bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the 1,3- and 2-Positional Distribution of Fatty Acids in Olive Oil Triacylglycerols by 13C Nuclear Magnetic Resonance Spectroscopy
Authors: Vlahov Giovanna 
Published: February 2020

Abstract
Linear models were selected from a large data set acquired for Italian olive oil samples by quantitative 13C nuclear magnetic resonance (NMR) spectroscopy with distortionless enhancement by polarization transfer (DEPT). The models were used to determine the composition of the 2 fatty acid pools esterifying the 1,3- and 2-positions of triacylglycerols. The linear models selected proved that the 1,3- and 2-distribution of saturated, oleate, and linoleate chains in olive oil triacylglycerols deviated from the random distribution pattern to an extent that depended on the concentration of the fatty acid in the whole triacylglycerol. To calculate the fatty acid composition of the 1,3- and 2-positions of olive oil triacylglycerols, the equations of the selected linear models were applied to the fatty acid percentages determined by gas chromatography. These data were compared with the values predicted by the computer method (used to determine the theoretical amounts of triacylglycerols), which is based on the 1,3-random-2-random theory of the fatty acid distribution in triacylglycerols. The biggest differences were found in the linoleate chain, which is the chain that deviated the most from a random distribution pattern. The results confirmed that the 1,3-random-2-random distribution theory provides an approximate method for determining the structure of triacylglycerols; however, the linear models calculated by the direct method that applies 13C NMR spectroscopy represent a more precise measurement of the composition of the 2 fatty acid pools esterifying the 1,3- and 2-positions of triacylglycerols.
Microbiological Assay for Lomefloxacin in Coated Tablets
Authors: Gomes Greici Cristiani , Salgado Hérida Regina Nunes 
Published: February 2020

Abstract
The validation of a microbiological assay, applying cylinder plate method for determination of the activity of lomefloxacin in coated tablets is described. Using a strain of Bacillus subtilis ATCC 9372 as the test organism, lomefloxacin was measured in concentrations ranging from 2.0 to 8.0 μg/mL. The method validation showed that it is linear (r = 0.9999), precise (relative standard deviation = 1.15%), and accurate (it measured the added quantities). The excipients did not interfere in the determination. It was concluded that the microbiological assay is satisfactory for quantitation of lomefloxacin in tablets.
A Highly Sensitive Spectrofluorometric Method for the Determination of a New Antidepressant Drug, Reboxetine, in Tablets
Authors: Önal ArmaĞan 
Published: February 2020

Abstract
A highly sensitive, selective, and rapid spectrofluorometric method has been developed for the determination of reboxetine (REB) in tablets. The method is based on derivatization with 7-chloro-4-nitrobenzofurazan. The product showed an absorption maximum at 476 nm and a fluorescence emission peak at 533 nm in ethyl acetate. The optimum conditions of the reaction were investigated, and it was found that the reaction proceeded quantitatively at pH 8.5, 70C in 5 min. The calibration graph is rectilinear over the range of 0.02-0.40 μg/mL. The relative standard deviation values for intraday and interday precision were 0.40-0.93 and 0.54-1.37%, respectively. The proposed method was applied to the assay of REB in tablets. Mean recovery of REB from the tablets ranged between 99.91-100.20%. The results were compared statistically with those obtained by a method reported in the literature. The method is sensitive, simple, and selective, and can be used for routine quality control analysis.
Modification to the AOAC Sporicidal Activity of Disinfectants Test (Method 966.04): Collaborative Study
Authors: Tomasino Stephen F , Hamilton Martin A , Garza H Chan A ,   Collaborators:, Buen M , Chan Myers H , Garza A , Gonzales E , Kallander K , Rodriguez A , Stahnke P , To T 
Published: February 2020

Abstract
In an effort to improve AOAC Method 966.04, the Sporicidal Activity of Disinfectants Test, selected modifications to the procedure were evaluated in a collaborative study. Method 966.04 is used to generate efficacy data to support the product registration of sporicides and sterilants. The method is a carrier-based test that provides a qualitative measure of product efficacy against spores of Bacillus subtilis and Clostridium sporogenes. The use of garden soil extract and the lack of standard procedures for the enumeration of spores and neutralization of the test chemicals have been considered problematic for many years. The proposed modifications were limited to the B. subtilis and hard surface carrier (porcelain penicylinder) components of the method. The study included the evaluation of a replacement for soil extract nutrient broth and an establishment of a minimum spore titer per carrier, both considered crucial for the improvement and utilization of the method. Additionally, an alternative hard surface material and a neutralization confirmation procedure were evaluated. To determine the equivalence of the proposed alternatives to the standard method, 3 medium/carrier combinations, (1) soil extract nutrient broth/porcelain carrier (current method), (2) nutrient agar amended with 5 g/mL manganese sulfate/porcelain carrier, and (3) nutrient agar amended with 5 g/mL manganese sulfate/stainless steel carrier were analyzed for carrier counts, HCl resistance, efficacy, quantitative efficacy, and spore wash-off. The test chemicals used in the study represent 3 chemical classes and are commercially available antimicrobial liquid products: sodium hypochlorite (bleach), glutaraldehyde, and a combination of peracetic acid and hydrogen peroxide. Four laboratories participated in the study. The results of the spore titer per carrier, HCl resistance, efficacy, and wash-off studies demonstrate that amended nutrient agar in conjunction with the porcelain is comparable to the current method, soil extract nutrient broth/porcelain. The nutrient agar method is simple, inexpensive, reproducible, and provides an ample supply of high quality spores. Due to the current use of porcelain carriers for testing C. sporogenes, it is advisable to retain the use of porcelain carriers until stainless steel can be evaluated as a replacement carrier material for Clostridium. The evaluation of stainless steel for Clostridium has been initiated by the Study Director. Study Director recommendations for First Action revisions are provided in a modified method.
Determination of Benzimidazole Fungicides in Soil Samples Using Microwave-Assisted Micellar Extraction and Liquid Chromatography with Fluorescence Detection
Authors: Halko Radoslav , Sanz Carolina PadrÓn , Ferrera Zoraida Sosa , RodrÍguez JosÉ Juan Santana 
Published: February 2020

Abstract
A simple and fast analytical method was developed for the determination of benzimidazole fungicides (benomyl, carbendazim, thiabendazole, and fuberidazole) in soil samples. The analytes were extracted from the soil samples by means of conventional microwave-assisted extraction, using the non-ionic surfactants polyoxyethylene 10 lauryl ether (POLE) and oligoethylene glycol monooalkyl ether (Genapol X-080) as extractants. Determinations were made by using liquid chromatography with direct fluorescence detection. The use of an analytical column Symmetry C-18 offered short retention times of analytes without the need of any pH regulators with mobile phase methanolwater (50 + 50, v/v). The best results were obtained using 5% (v/v) POLE as extractant with recoveries of the fungicides in spiked soil samples between 71 and 105%. The results were compared with those obtained when Soxhlet extraction was applied to the same soil samples.
Determination of Eight Synthetic Pyrethroids in Bovine Fat by Gas Chromatography with Electron Capture Detection
Authors: Akre Christine J , MacNeil James D 
Published: February 2020

Abstract
Synthetic pyrethroids are among the most widely used classes of insecticides, and their uses are varied, including plant protection, animal dips, and as a treatment for human clothing and bedding in very hot climates. Veterinary applications include ear tags, pour-on formulations, sprays, and dips. Persistent residues have been reported in livestock, and routine monitoring programs in other countries have found detectable residues of various pyrethroids in fat. A method has been developed using solid-phase extraction that reduces the quantities of solvents used, the time required, and the amount of glassware used compared to an earlier method on which it was based. The scope of analytes tested included the 5 compounds cited in the earlier method (flucythrinate, permethrin, cypermethrin, fenvalerate, and deltamethrin) and, in addition, cyfluthrin, λ-cyhalothrin, and fluvalinate. Sample extracts were analyzed by gas chromatography with electron capture detection using selected chromatographic peaks characteristic of each compound. Limits of quantification for the compounds were from 25-50 μg/kg, with a linear response for all compounds to 200 μg/kg. Recoveries ranged from 80 to 123%.
Validation of a Liquid Chromatographic Method for Determination of Tacrolimus in Pharmaceutical Dosage Forms
Authors: Moyano MarÍa A , Simionato Laura D , Pizzorno Mara T , Segall Adriana I 
Published: February 2020

Abstract
An accurate, simple, and reproducible liquid chromatographic method was developed and validated for the determination of tacrolimus in capsules. The analysis is performed at room temperature on a reversed-phase C18 column with UV detection at 210 nm. The mobile phase is methanolwater (90 10) at a constant flow rate of 0.8 mL/min. The method was validated in terms of linearity, precision, accuracy, and specificity by forced decomposition of tacrolimus, using acid, base, water, hydrogen peroxide, heat, and light. The response was linear in the range of 0.090.24 mg/mL (r2 0.9997). The relative standard deviation values for intra- and interday precision studies were 1.28 and 2.91%, respectively. Recoveries ranged from 98.06 to 102.52%.
Feasibility Study for the Production of Certified Calibrants for the Determination of Deoxynivalenol and Other B-Trichothecenes: Intercomparison Study
Authors: Krska Rudolf , Welzig Elvira , Drs Elisabeth , Josephs Ralf D , Schothorst Ronald C , Egmond Hans P Van , Pettersson Hans , Chan Danny , MacDonald Susan 
Published: February 2020

Abstract
Thirteen European laboratories experienced in the analysis of mycotoxins participated in an intercomparison study within a European Commission-funded project. Goals of the study were to check the fitness for purpose of a small batch of gravimetrically prepared calibrants; to compare individually prepared calibrants with common calibrants; to check the feasibility of toxin mixtures as calibrant solutions; and to give recommendations on the production of future certified reference materials (CRMs) with regard to the nature of the calibrant and the means of certification. Each laboratory received ampules of each common calibrant containing single toxins [solution containing either deoxynivalenol (DON), 3-acetyl-DON (3-Ac-DON), nivalenol (NIV), or 15-acetyl-DON (15-Ac-DON)] and 3 ampules of toxinmixture (solutions of DON 3-Ac-DON NIV in acetonitrile) of known concentrations (about 20 g/mL). Ampules with single toxins (solution containing either DON, 3-Ac-DON, NIV, or 15-Ac-DON) and a toxinmixture (solutions of DON 3-Ac-DON NIV in acetonitrile) of unknown concentrations were distributed to the participants for quantification. The participating laboratories used mainly high-performance liquid chromatography (HPLC)diode array detection UV for DON, 3-Ac-DON, NIV, and 15-Ac-DON; gas chromatography-electron capture detection (GC-ECD) and GC-mass spectrometry methods were used sparingly. Linear calibration curves were achieved by &gt;90% of the participants. Relative between-day variation (RSDr) of 26% of the laboratories was greater than the target value of 5% for HPLC, and RSDr of 32% of the laboratories was greater than the desired value of 10% for GC. Relative between-laboratory variation (RSDR) of the GC results obtained with single common calibrants was greater than the target value of 16% for all laboratories. RSDR of the HPLC results for the common unknown single toxin solutions was less than the target value of 8% except for 15-Ac-DON. Generally, better recoveries were observed from common calibrants (102% for mix calibrants and 98% for single calibrants) than from individually prepared calibrants (95%). This international comparison study clearly showed the high scattering of results in the analysis of type-B trichothecenes, particularly when GC was used. Obviously, this intercomparison study was not suited for the certification of B-trichothecenes. A certification of the proposed calibrant material was therefore recommended on the basis of its gravimetrical preparation.
A Novel Correlation for Rapid Lactose Determination in Milk by a Cryoscopic Technique
Authors: Colinas Carmen , Barrera Ignacio , Blanco Carlos A 
Published: February 2020

Abstract
Residual lactose in special milk was systematically determined for people with lactose intolerance by means of a rapid on-line measurement of the cryoscopic point. A proposed cryoscopic procedure was compared to 2 conventional yet highly laborious methods: the enzymatic procedure with spectrophotometric control and the polarimetric method. Several experiments with different mixtures of both semi-skimmed and low-lactose milk were performed. A lineal relationship was found between lactose concentration and freezing point, the analytical equation for which shows a close relationship regarding the 3 methods used. The advantages of the cryoscopic procedure include speed in obtaining results and operational simplicity at a low cost, better monitoring of enzymatic hydrolysis kinetics, and greater control over the production process for delactosed milk. The equation obtained also enables prediction of the lactose percentage in commercial milk by a simple measurement of freezing point.
Quantitative Assessment of Hard Surface Disinfectant Activity Against the Foodborne Pathogen Listeria monocytogenes
Authors: Arnold Judy W , DeLaubenfels Eric , Zambelli-Weiner April 
Published: February 2020

Abstract
Listeria monocytogenes is an important foodborne pathogen that must be controlled to ensure food safety. For the years 2003 and 2004, L. monocytogenes caused 20 deaths per 100 listeriosis cases and was responsible for most food recalls for pathogen contamination. The objective of this work was to develop a quantitative method to assess disinfectant activity against L. monocytogenes. Standard procedures for testing disinfectants against 3 bacteria are described in the AOAC Official Methods of Analysis as use-dilution methods. No standard methods are provided for L. monocytogenes. In this study, preliminary efficacy of a quaternary ammonium compound with hydroperoxide ion was determined for 25 bacterial strains. The zones of inhibition ranged from 7.0 to 12.5 mm, and the minimum inhibitory concentration ranged from 5 to 250 ppm. For final efficacy, stainless steel carriers were contaminated with L. monocytogenes and tested separately for 5, 10, and 15 min in disinfectant or phenol. After exposure, the carriers were placed into 2 series of D/E neutralization broth. For 3 replications with duplicate samples, the phenol coefficient was 3.3. This research presents a technique-sensitive method that provides quantitative data for comparison and analysis of disinfectant activity against L. monocytogenes.
On Determining a 1-Tailed Upper Limit for Future Sample HorRat Values
Authors: McClure Foster D , Lee Jung K 
Published: February 2020

Abstract
Two formulas were developed for use in computing 1-tailed upper limits for future HorRat values obtained from the collaborative study of materials. One formula is applicable when a future sample HorRat value &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq1.gif"/&gt; &lt;/inline-formula&gt; is computed based on a known concentration (e.g., C spike level and RSDR is the sample relative reproducibility standard deviation) and the other formula is applicable when the true concentration (C) is unknown and a future sample HorRat value &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq2.gif"/&gt; &lt;/inline-formula&gt; is computed using the sample mean (e.g., &lt;inline-formula&gt; &lt;inline-graphic href="inline_eq3.gif"/&gt; &lt;/inline-formula&gt;, the collaborative study overall mean for an analyte). A Monte Carlo simulation procedure was developed using the Statistical Analysis System (SAS) software to assess the accuracy of the 2 developed formulas. Based on the degree of closeness between the simulated and calculated limits, the formulas for computing upper limits for future sample HorRat values will prove to be useful to Study Directors in determining worst case scenarios concerning a method's reproducibility precision relative to that predicted using the Horwitz equation. We also define the current empirical HorRat limits as 1-tailed 100p% upper limits to assess the statistical consequence, in a probability sense, of their application as an analytical methods screening tool.
Quantitative Estimation of Parthenolide in Tanacetum parthenium (L.) Schultz-Bip. Cultivated in Egypt
Authors: El-Shamy Ali M , El-Hawary Seham S , Rateb Mostafa E M 
Published: February 2020

Abstract
Parthenolide, a germacranolide-type sesquiterpene lactone, was estimated in Tanacetum parthenium (L.) cultivated in Egypt by using colorimetric, planar chromatographic, and high-performance liquid chromatographic (HPLC) methods. Parthenolide levels in the open-field herb and aseptically germinated shoots were also compared by using the HPLC method. Parthenolide was produced and estimated for the first time in the callus culture of the plant. In addition, 2 Egyptian market preparations were analyzed for their parthenolide content by using the HPLC method. The relative standard deviations were 0.093, 0.095, and 0.098% (n = 5,5,and 7, respectively), and the corresponding recoveries were 98.2, 98.9, and 99.4% for the colorimetric, planar chromatographic, and HPLC determinations, respectively.
A Novel Method for Determination of Protein in Human Serum Utilizing the Trihydroxylphenylfluorone-Molybdenum(VI) Complex as a Probe by Fluorescence Spectrometry
Authors: Wei Qin , Ma Hongmin , Duan Caihong , Wang Jin , Liu Shuyuan , Du Bin 
Published: February 2020

Abstract
The fluorescence intensity of the trihydroxylphenylfluorone-molybdenum(VI) Mo(VI) complex is quenched by protein. Based on this, a novel method for protein assay in aqueous solution was developed. With pH 3.75 acetic acidsodium acetate buffer solution, in the presence of p-octyl polyethylene glycol phenyl ether microemulsion, the quenched fluorescence intensity is proportional to the concentration of bovine serum albumin (BSA) in the range of 07.00 μg/mL, and the detection limit of BSA is 5.65 ng/mL. There is no interference from amino acids and most metal ions. The method developed in this paper has been used for the successful determination of protein in human serum.
Pesticide Residue Analysis of Vegetables by Gas Chromatography with Electron-Capture Detection
Authors: Fenoll José , Hellín Pilar , Martínez Carmen M , Flores Pilar 
Published: February 2020

Abstract
A new and original analytical method was developed for the routine analysis of 28 multiclass pesticide residues in vegetables (green pepper, red pepper, and tomato). The extraction was performed with acetone, and the pesticides were partitioned into ethyl acetatecyclohexane (1 + 1, v/v). Residue levels in vegetables were determined by gas chromatography (GC) with electron-capture detection. Residue identities were confirmed by GC coupled with mass spectrometry in the selected ion monitoring mode. The average recoveries in pepper and tomato obtained for all analytes studied were 67.3 and 123.1%, respectively, with relative standard deviation between 1.8 and 7.0%. The detection limit for the pesticides studied varied from 0.1 to 2.6 μg/kg. The proposed method was applied to the analysis of these compounds in vegetables grown in experimental greenhouses.
Determination of Inorganic Arsenic(III) and Arsenic(V) in Water Samples by Ion Chromatography/Inductively Coupled Plasma-Mass Spectrometry
Authors: Yip Yiu-Chung , Chu Hei-Shing , Yuen Chung-Fai , Sham Wing-Cheong 
Published: February 2020

Abstract
A method was validated for the direct determination of As(III) and As(V) in water samples by ion chromatography/inductively coupled plasma-mass spectrometry. Sample preservation required only dilution with a mobile phase containing a sufficient amount of ethylenediaminetetraacetic acid and acetic acid. Analyses of 6 certified reference materials (CRMs) of various water matrixes, including seawater, demonstrated good method accuracy. The matrixes included 2 natural water samples National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1643e and NIST SRM 1640, 1 fortified standard solution (TMDA-64), 1 fortified water sample (TM-DWS), and 2 seawater samples (CASS-4 and NASS-5). The sum of As(III) and As(V) in each CRM agreed with the respective certified value for the total amount of As within its stated uncertainty. Quantitative recoveries (96.7-102.1%) were obtained. Satisfactory results were achieved for intraday repeatability relative standard deviation (RSD 0.3-5.1%] and interday precision (RSD 0.7-4.1%). In the study of fortified blanks and fortified CRMs, quantitative recoveries of As(III) and As(V) (92.5-102.6%) were obtained. Interconversion of As(III) and As(V) was not observed under the conditions of sample preservation. International comparability of analytical results was demonstrated by the analysis of 2 interlaboratory proficiency test samples, NY7011 and NY8511, from the New York State Department of Health.
Determination of Synephrine in Bitter Orange Raw Materials, Extracts, and Dietary Supplements by Liquid Chromatography with Ultraviolet Detection: Single-Laboratory Validation
Authors: Roman Mark C , Betz Joseph M , Hildreth Jana 
Published: February 2020

Abstract
A method has been developed to quantify synephrine in bitter orange raw material, extracts, and dietary supplements. Single-laboratory validation has been performed on the method to determine the repeatability, accuracy, selectivity, limit of detection/limit of quantification (LOQ), ruggedness, and linearity for p-synephrine and 5 other biogenic amines: octopamine, phenylephrine (m-synephrine), tyramine, N-methyltyramine, and hordenine, which may be present in bitter orange. p-Synephrine was found to be the primary biogenic amine present in all materials tested, accounting for &gt;80 of the total biogenic amine content in all samples except a finished product. Repeatability precision for synephrine was between 1.48 and 3.55 RSD. Synephrine recovery was between 97.5 and 104. The minor alkaloids were typically near the LOQ of the method (300900 g/g) in the test materials, and between-day precision for the minor compounds was poor because interferences could sometimes be mistakenly identified as one of the minor analytes. Recoveries of the minor components ranged from 99.1 to 103 at approximately 6000 g/g spike level, to 90.7 to 120 at 300 g/g spike level.