bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid Extraction of Aflatoxin from Creamy and Crunchy Peanut Butter
Authors: Vega Victor A 
Published: February 2020

Abstract
A rapid extraction technique was developed for the isolation and subsequent liquid chromatographic determination of aflatoxins B1, B2, G1, and G2 in creamy and crunchy peanut butter. Peanut butter samples were extracted with a methanol 15% sodium chloride (7 + 3) solution followed by a second extraction with methanol. The extract was subjected to a cleanup using a Vicam Aflatest® immunoaffinity column. Control samples for both smooth and crunchy peanut butter were fortified at 4 different levels for aflatoxin B1, B2, G1, and G2. The average aflatoxin B1, B2, G1, and G2 recoveries from smooth peanut butter were 95.2, 89.9, 94.1, and 62.4%, respectively, and 92.4, 84.3, 85.5, and 53.7%, respectively, from crunchy peanut butter. This extraction method and the official AOAC Method 991.31 produced comparable results for peanut butter samples. This method provides a rapid, specific, and easily controlled assay for the analysis of aflatoxins in peanut butter with minimal solvent usage. Organic solvent consumption was decreased by 85% and hazardous waste production was decreased by 80% in comparison with the AOAC method. Along with the decreased solvent consumption, significant savings in time were observed.
Evaluation of Results of an Interlaboratory Comparison Test on Determination of Acrylamide in Crispbread Samples
Authors: Wenzl Thomas , Anklam Elke 
Published: February 2020

Abstract
The European Commission's Directorate General Joint Research Centre has organized several proficiency tests on the determination of acrylamide (AA) in food. This paper presents the results and outcome of a proficiency test that focused on the determination of AA in crispbread samples. One of the goals was the identification of the influence of different parameters such as analyte extraction or instrument calibration on the analytical results. A set of samples, containing 3 different crispbread samples as well as extracts of one crispbread sample and AA standard solutions, was shipped to each participant. A total of 42 European laboratories reported analytical results that were evaluated by applying internationally accepted protocols and procedures. The study found that, for each sample, the results of 4–8 laboratories were outside the range formed by the target value plus or minus the 2-fold of the target standard deviation; thus, they did not perform satisfactorily. In transferring this knowledge to the data of monitoring databases of AA in food, care must be taken that data are quality controlled, as it is likely that some of them may be biased.
Use of Flow InjectionMultisite Detection as a Novel Approach for Blank Signal Correction in a Spectrophotometric Determination
Authors: Oliveira Teresa A C , Mesquita Raquel B R , Lima José L F C , Rangel António O S S 
Published: February 2020

Abstract
A flow injection multisite detection system was developed for correction of the sample blank in a colorimetric determination. By using detector relocation, a single spectrophotometer is used for the sequential reading of the sample blank and of the colored product; the sample crosses the flow cell to measure intrinsic absorption, the color reagent is subsequently added, and the flow cell is relocated to provide the reading of the resulting plug. The subsequent detector relocation immediately after peak maximum increases the determination frequency. This strategy was tested in the colorimetric determination of iron in soil samples based on the reaction of Fe (II) with 1,10-phenanthroline after reduction of Fe (III) to Fe (II) by ascorbic acid. The results obtained for 15 soil extracts were in good agreement with those obtained by the reference procedure. Relative standard deviations better than 4% were obtained, with a sampling rate of 30/h.
Solid-Phase Extraction of Vitamins A and E from Animal Feeds: A Substitute for Liquid–Liquid Extraction
Authors: Fedder Robert , Plöger Annette 
Published: February 2020

Abstract
A substitution was developed for the laborious liquid–liquid extraction method according to European Economic Community legislation for isolation of Vitamins A and E from feeds. A rapid method for the isolation of the 2 vitamins by means of solid-phase extraction on OASIS® columns gave reproducible results comparable to those of the European Union-recommended method. The vitamins in the feed were extracted with a minor modification of the official method (KOH in ethanol). After filtration, a portion was applied onto the OASIS column and then washed. The vitamins were eluted in ethyl acetate. The eluate evaporated under nitrogen, and the precipitate was dissolved in methanol before liquid chromatography analysis. Recovery for this method was 80% for Vitamin A and 110% for Vitamin E, as calculated as the result for National Institute of Standards and Technology (NIST) Infant Formula. Day-to-day reproducibility for the method was 21 and 11% of the average results for Vitamins A and E, respectively.
Simultaneous Quantification of Terpenelactones and Flavonol Aglycones in Hydrolyzed Ginkgo biloba Extract by Liquid Chromatography with Inline Ultraviolet and Evaporative Light Scattering Detection
Authors: Gray Dean E , Messer Dale , Porter Andrew , Ferguson Sherry , Harris Roger K , Clark Alice P , Algaier Joseph W , Overstreet J Diane , Smith Cynthia S 
Published: February 2020

Abstract
We report here a liquid chromatography (LC) method with inline ultraviolet/evaporative light scattering (UV/ELS) detection for the simultaneous quantification of the terpenelactones and flavonol aglycones in a single sample of hydrolyzed Ginkgo biloba extract (GBE). The sample is hydrolyzed by a rapid and convenient oven heating method for 1 h at 90°C with 10% hydrochloric acid. The 1 h hydrolysis was found to be equivalent to the 2.25 h reflux treatment for dry powder extract, where total flavonol glycosides were 28.4 and 28.1%, respectively. Acceptable precision was achieved for total terpenelactones [relative standard deviation (RSD) = 4.8%] by ELS detection, and total flavonol aglycones (RSD = 2.3%) by UV detection. The analytical range was 1.5 to 7.3% (w/w) for the individual terpenelactones (ELS) and 2.5 to 15.0% (w/w) for the individual glycosides (UV) calculated from the aglycones quercetin, kaempferol, and isorhamnetin. This improved method allows for the first time high throughput sample preparation coupled with the quantification of the predominant compounds generally used for quality control of GBE in a single assay.
New Liquid Chromatographic-Chemometric Approach for the Determination of Sunset Yellow and Tartrazine in Commercial Preparation
Authors: Dinç Erdal , Aktaş A Hakan , Üstündağ Özgür 
Published: February 2020

Abstract
A new liquid chromatographic (LC)-chemometric approach was developed for the determination of sunset yellow (SUN) and tartrazine (TAR) in commercial preparations. This approach uses LC and chemometric calibration methods, i.e., classical least-squares (CLS), principal component regression (PCR), and partial–least squares (PLS), simultaneously. The combined LC-chemometric approaches, denoted as LC-CLS, LC-PCR, and LC-PLS, are based on photodiode array (PDA) detection at multiple wavelengths. Optimum chromatographic separation of SUN and TAR with allura red as the internal standard (IS) was obtained by using a Waters Symmetry® C18 column, 5 μm, 4.6 × 250 mm, and 0.2 M acetate buffer (pH 5)–acetonitrile–methanol–bidistilled water (55 + 20 + 15 + 10, v/v) as the mobile phase at a flow rate of 1.9 mL/min. The LC data sets consisting of the ratios of analyte peak areas to the IS peak area were obtained by using PDA detection at 5 wavelengths (465, 470, 475, 480, and 485 nm). LC-chemometric calibrations for SUN and TAR were separately constructed by using the relationship between the peak-area ratio and the training sets for each colorant. LC-chemometric approaches were tested for different synthetic mixtures containing SUN and TAR in the presence of the IS. These LC-chemometric calibrations were applied to a commercial preparation of the 2 colorants. The experimental results of the LC-chemometric approaches were compared with those obtained by a developed classical LC method using single-wavelength detection.
Simultaneous Analysis of Cadmium, Lead, Mercury, and Arsenic Content in Foodstuffs of Animal Origin by Inductively Coupled Plasma/Mass Spectrometry after Closed Vessel Microwave Digestion: Method Validation
Authors: Noël Laurent , Dufailly Vincent , Lemahieu Nadège , Vastel Christelle , Guérin Thierry 
Published: February 2020

Abstract
A method validation of the total analysis of cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) in foodstuffs by inductively coupled plasma/mass spectrometry (ICP/MS) after closed vessel microwave digestion is presented. Due to the lack of reference method for ICP/MS techniques in food and, based on the project of the European Committee of Normalization (CEN/TC 275/WG 10), the Agence Française de Normalisation (AFNOR) guidelines NF V03–110 were used for the evaluation of this method based on 2 steps, sample preparation and multielement detection. Several criteria considered as compulsory (linearity, specificity, precision under repeatability conditions, and trueness) have been estimated and discussed, in addition to intermediate precision reproducibility, the limit of detection, and the limit of quantification. Furthermore, a comparison with in-house methods using electrothermal atomic absorption was performed using an external proficiency testing scheme and food samples. The results indicated that this method could be used in the laboratory for the routine determination of these 4 cumulative toxic metals in foodstuffs with acceptable analytical performance.
Gluten Determination by Gliadin Enzyme-Linked Immunosorbent Assay Kit: Interlaboratory Study
Authors: Gabrovská Dana , Rysová Jana , Filová Vanda , Plicka Jan , Cuhra Petr , KubíK, Martin , BaršOvá Soňa ,   Collaborators:, Bulawová H , Chirdo F G , Dermühl A , Iametti S , Kirinčič S , Pavelka J , Tlaskalová H 
Published: February 2020

Abstract
An interlaboratory study with 10 participants was performed to obtain validation and performance data for an enzyme-linked immunosorbent assay (ELISA) kit developed for quantitative gluten determination in foods. The ELISA kit used for this study is based on 2 monoclonal and 1 polyclonal antibody developed by Immunotech, a Beckman Coulter Co. This kit did not show any false positive results or cross-reactivity with oat, rice, maize, and buckwheat. The gliadin standard from the Working Group on Prolamin Analysis and Toxicity was included in the kit as reference material for calibration. All participants obtained a gliadin ELISA kit with Standard Operational Procedure and a form for recording test results. The study included 13 samples labeled as gluten-free and 2 samples spiked by wheat flour. Seven samples had gliadin content below the limit of quantitation (LOQ) of the method, and 1 sample exceeded the highest calibration level. Gliadin content in the range from 10 to 157 mg/kg (1st day) and from 11 to 183 mg/kg (2nd day) was found in 7 samples (including 2 spiked samples). Results of these samples were used for further statistical analysis and evaluation. The Cochran, Dixon, and Mandel statistical tests were applied for detection of outliers. The LOQ of the kit was estimated.
Testing Deviation for a Set of Serial Dilution Most Probable Numbers from a Poisson-Binomial Model
Authors: Blodgett Robert J 
Published: February 2020

Abstract
A serial dilution experiment estimates the microbial concentration in a broth by inoculating several sets of tubes with various amounts of the broth. The estimation uses the Poisson distribution and the number of tubes in each of these sets that show growth. Several factors, such as interfering microbes, toxins, or disaggregation of adhering microbes, may distort the results of a serial dilution experiment. A mild enough distortion may not raise suspicion with a single outcome. The test introduced here judges whether the entire set of serial dilution outcomes appears unusual. This test forms lists of the possible outcomes. The set of outcomes is declared unusual if any occurrence of an observed outcome is on the first list, or more than one is on the first or second list, etc. A similar test can apply when there are only a finite number of possible outcomes, and each outcome has a calculable probability, and few outcomes have tied probabilities.
Validation of the Antifactor Xa and Antifactor IIa Assays for the Potency Assessment of Nadroparin in Pharmaceutical Formulations
Authors: Dalmora Sérgio Luiz , Sangoi Maximiliano da Silva , Barth Thiago , Brum Liberato , Vaccari Silvana Ferreira 
Published: February 2020

Abstract
The low-molecular weight heparin nadroparin calcium is used clinically for the prevention and treatment of venous and arterial thrombosis. The antifactor Xa and antifactor IIa assays were validated by investigating the parameters of range, linearity (r2 0.9905 and r2 0.9914, respectively) precision, accuracy, and robustness. The 2 methods incorporated a chromogenic endpoint and detection at 405 nm, yielding good results with detection limits of 0.004 and 0.01 IU/mL and quantitation limits of 0.01 and 0.03 IU/mL, respectively, for the antifactor Xa and antifactor IIa assays. Nadroparin calcium pharmaceutical products were evaluated by the antifactor Xa assay and the antifactor IIa assay, giving potencies between 93.86 and 109.88%, with an antifactor Xa/antifactor IIa ratio between 3.2 and 3.7. The results demonstrated the validity of the assays that are useful methodologies for the routine quality control of nadroparin in pharmaceutical formulations.
Determination of Nifedipine in Serum ofWomen in Preterm Labor by High-Performance Liquid Chromatography with Diode Array Detection
Authors: Kowalczuk Dorota , Wawrzycka Maria Bożena , Maj Agnieszka Haratym 
Published: February 2020

Abstract
Nifedipine (Nif) is widely used in treating cardiovascular disorders (especially hypertension) and for inhibiting preterm labor. A fully validated selective high-performance liquid chromatographic method with diode array detection, using solid-phase extraction, was developed for the determination of Nif in human serum. To assess specificity, Nif and its degradation products were separated on a Purospher RP-18 (5m, 125×4 mm) column plus a LiChrospher 100&lt;sup/&gt; RP-18 (5 μm, 4×4 mm) precolumn with a mobile phase of methanol10 mM aqueous trifluoroacetic acid, pH 7.3 (57 + 43, v/v); chromatographic separation was followed by UV detection at 238 nm. For toxicological analysis, Nif in the presence of other calcium-channel antagonist drugs was identified under optimum chromatographic conditions. The calibration graph was constructed over the concentration range of 12.5400 ng/mL in serum with good correlation (r 0.9956). This method was not subject to interference by other plasma components and was successfully applied to the assay of Nif in spiked human serum and in serum of women in preterm labor after sublingual administration of 30 mg Nif per day divided into 3 equal doses. The mean recovery based on the ratio of the slopes of serum and mobile phase standard curves was 96.5%. The detection and quantification limits of the drug in spiked human serum were found to be 6 and 17.5 ng/mL, respectively. Validation of the method demonstrated good intraday and interday precision, which ranged from 2.18 to 6.67% and from 6.52 to 11.93%, respectively.
Determination of Four Nitroimidazoles in Poultry and Swine Muscle and Eggs by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Xia Xi , Li Xiaowei , Shen Jianzhong , Zhang Suxia , Ding Shuangyang , Jiang Haiyang 
Published: February 2020

Abstract
A rapid method is presented for the determination of 4 nitroimidazoles in poultry and swine muscle and eggs by liquid chromatographyelectrospray ionizationtandem mass spectrometry (LCESIMSMS). Samples were extracted with acetonitrile, then evaporated the organic phase. After filtration, the extract was directly injected into the LCESIMSMS system. The LC separation was made on a C8 column by applying a gradient composed of water and acetonitrile. Overall average recoveries ranged from 5086 for egg, 66115 for poultry muscle, and 79111 for swine muscle. The decision limits ranged from 0.05-0.25 μgkg for egg, 0.07-0.27 μgkg for poultry muscle, and 0.07-0.26 μgkg for swine muscle; and detection capabilities ranged from 0.510.68 gkg for egg, 0.41-0.75 μgkg for poultry muscle, and 0.53-0.78 μgkg for swine muscle.
Determination of Chloramphenicol Residue in Chicken Tissues by Immunoaffinity Chromatography Cleanup and Gas Chromatography with aMicrocell Electron Capture Detector
Authors: Zhang Suxia , Zhou Jinhui , Shen Jianzhong , Ding Shuangyang , Li Jiancheng 
Published: February 2020

Abstract
A rapid and sensitive gas chromatography (GC) method was developed to detect chloramphenicol in chicken tissues. The extracted samples were cleaned up using the immunoaffinity column prepared by coupling antichloramphenicol monoclonal antibody with cyanogen bromide-activated Sepharose 4B. The dynamic column capacity of chloramphenicol was 3265 ng/mL gel. The eluate was evaporated to dryness, and residues were derivatized and determined by GC with a microcell electron capture detector. Average recoveries were 86.6 to 96.9 for chicken muscle and 74.3 to 96.1 for chicken liver. The limit of quantitation of the method was 0.05 ng/g for chicken muscle and 0.1 ng/g for chicken liver.
Predicting Aflatoxin and Fumonisin in Shelled Corn Lots Using Poor-Quality Grade Components
Authors: Johansson Anders S , Whitaker Thomas B , Hagler Winston M , Bowman Daryl T , Slate Andy B , Payne Gary 
Published: February 2020

Abstract
A study was conducted to determine if aflatoxin and fumonisin are concentrated in the poor-quality grade components of shelled corn. Four 1.0 kg test samples were each taken from 23 lots of shelled corn marketed in North Carolina. Inspectors from the Federal Grain Inspection Service divided each test sample into 3 grade components: (1) damaged kernels (DM), (2) broken corn and foreign material (BCFM), and )3) whole kernels (WH). The aflatoxin and fumonisin concentration was measured in each component and a mass balance equation was used to calculate the total concentration of each mycotoxin in each test sample. Averaged across all test samples, the aflatoxin concentrations in the DM, BCFM, and WH components were 1300.3, 455.2, and 37.3 ppb, respectively. Averaged across all test samples, the fumonisin concentrations in the DM, BCFM, and WH components were 148.3, 51.3, and 1.8 ppm, respectively. The DM and BCFM components combined accounted for only 5.0% of the test sample mass, but accounted for 59.8 and 77.5% of the total aflatoxin and fumonisin mass in the test sample, respectively. Both aflatoxin mass (ng) and aflatoxin concentration (ng/g) in the combined DM and BCFM components had high correlations with aflatoxin concentration in the lot. The highest correlation occurred when aflatoxin mass (ng) in the combined DM and BCFM components was related to aflatoxin concentration in the lot (0.964). Similar results were obtained for fumonisin. This study indicated that measuring either aflatoxin or fumonisin in the combined DM and BCFM grade components could be used as a screening method to predict either aflatoxin or fumonisin in a bulk lot of shelled corn.
Determination of Aflatoxin B1 in Medical Herbs: Interlaboratory Study
Authors: Arranz Isabel , Sizoo Eric , Van Egmond Hans , Kroeger Katy , Legarda Teresa M , Burdaspal Pedro , Reif Klaus , Stroka Joerg 
Published: February 2020

Abstract
A method was developed for the determination of aflatoxin B1 in medical herbs (senna pods, botanical name Cassia angustifolia; devil's claw, botanical name Harpagophytum procumbens; and ginger roots, botanical name Zingiber officinale). The method, which was tested in a mini-collaborative study by 4 laboratories, is based on an immunoaffinity cleanup followed by reversed-phase high-performance liquid chromatography separation and fluorescence detection after post-column derivatization. It allows the quantitation of aflatoxin B1 at levels lower than 2 ng/g. A second extractant (acetonewater) was tested and compared to the proposed methanolwater extractant. Several post-column derivatization options (electrochemically generated bromine, photochemical reaction, and chemical bromination) as well as different integration modes (height versus area) were also investigated. No differences were found depending on the choice of derivatization system or the signal integration mode used. The method was tested for 3 different matrixes: senna pods, ginger root, and devil's claw. Performance characteristics were established from the results of the study and resulted in HorRat values ranging from 0.12 to 0.75 with mean recoveries from 78 to 91% for the extraction with methanolwater and HorRat values ranging from 0.101.03 with mean recoveries from 98 to 103% for the extraction with acetonewater. As a result, the method, with all tested variations, was found to be fit-for-purpose for the determination of aflatoxin B1 in medical herbs at levels of 1 g/kg and above.
Biosensor Analysis of β-Lactams in Milk Using the Carboxypeptidase Activity of a Bacterial Penicillin Binding Protein
Authors: SternesjÖ Åse , Gustavsson Eva 
Published: February 2020

Abstract
The applicability of a -lactam receptor protein for detection of β-lactam antibiotics in milk using surface plasmon resonance (SPR) biosensor technology was investigated. The advantage of using a receptor protein instead of antibodies for detection of β-lactams is that a generic assay, specific for the active form of the β-lactam structure, is obtained. Two assays based on the enzymatic activity of the dd-carboxypeptidase from Actinomadura R39 were developed, using a Biacore SPR biosensor. The carboxypeptidase converts a tri-peptide into a di-peptide, a reaction which is inhibited in the presence of β-lactams. Polyclonal antibodies against the 2 peptides were developed and used to measure the amount of enzymatic product formed (di-peptide assay) or the amount of remaining enzymatic substrate (tri-peptide assay), respectively. The 2 assays showed similar performances with respect to detection limits (1.2 and 1.5 μg/kg, respectively) and precision (coefficient of variation &lt;5%) for penicillin G in milk. Several other β-lactams were detected at or near their respective maximum residue limit. Furthermore, the 2 peptide assays were evaluated against 5 commercial kit tests in the screening of 195 producer milk samples. The biosensor assays showed 0% false-negative and 27% false-positive results, whereas the figures were 0% false-negative and 2753% false-positive results for other screening tests investigated.