bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the Acid Value of Instant Noodles: Interlaboratory Study
Authors: Hakoda Akiko , Sakaida Kenichi , Suzuki Tadanao , Yasui Akemi ,   Collaborators: ACE Cook Co., Ltd., Development Department; Sanyo Foods Co., Ltd., Research and Development; Toyo Suisan Kaisha, Ltd., Quality Assurance Department; Nissin Food Products Co., Ltd., Food Safety Research Institute Quality Assurance Division; Myojo Foods Co., Ltd., Division of Research and Development; Center for Food Quality, Labeling and Consumer Services (Headquarters: Otaru Center, Sendai Center, Yokohama Center, Nagoya Center, Kobe Center, Okayama Center, Moji Center)
Published: February 2020

Abstract
An interlaboratory study was performed to evaluate the method for determining the acid value of instant noodles, based on the Japanese Agricultural Standard (JAS), with extraction of lipid using petroleum ether at a volume of 100 mL to the test portion of 25 g. Thirteen laboratories participated and analyzed 5 test samples as blind duplicates. Statistical treatment revealed that the repeatability (RSDR) of acid value was &lt;6.5%, and the reproducibility (RSDR) of acid value was &lt;9.6%. The HorRat values (RSDR/predicted RSDR) were 1.21.8, where the RSDR and the predicted RSDR were obtained in terms of free fatty acids in the noodles per unit weight, using the equation [acid value = percent free fatty acids (as oleic) 1.99] and the extracted lipid contents. This method was shown to have acceptable precision by the present study.
A Reversed-Phase High-Performance Liquid Chromatographic Method for the Determination of Zafirlukast in Pharmaceutical Formulations and Human Plasma
Authors: SÜsÜl İncilay , AltinÖz Sacide 
Published: February 2020

Abstract
Zafirlukast (ZAF) is a leukotriene receptor antagonist used in the treatment of chronic asthma. In this study, a simple and sensitive reversed-phase, high-performance liquid chromatographic method was developed for the determination of ZAF in pharmaceutical formulations and human plasma. Piribedil was used as an internal standard. Analysis was carried out on a Nucleosil C18 100 Å(150 × mm 4.6 mm id, 5 ωm) column with acetonitrilepH 3.0 acetate buffer (70 30, v/v) as the mobile phase at a flow rate of 0.8 mL/min. The peak was detected by an ultraviolet detector set at a wavelength of 240 nm. The retention times were about 3.9 min for piribedil and 5.8 min for ZAF. The developed method was applied to the determination of ZAF in its pharmaceutical formulation and spiked human plasma. For quantification of ZAF in spiked plasma, proteins were precipitated with ethanol before chromatographic analysis. The calibration range was linear from 49.69437.50 ng/mL in spiked plasma. The absolute recovery from spiked plasma was 98.73 ± 0.42% at a concentration of 254.78 ng/mL of ZAF. No endogenous substances from plasma were found to interfere.
Rapid Determination and Confirmation of Biogenic Amines in Tuna Loin by Gas Chromatography/Mass Spectrometry Using Ethylchloroformate Derivative
Authors: Marks (Rupp) Heidi S , Anderson Collin R 
Published: February 2020

Abstract
A gas chromatography-mass spectrometry (GC/MS) method is described for the easy rapid determination and simultaneous confirmation of the biogenic amines putrescine (PUT), cadaverine (CAD), histamine (HTA), and spermidine (SPD) in fresh frozen tuna loin. The method can also be used to monitor tyramine (TYR). The method involves homogenization of fish tissue, extraction of biogenic amines into trichloroacetic acid solution, centrifugation, alkalization, and derivatization of supernatant with ethylchloroformate. All seafood species were fortified to contain 2.5, 5.0, 10.0, 12.5, and 25.0 μg/g (ppm) PUT, CAD, and SPD; and 10.0, 20.0, 40.0, 50.0, and 100.0 μg/g (ppm) HTA. Determination was based on standard curves for each analyte using peak areas with matrix standards equivalent to a concentration range bracketing the spike level. A set of 5 matrix controls (unfortified tuna tissue) was also analyzed; only endogenous SPD was found in all samples. The interassay average recoveries ranged from 57 to 79% across analytes and spike levels.
Development and Validation of Three Stability-Indicating Methods for Determination of Bisacodyl in Pure Form and Pharmaceutical Preparations
Authors: Metwally Fadia H , Abdelkawy Mohammed , Naguib Ibrahim A 
Published: February 2020

Abstract
Three new, simple, sensitive, and accurate stability-indicating methods were developed for quantitative determination of bisacodyl in the presence of its degradation products, monoacetyl bisacodyl (I) and desacetyl bisacodyl (II), in enteric coated tablets, suppositories, and raw material. The first is a spectrodensitometric method in which the drug is separated from I and II on silica gel plates using chloroformacetone (9 + 1, v/v) as the mobile phase with ultraviolet detection of the separated bands at 223 nm over a concentration range of 0.2-1.4 g/band for bisacodyl with mean recovery 100.35 ± 1.923%. The second method is fourth derivative D4 spectrophotometry, which allows determination of bisacodyl in the presence of its degradation products in raw material at 223 nm using acetonitrile as the solvent with adherence to Beer's law over the concentration range 2-18 μg/mL with mean recovery 99.77 ± 1.056%. In the third method, the spectrophotometric data of bisacodyl, I, and II using absolute ethanol as solvent were processed by 3 chemometric techniques: classical least-squares, principal component regression, and partial least-squares. A training set consisting of 15 mixtures containing different ratios of bisacodyl, I, and II was used for construction of the 3 models. A validation set consisting of 6 mixtures was used to validate the prediction ability of the suggested models. The 3 chemometric methods were applicable over a concentration range between 2-14 μg/mL for bisacodyl with mean recovery of 99.97 ± 0.865, 100.01 ± 0.749, and 99.97 ± 0.616% for the 3 models, respectively. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied to the analysis of raw material and pharmaceutical formulations containing bisacodyl, except for the second method that applies only for raw material. The validity of the suggested procedures was further assessed by applying the standard addition technique; the recoveries obtained were in accordance with those given by the reference method.
Determination of Two Antibacterial Binary Mixtures by Chemometrics-Assisted Spectrophotometry
Authors: Mohamed Abd El-Maaboud I , Abdelmageed Osama H , Refaat Ibrahim H 
Published: February 2020

Abstract
Simple chemometrics-assisted spectrophotometric methods are described for determination of 2 antibacterial binary mixtures. The mixtures are composed of norfloxacin in combination with tinidazole and erythromycin (as ethylsuccinate ester or stearate salt) in combination with trimethoprim. The normal UV absorption spectra of each pair of drugs in the studied mixtures, in the range of 200-400 nm, showed a considerable degree of spectral overlapping: 77.5% for the norfloxacintinidazole mixture and 84.3% for the erythromycintrimethoprim mixture. Resolution of the norfloxacintinidazole mixture and trimethoprim in the presence of erythromycin was accomplished successfully by using zero-crossing first derivative (1D), classical least-squares (CLS) regression analysis, and principal component regression (PCR) analysis methods. In addition, an alternative simple and accurate colorimetric method was developed for the determination of erythromycin in the presence of trimethoprim using 2,4-dinitrophenylhydrazine. All variables affecting the development of the colored chromogen were studied and optimized, and the product was measured at 526-529 and 538-542 nm for erythromycin stearate and erythromycin ethylsuccinate, respectively. For zero-crossing, first derivative technique Beer’s law was obeyed in the general concentration range of 250 μg/mL for norfloxacin, tinidazole, and trimethoprim with good correlation coefficients (0.9994-0.9996). Overall limits of detection (LOD) and quantification (LOQ) ranged from 0.59 to 2.81 and 1.96 to 9.33 μg/mL, respectively. The obtained results from CLS and PCR were compared with those obtained from a 1D spectrophotometric method. With the exception of erythromycin, overall recoveries in the average range of 97.33-103.0% were obtained with a considerable degree of accuracy when the suggested methods were applied to analysis of synthetic binary mixtures, some commercial dosage forms such as tablets and oral suspension without interference from the commonly encountered excipients and additives. For the colorimetric method, Beer's law was obeyed in the general concentration range of 7.21-28.84 μg/mL erythromycin with good correlation coefficients (0.9980-0.9996). Overall LOD and LOQ ranged from 0.73 to 1.65 and 2.43-5.49 μg/mL, respectively. Erythromycin derivatives were determined in the commercial dosage form, without interference from trimethoprim-encountered excipients and additives. The obtained results, with both chemometric and colorimetric methods, have been compared with those obtained from reported methods, and proper F- and t-values were observed, indicating no significant difference between the results of the suggested methods and reported method(s). The good percentage recoveries and proper statistical data obtained proved the efficiency of the proposed procedures for the determination of the studied drugs in their binary mixtures as well as in the commercial dosage forms with quite satisfactory precision.
Spectrofluorometric Determination of Fluvoxamine in Dosage Forms, Spiked Plasma, and Real Human Plasma by Derivatization with Fluorescamine
Authors: El-Enany Nahed 
Published: February 2020

Abstract
A sensitive, simple, and selective spectrofluorometric method was developed for the determination of fluvoxamine (FXM) in pharmaceutical formulations and biological fluids. The method is based upon the reaction between the drug and fluorescamine in borate buffer of pH 8.0 to yield a highly fluorescent derivative that is measured at 481 nm after excitation at 383 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The method was applied for the determination of the drug over the concentration range of 0.11.1 μg/mL with a detection limit of 0.01 μg/mL (2 10-8 M). The proposed method was successfully applied to the analysis of commercial tablets. The results obtained were in good agreement with those obtained using a reported spectrophotometric method. The method was applied for the determination of FXM in spiked human plasma with recovery (n = 4) of 97.32 1.23%, while that in real human plasma (n = 3) was 90.79 2.73%. A proposal for the reaction pathway is presented.
Microbiological Assay for Cefoxitin Sodium in Dosage Form
Authors: Nunes Salgado Hrida Regina , Gomes Tozo Greici Cristiani 
Published: February 2020

Abstract
A microbiological assay applying the cylinder-plate method is described for determination of the activity of cefoxitin sodium in injectables. Using a strain of Staphylococcus epidermidis ATCC 12226 as the test organism, cefoxitin sodium was measured in concentrations ranging from 50.0 to 200.0 g/mL. The validation showed that the method was linear (r = 0.9998), precise (RSD = 0.81%), and accurate. It was concluded that the microbiological assay is satisfactory for quantitation of cefoxitin sodium in injectables.
Gas Chromatographic Determination of Pesticide Residues in Malt, Spent Grains, Wort, and Beer with Electron Capture Detection and Mass Spectrometry
Authors: Vela Nuria , Prez Gabriel , Navarro Gins , Navarro Simn 
Published: February 2020

Abstract
A method for the simultaneous determination of 9 pesticides (dinitroanilines, organophosphorus, triazoles, and pyrimidines) in several products (malt, spent grains, wort, and beer) of the beer industry is reported. Solid samples (malt and spent grains) are extracted by homogenization with a waterhexane mixture, and the pesticides are partitioned with dichloromethane. Liquid samples (wort and beer) are extracted by sonication with a hexanedichloromethane mixture. Determination of pesticide residues was made by capillary gas chromatography with an electron capture detector (ECD). Confirmation of the compounds was performed by gas chromatography/ion trap mass spectrometry in the selected ion monitoring mode. Detection limits for GCECD varied from 0.2 to 5.5 pg for trifluralin and malathion, respectively. Recoveries of the pesticides from spiked samples ranged from 81.2 to 113.7% with a relative standard deviation between 3.47.5%. The method presents good linearity over the studied range (0.0052 g/mL). The proposed method is rapid and reliable and can be useful for routine monitoring during brewing.
Determination of Synthetic Hormones in Animal Urine by High-Performance Liquid Chromatography/Mass Spectrometry
Authors: Rbies Antoni , Cabrera Albert , Centrich Francesc 
Published: February 2020

Abstract
A method was developed for the extraction of stanozolol, taleranol, zeranol, hexestrol, dienestrol, ethynylestradiol, diethylstilbestrol, and trenbolone from animal urine. The analytes were extracted from the matrix by enzymatic hydrolysis, solid-phase extraction, and liquidliquid extraction. Detection and quantitation were performed on a high-performance liquid chromatography system coupled to a triple quadrupole mass spectrometer. The identification criteria met the European Union regulations. Validation of this method established a decision limit between 0.2 and 0.9 μg/L and a detection capability between 0.3 and 1.0 μg/L, depending on the analyte.
Kinetic Spectrophotometric Determination of Ethamsylate in Dosage Forms
Authors: El-Enany Nahed , Belal Fathalla , Rizk Mohamed 
Published: February 2020

Abstract
A simple and sensitive kinetic method has been developed for the determination of ethamsylate (ESL) in its pharmaceutical preparations. The method is based upon oxidation of ESL with 3-methyl-2-benzothiazolinone hydrazone hydrochloride in presence of cerium(IV) ammonium sulfate at room temperature for 20 min. The absorbance of the reaction product is measured at 514 nm. The absorbance-concentration plot was rectilinear over the range of 430 g/mL (r = 0.9999). The lower detection limit was 0.267 g/mL (9.110 106 M) and the lower quantitation limit was 0.808 g/mL. The different experimental parameters affecting the development and stability of the reaction product were studied and optimized. The proposed method was applied to the determination of ESL in formulations, and the results obtained were in good agreement with those obtained using a reference method. The proposed method was also used for the in vitro detection of ESL in spiked human plasma at its therapeutic concentration level.
Evaluation of Quantitative Recovery Methods for Listeria monocytogenes Applied to Stainless Steel
Authors: Kang David , Eifert Joseph D , Williams Robert C , Pao Steven 
Published: February 2020

Abstract
The ability of Listeria monocytogenes to attach to various food contact surfaces, such as stainless steel, polypropylene, and rubber compounds, is well documented. The retention of these or other pathogenic bacteria on food contact surfaces increases the risk of transmission to food products. The objective of this study was to compare several methods for quantitative recovery of Listeria monocytogenes from stainless steel surfaces. A cocktail of 4 serotypes of Listeria monocytogenes mixed in equivalent concentrations was inoculated onto type 304 stainless steel coupons in a 2 2 cm area. After 1 h exposure, coupons were sampled by one of the following methods: (1) swabbing with a premoistened Dacron swab; (2) rinsingwith phosphate-buffered saline; (3) direct contact onto tryptic soy agar containing 0.6% yeast extract (TSA + YE) plates for 10 s; (4) sonication in an ultrasonic water bath (40 kHz); (5) contact with the bristles of a sonicating brush head for 1 min; and (6) indirect contact (24 mm distance) with a sonicating brush head for 1 min. The 3 sonication methods yielded higher recovery than the other 3 methods (P &lt; 0.05). Brushing the coupons with the sonicating brush head (contact or noncontact) yielded a recovery level of about 60%. The lowest cell recovery (about 20%) was observed with the swab and direct agar contact methods. After a 12 h exposure, recoveries ranged from 17.4 (brush contact method) to 2% (swab method).
Sampling Hazelnuts for Aflatoxin: Effect of Sample Size and Accept/Reject Limit on Reducing the Risk of Misclassifying Lots
Authors: Ozay Guner , Seyhan Ferda , Yilmaz Aysun , Whitaker Thomas B , Slate Andrew B , Giesbrecht Francis G 
Published: February 2020

Abstract
About 100 countries have established regulatory limits for aflatoxin in food and feeds. Because these limits vary widely among regulating countries, the Codex Committee on Food Additives and Contaminants began work in 2004 to harmonize aflatoxin limits and sampling plans for aflatoxin in almonds, pistachios, hazelnuts, and Brazil nuts. Studies were developed to measure the uncertainty and distribution among replicated sample aflatoxin test results taken from aflatoxin-contaminated treenut lots. The uncertainty and distribution information is used to develop a model that can evaluate the performance (risk of misclassifying lots) of aflatoxin sampling plan designs for treenuts. Once the performance of aflatoxin sampling plans can be predicted, they can be designed to reduce the risks of misclassifying lots traded in either the domestic or export markets. A method was developed to evaluate the performance of sampling plans designed to detect aflatoxin in hazelnuts lots. Twenty hazelnut lots with varying levels of contamination were sampled according to an experimental protocol where 16 test samples were taken from each lot. The observed aflatoxin distribution among the 16 aflatoxin sample test results was compared to lognormal, compound gamma, and negative binomial distributions. The negative binomial distribution was selected to model aflatoxin distribution among sample test results because it gave acceptable fits to observed distributions among sample test results taken from a wide range of lot concentrations. Using the negative binomial distribution, computer models were developed to calculate operating characteristic curves for specific aflatoxin sampling plan designs. The effect of sample size and accept/reject limits on the chances of rejecting good lots (sellers' risk) and accepting bad lots (buyers' risk) was demonstrated for various sampling plan designs.
Determination of Added Sulfites in Dried Garlic with a Modified Version of the Optimized Monier-Williams Method
Authors: Lafeuille Jean-Louis , Lefevre Stephane , Achouri Djamila 
Published: February 2020

Abstract
The optimized Monier-Williams method is slightly modified so that it could be applied for determining sulfite content in dried garlic. Dried garlic sample is directly acidified in a reactor at a pH below 3. At this pH level, the alliinase enzyme activity is irreversibly blocked, and the sulfur-containing amino acids such as alliin (the most abundant) present in dried garlic cannot be transformed into corresponding thiosulfinates such as allicin, which is absent in dried garlic. This prevents allicin from reacting with added sulfites and being probably converted to S-allyl thiosulfate, which is not volatile and has no taste. It is found that at a pH below 2.4 and at boiling water temperature, alliin produces sulfur dioxide in adequate quantity to explain the false-positive results when utilizing the optimized Monier-Williams method with allicin suppression for unsulfited dried garlic samples. Finally, when garlic samples are stabilized in a phosphoric acid buffer at a final pH around 2.4, no sulfite is produced during the Monier-Williams distillation, which is further proof there are no naturally occurring sulfites in unsulfited dried garlic under these mild conditions.
Validation of Erythromycin Microbiological Assay Using an Alternative Experimental Design
Authors: Loureno Felipe Rebello , Kaneko Telma Mary , Pinto Terezinha De Jesus Andreoli 
Published: February 2020

Abstract
The agar diffusion method, widely used in antibiotic dosage, relates the diameter of the inhibition zone to the dose of the substance assayed. An experimental plan is proposed that may provide better results and an indication of the assay validity. The symmetric or balanced assays (2 2) as well as those with interpolation in standard curve (5 1) are the main designs used in the dosage of antibiotics. This study proposes an alternative experimental design for erythromycin microbiological assay with the evaluation of the validation parameters of the method referring to linearity, precision, and accuracy. The design proposed (3 1) uses 3 doses of standard and 1 dose of sample applied in a unique plate, aggregating the characteristics of the 2 2 and 5 1 assays. The method was validated for erythromycin microbiological assay through agar diffusion, revealing its adequacy to linearity, precision, and accuracy standards. Likewise, the statistical methods used demonstrated their accordance with the method concerning the parameters evaluated. The 3 1 design proved to be adequate for the dosage of erythromycin and thus a good alternative for erythromycin assay.
Development of a Method for the Detection of -Lactamases in Milk Samples
Authors: Cui Shenghui , Li Jingyun , Hu Changqin , Jin Shaohong , Ma Yue 
Published: February 2020

Abstract
With the rapid growth of the dairy industry and the establishment of strict antimicrobial residue limits in the People's Republic of China's (PRC) milk supply, a -lactamase product known as antimicrobial destroyer was introduced into dairy production without regulatory review. We developed a method for detecting this product in milk samples based on a modified cylinder plate method. The presence of -lactamase is defined as a difference between the inhibitory zones of the test samples (supplemented with 25 g/mL sulbactam plus 0.5 g/mL penicillin G) and control samples (supplemented only with 0.5 g/mL penicillin G) 3 mm. Using this method, 77 individually packaged milk samples were randomly collected from 5 retail stores in 3 cities over a 4-month period (May to August 2006). Of the 77 samples, 49 were found to be -lactamase-positive. In 2 undiluted milk samples showing extremely high -lactamase activity, 25 g/mL sulbactam could not inhibit penicillin G activity. Because there is a lack of safety data on -lactamases in milk products, these data indicated a potentially serious safety concern for the dairy industry in the PRC.
Stability-Indicating Method for Determination of Oxyphenonium Bromide and Its Degradation Product by High-Performance Liquid Chromatography
Authors: EL-Gindy Alaa , Emara Samy , Shaaban Heba 
Published: February 2020

Abstract
A high-performance liquid chromatographic (HPLC) method was developed for determination of oxyphenonium bromide (OX) and its degradation product. The method was based on the HPLC separation of OX from its degradation product, using a cyanopropyl column at ambient temperature with mobile phase of acetonitrile25 mM potassium dihydrogen phosphate, pH 3.4 (50 + 50, v/v). UV detection at 222 nm was used for quantitation based on peak area. The method was applied to the determination of OX and its degradation product in tablets. The proposed method was also used to investigate the kinetics of the acidic and alkaline degradation of OX at different temperatures, and the apparent pseudo first-order rate constant, half-life, and activation energy were calculated. The pH-rate profile of the degradation of OX in Britton-Robinson buffer solutions within the pH range 212 was studied.