bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Inorganic Oxidants to the Spectrophotometric Determination of Ribavirin in Bulk and Capsules
Authors: Darwish Ibrahim A , Khedr Alaa S , Askal Hassan F , Mohamed Ramadan M 
Published: February 2020

Abstract
Eight spectrophotometric methods for determination of ribavirin have been developed and validated. These methods were based on the oxidation of the drug by different inorganic oxidants: ceric ammonium sulfate, potassium permanganate, ammonium molybdate, ammonium metavanidate, chromium trioxide, potassium dichromate, potassium iodate, and potassium periodate. The oxidation reactions were performed in perchloric acid medium for ceric ammonium sulfate and in sulfuric acid medium for the other reagents. With ceric ammonium sulfate and potassium permanganate, the concentration of ribavirin in its samples was determined by measuring the decrease in the absorption intensity of the colored reagents at 315 and 525 nm, respectively. With the other reagents, the concentration of ribavirin was determined by measuring the intensity of the developed colored reaction products at the wavelengths of maximum absorbance: 675, 780, 595, 595, 475, and 475 nm for reactions with ammonium molybdate, ammonium metavanidate, chromium trioxide, potassium dichromate, potassium iodate, and potassium periodate, respectively. Different variables affecting the reaction conditions were carefully studied and optimized. Under the optimum conditions, linear relationships with good correlation coefficients (0.99840.9998) were found between the absorbance readings and the concentrations of ribavirin in the range of 41400 g/mL. The molar absorptivities were correlated with the oxidation potential of the oxidants used. The precision of the methods were satisfactory; the values of relative standard deviation did not exceed 1.64%. The proposed methods were successfully applied to the analysis of ribavirin in pure drug material and capsules with good accuracy and precision; the recovery values were 99.2101.2 0.481.30%. The results obtained using the proposed spectrophotometric methods were comparable with those obtained with the official method stated in the United States Pharmacopeia.
Determination ofMagnesium Stearate in Capsule- or Tablet-Type Supplements
Authors: Uematsu Yoko , Ogimoto Mami , Kabashima Junichirou , Ito Kouichi , Yasuda Kazuo 
Published: February 2020

Abstract
A simple method for the determination of magnesium stearate in capsule- or tablet-type supplements was developed. Free stearic acid in the sample was removed by extraction with tetrahydrofuran. The remaining stearate was converted to stearic acid by reaction with a cation-exchange resin. The resulting stearic acid was determined by gas chromatography with a polar column. Esters of stearic acid were not converted to stearic acid and would not cause a positive error in the amount of stearate. The amount of magnesium stearate was calculated based on the stearic acid concentration thus obtained. Magnesium stearate levels in 5 out of 25 supplements exceeded 2500 g/g, which indicated the possible admixture of magnesium stearate.
Matrix Solid-Phase DispersionMicroextraction and Determination of Pesticide Residues in Medicinal Herbs by Gas Chromatography with a Nitrogen-Phosphorus Detector
Authors: Tang Feng , Yue Yongde , Hua Rimao , Cao Haiqun 
Published: February 2020

Abstract
Agas chromatography method for the determination of residues of 6 pesticides in Isatis indigotica Fort and Paeonia lactiflora Pall is described. Optimizations of different parameters were performed. The method used 0.5 g herb sample, silica gel as thematrix solid-phase dispersion sorbent, and acetone as the eluting solvent. Recoveries at spiked concentrations between 0.1 and 5mg/kg were between 80.63 and 110.12, with relative standard deviations ranging from 0.43 to 17.67. The limits of quantitation were 0.01 mg/kg for metalaxyl, triadimefon, and paclobutrazol and 0.05mg/kg for vinclozolin, tebuconazole, and fenarimol. The method may be useful as a screening protocol for the determination of these pesticides in medicinal herb samples.
Verification of a Method for Microcoulometric Determination of Adsorbable Organic Halide Pollutants in Natural, Drinking, Waste, and Treated Waters
Authors: Ivanova Pavlina , Stratiev Ditso , Pavlova Antoaneta 
Published: February 2020

Abstract
A microcoulometric method is described for the determination of organic-halide pollutants at 2-2000 μg/L in natural, drinking, waste, and treated waters. The conditions for the adsorption of organic halides, using a microcolumn with activated charcoal-and for the desorption of inorganic halides-as well as for the pyrolysis process, were optimized for the successful determination of priority organic halide pollutants. An appropriate criterion was proposed to stop the desorption step. The mean recovery was 100.3%, and the mean relative standard deviation was 9.9%. The detection limit based on 3 times the standard deviation of the blank sample was 2 μg/L.
Method Validation for Determination of the 15 European-Priority Polycyclic Aromatic Hydrocarbons in Primary Smoke Condensates by Gas Chromatography/Mass Spectrometry: Interlaboratory Study
Authors: Simon Rupert , Palme Sonja , Anklam Elke , Hanot M W  V ,   Collaborators:, Delaire L , Hanot V , Holzer H , Jira W , Levasseur C , Monteau F , Obiedzinski M W , Ojala; M , Peschke D , Ramakrishnan S , Ranta C , Ruthenschrör A , Schirmacher M , Seidel A , Sopelana P , Wolz G , Wright C 
Published: February 2020

Abstract
A collaborative study was conducted to validate an analytical method for quantification of the 15 polycyclic aromatic hydrocarbons (PAHs) regarded in 2002 as a health concern by the former Scientific Committee on Food of the European Commission (SCF) in primary smoke condensates. The method is based on gas chromatography/mass spectrometry of a cyclohexane extract with solid-phase cleanup through silica gel. The analytes were detected in the selected-ion monitoring mode and quantified by using 3 isotopically labeled internal standard compounds. Seventeen laboratories participated in the collaborative validation study, of which 12 reported valid results. The data were subjected to Cochran, single Grubbs, and double Grubbs tests for statistical outliers. A maximum of 2 outliers was eliminated before further statistical evaluation of the method performance characteristics. Depending on the analyte, the results showed relative standard deviations for repeatability between 4.2 and 30% and for reproducibility from 9.9 to 60%. The recoveries varied between about 50 and 85%, except those for cyclopenta[cd]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene. Nevertheless, because Commission Directive 2005/10/EC allows for a recovery range of 50120% for (BaP) benzo[a]pyrene in various foods, it can be concluded that the method performs appropriately within the analytical range between 5 and 25 μg/kg of primary smoke condensate. For BaP the validated analytical range covered 520 μg/kg, and for benzo[a]anthracene (BaA) 1025 μg/kg. The method is suitable for monitoring BaP and BaA at their respective maximum permitted levels of 10 and 20 μg/kg. Three analytes, benzo[b]-, benzo[j]-, and benzo[k]-fluoranthene could not be separated by all of the participants and were therefore treated as the sum. Nevertheless, with this method the pattern of the respective concentrations of these 15 PAHs can be monitored in primary smoke condensate as suggested by the SCF.
Determining a One-Tailed Upper Limit for Future Sample Relative Reproducibility Standard Deviations
Authors: McClure Foster D , Lee Jung K 
Published: February 2020

Abstract
A formula was developed to determine a one-tailed 100p% upper limit for future sample percent relative reproducibility standard deviations &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq1.gif"/&gt; &lt;/inline-formula&gt; , where sR is the sample reproducibility standard deviation, which is the square root of a linear combination of the sample repeatability variance ( &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq2.gif"/&gt; &lt;/inline-formula&gt; ) plus the sample laboratory-to-laboratory variance ( &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq3.gif"/&gt; &lt;/inline-formula&gt; ), i.e., &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq4.gif"/&gt; &lt;/inline-formula&gt; , and y is the sample mean. The future RSDR, % is expected to arise from a population of potential RSDR, % values whose true mean is &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq5.gif"/&gt; &lt;/inline-formula&gt; , where R and are the population reproducibility standard deviation and mean, respectively.
Immunobiosensor Detection of Domoic Acid as a Screening Test in Bivalve Molluscs: Comparison with Liquid Chromatography-Based Analysis
Authors: Traynor Imelda M , Plumpton Laura , Fodey Terence L , Higgins Cowan , Elliott Christopher T 
Published: February 2020

Abstract
A rapid and sensitive immuno-based screening method was developed to detect domoic acid (DA) present in extracts of shellfish species using a surface plasmon resonance-based optical biosensor. A rabbit polyclonal antibody raised against DA was mixed with standard or sample extracts and allowed to interact with DA immobilized onto a sensor chip surface. The characterization of the antibody strongly suggested high cross-reactivity with DA and important isomers of the toxin. The binding of this antibody to the sensor chip surface was inhibited in the presence of DA in either standard solutions or sample extracts. The DA chip surface proved to be highly stable, achieving approximately 800 analyses per chip without any loss of surface activity. A single analytical cycle (sample injection, chip regeneration, and system wash) took 10 min to complete. Sample analysis (scallops, mussels, cockles, oysters) was achieved by simple extraction with methanol. These extracts were then filtered and diluted before analysis. Detection limits in the ng/g range were achieved by the assay; however, the assay parameters chosen allowed the test to be performed most accurately at the Euopean Union's official action limit for DA of 20 g/g. At this concentration, intra- and interassay variations were measured for a range of shellfish species and ranged from 4.5 to 7.4% and 2.3 to 9.7%, respectively.
Biosensors for the Analysis of Food- and Waterborne Pathogens and Their Toxins
Authors: Rasooly Avraham , Herold Keith E 
Published: February 2020

Abstract
Biosensors are devices which combine a biochemical recognition element with a physical transducer. There are various types of biosensors, including electrochemical, acoustical, and optical sensors. Biosensors are used for medical applications and for environmental testing. Although biosensors are not commonly used for food microbial analysis, they have great potential for the detection of microbial pathogens and their toxins in food. They enable fast or real-time detection, portability, and multipathogen detection for both field and laboratory analysis. Several applications have been developed for microbial analysis of food pathogens, including E. coli O157:H7, Staphylococcus aureus, Salmonella, and Listeria monocytogenes, as well as various microbial toxins such as staphylococcal enterotoxins and mycotoxins. Biosensors have several potential advantages over other methods of analysis, including sensitivity in the range of ng/mL for microbial toxins and &lt;100 colony-forming units/mL for bacteria. Fast or real-time detection can provide almost immediate interactive information about the sample tested, enabling users to take corrective measures before consumption or further contamination can occur. Miniaturization of biosensors enables biosensor integration into various food production equipment and machinery. Potential uses of biosensors for food microbiology include online process microbial monitoring to provide real-time information in food production and analysis ofmicrobial pathogens and their toxins in finished food. Biosensors can also be integrated into Hazard Analysis and Critical Control Point programs, enabling critical microbial analysis of the entire food manufacturing process. In this review, the main biosensor approaches, technologies, instrumentation, and applications for food microbial analysis are described.
Evaluation of a Polymerase Chain Reaction-Based Heteroduplex Assay for Detecting the Adulteration of Processed Orange Juice with Mandarin Juice
Authors: Mooney Rachel , Chappell Louise , Knight Angus I 
Published: February 2020

Abstract
A polymerase chain reaction (PCR)-based heteroduplex assay was evaluated for the detection of mandarin juice in processed orange juice. PCR amplification of a fragment of the chloroplast trnT-trnL intergenic spacer derived from mixtures of DNA extracted from orange and mandarin juice resulted in heteroduplex formation. The heteroduplex resulted from the co-amplification of a fragment containing an 8 base-pair indel that distinguished mixtures of orange and mandarin juice from orange juice and mandarin juice alone. The heteroduplex assay was evaluated against authentic juices obtained from different citrus species and confirmed that the marker was homogeneous within Citrus. The data obtained demonstrated maternal inheritance of chloroplast type in Citrus sp. and allowed the identification and confirmation of the maternal parentage of unknown and known citrus hybrids. Analysis of the quantitative potential of the PCR and polyacrylamide gel electrophoresis (PAGE) analysis demonstrated good repeatability with a coefficient of variation of 7.5%. Greatest sources of variance in experimental results were attributable to species and varietal differences in the levels of the PCR target. Mandarin juice contained approximately 18% (w/v) less PCR target sequence than did orange juice. The assay was tested in a blind trial using processed juices and correctly identified 20/22 samples with no false-positive results.
An Overview of the Health Effects of Isoflavones with an Emphasis on Prostate Cancer Risk and Prostate-Specific Antigen Levels
Authors: Messina Mark , Kucuk Omer , Lampe Johanna W 
Published: February 2020

Abstract
Soybean isoflavones possess hormonal and nonhormonal properties that may reduce the risk of coronary heart disease, osteoporosis, and certain cancers, and alleviate hot flashes in menopausal women. Among the various cancers whose risk may be reduced by isoflavones, there is particular interest in prostate cancer. Eleven trials have examined the effects of isoflavones on serum prostate-specific antigen (PSA) levels. The dose of isoflavones in these trials from supplements or soy protein ranged from 60 to 900 mg/day (typical Japanese intake is 3050 mg/day), subject number/group ranged from 8 to 62, and study duration from 20 days to 1 year. Isoflavones did not affect serum PSA in healthy subjects. In contrast, in 4 of 8 trials involving prostate cancer patients, isoflavones significantly favorably affected PSA although in no studies was there an absolute decrease in PSA concentrations. The mechanism by which isoflavones affect PSA could not be determined from the existing research, although hormonal changes do not seem to be a factor. The clinical evidence is sufficiently encouraging to justify considering additional Phase II and III clinical trials investigating the efficacy of soy isoflavones in different populations of prostate cancer patients alone and in combination with other treatments.
Mammary Gland Tumor Promotion in F1 Generation Offspring from Male and Female Rats Exposed to Soy Isoflavones for a Lifetime
Authors: Mehta Rekha , Lok Eric , Caldwell Donald , Mueller Rudolf , Kapal Kamla , Taylor Marnie , Cooke Gerard M , Curran Ivan H A 
Published: February 2020

Abstract
The effect of dietary isoflavones in the form of NOVASOY (NS) was investigated on methylnitrosourea-initiated mammary gland cancer in F1 generation female Sprague Dawley rats from parents who had undergone lifetime exposure to variable levels of dietary NS. In comparison to NS-free dietary groups, lifetime exposure of F1 rats to 40 and 1000 mg/kg diets of NS reduced tumor latency, but did not significantly affect tumor incidence, tumor size, or tumor multiplicity. A significantly lower tumor multiplicity was, however, observed in rats fed the soy-based, NS-free diet compared to the casein-based, NS-free diet. An evaluation of a dose-response relationship pointed towards a biphasic effect, with a trend showing lower tumor incidence, lower tumor multiplicity, and lower tumor size in rats fed 1000 mg/kg diet NS compared to 40 mg/kg diet NS; however, the data failed to achieve statistical significance. Histologically, tumor type significantly differed according to the administered basal diet variety and NS dose. Our data and that of others provide conflicting evidence for chemopreventive effects of soy isoflavones on mammary gland tumor induction. We suggest standardization of interlaboratory experimental approaches for establishing low dose-response relationships for soy and its isoflavones to aid in risk assessment.
Ion Chromatographic Determination of Phosphorus Soluble in Different Extracting Media in Fertilizers
Authors: Mazzei Raffaele Antonio , Scuppa Stefano 
Published: February 2020

Abstract
A new method based on ion chromatography (IC) was developed for the determination of phosphorus in fertilizers. Fertilizers were extracted with water, mineral acids, and 2% formic acid, 2% citric acid, and neutral ammonium citrate solutions according to European Regulation No. 2003/2003 of the European Parliament and the Council of October 13, 2003, or the Decree of the Italian Agriculture Minister of June 17, 2002; the extracts were analyzed by direct injection, after simple filtration, by IC on an IonPac AS19 (250 × 4 mm id) column, using a KOH (21-50-21 mM) gradient and suppressed conductivity detection. The calibration plot was linear over the range of 550 mg/L (r2 of &gt;0.999). The method was evaluated by comparison with a gravimetric method according to established norms. Associated uncertainty at the 95% confidence level was established as 0.47% for the determination of 346% P2O5 by IC. A good chromatographic separation of phosphorus forms such as phosphates and phosphites, and some other important anions like nitrates, chlorides, and sulfates present in many commercial fertilizers was also possible, with a linear response over the range of 550 mg/L. After a more complete validation, this IC determination of phosphorus could replace more tedious methods such as those using gravimetric determinations.
Highly Sensitive Spectrofluorimetric Determination of Ephedrine Hydrochloride in Pharmaceutical Preparations
Authors: Ulu Sevgi Tatar 
Published: February 2020

Abstract
A sensitive and specific spectrofluorimetry method was developed and validated for the quantification of ephedrine (EP) in pharmaceutical preparations. The method is based on the fluorescent enhancing reaction of EP with 7-chloro-4-nitrobenzofurazan (NBD-CI; derivatization reagent), in borate buffer of pH 9 to yield a yellow, fluorescent product. Under these experimental conditions, the derivatized product of EP had excitation and emission wavelength maxima at 458 and 516 nm, respectively. The linear range of this method was 202500 ng/mL. The detection limit was 7.3 ng/mL EP. Intra- and interday precisions of the assay at 3 concentrations within this range were 0.0371.77%. The low relative standard deviation values indicate good precision, and high recovery values indicate excellent accuracy of the method. The proposed method was applied to the determination of the examined drugs in pharmaceutical formulations, and the results indicate that the method is equally as accurate, precise, and reproducible as the official method.
Validation of Liquid Chromatography and Liquid Chromatography/Tandem Mass Spectrometry Methods for the Determination of Etoricoxib in Pharmaceutical Formulations
Authors: Brum Liberato , Fronza Marcio , Ceni Danieli Catia , Barth Thiago , Dalmora Sergio Luiz 
Published: February 2020

Abstract
Reversed-phase liquid chromatography (LC) and LC/tandem mass spectrometry (LC/MS/MS) methods were developed and validated for the determination of etoricoxib in pharmaceutical dosage forms. The LC method was performed by reversed-phase chromatography on a Synergi fusion C18 column (150 × 4.6 mm id) maintained at ambient temperature. The mobile phase consisted of 0.01 M phosphoric acid, pH 3.0acetonitrile (62 + 38, v/v) at a flow rate of 1.0 mL/min, and photodiode array detection at 234 nm was used. The chromatographic separation was obtained within 7.0 min, and calibration curves were linear in the concentration range of 0.02-150 μg/mL. The LC/MS/MS method was performed on a Luna C18 column (50 × 3.0 mm id). The mobile phase consisted of acetonitrilewater (95 + 5)0.1% acetic acid (90 + 10, v/v). Detection was performed by positive electrospray ionization in the multiple reaction monitoring mode, monitoring the transitions 359.3 &gt; 280.0 and 332.0 &gt; 95.0 for etoricoxib and piroxicam (internal standard), respectively. The chromatographic separation was obtained within 2.0 min, and calibration curves were linear in the concentration range of 15000 ng/mL. Validation parameters, such as specificity, linearity, precision, accuracy, and robustness, were evaluated, which gave results within the acceptable range for both methods. Moreover, the proposed methods were successfully applied for routine quality control analysis of pharmaceutical products and showed significant correlation (r = 0.9999) of the results.
A Validated Spectrofluorometric Assay for the Determination of Certain Macrolide Antibiotics in Pharmaceutical Formulations and Spiked Biological Fluids
Authors: El-Rabbat Nawal , Askal Hassan F , Khashaba Pakinaz Y , Attia Noha N 
Published: February 2020

Abstract
This paper describes a simple spectrofluorometric method for the analysis of 4 macrolide antibiotics. The method is based on the condensation of 10% (w/v) malonic acid and acetic acid anhydride under the catalytic effect of tertiary amine groups of the studied macrolides. The relative fluorescence intensity of the condensation product was measured at 397/452 nm (excitation/emission) for azithromycin dihydrate and at 392/445 nm (for clarithromycin, erythromycin ethylsuccinate, and roxithromycin. All variables affecting the reaction conditions were studied. The effects of potential interference due to common excipients, such as starch, lactose, sucrose, glucose, gum acacia, and magnesium stearate, as well as trimethoprim and sulfisoxazole acetyl formulated in primomycin capsules and pediazole oral suspension, respectively, were studied. A validation study for the proposed method was carried out according to U.S. Pharmacopeia 2002. The linearity ranges were 380 ng/mL for all of the cited macrolides. The limit of detection range was 0.741.20 ng/mL, while the limit of quantitation range was 2.474.02 ng/mL. The method was applied for the assay of the studied macrolides in pure pharmaceutical formulations and in spiked biological fluids. Results were compared with those obtained from the reported method, where calculated t- and F-values indicated high accuracy and good precision for the proposed method.