bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation Procedures for Quantitative Food Allergen ELISA Methods: Community Guidance and Best Practices
Authors: Abbott Michael , Hayward Stephen , Ross William , Godefroy Samuel Benrejeb , Ulberth Franz , Van Hengel Arjon J , Roberts James , Akiyama Hiroshi , Popping Bert , Yeung Jupiter M , Wehling Paul , Taylor Steve L , Poms Roland Ernest , Delahaut Philippe 
Published: February 2020

Abstract
This document provides supplemental guidance on specifications for the development and implementation of studies to validate the performance characteristics of quantitative ELISA methods for the determination of food allergens. It is intended as a companion document to other existing publications on method validation. The guidance is divided into two sections: information to be provided by the method developer on various characteristics of the method, and implementation of a multilaboratory validation study. Certain criteria included in the guidance are allergen-specific. Two food allergens, egg and milk, are used to demonstrate the criteria guidance. These recommendations will be the basis of the harmonized validation protocol for any food allergen ELISA method, whether proprietary or nonproprietary, that will be submitted to AOAC and/or regulatory authorities or other bodies for status recognition. Regulatory authorities may have their own particular requirements for data packages in addition to the guidance in this document. Future work planned for the implementation and validation of this guidance will include guidance specific to other priority allergens.
Validation and Application of Chemometrics-Assisted Spectrophotometry and Liquid Chromatography for Simultaneous Determination of Two Ternary Mixtures Containing Drotaverine Hydrochloride
Authors: El-Gindy Alaa , Emara Samy , Shaaban Heba 
Published: February 2020

Abstract
Three methods were developed for the determination of two ternary mixtures containing drotaverine hydrochloride (DR) with caffeine and paracetamol (mixture 1) and DR with metronidazole and diloxanide furoate (mixture 2). The first method depends on HPLC separation on an RP C18 column at ambient temperature with the mobile phase methanolwater, pH 3.1 (50 + 50, v/v) and UV detection at 213 nm for mixture 1, and the mobile phase acetonitrile25 mM potassium dihydrogen phosphate, pH 4.6 (55 + 45, v/v) with UV detection at 235 nm for mixture 2. The other two chemometric methods applied were partial least squares (PLS-1) and principal component regression (PCR). These approaches were successfully applied to quantify the five drugs in two ternary mixtures using information included in the UV absorption spectra of appropriate solutions in the wavelength range of 210300 nm with 1 nm intervals. Calibration of PCR and PLS-1 models was evaluated by internal validation (prediction of compounds in its own designed training set of calibration), by cross-validation (obtaining statistical parameters that show the efficiency for a calibration fit model), and by external validation (using laboratory-prepared mixtures and pharmaceutical preparations). The proposed methods were successfully applied for the determination of the two ternary combinations in laboratory-prepared mixtures and commercial tablets; the results of PLS-1 and PCR methods were compared with the HPLC method, and a good agreement was found.
Determination of Immunoglobulin G in Bovine Colostrum and Milk Powders, and in Dietary Supplements of Bovine Origin by Protein G Affinity Liquid Chromatography: Collaborative Study
Authors: Abernethy Grant , Otter Don ,   Collaborators:, Arnold K , Austad J , Christiansen S , Ferreira I , Irvine F , Marsh C , Massom L R , Otter D , Pearce K , Stevens J , Szpylka J , Vyas P , Woollard D , Wu C 
Published: February 2020

Abstract
An AOAC collaborative study was conducted to evaluate an affinity LC procedure for measuring immunoglobulin G (IgG) in selected dairy powders. The powders were extracted with 0.15 M sodium chloride solution and the pH was adjusted to 4.6 to precipitate caseins, which would otherwise lead to an overestimation of IgG. The analyte was then bound to a commercially available Protein G affinity cartridge and selectively eluted with a glycine buffer at pH 2.5. Detection was at 280 nm and quantification was made against a calibration curve prepared from bovine serum IgG. The samples analyzed included the likely matrixes for which this assay will find commercial use, namely, high- and low-protein-content colostrum powders, tablets containing colostrum powder, and some IgG-containing dairy powders; milk protein isolate, whey protein concentrate, and skim milk powder. Eleven laboratories provided data for the study and assayed blind duplicates of six materials. The repeatability RSD values ranged from 2.1 to 4.2 and the reproducibility RSD values ranged from 6.4 to 18.5. The Protein G method with casein removal has adequate reproducibility for measuring IgG in colostrum-derived powders that are traded on the basis of IgG content as a colostral marker.
Multiresidue Determination of Pesticides in Lanolin Using Matrix Solid-Phase Dispersion
Authors: Pérez Andrés , González Gabriel , González Joaquín , Heinzen Horacio 
Published: February 2020

Abstract
An efficient, fast, and accurate matrix solid-phase dispersion sample cleanup procedure was developed specifically for the determination of pesticide residues in lanolin. The scope of the method for organophosphorus, organochlorine, and pyrethroid insecticides is the same as that of official methods from various pharmacopeias. After lanolin dispersion on C18 bonded silica, pesticides are eluted with acetonitrile saturated with n-hexane. Recoveries ranged from 83 to 118 with RSD values of &lt;20 for most pesticides listed, in compliance with the requirements of European and U.S. pharmacopeias.
Construction of Measurement Uncertainty Profiles for Quantitative Analysis of Genetically Modified Organisms Based on Interlaboratory Validation Data
Authors: Macarthur Roy , Feinberg Max , Bertheau Yves 
Published: February 2020

Abstract
A method is presented for estimating the size of uncertainty associated with the measurement of products derived from genetically modified organisms (GMOs). The method is based on the uncertainty profile, which is an extension, for the estimation of uncertainty, of a recent graphical statistical tool called an accuracy profile that was developed for the validation of quantitative analytical methods. The application of uncertainty profiles as an aid to decision making and assessment of fitness for purpose is also presented. Results of the measurement of the quantity of GMOs in flour by PCR-based methods collected through a number of interlaboratory studies followed the log-normal distribution. Uncertainty profiles built using the results generally give an expected range for measurement results of 50200 of reference concentrations for materials that contain at least 1 GMO. This range is consistent with European Network of GM Laboratories and the European Union (EU) Community Reference Laboratory validation criteria and can be used as a fitness for purpose criterion for measurement methods. The effect on the enforcement of EU labeling regulations is that, in general, an individual analytical result needs to be &lt;0.45 to demonstrate compliance, and &gt;1.8 to demonstrate noncompliance with a labeling threshold of 0.9.
High-Performance Thin-Layer Chromatography and Three-Dimensional Image Analysis for the Determination of Rutin in Pharmaceutical Preparations
Authors: Soponar Florin , MoŢ Augustin C , Sârbu Costel 
Published: February 2020

Abstract
A novel HPTLC method was developed for fast and simple quantitative determination of rutin in pharmaceutical preparations. The proposed method combines the advantages of HPTLC with the comfort and the convenience of digital processing of images. For the separation of rutin, silica gel with attached amino groups was used as the stationary phase and ethyl acetateformic acidmethanolwater (10 + 0.9 + 1.1 + 1.7, v/v/v/v) as the mobile phase. The chromatographic plate was sprayed with 2-aminoethyldiphenyl borate solution for visual detection of the spots. For the construction of a three-dimensional chromatogram, Melanie 7.0 software was used together with an HP flatbed scanner that allowed capture of the images on chromatographic plates. The calibration curve was linear within the range of 0.954.78 g/spot with an r value of 0.9984. The RSD for six replicates at three concentration levels was less than 3, while the recovery was between 97.28 and 103.27. The proposed method was found to be simple, precise, sensitive, and accurate and has been applied for the determination of rutin in two commercial drugs. The results were compared with the results of other techniques that generate bidimensional chromatograms and validated by UV-Vis spectrophotometry.
Validated HPTLC Methods for Quantification of Mexiletine Hydrochloride in a Pharmaceutical Formulation
Authors: Pietraś Rafał , Skibiński Robert , Komsta Łukasz , Kowalczuk Dorota , Panecka Ewa 
Published: February 2020

Abstract
Two simple, accurate, and precise HPTLC methods have been established for the determination of mexiletine hydrochloride, an antiarrhythmic agent, in Mexicord capsules. Analyses were performed in horizontal chambers on RP C18F254s and normal-phase amino (NH2) HPTLC precoated plates with the mobile phases tetrahydrofurancitrate buffer, pH 4.45 (3 + 7, v/v) and chloroformtetrahydrofuranhexaneethylamine (3 + 2 + 5 + 0.1, v/v/v/v), respectively. The plates were developed for a distance of 40 mm in both cases. Densitometric measurements were achieved in the UV mode at 217 nm based on peak areas with semilinear calibration curves (R2 0.97) in the concentration range 0.58.0 g/spot for the NH2 and C18 HPTLC methods. The elaborated chromatographic methods were validated in accordance with International Conference on Harmonization guidelines in terms of linearity, accuracy (99.64 for NH2 and 99.53 for C18), precision (intraday RSD 1.16 and 2.71, respectively), sensitivity (LOD 0.1 g/spot for both systems), and specificity.
Microwave-Assisted Extraction Coupled with Single Drop Microextraction and High-Performance Column Liquid Chromatography for the Determination of Trace Estrogen Adulterants in Soybean Isoflavone Dietary Supplements
Authors: Xiao Xiaohua , Yin Yi , Hu Yuling , Li Gongke 
Published: February 2020

Abstract
A sensitive and accurate method consisting of microwave-assisted extraction (MAE) coupled with single drop microextraction (SDME) and HPLC was developed for the determination of four trace estrogen adulterants, including estriol (E3), estradiol (E2), ethinyl estradiol (EE), and estrone (E1), in different soybean dietary supplements. The samples were extracted by MAE; the extracts were cleaned up and enriched by SDME, and then analyzed by HPLC. The conditions of MAE were optimized, and the effects of solvent and extraction time in SDME on the enrichment capacity were studied. The enrichment factors of E3, E2, EE, and E1 under the optimized conditions were 247-, 335-, 316-, and 319-fold, respectively. The linear range of the MAE-SDME-HPLC method ranged from 5.0 to 180.0 g/L, and the detection limit from 1.1 to 1.2 g/L. The RSD ranged from 7.9 to 9.6. Three soybean dietary supplements, including oral liquid, capsule, and tablet forms, were analyzed. The spike recovery was more than 70, with RSD lower than 13.2. It was shown that the proposed method was accurate, sensitive, and suitable for the determination of trace analytes in complex samples.
Simultaneous Determination of Imipramine Hydrochloride and Chlordiazepoxide in Pharmaceutical Preparations by Spectrophotometric, RP-HPLC, and HPTLC Methods
Authors: Patel Sejal K , Patel Natvarlal J 
Published: February 2020

Abstract
A binary mixture of imipramine HCl and chlordiazepoxide was determined by three different methods. The first involved determination of imipramine HCl and chlordiazepoxide using the first derivative spectrophotometric technique at 219 and 231.5 nm over the concentration ranges of 120 and 224 g/mL with mean accuracies of 99.47 0.78 and 101.43 1.20, respectively. The second method utilized RP-HPLC with methanolacetonitrile0.065 M ammonium acetate buffer (45 + 25 + 30, v/v/v, pH adjusted to 5.6 0.02 with phosphoric acid) as the mobile phase pumped at a flow rate of 1.0 mL/min. Quantification was achieved using UV detection at 240 nm over concentration ranges of 0.254.0 and 0.11.6 g/mL, with mean accuracies of 101.17 0.56 and 100.67 0.40 for imipramine HCl and chlordiazepoxide, respectively. The third method was HPTLC with carbon tetrachlorideacetonetriethylamine (pH 8.3; 6 + 3 + 0.3, v/v/v) as the mobile phase. Quantification was achieved with UV detection at 240 nm over concentration ranges of 50600 and 20240 ng/spot with mean accuracies of 99.51 0.59 and 100.59 0.84 for imipramine HCl and chlordiazepoxide, respectively. The suggested procedures were checked using prepared mixtures, and were successfully applied for the analysis of pharmaceutical preparations. The accuracy and precision of the methods were confirmed when the standard addition technique was applied. The results obtained by applying the proposed methods were statistically analyzed.
Optimization and Establishment of a Validated Stability-Indicating HPLC Method for Study of the Stress Degradation Behavior of Metoprolol Succinate
Authors: Phale Mitesh D , Hamrapurkar Purnima D 
Published: February 2020

Abstract
A stability-indicating HPLC method has been established for analysis of metoprolol succinate in the presence of products generated in a stress degradation study. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis, and thermal decomposition. Extensive degradation was found to occur in an alkaline medium and under thermal stress. Minimum degradation was observed in an acidic medium and under photolytic and oxidative stress. Successful separation of the drug from its degradation products formed under stress conditions was achieved on a C18 column using sodium dihydrogen phosphate bufferacetonitrile (70 + 30) mobile phase. The flow rate was 1 mL/min, and the detection wavelength was 274 nm. The method was validated for linearity, range, precision, accuracy, LOQ, and LOD. Because the method effectively separates the drugs from their degradation products, it can be used as a stability-indicating method.
Ionic Liquid-Based, Single-Drop Microextraction for Preconcentration of Cobalt Before Its Determination by Electrothermal Atomic Absorption Spectrometry
Authors: Amjadi Mohammad , Manzoori Jamshid L , Abulhassani Jafar 
Published: February 2020

Abstract
An effective and environmentally friendly single-drop microextraction method was developed for the preconcentration of ultratraces of cobalt before its determination by electrothermal atomic absorption spectrometry (ETAAS). A microdrop of 1-hexyl-3-methylimidazolium hexafluorophosphate, [C6MIM][PF6], was used to extract Co(II) ions as an ammonium pyrroldinedithiocarbamate (APDC) complex. The sensitivity was improved by increasing the volume of the suspended drop. Several variables affecting microextraction efficiency and the ETAAS signalsuch as pyrolysis and atomization temperature, pH, APDC concentration, extraction time, drop volume, and stirring ratewere investigated and optimized. Under the optimum experimental conditions, the detection limit (3 SD) was 0.04 g/L, and the enrichment factor was 120. The RSD for five replicate determinations of Co(II) at 0.5 g/L was 4.5. The developed method was validated by analysis of a Standard Reference Material and applied to the determination of cobalt in water samples.
A Porous Graphitized Carbon Column HPLC Method for the Quantification of Paracetamol, Pseudoephedrine, and Chlorpheniramine in a Pharmaceutical Formulation
Authors: Kalogria Eleni , Koupparis Michael , Panderi Irene 
Published: February 2020

Abstract
A simple, rapid, and stability-indicating HPLC method has been developed, fully validated, and applied to the quantification of paracetamol, pseudoephedrine hydrochloride, and chlorpheniramine maleate in a pharmaceutical formulation, using hydrochlorothiazide as an internal standard. Chromatographic separation was achieved isocratically on an RP porous graphitized carbon analytical column (125 2.1 mm id, particle size 5 m) using 5.0 mM ammonium acetateacetonitrile (35 + 65, v/v) mobile phase at a flow rate of 0.50 mL/min. UV spectrophotometric detection at 220 nm was used. The method had linear calibration curves over the range of 3070 g/mL for paracetamol, 1.84.2 g/mL for pseudoephedrine hydrochloride, and 120280 ng/mL for chlorpheniramine maleate. The intraday and interday RSD values were less than 3.2 for all compounds, while the relative error was less than 2.9. Accelerated stability studies performed under various stress conditions proved the selectivity of the method. The developed method was applied successfully to QC and content uniformity tests of commercial tablets.
Validation of a Novel, Fully Automated High Throughput High-Performance Liquid Chromatographic/Tandem Mass Spectrometric Method for Quantification of Pantoprazole in Human Plasma
Authors: Dotsikas Yannis , Apostolou Constantinos , Soumelas Stefanos , Kolocouri Filomila , Ziaka Afroditi , Kousoulos Constantinos , Loukas Yannis L 
Published: February 2020

Abstract
An automated high-throughput HPLC/MS/MS method was developed for the quantitative determination of pantoprazole in human plasma. Only 100 L plasma was placed in 2.2 mL 96 deep-well plates, and both pantoprazole and omeprazole (IS) were extracted from human plasma by liquidliquid extraction, using diethyl etherdichloromethane (70:30, v/v) as the organic solvent. Robotic liquid-handling workstations were used for all liquid transfer and solution preparation steps and resulted in a short sample preparation time. After vortexing, centrifugation, and freezing, the supernatant organic solvent was evaporated and reconstituted in a small volume of reconstitution solution. Sample analysis was performed by utilizing the combination of RP-HPLC/MS/MS, with positive-ion electrospray ionization and multiple reaction monitoring detection. The chromatographic run time was set at 1.8 min with a flow rate of 0.6 mL/min on a Nucleosil octylsilyl (C8) analytical column. The method was proven to be sensitive, specific, accurate, and precise for the determination of pantoprazole in human plasma. The method was applied to a bioequivalence study after per os administration of a 40 mg pantoprazole gastric retentive tablet.
Listeria monocytogenes: Knowledge Gained Through DNA Sequence-Based Subtyping, Implications, and Future Considerations
Authors: Nightingale Kendra 
Published: February 2020

Abstract
The purpose of subtyping is to differentiate bacterial isolates beyond the classification of species or subspecies. Subtyping methods can be grouped into two broad categories based on the cellular components targeted: (1) phenotypic subtyping methods that differentiate isolates by the enzymes, proteins, or other metabolites expressed by the cell, and (2) molecular subtyping methods that discriminate isolates based on interrogation of nucleic acid sequences. The two major types of molecular subtyping methods include band-based methods based on fragment pattern data or DNA fingerprints, and methods that generate DNA sequence data. Molecular subtyping methods have shown that Listeria monocytogenes isolates can be classified into four genetic lineages or divisions. Although band-based molecular subtyping methods continue to serve as the gold standard for routine molecular subtyping of most clinically important foodborne pathogens, including L. monocytogenes, the explosion of recently completed and ongoing DNA sequencing projects, and thus available DNA sequence data, have stimulated efforts to develop highly discriminatory and high-throughput DNA sequence-based subtyping methods for L. monocytogenes. L. monocytogenes represents one of the most highly sequenced human pathogens; more than 20 genome sequences are currently available for this organism. This review provides an overview of the concepts behind subtyping and discusses the application of molecular subtyping methods, with an emphasis on DNA sequence-based subtyping methods to characterize L. monocytogenes.
High-Performance Thin Layer Chromatography for Quality Control of Multicomponent Herbal Drugs: Example of Cangzhu Xianglian San
Authors: Li Zhi , Merfort Irmgard , Reich Eike 
Published: February 2020

Abstract
Due to their complexity, multicomponent herbal drugs pose enormous analytical challenges for quality control (QC). Although they may have traditionally been used for hundreds of years, the information about their chemical composition is often still limited. Selecting suitable markers to monitor the identity and potency of the mixture is, therefore, difficult. There is also the possibility of natural variability for each plant. This paper illustrates a pragmatic and practical approach to QC of a multicomponent herbal drug by HPTLC. Cangzhu Xianglian San (CXS), composed of the herbal drugs Coptis rhizome, Aucklandia root, and Atractylodes rhizome (30 + 20 + 60, w/w/w), is used as an example. A characteristic fingerprint can be generated for CXS with tolueneethyl acetatemethanolisopropanolwater (60 + 30 + 20 + 15 + 3, v/v/v/v/v) mobile phase on HPTLC silica gel 60 conditioned with ammonia. While the corresponding monograph of the Chinese Veterinary Pharmacopoeia focuses only on the detection of berberine, one of the principal components of Coptis rhizome, the proposed method of identification determines the presence of all three components in the drug after derivatization with anisaldehyde reagent. The same method can also be used to quantitatively determine the content of berberine by scanning densitometry. This paper provides details about the validation of the qualitative and quantitative determinations.
Sensitive Determination of Indomethacin in Pharmaceuticals and Urine by Sequential Injection Analysis and Optosensing
Authors: Molina-García Lucía , Córdova M Luisa Fernández-de , Ruiz-Medina Antonio 
Published: February 2020

Abstract
A selective and sensitive method based on coupling of sequential injection analysis (SIA) and optosensing was developed and applied to the determination of indomethacin in pharmaceutical and urinary samples. After alkaline hydrolysis, the fluorescent product generated from indomethacin is inserted in the flow system, transitorily retained on an active solid support (Sephadex QAE A-25) filling the flowcell, and monitored at 283/371 nm (λex/λem). The system was calibrated for two sample volumes, 100 and 1000 µL. It showed a linear dynamic range of 0.56.5 ng/mL, with an LOD of 0.15 ng/mL and an RSD of 3.9% (n = 10) when the highest sample volume was used. The proposed fluorometric SIA optosensor was applied to the determination of indomethacin in both pharmaceuticals and urine samples, and satisfactory results were obtained.