bluuebunny/crossref_metadata_2025_split huggingface dataset:
13C-IRIS: An Improved Method To Detect the Addition of Low Levels of C4-Derived Sugars to Juices
Authors: Day Martin P , Correia Patricia , Hammond David A 
Published: February 2020

Abstract
A method to improve the detection of cane or corn sugar addition to fruit juices has been developed. This involves the isolation of the individual sugars and measurement of their carbon isotope ratios. Using the Isotopic Relations of Individual Sugars approach, the additions of cane sucrose or cane invert as low as 4% of the total sugars can be detected in orange juice. This method offers a significant improvement over the conventional carbon isotopic method that has a detection limit of about 10%.
Isolation of Lipid and 2-Alkylcyclobutanones from Irradiated Foods by Supercritical Fluid Extraction
Authors: Stewart Eileen M , McRoberts W Colin , Hamilton John T G , Graham William D 
Published: February 2020

Abstract
The 2-alkylcyclobutanone method was adopted as a European Standard (EN1785) and MAFF Validated Method (MAFF V37) in 1996 for the detection of irradiated food containing fat. As the method requires a relatively long period (ca 2 days) of time for extraction of the 2-alkylcyclobutanones from a foodstuff, a means was sought to increase the speed at which these irradiation markers could be isolated while at the same time decreasing the amount of organic solvents required. Thus, the technique of supercritical fluid extraction (SFE) was investigated. Results showed that SFE can be used for the rapid extraction (60 min) of lipid from irradiated foods such as chicken, pork, liquid whole egg, ground beef, and from the seeds of irradiated mango and papaya with only 10 mL n-hexane being necessary for collection of the extracted sample. A method was also developed whereby the 2-alkylcyclobutanones can be selectively extracted from irradiated foods without prior extraction of the lipid. The sample extract, in 10 mL n-hexane, is purified through a Florisil SPE cartridge which is washed with 10 mL n-hexane and the 2-alkylcyclobutanones eluted with 10 mL 2% diethyl ether in n-hexane before analysis by gas chromatography/mass spectrometry. 2-Dodecylcyclobutanone and 2-tetradecylcyclobutanone were selectively extracted from irradiated chicken meat, liquid whole egg, ground beef, and mango as well as from beef burgers and baked products containing irradiated ground beef and liquid whole egg, respectively. Using this method, samples can be analyzed for irradiation treatment within 6 h as opposed to the 2-day period required for the EN1785/MAFF V37 validated method.
Comparison of Liquid Chromatography/Mass Spectrometry, ELISA, and Phosphatase Assay for the Determination of Microcystins in Blue-Green Algae Products
Authors: Lawrence James F , Niedzwiadek Barbara , Menard Cathie , Lau Benjamin P Y , Lewis David , Kuper-Goodman Tine , Carbone Susan , Holmes Charles 
Published: February 2020

Abstract
More than 100 samples of blue-green algae products (consisting of Aphanizomenon, Spirulina, and unidentified blue-green algae) in the form of pills, capsules, and powders were collected from retail outlets from across Canada. The samples were extracted with 75% methanol in water and centrifuged to remove solids. Aliquots of the extracts along with spiked blank sample extracts were sent to each participating laboratory and independently analyzed for microcystins by enzyme-linked immunosorbent assay (ELISA), protein phosphatase inhibition assay, and by liquid chromatography–tandem mass spectrometry (LC–MS/MS) after sample cleanup using C18 solid–phase extraction. The results obtained by ELISA and LC–MS/MS agreed very well over a concentration range of about 0.5–35 μg/g. The colorimetric phosphatase results generally agreed with the other 2 methods. While the 2 biochemical assays measured total microcystin content compared with a standard of microcystin LR, the LC–MS/MS method measured specific microcystins (LA, LR, RR, YR) using external standards of these for identification and quantitation. Microcystin LR was found in all positive samples by LC–MS/MS. Microcystin LA was the only other microcystin found in the samples analyzed. These 2 microcystins represent essentially all the microcystins that were present in the extracts. Otherwise, the LC–MS/MS results would have been significantly lower than the results of the biochemical assays had other unknown microcystins been present.
Rapid Determination of Total trans Fat Content—An Attenuated Total Reflection Infrared Spectroscopy International Collaborative Study
Authors: Mossoba Magdi M , Adam Michael , Lee Theresa ,   Collaborators:, Bastyr J , Bhat S N , Dawson T , Guldan M , Hansen S , Hayes C , Lambert E S , Lee T , Mossoba M M , Reh C , Sedman J , Smith G , van Schaick M A , van Velzen E J J 
Published: February 2020

Abstract
Interest in trans fat labeling has prompted efforts to develop new, more efficient methods for rapidly and accurately determining trans fat content of foods. A novel and rapid (5 min) attenuated total reflection–Fourier transform infrared (ATR–FTIR) spectroscopic procedure was recently developed and applied to food products. This procedure was voted official method AOCS Cd 14d-99 by the American Oil Chemists' Society in 1999 after testing in a 12 laboratory international collaborative study. The results of the study are described in this paper. Analytical ATR–FTIR results exhibited high accuracy in the range 5–40% trans; results tended to have &lt;2% high bias relative to the gravimetrically determined values. The precision of this internal reflection method was found to be superior to the precision of transmission infrared official methods. It is recommended that the applicability of the ATR–FTIR method be limited to trans levels of &gt;5% (as percent of total fat).
Multiresidue Determination of Pesticides in Honey by Matrix Solid-Phase Dispersion and Gas Chromatography with Electron-Capture Detection
Authors: Albero Beatriz , Sánchez-Brunete Consuelo , Tadeo José L 
Published: February 2020

Abstract
A multiresidue method was developed for the determination of 15 pesticides (organochlorines, organophosphorus compounds, pyrethroids, and other acaricides) in various commercial honeys (eucalyptus, lavender, orange, rosemary, and multifloral). The analytical procedure is based on the matrix solid-phase dispersion of honey in a mixture of Florisil and anhydrous sodium sulfate; the mixture is placed in small plastic columns and extracted with hexane–ethyl acetate (90 + 10, v/v). The pesticide residues are determined by capillary gas chromatography with electron-capture detection. Recoveries with the method at concentrations between 0.15 and 1.5 μg/g ranged from 80 to 113%, and relative standard deviations were &lt;10% for all the pesticides studied. The pesticide detection limits were within the range 0.5–5 mg/kg for organochlorines, around 3 μg/kg for the chlorinated organophosphorus pesticides studied, near 15 μg/kg for fluvalinate, and about 3 μg/kg for the other pyrethroids.
Fluorophotometric Thin-Layer Chromatography of Ginkgo Terpenes by Postchromatographic Thermochemical Derivatization and Quality Survey of Commercial Ginkgo Products
Authors: Peishan Xie , Yuzhen Yan , Haoquan Qian , Qiaoling Lin 
Published: February 2020

Abstract
Terpenoid lactones in Ginkgo biloba leaves are the main active constituents and the content of these terpenes is therefore the key factor for evaluating the quality of the leaves, the extract, and its preparations distributed on the market. The precleanup sample solutions were applied onto the silica gel plate modified with sodium acetate solution and developed with a solvent system of toluene–ethyl acetate–acetone–methanol, and a fluorescence chromatogram was generated by means of postchromatographic thermal chemical reaction. Fluorescence scanning was conducted quantitatively. The methodology validation confirmed that it is a practical alternative for routine quality control for ginkgo terpenes and the results are comparable with those obtained by high-performance liquid chromatography (HPLC). On the basis of the method established, a quality survey of the various commercial ginkgo products from different sources was undertaken. The obtained data demonstrated that the fluctuation of the content of individual terpene and/or the total terpenes among replicate samples is so significant as to cast doubts on the consistency of their pharmacological and clinical efficacy.
Development of a Rapid Method for the Detection of Cocoa Butter Equivalents in Mixtures with Cocoa Butter
Authors: Barcarolo Robertino , Anklam Elke 
Published: February 2020

Abstract
A simple and rapid gas chromatographic (GC) method was developed for the detection of cocoa butter equivalents (CBEs) in cocoa butter (CB). It is based on the use of a 5 m nonpolar capillary column for the separation of the main triglycerides of CB according to their acyl/carbon numbers. The GC procedure was optimized to avoid thermal degradation of the triglycerides. By computing the ratio C54/C50 and (C54/C50) × C52 and by 2-dimensional plotting of these values, authentic CB samples were clearly distinguished from samples containing various CBEs. The detection of little as 1% CBE in CB (corresponding to about 0.3% CBE in chocolate) in a model system was shown to be possible. Under real conditions, for a wide range of CBs, about 2.5%CBEs in CB were detected. With this method, quantitation was possible at a concentration of 5% CBEs in CB mixtures, which corresponds to around 1% in chocolate; this value is far below the maximum level of 5% CBEs allowed to be added to chocolate.
Recognition of the Bouquet of Chinese Spirits by Artificial Neural Network Analysis
Authors: Chen Hua , Yu Zhiyong , Zhu Guobin 
Published: February 2020

Abstract
Forty-six samples of Chinese spirits, whose bouquets were determined by sensory evaluations, and 17 compounds characteristic of the flavors determined by gas chromatography/gas chromatography–mass spectrometry (GC/GC–MS), were subjected to neural network analysis and their corresponding factor scores developed. To make the bouquet recognition more efficient, an improved artificial back-propagation neural network (BPNN) was applied. In each kind of data, the BPNN was trained repeatedly until the error rate was less than the predetermined threshold error; then the trained network was applied to the test set that was not involved in the training process to establish the validity of the network, and a correct prediction rate of 100% was obtained. The BPNN provided a correlation between the data offered from sensory evaluations and the data of chemical compositions determined by instrumental analysis. The BPNN approach is feasible regardless of whether the crude data or the factor scores are used; however, recognition results were better with the latter than with the former. In a comparison of all the results obtained by BPNN, cluster analysis, and discriminant analysis, the method of artificial neural network analysis appeared to be the optimal technique for recognizing the bouquet of Chinese spirits.
Determination of Isoflavones in Soy and Selected Foods Containing Soy by Extraction, Saponification, and Liquid Chromatography: Collaborative Study
Authors: Klump Stephen P , Allred Maryann C , MacDonald John L , Ballam Joan M ,   Collaborators:, Arora A , Cole S , Collison M , Ellefson W , Gensic J , Hazebroek J , Johns P , Klump S , Lewis S , Moghaddam M , Murphy P , Woollard D C 
Published: February 2020

Abstract
Isoflavones are biologically active compounds occurring naturally in a variety of plants, with relatively high levels found in soybeans. Twelve laboratories participated in a collaborative study to determine the aglycon isoflavone content of 8 test samples of soy and foods containing soy. The analytical method for the determination of isoflavones incorporates a mild saponification step that reduces the number of analytes measured and permits quantitation versus commercially available, stable reference standards. Test samples were extracted at 65°C with methanol–water (80 + 20), saponified with dilute sodium hydroxide solution, and analyzed by reversed-phase liquid chromatography with UV detection at 260 nm. Isoflavone results were reported as μg/aglycon/g or μg aglycon equivalents/g. The 8 test samples included 2 blind duplicates and 4 single test samples with total isoflavone concentrations ranging from approximately 50 to 3000 μg/g. Test samples of soy ingredients and products made with soy were distributed to collaborators with appropriate reference standards. Collaborators were asked to analyze test samples in duplicate on 2 separate days. The data were analyzed for individual isoflavone components, subtotals of daidzin–daidzein, glycitin–glycitein, and genistin–genistein, and total isoflavones. The relative standard deviation (RSD) for repeatability was 1.8–7.1%, and the RSD for reproducibility was 3.2–16.1% for total isoflavone values of 47–3099 μg/g.
Determination of Chlormequat in Fruit Samples by Liquid Chromatography-Electrospray-Mass Spectrometry/Mass Spectrometry
Authors: Castro Rocio , Moyano Encarnación , Galceran Maria Teresa 
Published: February 2020

Abstract
An ion-pair liquid chromatography-mass spectrometry/mass spectrometry method was developed for the determination of chlormequat in fruit samples. A solid-phase extraction cleanup procedure with C18 cartridges was used. Sample preparation was simple and the achieved detection limit (0.03 mg/kg) and quantitation limit (0.08 mg/kg) were below the maximum residue levels legislated by the European Union. The chromatographic separation was performed by using a C8 column and heptafluorobutyric acid as ion pair reagent. The detection was conducted with an electrospray source and an ion trap as a mass analyzer. The reproducibility of the method gave good run-to-run (8–9%) and day-to-day (9–13%) precision values, and its applicability to the determination of chlormequat in pears and grapes, purées, and pear, apple, and grape juices was demonstrated.
Collection and Preparation of Sidestream Cigarette Smoke for Trace Elemental Determinations by Graphite Furnace Atomic Absorption Spectrometry and Inductively Coupled Plasma Mass Spectrometry
Authors: Wagner Karl A , McDaniel Reta , Self David 
Published: February 2020

Abstract
A novel method for the collection and preparation of sidestream cigarette smoke condensate is described for trace elemental analysis by inductively coupled plasma mass spectrometry and graphite furnace atomic absorption spectrometry. The smoke collection method utilizes a specially designed chimney that collects and directs the sidestream smoke (SS) to a 2-stage trapping system consisting of an impaction trap followed by a 0.8 μm mixed cellulose ester filter. The samples are digested with nitric acid in a commercial heating block before analysis. The method limits of detection (LODs) are 1, 0.2, 2, 9, 6, and 7 ng/cigt for As, Cd, Pb, Ni, Se, and Cr, respectively. The SS collected from an industry reference cigarette, 1R4F, produced by the University of Kentucky was analyzed. The concentrations of As, Cd, and Pb in 1R4F were determined to be 27.3 ± 2.1, 412 ± 14, and 43.8 ± 2.0 ng/cigt, respectively, while the concentrations of Ni, Cr, and Se are below the method LOD. Consequently, this novel method successfully addresses contamination, instrumentation, and collection issues for performing trace elemental analysis of sidestream cigarette smoke condensate.
Uptake of Cadmium, Copper, Iron, Manganese, and Zinc in Mushrooms (Boletaceae) from Croatian Forest Soil
Authors: Blanuša Maja , Kučak Antun , Varnai Veda-Marija , Sarić Marijana Matek 
Published: February 2020

Abstract
The concentration of trace elements (Cd, Cu, Fe, Mn, and Zn) was measured in different species of mushrooms (Boletaceae) and correlated with corresponding elements in soil. Five different species of Boletaceae mushrooms and soil samples were collected from forests of Varaždin county in Croatia. Trace elements were analyzed by atomic absorption spectrometry in mushrooms and in EDTA-extracted soil. The results showed that Cd, Cu, and Zn are concentrated in mushroom tissue from soil with transfer factors (mushroom/soil) of 27.0, 10.5, and 12.5, respectively. Cadmium incorporated much less in Leccinum (mean 0.73 mg/kg dry weight) than in Boletus, Xerocomus, or Gyroporus (respective means, 6.8, 8.4, and 12.3 mg/kg). Copper and Zn were accumulated in all collected mushrooms (14.7–35.6 and 109–179 mg/kg, respectively) with no difference among species. There was no accumulation of Fe and Mn in mushrooms, but concentrations differed between species, with lowest values in Leccinum. Iron varied from 31 to 878 mg/kg and Mn from 2.9 to 409 mg/kg. Correlations between elements in mushrooms and soil were significant only for Mn. Because no significant correlations for Cd, Cu, Zn, and Fe between mushrooms and soil were found, more studies are needed with only one species of mushrooms collected at locations with different levels of soil contamination. In spite of higher concentrations of Cd in some Boletaceae species, it is assumed that Cd intake through moderate mushroom consumption remains below suggested Provisional Tolerable Weekly Intake (FAO/WHO).
Multielemental Analysis of Food and Agricultural Matrixes by Inductively Coupled Plasma-Mass Spectrometry
Authors: Cubadda Francesco , Andrea Andrea , Testoni Antonella , Fabio Fabio 
Published: February 2020

Abstract
The suitability of quadrupole inductively coupled plasma-mass spectrometry (ICP-MS) for multielemental analysis of food following microwave closed vessel digestion of samples was evaluated in relation to analytical challenges presented by some major food and agricultural matrixes. Fifteen key analytes (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sn, V, Zn) were determined in 9 reference materials representative of 3 major groups of staple foods (cereals, seafood, and meat). For all measurements, the method of external calibration was used and Rh was selected as internal standard. Matrix-induced interferences were evaluated for each material, and suitable methods to overcome them were applied. Spectral interferences caused by C, Cl, and Ca content of digestates were quantitated and corrected by entering a simple system of mathematical correction equations into the instrument software before each analytical run. Full mastering of interferences together with adoption of a series of measures to control the reliability of analytical measurements produced accurate results for all the analytes. A standard analytical protocol is outlined for the benefit of both research and routine high-throughput laboratories that perform ICP-MS analyses of food.
Determination of Insecticides in Honey by Matrix Solid-Phase Dispersion and Gas Chromatography with Nitrogen–Phosphorus Detection and Mass Spectrometric Confirmation
Authors: Sánchez-Brunete Consuelo , Albero Beatriz , Miguel Ester , Tadeo José Luis 
Published: February 2020

Abstract
A multiresidue method was developed for the determination of 12 organophosphorus insecticides (diazinon, parathion methyl, fenitrothion, pirimiphosmethyl, malathion, fenthion, chlorpyrifos, quinalphos, methidathion, ethion, azinphosmethyl, coumaphos), one carbamate (pirimicarb), and one amidine (amitraz) in unifloral and multifloral honeys. The analytical procedure was based on the matrix solid-phase dispersion of honey on a mixture of Florisil and anhydrous sodium sulfate in small glass columns and subsequent extraction with a low volume of hexane–ethyl acetate (90 + 10, v/v), assisted by sonication. The insecticide residues were determined by capillary chromatography with nitrogen–phosphorus detection and confirmed by mass spectrometry. Average recoveries at the 0.05–0.5 μg/g levels were &gt;80% for organophosphorus insecticides and about 60% for the other insecticides, pirimicarb and amitraz, with relative standard deviations &lt;10%. The detection limit for the different insecticides ranged between 6 and 15 μg/kg. The main advantages of the proposed method are that extraction and cleanup are performed in a single step with a low volume of organic solvent. The method is simple, rapid, and less laborious than conventional methods. Several Spanish honeys were analyzed with the proposed method and no residues of the studied insecticides were found.
Liquid Chromatographic Determination of Multiple Sulfonamides, Nitrofurans, and Chloramphenicol Residues in Pasteurized Milk
Authors: Perez Norma , Gutierrez Rey , Noa Mario , Diaz Gilberto , Luna Hector , Escobar Irma , Munive Zenaida 
Published: February 2020

Abstract
A rapid and selective liquid chromatographic method was developed to detect 6 sulfonamides, 3 nitrofurans, and chloramphenicol residues in pasteurized milk. The 10 drugs were extracted with chloroform–acetone and the organic phase was evaporated; the residues were dissolved in an aqueous sodium acetate buffer solution 0.02M (pH = 4.8), and the fat was removed by washing with hexane. The aqueous layer was collected, filtered, and injected. The 6 sulfonamides and chloramphenicol were detected at 275 nm ultraviolet (UV) using a gradient system starting with sodium acetate buffer solution–acetonitrile (95 + 5) and finishing with sodium acetate buffer solution–acetonitrile (80 + 20). Nitrofurans were detected at 375 nm (UV) isocratically with sodium acetate buffer solution–acetonitrile (80 + 20). For 50 ppb fortified milk, the average recoveries were (sulfathiazole) 65.52%; (sulfamerazine) 75.36%; (sulfamethazine) 93.94%; (sulfachlorpyridazine) 75.94%; (sulfamethoxazole) 85.18%; (sulfamonomethoxine) 83.45%; (chloramphenicol) 104.17%; (nitrofurazone) 91.81%; (furazolidone) 100.76%; and (furaltadone) 72.38%. Method detection limits ranged from 4 ppb (nitrofurazone) to 16 ppb (sulfamethazine). Some matrix interferences (3–7 ppb) were observed only with sulfonamides.
Validation of a Simple Liquid Chromatographic Method for Determination and Quantitation of Residual Ivermectin and Doramectin in Pig Liver
Authors: Knold Lone , Reitov Marianne , Mortensen Anna Birthe , Hansen-Møller Jens 
Published: February 2020

Abstract
A rapid and quantitative method for the extraction, derivatization, and liquid chromatography with fluorescence detection of ivermectin (IVM) and doramectin (DOM) residues in porcine liver was developed and validated. IVM and DOM were extracted from the liver samples with acetonitrile, the supernatant was evaporated to dryness at 37°C under nitrogen, and the residue was reconstituted in 1-methylimidazole solution. After 2 min at room temperature, IVM and DOM were converted to a fluorescent derivative and then separated on a Hypersil ODS column. The derivatives of IVM and DOM were detected and quantitated with high specificity by fluorescence (excitation: 365 nm, emission: 475 nm). Abamectin was used as an internal standard. The mean extraction efficiencies from fortified samples (15 ng/g) were 75% for IVM and 70% for DOM. The limit of detection was 0.8 ng/g for both IVM and DOM.