Reversed Phase Hplc
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2022 ◽  
Vol 20 (2) ◽  
pp. 383-387
Author(s):  
Yahia Z. Tabaza ◽  
Kamal M. Mansi ◽  
Hanan A. Azzam ◽  
Farah F. Al-Mamoori ◽  
Ali M. Al-Samydai ◽  
...  

Purpose: To develop a reversed phase high performance liquid chromatography (HPLC) method for the determination of dehydroepiandrosterone (DHEA) in dietary supplements. Methods: A reversed-phase high performance liquid chromatography (HPLC) method was developed for the determination of DHEA in dietary supplements. An isocratic system consisting of methanol and water (70:30 v/v) was run at a flow rate of 1 mL/min on a C18 HPLC column to achieve the separation. The method was validated with regard to linearity, intra-day and inter-day precision, and limits of both detection and quantification. Results: The method achieved a retention time of 10.8 min, a resolution of 4.12, a detection limit (LOD) of 50 ng/μL, a quantification limit (LOQ) of 166.7 ng/μL and a label claim of 108.6 % with a relative standard deviation (RSD) of 0.38 % over a range of 0.0625 – 0.50 mg/mL with a correlation coefficient of 0.9997. Conclusion: The method is simple, cost effective, time-saving and reliable for determining DHEA when compared to other reported methods in literature. Thus, it will be of benefit to manufacturers of this dietary supplement to adopt the method for quantitative laboratory analysis.


Author(s):  
Olga Chorna ◽  
Vasyl Chornyi ◽  
Oleksandr Сhubenko ◽  
Ihor Hrubnyk ◽  
Volodymyr Mishchenko

The aim of the work. Currently, a large number of cases of non-medical use of benzydamine hydrochloride have been described. The identification of benzydamine and its metabolite, benzydamine N-oxide, in the presence of some non-steroidal anti-inflammatory drugs, has been insufficiently studied. Therefore, the development of a method for its identification in biological material is an urgent task. Materials and methods. The subjects of the study were benzydamine hydrochloride and its metabolite, as well as some non-steroidal anti-inflammatory drugs, which are its analogues in terms of pharmacological action. The studies were carried out by methods of thin layer chromatography and high-performance liquid chromatography. Results. At the first stage a screening method for benzydamine identification was studied using the extraction in acidic and basic conditions. It was shown that benzydamine can be isolated in both medias with subsequent development with a solution of iodoplatinate and Dragendorff's reagent according to Munier or with Mandelin reagent respectively. The mobile phase was selected and respective hRf for the target molecule were defined. After a preliminary identification of benzydamine a reference method for the final confirmation of the drug that had led to poisoning was proposed. A robust, specific and accurate reversed phase HPLC method was chosen. It was shown that benzydamine exists in biological material mainly in a form of metabolite – benzydamine N-oxide. The selected method was able to separate and determine key analytes in biological samples after a preparative isolation by TLC method. The comparison with UV spectra of the reference standard of benzydamine hydrochloride was proposed to avoid false positive conclusion of drug identification. Conclusions. Proposed methodology can be applied for routine identification of benzydamine poisoning in toxicological laboratories


2021 ◽  
pp. 38-41
Author(s):  
Олеся Сергеевна Егорова ◽  
Лариса Ильинична Розина ◽  
Диляра Рамилевна Акбулатова ◽  
Алексей Александрович Шилкин ◽  
Дмитрий Александрович Свиридов ◽  
...  

Комплексная переработка сырья, в том числе вторичных сырьевых ресурсов - один из важнейших факторов, обеспечивающих экологическую безопасность и экономическую эффективность производства. Отходы переработки плодов могут служить основой для производства вторичных продуктов, обладающих ценными потребительскими свойствами и богатым биологическим составом. Большой интерес представляют отходы, образующиеся в результате производства винодельческой продукции из плодового сырья, обладающие ценным химическим составом. В виноделии важным является вопрос о безотходной переработке выжимок темноокрашенных плодов, которые могут служить ценным сырьем для получения натуральных антоциановых красителей. Целью работы было изучение антоцианового комплекса экстрактов, полученных путем экстрагирования сушеной и замороженной выжимки аронии черноплодной. Для предварительной оценки состава растворов применяли метод тонкослойной хроматографии (ТСХ) на силикагеле. Ввиду сходной структуры и мало различающегося Rf антоцианы и флавоноиды плохо поддаются разделению методом классической и тонкослойной хроматографии, поэтому для оценки качественного и количественного состава антоцианового комплекса полученных красителей использовали метод обращенно-фазовой ВЭЖХ с диодно-матричным и масс-спектрометрическим детектированиями. Во всех исследуемых образцах красителей были идентифицировано четыре основных антоциана: цианидин-3-галактозид, цианидин-3-арабинозид, цианидин-3-глюкозид, цианидин-3-ксилозид. Установлено, что максимальное извлечение антоцианов было достигнуто при экстрагировании сушеной выжимки. Образец, полученный в результате экстрагирования шрота, характеризовался минимальными значениями концентрации антоцианов. Вероятно, для данного вида сырья необходим подбор дополнительных технологических параметров или иного вида экстрагента. Complex processing of raw materials, including secondary raw materials, is one of the most important factors ensuring environmental safety and economic production efficiency. Waste from fruit processing can serve as the basis for the production of secondary products with valuable consumer properties and a rich biological composition. Of great interest are the wastes resulting from the production of wine products from fruit raw materials, which have a valuable chemical composition. In winemaking, an important issue is the non-waste processing of pomace of dark-colored fruits, which can serve as a valuable raw material for obtaining natural anthocyanin dyes. The aim of the work was to study the anthocyanin complex of extracts obtained by extracting dried and frozen pomace of chokeberry. To preliminary estimate the composition of the solutions, the method of thin layer chromatography (TLC) on silica gel was used. Due to the similar structure and slightly different Rf, anthocyanins and flavonoids are difficult to separate by classical and thin-layer chromatography; therefore, to assess the qualitative and quantitative composition of the anthocyanin complex of the obtained dyes, we used the method of reversed-phase HPLC with diode-matrix and mass-spectrometric detections. In all the studied dye samples, four main anthocyanins were identified: cyanidin-3-galactoside, cyanidin-3-arabinoside, cyanidin-3-glucoside, cyanidin-3-xyloside. It was found that the maximum extraction of anthocyanins was achieved when extracting dried pomace. The sample obtained as a result of the meal extraction was characterized by the minimum values of the concentration of anthocyanins. Probably, for this type of raw material, it is necessary to select additional technological parameters or another type of extractant.


Author(s):  
Adnan Al Dalaty ◽  
Benedetta Gualeni ◽  
Sion A. Coulman ◽  
James C. Birchall

AbstractMicroneedle (MN)-based technologies have been proposed as a means to facilitate minimally invasive sustained delivery of long-acting hormonal contraceptives into the skin. Intradermal administration is a new route of delivery for these contraceptives and therefore no established laboratory methods or experimental models are available to predict dermal drug release and pharmacokinetics from candidate MN formulations. This study evaluates an in vitro release (IVR) medium and a medium supplemented with ex vivo human skin homogenate (SH) as potential laboratory models to investigate the dermal release characteristics of one such hormonal contraceptive that is being tested for MN delivery, levonorgestrel (LNG), and provides details of an accompanying novel two-step liquid–liquid drug extraction procedure and sensitive reversed-phase HPLC–UV assay. The extraction efficiency of LNG was 91.7 ± 3.06% from IVR medium and 84.6 ± 1.6% from the medium supplemented with SH. The HPLC–UV methodology had a limit of quantification of 0.005 µg/mL and linearity between 0.005 and 25 µg/mL. Extraction and detection methods for LNG were exemplified in both models using the well-characterised, commercially available sustained-release implant (Jadelle®). Sustained LNG release from the implant was detected in both media over 28 days. This study reports for the first time the use of biologically relevant release models and a rapid, reliable and sensitive methodology to determine release characteristics of LNG from intradermally administered long-acting drug delivery systems. Graphical abstract


2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Darinka Brodnjak Vončina ◽  
Maša Islamčivic Razboršek ◽  
Marjana Simonič

The aim of this study was to develop a method for identification and quantification of phenolic acids in different wine samples. The simple reversed-phase HPLC-UV method for simultaneous determination of p-coumaric and ferulic acid was developed. The method was validated and working range, linearity, repeatability, accuracy, limit of quantitation LOQ and limit of detection LOD were determined. The linearity of the method was tested in concentration ranges 0.1-1 mg L-1 and 1-10 mg L-1. The correlation coefficients (r2) were greater than 0.996 and quality coefficients (QC) ≤ 5%. Detection limit for both compounds was 0.01 mg L-1. The method is precise (RSD


Separations ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 215
Author(s):  
Thomas Chaigneau ◽  
Arnaud Pallotta ◽  
Fatima Zahra Benaddi ◽  
Lucie Sancey ◽  
Said Chakir ◽  
...  

There is intensive research using gold nanoparticles for biomedical purposes, which have many advantages such as ease of synthesis and high reactivity. Their possible small size (<10 nm) can lead to the crossing of biological membranes and then to problematic dissemination and storage in organs that must be controlled and evaluated. In this work, a simple isocratic HPLC method was developed and validated to quantify the gold coming from nanoparticles in different biological samples. After a first carbonization step at 900 °C, the nanoparticles were oxidized by dibroma under acidic conditions, leading to tetrachloroaurate ions that could form ion pairs when adding rhodamine B. Finally, ion pairs were extracted and rhodamine B was evaluated to quantify the corresponding gold concentration by reversed-phase HPLC with visible detection. The method was validated for different organs (liver, spleen, lungs, kidneys, or brain) and fluids (plasma and urine) from rats and mice. Lastly, the developed method was used to evaluate the content of gold in organs and fluids after intravenous (IV) injection of nanoparticles.


2021 ◽  
Vol 12 ◽  
Author(s):  
Sofia Speranza ◽  
Rebecca Knechtl ◽  
Ragnar Witlaczil ◽  
Regine Schönlechner

Sorghum is raising great interest as a grain for the future, for its agricultural advantages in times of climate change, and for the positive impact of its bioactive compounds on human health. These compounds comprise phenolic acids, in a free, conjugated, and bound form, and flavonoids. The most commonly used extraction methods require high volumes of chemicals and are non-practical when handling many samples at a time. The main aim of this study was to develop a microscale extraction procedure for both phenolic acids and flavonoids to improve yield and diversity, labor time, and chemicals usage. The improved protocols allowed to perform the extraction in 2-ml safe-lock tubes using around 60 times less chemical volume for phenolic acids and 6 times less for flavonoids. In addition, compared to the macroscale method, the microscale approach was effective in extracting a comparable amount of phenolic acids (between 0.99 and 1.57 mg ferulic acid/g) and even a higher quantity of flavonoids (between 1.10 and 2.24 mg ferulic acid/g). With the established methods, phenolic compounds were extracted from eight varieties of sorghum grown in Austria, previously shown to be promising for food processing. In all sorghum varieties, protocatechuic, vanillic, caffeic, syringic, P-coumaric, and ferulic acids were detected in free, conjugated and bound form, with the last being the most abundant. Arsky and Icebergg varieties presented the lowest (922.65 μg/g) and the highest (1,269.28 μg/g) levels of total phenolic acids, respectively, recorded using high-performance liquid chromatography (HPLC). Flavonoids, comprising luteolinidin, apigenidin, naringenin, apigenin, 5-methoxy-luteolinidin (5-MetO-Lut), and 7-methoxy-apigeninidin (7-MetO-Api), were detected in amounts between 27.03 (Kalatur variety) and 87.52 μg/g (Huggo variety). The red varieties, Huggo, Armorik, and Arsky, had the highest antioxidant activity measured as 2,2-Diphenyl-1-picrylhydrazyl (DPPH) [around 5.00 μg Trolox equivalent (TE)/g] and Azino-bis(3-ehtylbenzthiazoline-6-sulfonic acid) (ABTS) (around 3.00 μg TE/g) scavenging capacity for both phenolic acids and flavonoids. Ferric reducing antioxidant power (FRAP) was the highest for the phenolic acids extracted from a white Ggolden variety.


2021 ◽  
Author(s):  
Alexzander Samuelsson ◽  
Eric Janusson ◽  
Sajni Shah ◽  
Markus Roggen

The alkaloid psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) and the neurologically active psilocin (4-hydroxy-N,N-dimethyltryptamine) are the foremost compounds of pharmaceutical interest in Psilocybe mushrooms. As these compounds are infrequently analyzed in analytical labs, validated methods for rapid purity analysis are lacking. Newfound therapeutic use has invigorated academic and commercial interests in the molecules and new methods of production and available products are expanding. As a result, high-throughput methods of analysis for psilocybin must be improved to promptly determine chemical differences between mushroom genera or other sources of psilocybin and psilocin, as well as refined product purity. To address this, we developed an inexpensive HPLC technique for the efficient quantification of psilocybin and psilocin by using readily available equipment and dilute reagents. Aqueous ammonium formate (0.143 mM) was found to be preferable over techniques with much higher buffer concentrations or stronger acids for controlling psilocybin Zwitterion resolution. The chromatographic run time satisfied high-throughput analytical requirements with an efficient total runtime under 2 minutes. A standard octadecyl silica (C18) column provided excellent resolution between psilocybin and psilocin signals. The quality of the method was validated using certified analytical reference standards and was found to be accurate (3.5% bias, Psilocybin), reliable (0.32% RSD), and efficient (Psilocybin k’ = 1.78).


2021 ◽  
Vol 12 (4) ◽  
pp. 5647-5662

Today, emerging infectious diseases caused by multidrug-resistant bacteria (MDRB) are a major public health problem. These bacteria are gradually becoming more resistant to conventional antimicrobial agents. Thus, there is an urgent requirement to explore new antimicrobial compounds. This study focuses on a screening program of marine actinobacteria for useful bioactive compounds against MDRB, and four endophytic actinobacteria strain isolated from the unexploited marine brown alga Carpodesmia tamariscifolia, harvested from the Atlantic coast of Morocco, were screened for their antimicrobial activities using the agar diffusion assay. Fermentation broths of the two selected promising isolates KC179 and KC180 were extracted with different organic solvents and showed antibacterial activity against methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa. From the butanolic extract of KC180's culture broth and in addition to the known metabolite desferrioxamine B, a new desferrioxamine derivative, desferrioxamine B2, was purified using flash chromatography and reversed-phase HPLC, and its structure was elucidated using HRMS and NMR spectroscopy. The 16S rRNA molecular taxonomic characterization of the producing strain KC180 showed Streptomyces albidoflavus as the nearest relative, with a sequence similarity of 99.71 %.


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