bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the VIDAS® Listeria (LIS) Immunoassay for the Detection of Listeria in Foods Using Demi-Fraser and Fraser Enrichment Broths, as Modification of AOAC Official Method 999.06 (AOAC Official Method 2004.06)
Authors: Silbernagel Karen M , Jechorek Robert P , Kaufer Amanda L , Johnson Ronald L ,   Collaborators:, Aleo V , Brown B , Buen M , Buresh J , Carson M , Franklin J , Ham P , Humes L , Husby G , Hutchins J , Jechorek R , Jenkins J , Kaufer A , Kexel N , Kora L , Lam L , Lau D , Leighton S , Loftis M , Luc S , Martin J , Nacar I , Nogle J , Park J , Schultz A , Seymore D , Smith C , Smith J , Thou P , Ulmer M , Voss R , Weaver V 
Published: February 2020

Abstract
A multilaboratory study was conducted to compare the VIDAS® LIS immunoassay with the standard cultural methods for the detection of Listeria in foods using an enrichment modification of AOAC Official Method 999.06. The modified enrichment protocol was implemented to harmonize the VIDAS LIS assay with the VIDAS LMO2 assay. Five food types—brie cheese, vanilla ice cream, frozen green beans, frozen raw tilapia fish, and cooked roast beef—at 3 inoculation levels, were analyzed by each method. A total of 15 laboratories representing government and industry participated. In this study, 1206 test portions were tested, of which 1170 were used in the statistical analysis. There were 433 positive by the VIDAS LIS assay and 396 positive by the standard culture methods. A Chi-square analysis of each of the 5 food types, at the 3 inoculation levels tested, was performed. The resulting average Chi square analysis, 0.42, indicated that, overall, there are no statistical differences between the VIDAS LIS assay and the standard methods at the 5% level of significance.
Testing Green Coffee for Ochratoxin A, Part II: Observed Distribution of Ochratoxin A Test Results
Authors: Vargas Eugenia Azevedo , Whitaker Thomas B , dos Santos Eliene Alves , Slate Andrew B , Lima Francisco B , Franca Regina C A 
Published: February 2020

Abstract
The suitability of 4 theoretical distributions (normal, lognormal, negative binomial, and gamma) to predict the observed distribution of ochratoxin A (OTA) in green coffee was investigated. One symmetrical and 3 positively skewed theoretical distributions were each fitted to 25 empirical distributions of OTA test results for green coffee beans. Parameters of each theoretical distribution were calculated by using Methods of Moments. The 3 skewed theoretical distributions provided acceptable fits to each of the 25 observed distributions. Because of its simplicity, the lognormal distribution was selected to model OTA test results for green coffee. Using variance equations determined in previous studies, mathematical expressions were developed to calculate the parameters of the log normal distribution for a given OTA lot concentration and test procedure. Observed acceptance probabilities were compared to an operating characteristic curve predicted from the lognormal distribution, and all 25 observed acceptance probabilities were found to lie within the 95% confidence band associated with the predicted operating characteristic curve. The parameters of compound gamma distribution were used to calculate the fraction of OTA contamination beans within a contaminated lot. The percent-contaminated beans were a function of the lot concentration and increased with lot concentration. At a lot concentration of 5 μg/kg, approximately 6 beans per 10 000 beans are contaminated.
Dietary Protein Quality in Humans—An Overview
Authors: Moughan Paul J 
Published: February 2020

Abstract
The first objective in evaluating protein quality is to permit a ranking of proteins according to their potential nutritive value and to permit detection of changes in nutritive value due to processing and/or storage. The second objective is to permit prediction of the contribution a food protein, or mixture of food proteins, makes toward meeting nitrogen and amino acid requirements for growth or maintenance. Different approaches are used in meeting these distinct aims. The preferred current method to meet the second aim is the protein digestibility corrected amino acid score (PDCAAS). This article introduces the concept of PDCAAS and places it in the context of the series of papers published in this Special Guest Editor Section addressing aspects of dietary amino acid utilization.
The Effect of Hydrolysis Time on Amino Acid Analysis
Authors: Darragh Alison J , Moughan Paul J 
Published: February 2020

Abstract
Determining the amino acid content of a protein involves the hydrolysis of that protein, usually in acid, until the protein-bound amino acids are released and made available for detection. Both the variability in the ease of peptide bond cleavage and differences in the acid stability of certain amino acids can significantly affect determination of a protein's amino acid content. By using multiple hydrolysis intervals, a greater degree of accuracy can be obtained in amino acid analysis. Correction factors derived by linear extrapolation of serial hydrolysis data are currently used. Compartmental modeling of the simultaneous hydrolysis (yield) and degradation (decay) of amino acids by nonlinear multiple regression of serial hydrolysis data has also been validated and applied to determine the amino acid composition of various biological samples, including egg-white lysozyme, human milk protein, and hair. Implicit in the routine application of serial hydrolysis in amino acid analysis, however, is an understanding that correction factors, derived either linearly or through the more accurate nonlinear multiple regression approach, need to be determined for individual proteins rather than be applied uniformly across all protein types.
Validation Assay for Total Flavonoids, as Rutin Equivalents, from Trichilia catigua Adr. Juss (Meliaceae) and Ptychopetalum olacoides Bentham (Olacaceae) Commercial Extract
Authors: Rolim André , Maciel Carolina P M , Kaneko Telma M , Consiglieri Vladi O , Salgado-Santos Idalina M N , Velasco Maria Valéria R 
Published: February 2020

Abstract
An ultraviolet spectrophotometric method was validated for total flavonoid quantitation, as rutin equivalents, present in the Trichilia catigua Adr. Juss (Meliaceae) and Ptychopetalum olacoides Bentham (Olacaceae) commercial extract. Parameters as linearity, interval (range), specificity, estimated limit of detection (LOD, μg/mL), estimated limit of quantitation (LOQ, μg/mL), recovery (R, %), precision or relative standard deviation (RSD, %), and accuracy (E, %) were established. The analytical method was validated according to the experimental results: correlation coefficient (r = 0.9997); interval (RSD = 0.15–0.47%; E = 98.98–101.24%); specificity to total flavonoids quantitation, as rutin equivalents, at wavelength 361.0 nm; LOD = 0.09 μg/mL and LOQ = 0.27 μg/mL; R = 99.36–102.14%; adequate intraand interrun precision (0.30–0.49% and 0.31–0.81%), and intra- and interrun accuracy (100.60–102.38% and 98.58–100.38%).
Determination of Glucosamine in Raw Materials and Dietary Supplements Containing Glucosamine Sulfate and/or Glucosamine Hydrochloride by High-Performance Liquid Chromatography with FMOC-Su Derivatization: Collaborative Study
Authors: Zhou Joseph Ziqi , Waszkuc Ted , Mohammed Felicia ,   Collaborators:, Blumhorst M , Buren R , Das R , Huang L , Jabusch J , Kou X , Nagarajan M , Nguyen H , Orellana K , Peng T S , Podhola B , Ray C , Reif K , Shevchuk C , Solyom A , Sullivan D , Wang J , Wang W , Yang Q , Zheng Q 
Published: February 2020

Abstract
A collaborative study was conducted for determination of glucosamine in raw materials and dietary supplements containing glucosamine sulfate and/or glucosamine hydrochloride by high-performance liquid chromatography (HPLC) with N-(9-fluorenyl-methoxycarbonyloxy) succinimide (FMOC-Su) derivatization. Thirteen blind materials, one pair of which were duplicates, were tested by 12 collaborating laboratories. The test samples consisted of various commercial products, including tablets, capsules, drink mix, and liquids as well as raw materials, blanks, and those for spike recovery analyses. The tests with blank products and products spiked with glucosamine showed good specificity of the method. The average recoveries at spike levels of 100 and 150% of the declared amount were 99.0% with a relative standard deviation (RSD) of 2.1%, and 101% with an RSD of 2.3%, respectively. The test results between laboratories on each commercial product were reproducible with RSD values of no more than 4.0%, and the results were repeatable in the same laboratory with an average RSD of 0.7%. HorRat values ranged from 0.5 to 1.7 on both tests of spike recovery and reproducibility between laboratories on commercial products. The average determination coefficient of the calibration curves from the laboratories was 0.9995 with an RSD of 0.03%. All of the 12 collaborating laboratories succeeded in the study and none of their reported test results were outliers, partly indicating the robustness of the method. It is recommended that the method be accepted by AOAC INTERNATIONAL as Official First Action.
Capillary Electrophoresis Method for Fexofenadine Hydrochloride in Capsules
Authors: Breier Ana R , Garcia Sílvia S , Jablonski André , Steppe Martin , Schapoval Elfrides E S 
Published: February 2020

Abstract
A simple, accurate, and effective capillary electrophoresis method with ultraviolet absorbance detection was developed and validated for the quantitation of the antihistamine fexofenadine in capsules. The separation was performed with an uncoated fused-silica capillary (47 cm × 75 μm id) and was operated at 20 kV potential. Temperature was maintained at 25°C. The run buffer was prepared with 20mM Na2B4O7 × 10 H2O. Software was used for system control, data acquisition, and analysis. Method validation was performed by evaluation of the analytical parameters linearity, precision, accuracy, limits of detection and quantitation, and specificity. The method was linear (r = 0.9999) at concentrations ranging from 20 to 100 μg/mL, precise (relative standard deviation intra-assay = 1.2, 1.6, and 1.8% and interassay = 1.5%); accurate (recovery = 98.1%); and specific. The limits of detection and quantitation were 0.69 and 2.09 μg/mL, respectively. The method was compared to the liquid chromatography method developed previously by the authors for the same drug, and no significant difference was found between the 2 methods in fexofenadine hydrochloride quantitation.
Determination of β-Carotene in Supplements and Raw Materials by Reversed-Phase High Pressure Liquid Chromatography: Collaborative Study
Authors: Szpylka John , DeVries Jonathan W ,   Collaborators:, Bhandari S , Bui M H , Ji D , Konings E , Lewis R , Maas P , Parish H , Post B , Schierle J , Sullivan; D , Taylor A , Wang J , Ware G , Woollard D , Wu T 
Published: February 2020

Abstract
Twelve laboratories representing 4 countries participated in an interlaboratory study conducted to determine all-trans-β-carotene and total β-carotene in dietary supplements and raw materials. Thirteen samples were sent as blind duplicates to the collaborators. Results obtained from 11 laboratories are reported. For products composed as softgels and tablets that were analyzed for total β-carotene, the reproducibility relative standard deviation (RSDR) ranged from 3.35 to 23.09% and the HorRat values ranged from 1.06 to 3.72. For these products analyzed for trans β-carotene, the reproducibility relative standard deviation (RSDR) ranged from 4.28 to 22.76% and the HorRat values ranged from 0.92 to 3.37. The RSDr and HorRat values in the analysis of a beadlet raw material were substantial and it is believed that the variability within the material itself introduced significant variation in subsampling. The method uses high pressure liquid chromatography (LC) in the reversed-phase mode with visible light absorbance for detection and quantitation. If high levels of α-carotenes are present, a second LC system is used for additional separation and quantitation of the carotene species. It is recommended that the method be adopted as an AOAC Official Method.
Simultaneous Determination of 16 Sulfonamides in Honey by Liquid Chromatography/TandemMass Spectrometry
Authors: Pang Guo-Fang , Cao Yan-Zhong , Zhang Jin-Jie , Jia Guang-Qun , Fan Chun-Lin , Li Xue-Min , Liu Yong-Ming , Li Zeng-Yin , Shi Yu-Qiu 
Published: February 2020

Abstract
A method is described for the determination of 16 sulfonamides in honey. Samples are dissolved in phosphoric acid solution (pH2), cleaned up with 2 solid-phase extraction (SPE) cartridges, an aromatic sulfonic cation-exchange cartridge and an Oasis HLB SPE cartridge, and analyzed both qualitatively and quantitatively by liquid chromatography/tandem mass spectrometry (LC/MS/MS) under the selected conditions. Without exception, calibration curves were linear (r = &gt;0.995), when sulfamethizole was between 1.0 and 25.0 μg/kg; sulfacetamide, sulfapyridine, sulfadiazine, sulfachloropyridazine, sulfamethoxazole, sulfamerazine, sulfisoxazole, sulfamonomethoxine, and sulfadoxine were between 2.0 and 50.0 μg/kg; sulfamethoxypyridazine, sulfadimethoxine, and sulfathiazole were between 4.0 and 100.0 μg/kg; sulfamethazine and sulfameter were between 8.0 and 200.0 μg/kg; and sulfaphenazole was between 12.0 and 300.0 μg/kg. Average recoveries at 4 fortification levels in the range of 1.0–300 μg/kg in honey were 70.9–102.5%, and relative standard deviations were 2.02–11.52%. The limits of quantitation for the 16 sulfonamides were between 1.0 and 12.0 μg/kg, with the LC/MS/MS method.
Determination of Allura Red in Some Food Samples by Adsorptive Stripping Voltammetry
Authors: Alghamdi Ahmad H 
Published: February 2020

Abstract
Square wave (SW) voltammetry was used to explore the adsorption properties of the food additive dye Allura Red on a hanging mercury drop electrode (HMDE). By using the adsorptive stripping voltammetric approach, we developed a sensitive electroanalytical method for the determination of this azo dye. A well-developed voltammetric peak probably related to the cathodic reduction of the azo moiety was obtained in pH 9 Britton-Robinson (B-R) buffer at 613 mV. Cyclic voltammetric studies indicated that the reduction process was irreversible and primarily controlled by adsorption. The adsorptive voltammetric signal was evaluated with respect to various experimental conditions; the optimized values were supporting electrolyte, B-R buffer; pH 11; accumulation time, 180s; accumulation potential, 0.0V; scan rate, 900 mV/s; pulse amplitude, 75 mV; and SW frequency, 90 Hz. Adsorptive voltammetric peak current showed a linear response for Allura Red in the concentration range of 2.5 × 10−8 to 2.0 × 10−7 mol/L (r = 0.998). The limit of detection was 8.5 × 10−9 mol/L (4.2 ng/mL), the precision in terms of relative standard deviation was 1.3%, and the mean recovery was 102%. Possible interferences by several substances usually present in food products such as food additive azo dyes (E110, E102), gelatin, natural and artificial sweeteners, preservatives, and antioxidants were also evaluated. The proposed electrochemical procedure was successfully applied to the determination of this food dye in commercially available candy and a soft drink. The results were compared by statistical evaluation with those obtained by a reference spectrophotometric method.
An Approach to the Application of Microwave-Assisted Micellar Extraction and Liquid Chromatography with Ultraviolet Detection to the Extraction and Determination of Organophosphorus Pesticides in Tomato Samples
Authors: Padrón-Sanz Carolina , Sosa-Ferrera Zoraida , Santana-Rodríguez Jose J 
Published: February 2020

Abstract
Microwave-assisted micellar extraction methodology was applied to extract a mixture of 8 organophosphorus pesticides from the cuticle of tomato samples prior to analysis by liquid chromatography with ultraviolet detection. This technique provided very good results and was simple, fast, and environmentally friendly. The pesticides under study were extracted using the nonionic surfactants polyoxyethylene 10 lauryl ether (POLE) and oligoethylene glycol monoalkyl ether (Genapol X-080). The optimal extraction variables to be applied were determined for each surfactant and then compared. POLE proved to be the most suitable for the extraction, with recoveries over 70% in the majority and relative standard deviation values under 4.8%. After validation using a tomato sample enriched with a certified mixture, the proposed method was applied to the analysis of organophosphorus pesticides in lettuce and pepper samples.
Development and Validation of a Method for Determination of Caffeine in Diuretic Tablets and Capsules by High-Performance Thin-Layer Chromatography on Silica Gel Plates with a Concentration Zone Using Manual Spotting and Ultraviolet Absorption Densitometry
Authors: Sullivan Caitlin , Sherma Joseph 
Published: February 2020

Abstract
A new quantitative method using silica gel high-performance thin-layer chromatography plates with channels and a concentration zone, manual application of standards and samples, development with methanol–ethyl acetate (15 + 85) mobile phase, and ultraviolet absorption densitometry is reported for the determination of caffeine in diuretic pharmaceutical preparations. Tablet and capsule products containing potassium salicylate, acetaminophen, and salicylamide as active ingredients were analyzed to test the applicability of the new method, and precision, accuracy, linearity, limits of detection and quantitation, and selectivity were validated. The milligrams of caffeine in each tablet ranged from 48.0 to 51.0, and the milligrams in each capsule from 37.9 to 40.3. Within-day precision was 1.48 and 1.78% (n = 6), and interday precision 0.723 and 1.26% (n = 5) for analysis of 2 tablets and 2 capsules, respectively. Accuracy validation of the tablet and capsule results produced errors of 1.0 and 1.9% for spiked blank analyses and 2.6 and 3.5% for standard addition analyses, respectively. A comparative study using a caffeine standard solution and a multicomponent analgesic tablet solution containing caffeine, acetaminophen, and acetylsalicylic acid showed that manual application on the concentration zone, instrumental application on the concentration zone, and instrumental application on the silica gel gave quite similar results in terms of number of theoretical plates, resolution, limit of detection, and linearity.
Simultane ous Determination of Protopseudohypericin, Pseudohypericin, Protohypericin, and Hypericin Without Light Exposure
Authors: Baugh Steven F 
Published: February 2020

Abstract
St. John's wort products are commonly standardized to total naphthodianthrones and hyperforin. Determination of these marker compounds is complicated because of the photochemistry of the naphthodianthrones pseudohypericin and hypericin and the instability of hyperforin in solution. Protopseudohypericin and protohypericin have been identified as naturally occurring naphthodianthrones and, when exposed to light, they are converted into pseudohypericin and hypericin, respectively. However, exposure to light and the resulting naphthodianthrone free-radical reactions oxidize hyperforin. A mathematical relationship between the response of the proto compound and the resulting naphthodianthrone can be established by comparing the analytical response of the proto compound in a solution protected from light with the increase in the analytical response of naphthodianthrone in the same solution after exposure to light. By mathematically converting the proto compounds to their respective products, exposure to light can be avoided while still including proto compounds in a single assay. The method presented here details the reporting of all significant naphthodianthrones, including protopseudohypericin and protohypericin, without exposure to light. This approach includes the benefits of improved naphthodianthrone precision and protection of hyperforin from oxidation.
New Methods for Determination of Cinnarizine in Mixture with Piracetam by Spectrodensitometry, Spectrophotometry, and Liquid Chromatography
Authors: Metwally Fadia H , Elzeany B A , Darwish H W 
Published: February 2020

Abstract
Four new methods were developed and validated for the determination of cinnarizine HCl in its binary mixture with piracetam in pure and pharmaceutical preparations. The first one was a densitometric analysis that provides a simple and rapid method for the separation and quantification of cinnarizine HCl. The method depends on the quantitative densitometric evaluation of thin-layer chromatograms of cinnarizine HCl at 252 nm over concentration range of 1–6 μg/spot, with a mean accuracy of 100.05 ± 0.91%. The second method was determination of the drug using a colorimetric method that utilizes the reaction of 3-methylbenzothiazolin-2-one in the presence of FeCl3 as an oxidant. The green color of the resulting product was measured at 630 nm over concentration range 10–40 μg/mL, with a mean accuracy of 100.10 ± 1.13%. The third method was a direct spectrophotometric determination of cinnarizine HCl at 252 nm over the concentration range 7–20 μg/mL, while piracetam was determined by derivative ratio spectrophotometry at 221.6 nm over concentration range 5–30 μg/mL, with a mean accuracy of 100.14 ± 0.79 and 100.26 ± 1.24% for cinnarizine HCl and piracetam, respectively. The last method was a liquid chromatography analysis of both cinnarizine HCl and piracetam, depending on quantitative evaluation of chromatograms of cinnarizine HCl and piracetam at 252 and 212 nm, respectively, over the concentration range 10–200 μg/mL for cinnarizine HCl and 20–500 μg/mL for piracetam, with a mean accuracy of 100.03 ± 0.89 and 100.40 ± 0.94% for cinnarizine HCl and piracetam, respectively. The proposed procedures were checked using laboratory-prepared mixtures and successfully applied for the analysis of their pharmaceutical preparations. The validity of the proposed procedures was further assessed by applying the standard addition technique. Recoveries were quantitative, and the results obtained agreed with those obtained by other reported methods.
Gravimetric Method for the Determination of Diclofenac in Pharmaceutical Preparations
Authors: Tubino Matthieu , Souza Rafael L de 
Published: February 2020

Abstract
A gravimetric method for the determination of diclofenac in pharmaceutical preparations was developed. Diclofenac is precipitated from aqueous solution with copper(II) acetate in pH 5.3 (acetic acid/acetate buffer). Sample aliquots had approximately the same quantity of the drug content in tablets (50 mg) or in ampules (75 mg). The observed standard deviation was about ± 2 mg; therefore, the relative standard deviation (RSD) was approximately 4% for tablet and 3% for ampule preparations. The results were compared with those obtained with the liquid chromatography method recommended in the United States Pharmacopoeia using the statistical Student's t-test. Complete agreement was observed. It is possible to obtain more precise results using higher aliquots, for example 200 mg, in which case the RSD falls to 1%. This gravimetric method, contrary to what is expected for this kind of procedure, is relatively fast and simple to perform. The main advantage is the absolute character of the gravimetric analysis.