bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectrofluorimetric Determination of Acetaminophen with N-Bromosuccinimide
Authors: Abdel-Wadood Hanaa M , Mohamed Niveen A , Mohamed Fardous A 
Published: February 2020

Abstract
A simple, sensitive, and selective method for determination of acetaminophen based on its oxidation using N-bromosuccinimide (NBS) to produce a highly fluorescent product. Optimization of reaction variables was carried out concerning NBS concentration, pH, temperature, reaction time, and stability time. Under optimal analytical conditions, the fluorescent intensity was measured at λemission. 442 nm (excitation at λ 330 nm). The linearity range is 120–800 ng/mL with lower detection limit of 33.6 ng/mL acetaminophen. The method was applied successfully to the determination of the compound in pharmaceutical preparations, with average recovery of 100.3 ± 2%. The method was also applied successfully to the determination of the drug in spiked plasma samples, with an average recovery of 101.2 ± 1%. Interference effects of some compounds, present in combination with acetaminophen, were studied and the tolerance limits of these compounds were determined.
Spectrophotometric Study of Etodolac Complexes with Copper (II) and Iron (III)
Authors: Amer Sawsan M , El-Saharty Yasser S , Metwally Fadia H , Younes Kareem M Younes 
Published: February 2020

Abstract
A rapid, simple, and selective method was developed for the determination of etodolac. The method depends on complexation of etodolac with copper (II) acetate and iron (III) chloride followed by extraction of complexes with dichloromethane and then measuring the extracted complexes spectrophotometrically at 684 and 385 nm in case of Cu (II) or Fe (III), respectively. Different factors affecting the reaction, such as pH, reagent concentration, and time, were studied. By use of Job's method of continuous variation, the molar ratio method, and elemental analysis, the stoichiometry of the reaction was found to be in the ratio of 1:2 and 1:3, metal:drug in the case of Cu (II) and Fe (III), respectively. The method obeys Beer's law in a concentration range of 2.00–9.00 and 0.50–2.00 mg/mL in case of Cu (II) and Fe (III), respectively. The stability of the complexes formed was also studied, and the reaction products were isolated for further investigation. The complexes have apparent molar absorptivities of about 32.14 ± 0.97 and 168.32 ± 1.12 for Cu (II) and Fe (III), respectively. The suggested procedures were successfully applied to the analysis of pure etodolac and its pharmaceutical formulations. The validity of the procedures was further ascertained by the method of standard additions, and the results were compared with other reported spectrophotometric methods and showed no significant difference in accuracy and precision.
Residue Analysis for Halofuginone in Sturgeon Muscle by Immunoaffinity Cleanup and Liquid Chromatography
Authors: Ding Shuangyang , Hou Yali , Wu Ningpeng , Shen Jiangzhong 
Published: February 2020

Abstract
A high-performance liquid chromatography (LC) method was developed for the determination of halofuginone (HFG) in sturgeon muscle. The extracted samples were cleaned up by an immunoaffinity chromatography column that was prepared by covalently coupling polyclonal antibodies against HFG to cyanogen bromide (CNBr) activated Sepharose 4B. The eluate was evaporated to dryness, and residues were determined by LC with absorbance detection at 243 nm. Recoveries of HFG from samples fortified at 20–200 μg/kg levels ranged 74.6–81.1%, with coefficients of variation of 0.7–8.6%. The detection limit was estimated to be 10 μg/kg in a 2 g sample.
Simultaneous Determination of Chlorpheniramine Maleate and Dexamethasone in a Tablet Dosage Form by Liquid Chromatography
Authors: Moyano María A , Rosasco María A , Pizzorno María T , Segall Adriana I 
Published: February 2020

Abstract
An accurate, simple, reproducible, and sensible liquid chromatographic method was developed and validated for the determination of chlorpheniramine maleate and dexamethasone in a tablet formulation. The analysis was performed at room temperature on a reversed-phase C18 column with UV detection at 254 nm. The mobile phase consisted of 7.5 mM monobasic potassium phosphate in methanol–water (62.5 + 37.5) at a constant flow rate of 1 mL/min. The method was validated in terms of linearity, precision, accuracy, and specificity by forced decomposition of chlorpheniramine maleate and dexamethasone initiated by using acid, base, water, hydrogen peroxide, heat, and light. The response was linear in the ranges of 0.04–0.12 and 0.006–0.016 mg/mL for chlorpheniramine maleate (r2 = 0.9999) and dexamethasone (r2 = 0.9994), respectively. The relative standard deviation values for intra- and interday precision studies were 2.39 and 2.02, respectively, for chlorpheniramine maleate and 2.39 and 1.25, respectively, for dexamethasone. Recoveries ranged from 95.07 to 101.95% for chlorpheniramine maleate and from 97.75 to 102.10% for dexamethasone.
Improved Method for the Determination of Anatoxin-a and Two of Its Metabolites in Blue-Green Algae Using Liquid Chromatography with Fluorescence Detection
Authors: Rawn Dorothea F K , Lau Benjamin P-Y , Niedzwiadek Barbara , Lawrence James F 
Published: February 2020

Abstract
Anatoxin-a, a neurotoxin produced by blue-green algae (BGA) species, can cause death to exposed organisms. In North America, BGA are harvested and sold as food supplements, some of which contain elevated levels of other algal toxins, such as microcystins. Concern that elevated levels of anatoxin-a also may be present in BGA food supplements has led to the development of a simple method to determine the presence of anatoxin-a in BGA. Some researchers have successfully analyzed this compound using liquid chromatography with fluorescence detection by forming a fluorescent derivative with 4-fluoro-7-nitrobenzofurazan (NBD-F) in water and phytoplankton extracts. With this method, the background noise is high in BGA extracts due to the presence of co-extractives. Addition of o-phthaldialdehyde (OPA) and mercaptoethanol to the extract before addition of the NBD-F resulted in the successful removal of primary amines from the background noise when the NBD-F derivatives were detected with fluorescence. Improved chromatograms were obtained when extracts were cleaned up in this manner, leading to a lower detection limit (approximately 50 μg/kg) for anatoxin-a. The detection limits obtained for the 2 degradation products dihydroanatoxin-a and epoxyanatoxin-a in BGA extracts were similarly low (55 and 65 μg/kg, respectively).
Determination of Fludioxonil and Famoxadone in Processed Fruits and Vegetables by Liquid Chromatography/Electrospray Tandem Mass Spectrometry
Authors: Sannino Anna , Bandini Mirella 
Published: February 2020

Abstract
The feasibility of using liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) for determining 2 fungicides (fludioxonil and famoxadone) in tomato pulp, pear purée, and concentrated lemon juice has been evaluated. A miniaturized extraction-partition procedure requiring small amounts of nonchlorinated solvents was used. The extracts (5 μL) were analyzed by LC/ESI-MS/MS without previous cleanup. Chromatographic determination was performed using a C18 column with isocratic elution. Four MS/MS transitions of precursor ions were monitored simultaneously (2 for each pesticide) by means of negative ESI. Mean recoveries from samples at fortification levels of 0.002–0.020 mg/kg (fludioxonil) and 0.010–0.100 mg/kg (famoxadone) ranged from 77.1 to 96.5%, with associated relative standard deviations between 4.2 and 11.5%.
Species Identification of Crassostrea and Ostrea Oysters by Polymerase Chain Reaction Amplification of the 5S rRNA Gene
Authors: Cross Ismael , Rebordinos Laureana , Diaz Edgardo 
Published: February 2020

Abstract
A specific multiplex polymerase chain reaction (PCR) was developed for the identification of Crassostrea angulata, C. gigas, Ostrea edulis, and O. stentina oyster species. Universal primers were used for the amplification of complete repetition units of 5S rDNA in each of the 4 species. The alignment of the obtained sequences was the basis for the specific design of species-specific primers (ED1, ED2, ST1, ST2, CR1, and CR2) located in the nontranscribed spacer regions. The different sizes of the species-specific amplicons, separated by agarose gel electrophoresis, allowed identification of Crassostrea and Ostrea species. A multiplex PCR with a set of the 6 designed primers showed that they did not interfere with each other and bound specifically to the DNA target. This genetic marker can be very useful for traceability of the species, application in the management of oyster cultures, and conservation of the genetic resources of the species.
Determination of Acrylamide Formed in Asparagine/d-Glucose Maillard Model Systems by Using Gas Chromatography with Headspace Solid-Phase Microextraction
Authors: El-Ghorab Ahmed H , Fujioka Kazutoshi , Shibamoto Takayuki 
Published: February 2020

Abstract
A gas chromatographic method, along with a headspace solid-phase microextraction (HS-SPME), was developed for the determination of acrylamide formed in Maillard reaction model systems. The developed method was validated by liquid chromatography/mass spectrometry. A headspace sample was collected from an aqueous acrylamide solution (100 μg/mL) by SPME and directly injected into a gas chromatograph equipped with a nitrogen-phosphorus detector. The recovery of acrylamide from an aqueous solution was satisfactory, i.e, &gt;93% under the conditions used. Acrylamide formed in an asparagine/d-glucose (molar ratio, 1/2) Maillard reaction model system heated at 150 and 170C for 20 min was collected and analyzed by the newly developed method using gas chromatography with nitrogen-phosphorus detection and HS-SPME. The amounts of acrylamide were 318 33 μg/g asparagine from a sample heated at 150C and 3329 176 g/g asparagine from a sample heated at 170C. Addition of cysteamine or glutathione to the above model system reduced acrylamide formation. Acrylamide formation was not observed when cysteamine or glutathione was added to asparagine in the above model systems to obtain equimolar concentrations of both compounds. This newly developed method is simple and sensitive, and requires no solvent extraction.
A Method for the Analysis of Ginsenosides, Malonyl Ginsenosides, and Hydrolyzed Ginsenosides Using High-Performance Liquid Chromatography with Ultraviolet and PositiveMode Electrospray IonizationMass Spectrometric Detection
Authors: Sloley Brian Duff , Lin Yi-Chan James , Ridgway Douglas , Semple Hugh Alexander , Tam Yun Kau , Coutts Ronald Thomson , Löbenberg Raimar , Tam-Zaman Nuzhat 
Published: February 2020

Abstract
A high-performance liquid chromatographic separation coupled to diode array absorbance and positive mode electrospraymass spectrometric detection has been developed for the analysis of ginsenosides, malonyl ginsenosides, and hydrolyzed ginsenosides in extracts of Asian ginseng (Panax ginseng) and American ginseng (P. quinquefolius). The method is capable of separating, identifying, and quantifying the predominant ginsenosides found in heated alcoholic extracts of Asian and American ginseng roots routinely sold as nutraceuticals. It also separates and identifies the malonyl ginsenosides often found in cold alcoholic extracts of ginseng root and has the potential to quantify these compounds if pure standards are available. Furthermore, it can separate and identify ginsenoside hydrolysis products such as those readily produced in situations mimicking gastric situations, including those used for dissolution studies (i.e., 0.1 N HCl, 37C).
Determination of Campesterol, Stigmasterol, and beta-Sitosterol in Saw Palmetto RawMaterials and Dietary Supplements by Gas Chromatography: Single-Laboratory Validation
Authors: Sorenson Wendy R , Sullivan Darryl 
Published: February 2020

Abstract
In conjunction with an AOAC Presidential Task Force on Dietary Supplements, a method was validated for measurement of 3 plant sterols (phytosterols) in saw palmetto raw materials, extracts, and dietary supplements. AOAC Official Method 994.10, Cholesterol in Foods, was modified for purposes of this validation. Test samples were saponified at high temperature with ethanolic potassium hydroxide solution. The unsaponifiable fraction containing phytosterols (campesterol, stigmasterol, and beta-sitosterol) was extracted with toluene. Phytosterols were derivatized to trimethylsilyl ethers and then quantified by gas chromatography with a hydrogen flame ionization detector. The presence of the phytosterols was detected at concentrations greater than or equal to 1.00 mg100 g based on 23 g of sample. The standard curve range for this assay was 0.00250 to 0.200 mgmL. The calibration curves for all phytosterols had correlation coefficients greater than or equal to 0.995. Precision studies produced relative standard deviation values of 1.52 to 7.27% for campesterol, 1.62 to 6.48% for stigmasterol, and 1.39 to 10.5% for beta-sitosterol. Recoveries for samples fortified at 100% of the inherent values averaged 98.5 to 105% for campesterol, 95.0 to 108% for stigmasterol, and 85.0 to 103% for beta-sitosterol.
Scoring in Genetically Modified Organism Proficiency Tests Based on Log-Transformed Results
Authors: Thompson Michael , Ellison Stephen L R , Owen Linda , Mathieson Kenneth , Powell Joanne , Key Pauline , Wood Roger , Damant Andrew P 
Published: February 2020

Abstract
The study considers data from 2 UK-based proficiency schemes and includes data from a total of 29 rounds and 43 test materials over a period of 3 years. The results from the 2 schemes are similar and reinforce each other. The amplification process used in quantitative polymerase chain reaction determinations predicts a mixture of normal, binomial, and lognormal distributions dominated by the latter 2. As predicted, the study results consistently follow a positively skewed distribution. Log-transformation prior to calculating z-scores is effective in establishing near-symmetric distributions that are sufficiently close to normal to justify interpretation on the basis of the normal distribution.
Generic Nonextractive Spectrophotometric Method for Determination of 4-Quino-Naphthollone Antibiotics by Formation of Ion-Pair Complexes with -Naphthol
Authors: Darwish Ibrahim A , Refaat Ibrahim H , Askal Hassan F , Marzouq Mostafa A 
Published: February 2020

Abstract
This paper describes the development of a generic spontaneous nonextractive spectrophotometric method for determination of 13 pharmaceutically important 4-quinolone antibiotics. The method was based on the formation of yellow-colored water-soluble ion-pair complexes between 2% (w/v) -naphthol reagent and each of the studied drugs in sulfuric acid medium at room temperature. The formed ion-pair chromogens have maximum absorption peaks in the range of 365391 nm. The concentrations of the reagents and the experimental conditions affecting the reaction were optimized. Under the optimum conditions, linear relationships with good linear coefficients (0.99870.9995) were found between the absorbance and concentration of the investigated drugs in the range of 10350 g/mL. The assay limits of detection and quantitation were 19.9 and 3.432.9 g/mL, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the analysis of the investigated drugs in pure and pharmaceutical dosage forms with good accuracy and precision; the percentages of label claim ranged from 97.8102.8 0.351.60%. The results obtained by the proposed spectrophotometric method were comparable with those obtained by the official or reported methods. The proposed method is superior to all the previously reported ion-pair formation-based methods in terms of simplicity because it did not involve extraction procedures for the ion-pair complex. Therefore, this method might be recommended for routine use in quality control laboratories for analysis of the investigated 4-quinolone antibiotics in their pure forms, as well as in pharmaceutical dosage forms.
Reversed-Phase High-Performance Liquid Chromatography Determination of Selected Phenolic Acids in Propolis Concentrates in Terms of Standardization For Drug Manufacturing Purposes
Authors: Krzek Jan , Kaleta Jolanta , Hubicka Urszula , Niedzwiedz Aneta 
Published: February 2020

Abstract
A reversed-phase high-performance liquid chromatography method with gradient elution was developed for the determination of the caffeic, p-coumaric, and ferulic acids in propolis concentrates. Solid-phase extraction on an RP18 column was applied for preliminary purification, and chromatographic separation was performed on 100 RP18e Lichrospher column of particle size 5 m. The mobile phase was obtained by mixing in appropriate ratios 0.03 mM NaH2PO4, acidified with H3PO4 up to pH 3.0, with acetonitrile to obtain a gradient in the elution process. Spectrophotometric detection was conducted at 320 nm. Under the established conditions, the method featured high sensitivity, good precision, and comparability of results, as proven by method validation and statistical analysis of the obtained results. The limits of detection were 0.315, 0.325, and 0.695 g/mL for caffeic, p-coumaric, and ferulic acids, respectively. The corresponding recovery values were 98.14, 101.05, and 99.42 and the linearity ranges from 1.31 to 99.18 g/mL, 1.52 to 119.16 g/mL, and 2.42 to 184.14 g/mL. The precision of the method was expresed by relative standard deviation values that did not exceed 3. It was also shown that the propolis concentrates under examination had similar antibacterial activity against Staphylococcus aureus ranging from 119.8 to 124.3 g/mL, contrary to model mixtures that showed no antibacterial activity.
SubcriticalWater Extraction and Determination of Nifedipine in Pharmaceutical Formulations
Authors: Richter Pablo , Toral Maria Ines , Toledo Carla 
Published: February 2020

Abstract
A rapid and simple continuous method for the extraction of nifedipine from tablets was developed by using pressurized hot water at 150C. This is the first time that subcritical water was applied to the extraction of low-polarity compounds in pharmaceutical analysis. The method is based on the increment in solubility of nifedipine in subcritical water. Extraction temperature and static and dynamic extraction time were optimized in order to reach quantitative extraction of the drug from the tablets. After extraction, the drug was determined by spectrophotometry by measuring absorbance at 338 nm. Accuracy and precision of themethodwere determined by analysis of 10 synthetic samples of pharmaceutical formulations preparedwith common tablet excipients. Recoverywas found to be 99.2with a relative standard deviation of 1.9, which indicates that the excipients of the formulation do not interfere in the determination. The method was applied to the determination of the drug content uniformity in tablets.
Singlepathr® Salmonella: Performance-Tested MethodSM 060401
Authors: Thompson Lisa , Lindhardt Charlotte , Odumeru Joseph , Eifert Joseph D 
Published: February 2020

Abstract
Singlepath® Salmonella is an immunochromatographic (lateral flow) assay for the presumptive qualitative detection of Salmonella spp. in food. The AOAC Performance-Tested MethodSM study evaluated Singlepath Salmonella as an effective method for the detection of Salmonella spp. in the following selected foods: dried skimmed milk, black pepper, dried pet food, desiccated coconut, cooked peeled frozen prawns, raw ground beef, and raw ground turkey. When the foods were inoculated with Salmonella spp. at levels ranging from low 0.23–1.08 colony forming units (CFU)/25 g to high (2.3–6.0 CFU/25 g), a Chi-square value of 0.9 indicated that there was no significant difference between Singlepath Salmonella and the ISO 6579:2002 reference method. Singlepath Salmonella gave a false-positive rate of 7.3% and a false-negative rate of 2.5%. For the inclusivity study, all 105 Salmonella serovars reacted with Singlepath Salmonella. For the exclusivity study, 58 non-Salmonella spp. were tested. There were no cross-reactions with Singlepath Salmonella from these strains.
Influence of White Reference Measurement and Background on the Color Specification of Orange Juices by Means of Diffuse Reflectance Spectrophotometry
Authors: Melndez-Martnez Antonio J , Vicario Isabel M , Heredia Francisco J 
Published: February 2020

Abstract
The color of citrus beverages, in general, is related to the consumers' perception of flavor, sweetness, and other characteristics related to the quality of these products, so it is important to develop suitable methods for accurately assessing this attribute. In this study, the color of 2 different kinds of orange juices (ultrafrozen orange juices and orange juices from concentrate) were measured using different white references in order to demonstrate the influence of white reference measurement on the color parameters obtained. The results of this work indicated that the election of a wrong white reference measurement can affect dramatically the accuracy of the objective specification of orange juice color. Thus, the application of analysis of variance ( = 0.01) revealed that, in most cases, the parameters obtained were significantly different. In terms of color differences, the change of the background for the same white reference affected the measurements less than the changes of white references for the same background. On the other hand, important chromatic differences between the 2 types of orange juices studied were found.
Vitamin and Pseudovitamin Analysis with Biosensors in Food ProductsA Review
Authors: Kalman Andras , Caelen Isabelle , Svorc Jozef 
Published: February 2020

Abstract
Biosensors are becoming increasingly important in the food industry for application in safety and quality control among routinely used techniques such as microbiology, chromatography, or specific enzymatic methods. Biosensors offer advantages as alternatives to conventional methods because of their inherent specificity, simplicity, and rapid response. This article presents a short review of vitamin and pseudovitamin analysis techniques using biosensor technology as applied in the food industries, with particular attention to immobilization techniques of biorecognition elements, transducers, an overview of vitamin biosensors, and some future trends.
Rapid Analysis of Coumarins Using Surface Plasmon Resonance
Authors: Lacy Aoife , Dunne Lynsey , Fitzpatrick Brian , Daly Stephen , Keating Gary , Baxter Andrew , Hearty Stephen , O’kennedy Richard 
Published: February 2020

Abstract
Coumarin molecules are ubiquitous in nature. Several have come to prominence as potential clinical therapeutic candidates. The principal example is warfarin, which is a very widely prescribed anticoagulant. Other coumarin derivatives, such as aflatoxin B1, are insidious contaminants in crop-derived foodstuffs. Extreme potency is a common feature of all biochemically active coumarins and, thus reliable methods for their rapid and sensitive detection are of paramount importance. Accordingly, this review examines the current methods used in the analysis of these molecules and compares them with immunoassay-based strategies. As a case study, we report on our experiences with using coumarin-specific polyclonal, monoclonal, and recombinant antibodies in conjunction with a surface plasmon resonance-based biosensor for analysis of coumarins. We chart the assay development process and demonstrate high sensitivity and reproducibility that compares favorably with established methodologies.