chevron Energy Technology Company under Contract CW831200.VWe thank Fajon for sampling the water samples from the river Idrijca.
文摘Biogeochemially reactive inorganic mercury (RHg) is an important fraction of Hg. Researchers have attempted to measure RHg when characterizing Hg-impacted sites, conducting research and development of remediation practices, or evaluating remediation efficiency. In these uses, RHg will be the best choice for analysis in ways that total methyl, and other species of Hg cannot duplicate. The fraction has been inadequately measured using the Sn2+ reduction method and operationally defined as “Sn2+ reducible Hg2+”, but the resulting data did not reflect well the nature of the fraction and caused researchers to lose interest, thus limiting the use of RHg in past years. In this work, the problems of using the Sn2+ reduction method were discovered to be generating irreproducible and negatively biased results. Negative bias from 20% to 99% was found in different types of waters. To obtain reliable results, an ethylation-based GC-CVAFS method was used to determine RHg. The performance of the method was evaluated by comparing it to the Sn2+ reduction method. Biogeochemically meaningful results have been obtained in the application of the method to determine RHg in mercury mine-impacted waters from the Idrijca River in Slovenia.
文摘The World Health Organisation reported that over 20 % of the global disease burden and deaths are caused by environmental factors such as air and dust pollution. Legacy organic pollutants (LOPs) and emerging organic pollutants (EOPs) are among the biggest contributors to this burden. Herein we reviewed literature published for the period 2000–2023 on selected LOPs and EOPs in indoor dust and outdoor air in Africa to understand the occurrence, associated human health risks and common analytical techniques used to identify and quantify these contaminants. The findings revealed generally lower contamination levels for most pollutants than that in most regions outside Africa except for PCBs in outdoor air and OCPs in indoor settled dust. Apart from a few studies for polychlorinated biphenyls (PCBs), most studies reported hazard index (HI) values less than 1 for outdoor air and indoor dust exposure, which suggested negligible non-carcinogenic risks in children and adults. Gas Chromatography and mass spectrometry were the most frequently used analytical techniques for both air and dust probably due to their sensitivity and selectivity in detecting chemical traces at the pg m^(−3) and ng g^(−1) levels. Although the current contamination levels are generally low, their synergistic and cumulative effects may in the long run affect the environment and human health. There is also a paucity of data on most contaminants, especially for PCNs, and PFASs in both outdoor air and dust. Coordinated efforts are needed to limit the trade, importation, and disposal of products containing LOPs and EOPs in Africa.
基金supported by the National Key Research&Development Program of China(2022YFA1304500 to Liqin Zhang and Fan Xia,2020YFA0210800 to Huanghao Yang)the National Natural Science Foundation of China(22227805,22374004 to Liqin Zhang,T2188102,92353000 to Weihong Tan,22027805,22334004,22421002 to Huanghao Yang,22234003 to Xiaolei Zuo,and 22293031 to Chaoyong Yang)。
文摘Since their discovery,aptamers have steadily gained recognition as versatile molecular probes,with their significance further underscored by their inclusion in IUPAC's Top Ten Emerging Technologies in Chemistry in 2024.Generated through the in vitro selection process,these oligonucleotides combine high specificity,synthetic versatility,and structural adaptability,enabling diverse applications in diagnostics,biosensing,and targeted therapeutics.While early expectations positioned aptamers as direct competitors to antibodies,practical challenges—such as susceptibility to nucleases and limited functionality in complex biological environments—have prompted a strategic shift toward specialized applications.Recent innovations highlight their unique strengths,including electrochemical biosensing,integration with dynamic DNA networks for signal amplification,and targeting membrane proteins or intracellular molecules.Rather than directly replacing antibodies,aptamers are increasingly being utilized in areas where their structural flexibility and programmability provide distinct advantages.This review discusses recent advancements in aptamer selection and explores emerging applications that harness their unique capabilities.By analyzing the evolving landscape of aptamer-based technologies,we highlight key opportunities for further development and translation into practical bioanalytical and biomedical solutions.
