Stock Solution Research Articles

Implementation of Hydrotropic Solvents for UV Spectrophotometric Assessment of Esomeprazole-Loaded Microspheres: Greenness Evaluation

Background: The present framework is built on top of a basic UV-spectrophotometric method that was created and proven to be effective for measuring different dose forms and bulk esomeprazole. Numerous hydrotropic reagents were tried to improve the solubility of ESM to enhance the same. Materials and Methods: Esomeprazole has the highest absorbance at 299nm in 1MUrea solvent for a stock solution and subsequent dilutions. The ICH recommendations were used to determine a number of analytical parameters. Results: Precision it is the degree of repeatability (with the same conditions) or reproducibility (with the different conditions) of method; the% RSD for repeatability was 0.470, and (r2) was 0.998. The Accuracy was found to be for 50% was 101.7%, 100% was 100.1%, and 150% was 99.79% for esomeprazole. The linearity concentration of range was 2-10µg/ml. Discussion: Analytical Greenness compares different parameters and different steps of the analytical process and the AGREE report was found to be 0.64. Recovery studies corroborated and statistically validated the analysis's conclusions.

Effects of Spirulina platensis mediated TIO2NPS on biochemical analysis (Bombyx mori. L)

The treatment comprised S. platensis mediated TiO2NPs at different concentrations of 25, 50, 75, 100, 125 and 150ppm was diluted from the stock solution. The Double Hybrid silkworm (CSR6 ×CSR26) × (CSR2 × CSR 27) were fed with mulberry leaves treated with S. platensis mediated TiO2NPs.The application of mulberry leaves treated with S. platensis mediated TiO2NPs influenced silkworm economic parameters. The S. platensis mediated TiO2NPs at the concentration of 50 ppm treated mulberry leaves fed to silkworm which recorded increased Total haemolymph protein (8.62 and 8.63 mg/ml), Haemolymph carbohydrates(14.96 and 14.97 mg/ml) and Haemolymph lipids(19.99 and 20.00 mg/g)as compared to control.

High yield sterile filtration process for highly concentrated lentiviral vectors.

The development and manufacture of biopharmaceuticals are subject to strict regulations that specify the required minimum quality of the products. A key measure to meet these quality requirements is the integration of a sterile filtration step into the commercial manufacturing process. Whereas common procedures for most biologics exist, this is challenging for lentiviral vector (LVV) production for ex vivo gene therapy. LVVs nominal size is more than half the pore size (0.2µm) of filters used for sterile filtration. Hence, highly concentrated virus solutions are prone to filter clogging if aggregation of viruses occurs or impurities attach to the viruses. Several filters were screened aiming to identify those which allow filtering highly concentrated stocks of LVVs of up to 1E+9 transducing unitsmL-1 , which corresponds to 4.5E+12 particlesmL-1 . In addition, the effect of endonuclease treatment upstream of the purification process on filter performance was studied. In summary, three suitable filters were identified in a small-scale study (<15mL) with virus yields >80% and the process was successfully scaled-up to a final scale of 100mL LVV stock solution.

Profiling of Oxylipins as Markers of Oxidative Stress in Biological Samples.

Oxylipins are oxidized metabolites of polyunsaturated fatty acids (PUFAs). They represent a class of risk markers and/or therapeutic targets for diseases associated with inflammation, including cardiovascular disease and brain disorders. Because the biological activities of free PUFAs and oxylipins depend on their chemical structures and concentrations, monitoring PUFAs and oxylipin levels in biological systems is critical for understanding their roles in health and disease. Traditionally, accurate quantification of free PUFAs and oxylipins in biological samples was performed separately, as PUFAs are often 1000-fold more abundant than the derived oxidized fatty acids (oxylipins). This article describes a liquid chromatography multiple reaction monitoring tandem mass spectrometry method for the quantitative analysis of five free PUFAs and 88 oxylipins in various biological fluids, including plasma, platelet supernatants, and tissues. The same approach can also be used in conjunction with an alkaline hydrolysis step to quantify total oxylipins in fish oils. We observed that in some samples, linoleic acid levels in plasma and eicosapentaenoic acid and arachidonic acid levels in brain tissue were above the upper limit of quantification. To address this issue, we developed a data analysis method to obtain PUFA and oxylipin concentrations in these samples without additional sample preparation, thus significantly saving time and labor. © 2024 Wiley Periodicals LLC. Basic Protocol: Quantification of polyunsaturated fatty acids (PUFAs) and oxylipins using liquid chromatography multiple reaction monitoring tandem mass spectrometry Support Protocol 1: Preparation of internal standard mixed working solution Support Protocol 2: Preparation of standard mixed stock solution Support Protocol 3: Preparation of standard mixed working solution Alternate Protocol 1: Extraction and quantitation of free PUFAs and oxylipins from mouse brain tissue Alternate Protocol 2: Extraction and quantitation of total PUFAs and oxylipins from fish oil.

Electrochemical Multicomponent Synthesis of Alkyl Alkenesulfonates using Styrenes, SO2 and Alcohols.

A novel electrochemical approach to access alkyl alkenesulfonates via a multicomponent reaction was developed. The metal-free method features easy-to-use SO2 stock solution forming monoalkylsulfites from alcohols with an auxiliary base in-situ. These intermediates serve a dual role as starting materials and as supporting electrolyte enabling conductivity. Anodic oxidation of the substrate styrene, radical addition of these monoalkylsulfites and consecutive second oxidation and deprotonation preserve the double bond and form alkyl β-styrenesulfonates in a highly regio- and stereoselective fashion. The feasibility of this electrosynthetic method is demonstrated in 44 examples with yields up to 81 %, employing various styrenes and related substrates as well as a diverse set of alcohols. A gram-scale experiment underlines the applicability of this process, which uses inexpensive and readily available electrode materials.

Bio-efficacy of essential oils of &lt;i&gt;Eryngium foetidum&lt;/i&gt; L. and &lt;i&gt;Plectranthus amboinicus&lt;/i&gt; (Lour.) Spreng against &lt;i&gt;Anopheles gambiae&lt;/i&gt; Giles

&#x0D; Malaria and lymphatic filariasis transmitted by female Anopheles mosquitoes remain health challenges in tropical Africa. Resistance by vectors to synthetic insecticides limits control efforts. This study evaluated efficacy of essential oils of Eryngium foetidum and Plectranthus amboinicus against Anopheles gambiae. Test oils were obtained by hydro-distillation using Clevenger apparatus. From 1 mL stock solution, 31.25, 62.50, 125 and 250 and 500 μL/mL concentrations of E. foetidum and P. amboinicus oils were prepared using serial-dilution with tween 80 as diluent. Each concentration had eighty adult mosquitoes exposed. Results of knockdown and insecticidal tests after 30 and 60 minutes respectively revealed higher susceptibility of An. gambiae to E. foetidum. Eryngium foetidum (250μL/mL) elicited 100% knockdown after 20 minutes. In the insecticidal test, the same concentration resulted in 100% mortality at 40 minutes. Same effect was observed for 500 μL/mL of P. amboinicus oil at 25 and 60 minutes. From Probit analysis, KD50 values were 66.793 and 251.350 μL/mL for E. foetidum and P. amboinicus respectively. Values for LC50 were 85.818 and 428.663 μL/mL for E. foetidum and P. amboinicus respectively. Results demonstrate that E. foetidum oil holds promise as control agent against An. gambiae. Plectranthus amboinicus oil did not demonstrate appreciable efficacy.

Determining the Oxidation Mechanism through Radical Intermediates in Polysorbates 80 and 20 by Electron Paramagnetic Resonance Spectroscopy.

Polysorbates 20 and 80 (PS20 and PS80) are added to many commercial biologic and vaccine pharmaceuticals. It is commonly known that these polysorbates undergo a radical oxidation mechanism; however, the identity of these radical intermediates has not been clearly determined. Furthermore, PS20 and PS80 differ by the presence of a lauric acid instead of an oleic acid, respectively. The oxidation of PS80 is thought to be centered around the double bond of the oleic acid even though PS20 also undergoes oxidation, making the mechanism of oxidation unclear for PS20. Using commercial stocks of PS20 and PS80 alkyl (R•), alkoxyl (C-O•) and peroxyl (C-OO•) radicals were detected by electron paramagnetic resonance spectroscopy likely originating from radical-initiating species already present in the material. When dissolved in water, the peroxyl radicals (C-OO•) originally in the stocks were not detected but poly(ethylene oxide) radicals were. An oxidative pathway for polysorbates was suggested based on the radical species identified in the polysorbate stock material and solutions.

Liver and mucous secretion enzymatic biomarkers of Eobania vermiculata treated with some newly synthesized acrylamide derivatives

Abstract Background Acrylamide derivatives have a potential biological activity as well as acting as precursors in many organic syntheses. Moreover, acrylamides and their derivatives cause convulsions and diffused damage to different sections of the nervous system of infected animals. Novel copper and zinc chelates originated from (E)-3-(4-bromophenyl)-2-cyanoacrylamide (L1), and (E)-2-cyano-3-(4-nitrophenyl)acrylamide (L2) were prepared, and their chemical skeletons were identified by infrared and mass spectra. The obtained compounds were screened in vitro against the brown garden snail, Eobania vermiculata using the contact method along 72 h. Stock solutions of tested compounds were prepared utilizing distilled water and DMSO mixture, and four concentrations of each compound were prepared (50, 150, 250 and 350 ppm). Eobania vermiculata snails were treated with LC50 concentrations of prepared compounds for 3 days, and live snails were used to estimate the level of some liver and mucous secretion enzymatic biomarkers: transaminases enzymes (Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST)), Total Protein content (TP), Acid Phosphatases (ACP) and Alkaline Phosphatase (ALP). Results The results demonstrated that the examined compounds have a relatively toxic effect toward the screened species. Zinc complexes displayed a higher toxicity than copper ones. The results authenticated considerable high effects of the synthesized compounds on investigated enzymes. Conclusions The promising effects of Cu(II), Zn(II) complexes (1, 2) on stimulating the mucous secretion of tested snails are clear through the elevated levels of ALP and ACP enzymes of treated snails. The enhancement or reduction of AST, ALT level and TP content of treated snails demonstrated the effects of prepared compounds on liver functions of these species.

Silver nanoparticles enhanced enzyme-linked immunosorbent assay (ELISA) detection of cancer testis antigens (CTAs).

The Enzyme-Linked Immunosorbent Assay (ELISA) has been a cornerstone technique in laboratory medicine for over 55 years, relying on the specific binding of antibodies to antigens. ELISA's widespread use stems from its ability to detect low concentrations, its specificity, reproducibility, and potential for high-throughput screening. However, its sensitivity has limitations, prompting the exploration of innovative methods to improve the limit of detection (LOD). Nanoparticles provide a promising platform for enhancing ELISA sensitivity. Due to their high surface-to-volume ratio, they offer increased binding sites for capture elements and reporting tags, leading to amplified analytical signals. Recent studies have demonstrated improved sensitivity in ELISA through nanoparticle application, yielding faster detection times and enhanced sensitivities. This study investigates the potential of 50 nm citrate-capped silver nanoparticles to enhance ELISA's performance in quantifying cancer testis antigens (CTAs). In our study, we used the Human NY-ESO-1 ELISA kit (for research purposes) to determine the concentration of CTAs in randomly selected samples from healthy (n=89) and oncological (n=80) subjects, aged 18-75. We employed 50 nm citrate-capped silver nanoparticles (AGCB50-1M, BioPure Silver Nanoparticles - bare citrate, nano-Composix, San Diego, CA, USA). ELISA reactions followed the manufacturer's instructions, and data processing aligned with the same guidelines. Absorbance (OD) measurements occurred at 450 nm, influencing nanoparticle selection. Each ELISA well contained 5 ml of nanoparticles' stock solution with specified concentrations. CTAs concentrations were derived from the standard curve through CurveExpert Basic software. Statistical analysis was performed using SPSS v. 27 software, with p-values indicating significance if <0.03. The study adhered to Helsinki Declaration principles and received ethical approval. Participants provided informed written consent. The increased concentration values of CTAs for healthy individuals and cancer patients were determined in the case of the application of silver nanoparticles. The usage of nanoparticles can enhance the sensitivity of the ELISA method and positively influence its specific detection limit.

Self-hydrolyzing Submerged Flow Technology for Acid Coal Mine Drainage Treatment: Effective Removal of Iron Ions

In this study, mine wastewater from Leiyang, Hunan Province was taken as the research object to investigate the effect of using the method of self-hydrolytic submerged sedimentation to treat acid coal mine drainage. It was found in this study that the removal rate of sulfate ions and iron ions from the acidic coal mine drainage stock solution at pH=2.7 was very limited by self-hydrolytic sedimentation experiments relying only on pure vertical sedimentation flow treatment, but the hydrolytic treatment could greatly improve the solution environment and promote the formation of secondary minerals of sulfate ions and iron ions in the acidic coal mine drainage, which greatly improved the removal rate of iron ions. Both suspended and precipitated materials produced in the self-hydrolysis sedimentation experiments were hydroxylated iron sulfate secondary minerals- Schwertmannite [Fe8O8(OH)8-2X(SO4)X (1 ≤ x ≤ 175)], the formation of which is inextricably linked to the low pH environment and high concentration of sulfate and iron ions in coal mine wastewater. Self-hydrophoretic submerged flow can remove iron ions from acidic coal mine drainage at low cost and high efficiency, and the total iron removal rate of this system can reach 90.93% after 24 h of treatment, which has a favorable comprehensive utilization value.

Comparative Effects of Moringa oleifera upon Blood of Clarias batrachus (Linnaeus, 1758) Infected by Fenvalerate and Cypermethrin

Abstract: After the application of Moringa oleifera as a herbal agent upon the infected Catfish Clarias batrachus (Linnaeus, 1758) by Fenvalerate and Cypermethrin used as Insecticide and Pesticides shows many Biochemical fluctuations in their Comparative parameters. Fishes were acclimatized with pesticides for 96 hours (4 days) in two different tanks. Concentration of toxic agent Cypermethrin and Fenvalerate was taken as 0.25 µg/l of LC50 ¼ from 20EC stock solution and 25 µg/l of LC50 1/10 respectively which was continued as studies at every 24h of time interval as lethal concentration for acute toxicity. Powder of dried grinded green leaves and pod of herbal agent Moringa oleifera used in ratio of 1:1 proportion respectively taken as 0.125 gm / litre according to the capacity of water per day continued till 120 h of dose acclimatization upon fish infected with both pesticidal agents individually. Haematological changes were observed and compared among Normal, Fenvalerate, Cypermethrin, Fen Mo and Cyp Mo conditions.

DMSO-Related Effects on Ligand-Binding Properties of Lysine Methyltransferases G9a and SETD8.

Being the standard solvent for preparing stock solutions of compounds for drug discovery, DMSO is always present in assay buffers in concentrations ranging from 0.1 % to 5 % (v/v). Even at the lowest concentrations, DMSO-containing solutions can have significant effects on individual proteins and possible pitfalls cannot be eliminated. Herein, we used two protein systems, the lysine methyltransferases G9a/KMT1 C and SETD8/KMT5 A, to study the effects of DMSO on protein stability and on the binding of the corresponding inhibitors, using different biophysical methods such as nano Differential Scanning Fluorimetry (nanoDSF), Differential Scanning Fluorimetry (DSF), microscale thermophoresis (MST), and surface plasmon resonance (SPR), all widely used in drug discovery screening campaigns. We demonstrated that the effects of DMSO are protein- and technique-dependent and cannot be predicted or extrapolated on the basis of previous studies using different proteins and/or different assays. Moreover, we showed that the application of orthogonal biophysical methods can lead to different binding affinity data, thus confirming the importance of using at least two different orthogonal assays in screening campaigns. This variability should be taken into account in the selection and characterization of hit compounds, in order to avoid data misinterpretation.

Invigorasi Larutan Bawang Merah Terhadap Viabilitas dan Vigor Tiga Benih Padi Varietas Lokal

Rice production in South Kalimantan during January to September 2020 decreased compared to 2019. The use of rice seeds per hectare is generally still not in accordance with the recommendations. The local varieties of rice seeds that cultivated are from last year's cropping season, where storage was not good which could lead to a decrease in seed quality. Shallots contain hormones auxin and gibberellins, can be used as a natural growth regulator. This study used a solution of shallots on three local varieties of rice seeds. The purpose of this study was to provide information on the use of natural growth regulators in shallot solution as an alternative to increase seed viability to become a provider of quality seeds. This research carried out from October to November 2021 at the Production Laboratory of the Department of Agroecotechnology, Faculty of Agriculture, Lambung Mangkurat University. The implementation of the research is making shallot stock solution, seed preparation, seed soaking, seed germination, and maintenance. The method used was qualitative using single factor Completely Randomized Design with three levels of treatment and each treatment consisted of five replications. The results showed that treatment using onion solution invigoration had a significant effects on the parameters of growth uniformity and maximum growth potential of expired local rice seeds of Siam Banjar variety. The highest growth speed and seed germination were found in Siam Saba variety. The highest growth uniformity was found in Siam Unus variety. The highest maximum growth potential is found in Siam Mutiara variety.

Simultaneous Determination of Iron and Copper in Aqueous Solution Using Spectrophotometry

Iron and copper mixtures were quantitatively determined in aqueous solutions for the first time using the analytical method in this approach with the aid of T60U Spectrophotometer. The method is so simple, fast, economic, and can be carried out easily on a bench. The absorbencies for iron, copper and iron-copper mixtures in aqueous solution were measured using T60U adopted with UVWin6 software UV -VIS Spectrometer (pg instruments United Kingdom) by filling two 5 ml quartz cells of dimensions 1*1*5 cm, the first is filled with the blank solution which is a solution containing all the constituents of the sample except iron and copper and the other quartz cell is filled with the stock solution iron and/or copper under investigation. Absorbency of iron was determined by setting T60U spectrometer wavelength at 504 nm, meanwhile for copper absorbency measurements the apparatus is set at 304 nm. Iron, copper, and iron-copper mixture calibration curves were of very high accuracy with the least linear regression value of ≤ 1, i, e the measured data were of relative standard deviation value (RSD) of ≤ 1.5%.

Optimization of therapeutic drug monitoring of vancomycin in newborns using “Dried Blood Spot” method

Therapeutic drug monitoring (TDM) is used to increase the individualization of pharmacotherapy, especially in patient groups with a high interindividual variability in pharmacokinetic (PK) parameters. One of these groups of patients is newborn children, for whom drug therapy, especially drugs with a narrow therapeutic range, causes a few difficulties or cannot be used in principle.The aim of the work was to develop and validate quantitative HPLC-MS/MS methods for the determination of vancomycin in “dried blood spot” samples using new protocols and comparison of the results obtained with the results in plasma samples using standard sample preparation methods.Materials and methods. To prepare stock and standard solutions of vancomycin and norvancomycin as an internal standard, dry portions of the corresponding certified standards of vancomycin (Servier, France) and norvancomycin (Augsburg, Germany, purity grade &gt;95.0%) were used. A chromatographic separation of the components was carried out on a Poroshell 120 C18 column (4.6×50 mm, 2.7 µm). When developing conditions for a mass spectrometric detection of the desired substances using the multiple reaction monitoring (MRM) method, precursor ions and their corresponding product ions were determined.Results. A quantitative HPLC-MS/MS method for the determination of vancomycin in «dried blood spot» samples was developed and validated. A comparison was made between vancomycin concentrations in «dried blood spot» samples and plasma samples. Moreover, more than 95% of the calculated average concentrations are within the limits of d-2s and d+2s, which correspond to the values of –10.2 and 12.2. That confirms the suitability of the developed method for the analysis of patient samples.Conclusion. The results obtained make it possible for us to recommend the “dried blood spot” method for therapeutic monitoring of vancomycin, additional studies of PK in this group of patients with subsequent use of this drug in newborns and pediatric patients.

Physiological performance of brassinolide-conditioned green soybean seeds

Factors associated to biotic and abiotic stresses, such as high temperatures and prolonged droughts, can induce premature plant maturation and, thus, lead to the formation of green seeds. This is major issue for the soybean (Glycine max (L.) Merrill) production chain, due to low physiological seed quality. Although seed conditioning can improve seed germination and vigor, little is known on the use of the brassinolide (BL) phytohormone during this process in green soybean seeds. This study, therefore, aimed to elucidate BL conditioning effects on green soybean seeds. A BL stock solution was prepared and cultivar AS 3680 IPRO seeds were conditioned at 0.0, 0.2, 0.4, 0.6 and 0.8 μM BL concentrations followed by drying until reaching original water contents. Seed conditioning effects were investigated by assessing germination and accelerated aging test results, seedling shoot, and root lengths, electrical conductivity, germination speed index and dry seedling mass. Gas exchanges and chlorophyll a fluorescence parameters were determined in seedlings 15 days after sowing. Seed germination and vigor were superior when conditioned with 0.6 and 0.8 μM BL. Photosynthetic rates, effective quantum yields of PSII photochemical energy conversion and electron transport rates were improved in seeds treated with 0.4, 0.6 and 0.8 μM BL. Brassinolide-conditioned seeds exhibited histochemical reserve tissue differences and greater lipid and protein accumulation compared to the control group. These findings demonstrate that green soybean seed BL treatment can increase the quality and subsequent physiological development in soybean seedlings.

Antioxidant Effects of Rutin Trihydrate vs. Doxorubicin in Zebrafish Larvae: GSH, GPx, and GST Activity

This study aimed to compare the clinical relevance of the novel drug rutin trihydrate with doxorubicin concerning their influence on the antioxidant enzymes GST, GPX, and GSH. Zebrafish larvae were subjected to oxidative stress induced by H₂O₂ at 1mM concentration, and their antioxidant activity was assessed through enzymatic assays. The stock solution was prepared with DMSO, and zebrafish eggs were collected in a 1:1 male-to-female breeding ratio, followed by distribution into four petri plates for exposure to rutin trihydrate from 4 hours post-fertilization (hpf) to 96 hpf. Hatching rates were recorded after 96 hpf, and SPSS software was utilized for statistical analysis. Embryos exposed to compound dosage exhibited significantly increased enzyme activity (p &lt; 0.000, p &lt; 0.05) (8.5667.17593) compared to appropriate dosages (34.40000.07). With a total sample size of 30 and parameters including a 0.05 significance threshold, 80% statistical power, a 95% confidence interval, and an enrolment ratio of 1, the study revealed notable alterations in GPX (9%), GSH (5%), and GST (5%) activity in zebrafish larvae treated with rutin trihydrate and doxorubicin. The investigation’s significance level was determined to be p = 0.000 (p &lt; 0.05), signifying a statistically significant difference among the test groups. These findings shed light on the potential clinical implications of these compounds on zebrafish larvae’s antioxidant systems.

A study on the materials of smart barrier for selectively blocked TCE and TPH

Many barrier materials are used around industries, construction areas, livestock dump sites, waste landfills, and underground oil storage tanks. In the case of barriers, even if there is no inflow of contaminants, they do not provide selective permeability, develop water barrier properties, and hinder groundwater flow when contaminants encounter groundwater. Recently, contaminated sites that are difficult to resolve with current purification technologies continue to emerge. Pollutants flow into groundwater through the advection and diffusion by leaking. The pollutants introduced in this way cause pollution to the surrounding environment, and various types of severe underground environmental pollution problems occur depending on the type of pollutants leaked. Therefore, using a material that has the property of adsorbing organic contaminants and gelling them is harmless to the environment by penetrating groundwater under normal conditions. It has the property of selectively adsorbing the pollutant and gelling it upon contact with it underground. Therefore, the authors aim to study the applicability of polynorbornene and polyolefin as components of smart barrier materials that make barrier materials impermeable through the adsorption of pollutants, swelling, and coagulation behavior in this study. The components of smart barrier materials include Ottawa sand, organo-bentonite, polynorbornene, and polyolefin. Polynorbornene and polyolefin adsorb only organic pollutants selectively. Before applying polynorbornene and polyolefin to the barrier material, TCLP was performed to evaluate environmental hazards. As a result of heavy metal analysis, it was determined that there was no environmental hazard. The pH results are 7.27 for polynorbornene and 7.31 for polyolefin, indicating that both materials are slightly alkaline. In addition, as a result of testing with TCE (stock solution) and TPH (diesel crude oil) to confirm the swelling effect when in contact with organic pollutants, the efficiency of pollutant adsorption and swelling was found to be high when the ratio of polynorbornene: polyolefin = 6:4. Therefore, when using the material used in this study, it is expected that it can be applied as a component of a smart barrier material that selectively blocks pollutants.

Subsequent bilateral key comparison study - organic solvent calibration solution - gravimetric preparation and value assignment of aflatoxin B1 (AfB1) in acetonitrile (ACN)

Main textThe original CCQM-K154.b comparison was coordinated by the Bureau International des Poids et Mesures (BIPM) and the Chinese National Institute of Metrology (NIM) on behalf of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) for National Measurement Institutes (NMIs) and Designated Institutes (DIs) which provide measurement services in organic analysis under the 'Comité International des Poids et Mesures' Mutual Recognition Arrangement (CIPM MRA) and/or have participated in the BIPM's Mycotoxin Metrology Capacity Building and Knowledge Transfer (MMCBKT) project as part of its "Metrology for Safe Food and Feed in Developing Economies" Capacity Building Programme.Gravimetrically-prepared solutions having an assigned mass fraction of specified organic analytes are routinely used to calibrate measurement processes for the quantification of the same analytes in matrix samples. Appropriate assignments of the property value and associated uncertainty of calibration solutions thus underpin the traceability of routine analysis and are critical for accurate measurements. Evidence of successful participation in relevant international comparisons is needed to document calibration and measurement capability claims (CMCs) made by national metrology institutes and designated institutes. In total, eleven NMIs/DIs participated in the Track C, Model II, Key Comparison CCQM-K154.b [Gravimetric preparation and value assignment of aflatoxin B1 (AfB1) in acetonitrile (ACN)] for emerging areas of global interest and innovation. Participants were requested to gravimetrically prepare calibration solutions and value assign the mass fractions, expressed in mg/kg, of aflatoxin B1 (AfB1) in the acetonitrile (ACN) solution. Study samples, with assigned values and associated uncertainties were prepared by the comparison participants and sent to the coordinating laboratory for comparison. The Key Comparison Reference Values (KCRVs), calculated form values measured by the coordinating laboratory based on calibrations obtained from independent gravimetrically prepared calibrant solutions, agreed with participants reported values, within their stated uncertainties.AfB1 was selected to be representative of polar aflatoxins. Aflatoxins are a class of mycotoxins generally produced by fungi of the genus Aspergillus. It was anticipated to provide a challenge representative for the gravimetrical preparation and value assignment of calibration solutions in the mass fraction range of 2 mg/kg to 50 mg/kg of mycotoxins with broadly similar structural characteristics.In the original study CCQM-K154.b, nine participants of the MMCBKT programme were provided with a stock solution having a known AfB1 mass fraction and expanded uncertainty to use to gravimetrically prepare and value assign a calibration solution. Three NMIs/DIs also participated using their own calibration solutions. The use of in-house solutions required anadditional capacity to undertake a fit-for-purpose purity assessment. NIM was the only NMI participating using both the MMCBKT based and their own in-house assigned solutions in order to connect the two different groups.It was decided to propose separate KCRVs for each of the two ampoules provided by the participating NMIs/DIs based on the AfB1 mass fraction. This allowed participants to demonstrate the efficacy of their implementation of the approaches used to gravimetrically prepare calibrations solutions and to assess the AfB1 mass fraction.The majority of the AfB1 mass fraction KCRVs (wKCRV) for CCQM-K154.b spanned a mass fraction range of 2.02 mg/kg to 31.57 mg/kg. The relative expanded uncertainties U(wKCRV) ranged from 0.69 % to 2.93 %. Inspection of the degree of equivalence plots for the AfB1 mass fraction assignments in CCQM-K154.b indicated that there was an excellent agreement of results. Solely, the AfB1 mass fraction assignments of the INRAP (Institut National de Recherche et d'Analyse Physico-Chimique, Tunisia) did not agree with the KCRVs. It was found that the samples were altered as a result of an acid contamination.The INRAP has produced a new batch of AfB1 calibration solution using the AfB1 stock solution originally provided to MMCBKT participants to be able to demonstrate the efficacy of their implementation of the approaches used to gravimetrically prepare calibrations solutions and to assess the AfB1 mass fraction. The BIPM organized the present subsequent bilateral comparison CCQM-K154.b.1 to assess the new batch of AfB1 calibration solution of the INRAP. Inspection of the degree of equivalence plots for the AfB1 mass fraction assignments indicated that there is an excellent agreement of the INRAP results for CCQM-K154.b.1.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Quantification of asciminib by LC-MS/MS method in human plasma: Validation and stability studies

An accurate, sensitive, and linear liquid chromatographic tandem mass spectrometric method was developed for the quantification of asciminib in human plasma. Voriconazole, internal standard (IS), and asciminib were isolated from the plasma samples by C18-cartridges. Chromatographic isolation was processed with Atlantis/dC18 (2.1 × 100 mm, 3 μm) stationary phase and a mobile solvent system of formic acid (0.1%) and methyl alcohol (20:80, v:v), conveyed at a 0.7 ml/minute flowing rate. Analytes were quantified by ionization in a positive approach with electrospray ionization at the mass transitions of (m/z): asciminib, 450.11/239.09, and voriconazole (IS), 350.3/281.1. No interference by constituents of plasma blank or other components was detected. The association between asciminib concentration levels and their respective peak response fractions to voriconazole was rectilinear between 39.0 and 1,586.0 ng/ml. Intraday and interday precisions were ≤4.79% for asciminib. The interday bias was between −4.28% and 5.76%, and the intraday bias was −3.75% and 4.53%. The mean measured extraction recovery of asciminib was 99.06%. The recovery of IS was 98.34%. Asciminib was subjected to long-term, bench-top, freeze-thaw, short-term stability, dry extract, auto-sampling, and stock solution stability at Low quality control and High quality control levels, and it was stable at all these conditions. The established technique can be utilized for the regular quantification of asciminib in plasma samples in industries, forensic laboratories, and clinical research organizations.