bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective Extraction and Determination of Multiclass Pesticide Residues in Post-Harvest French Beans by Low-Pressure Gas Chromatography/Tandem Mass Spectrometry
Authors: Martínez Vidal Jose L , González-Rodríguez Manuel J , Arrebola Francisco J , Garrido Frenich Antonia , Sánchez López Francisco J , Díez Nielene Mora 
Published: February 2020

Abstract
A selective and reliable extraction procedure was developed and validated to determine multiclass pesticide residues in lyophilized agricultural plants by low-pressure gas chromatography coupled with tandem mass spectrometry. The method is based on a rapid and simple extraction of the lyophilized sample with dichloromethane. The results were compared with those obtained by using fresh and naturally dried samples. Slightly better recoveries and precision values were obtained for the lyophilized samples. The application of the proposed methodology was tested by analyzing French bean plants from an agricultural area of Almería (Spain). The availability of this methodology, which is capable of detecting a high number of analytes in a single analysis, has priority in analyses for a large number of pesticides used on individual commodities.
Single-Laboratory Validation of a Modified Liquid Chromatographic Method with UV Detection for Determination of Trenbolone Residues in Bovine Liver and Muscle
Authors: MacNeil James D , Reid Joann , Neiser Constance D , Fesser Adrian C E 
Published: February 2020

Abstract
Trenbolone acetate is a synthetic testosterone analog registered for use in a number of countries as a growth-promoting hormone, applied as an implant in the ears of feedlot cattle. The method is intended for the detection and quantitation of trace amounts of α- and β-trenbolone in bovine tissues (muscle, liver) by liquid chromatography (LC) with UV detection and eliminates the use of the structural analog, 19-nortestosterone, as an internal standard. Trenbolone residues are extracted from tissues that have been homogenized in sodium acetate with a 3-phase liquid–liquid extraction by adding a mixture of water–acetonitrile–dichloromethane– hexane, with trenbolone residues preferentially partitioned into the middle acetonitrile layer. The extract is passed through solid-phase extraction cartridges (both C18 and silica gel) using, respectively, methanol–water and acetone–toluene as eluents. Reversed-phase high-performance LC separation is performed, an octadecyl-bonded column with methanol–acetonitrile–water used as mobile phase for sample analysis. The limit of detection is 0.2 ng/g in muscle tissue and 0.6 ng/g in liver tissue, with coefficients of variation of 3.5–12.1% for α- and β-trenbolone at concentrations from 0.2 to 4.0 ng/g fortified in muscle and 3.3–26.0% from liver fortified at 0.6–10.0 ng/g. Absolute recoveries of 40–130% were observed, but the use of fortified matrix curves eliminated recovery correction. Critical control points were identified in a pH adjustment step and an evaporation step during method validation, which included ruggedness testing. Analysis of incurred tissues (bovine liver and muscle) stored at –20°C for over 25 weeks did not identify any significant loss of residues.
3M™ Petrifilm™ Staph Express Count Plate Method for the Enumeration of Staphylococcus aureus in Selected Types of Meat, Seafood, and Poultry: Collaborative Study
Authors: McMahon Wendy A , Aleo Victoria A , Schultz Ann M , Horter Barbara L , Lindberg Kathryn G ,   Collaborators:, Allen M , Anderson L , Barnes R , Bellow S , Bokina C , Boulter T , Caulkins L , Ceizyk M , Chavey C , Eastep Y , Gohil V , Guha S , Hall G , Hopkins K , Horter B , Kaufer A , Kaur D , Kim S , Kupski B , Lee J , Lester; T , Musch S , Silbernagel K , Sorce L , Steiner G , Sumpter R , Sutton J , Veach J 
Published: February 2020

Abstract
The 3M™ Petrifilm™ Staph Express Count plate method was compared with AOAC Official Method 975.55 for the enumeration of Staphylococcus aureus in selected foods. Four foods—cooked, diced chicken; cured ham; smoked salmon; and pepperoni—were analyzed for S. aureus by 12 collaborating laboratories. For each food tested, the collaborators received 8 blind test samples consisting of a control sample, a low inoculation level, a medium inoculation level, and a medium inoculation level with background flora, each in duplicate. The mean log10 counts for the methods were comparable for all 4 foods. The repeatability and reproducibility variances of the 24 h Petrifilm Staph Express Count plate method were similar to those of the 72 h standard method.
Immunoaffinity Column Cleanup with Liquid Chromatography Using Post-Column Bromination for Determination of Aflatoxin B1 in Cattle Feed: Collaborative Study
Authors: Stroka Joerg , von Holst Christoph , Anklam Elke , Reutter Matthias ,   Collaborators:, Barmark A , Brera C , Burdaspal P , Daily S , Declercq B , de Jong J , Eckstein H , Eklund E , Felgueiras I , Goto T , Hagler W , Joerissen U , Lew H , Ligi-Martins M , MacDonald S , Macho L , Marzna I , McGrath E , Michelet J Y , Nordkvist E , Noutio K , Pascale M , Roos A , Schwadorf K , Spanjer M , Szymanski L , Visconti A , Walsh M , Werner G , Whitaker T , Wilson D , Worswick R 
Published: February 2020

Abstract
A collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for determination of aflatoxin B1 in cattle feed at a possible future European regulatory limit (1 ng/g). The test portion was extracted with acetone–water (85 + 15), filtered, diluted with water, and applied to an immunoaffinity column. The column was washed with water to remove interfering compounds, and the purified aflatoxin B1 was eluted with methanol. Aflatoxin B1 was separated and determined by reversed-phase liquid chromatography (RP–LC) and detected by fluorescence after post column derivatization (PCD) involving bromination. PCD was achieved with either pyridinium hydrobromide perbromide (PBPB), used by 14 laboratories, or an electrochemical cell and addition of bromide to the mobile phase, used by 7 laboratories. Both derivatization techniques were not significantly different when compared by the t-test; the method was statistically evaluated for all laboratories together (bromination and PBPB). The cattle feed samples, both spiked and naturally contaminatedwithaflatoxinB1, were sent to 21 laboratories in 14 different countries (United States, Japan, and Europe). Test portions were spiked at levels of 1.2 and 3.6 ng/g for aflatoxin B1. Recoveries ranged from 74 to 157%. Based on results for spiked samples (blind pairs at 2 levels) as well as naturally con-taminated samples (blind pairs at 3 levels), the relative standard deviation for repeatability (RSDr) ranged from 5.9 to 8.7%. The relative standard deviation for reproducibility (RSDR) ranged from 17.5 to 19.6%. The method showed acceptable within-and between-laboratory precision for this matrix, as evidenced by HORRAT values, at the target levels of determination for aflatoxin B1. No major differences in RSD were observed, showing that the composition of the feeds was not a factor for the samples tested and that the method was applicable for all materials used.
Determination of Fluoride in Wine by Fluoride Selective Ion Electrode, Standard Addition Method: Collaborative Study
Authors: Trombella Bruno E , Caputi Arthur , Musso Daniel , Ribeiro Anthony , Ryan Timothy ,   Collaborators:, Andrade G , Burns G , Eder R , Gallego R G , Garcia J , Goriel A , Kupina S , Mabud A , Masschelin; J , Roberts D , Tusseau D , Wittkowski R 
Published: February 2020

Abstract
The accuracy, precision, and reproducibility of a rapid method for determination of fluoride in wine, using a fluoride selective ion electrode, were established by a collaborative study involving 12 laboratories, 5 in Europe and 7 in the United States. The laboratories assayed 6 Youden pairs of fluo-ride-fortified, red and white wine samples with fluoride concentrations ranging from 0.2 to 3.0 mg/L. The relative standard deviations of repeatability ranged from 1.94 to 4.88%; relative standard deviations of reproducibility ranged from 4.15 to 18.40%. HORRAT values ranged from 0.30 to 0.97. The average recovery was 99.97%. Based on the statistical results of this collaborative study, the Study Director recommends that this method be adopted First Action.
Extraction and Determination of Phenolic Derivatives in Water Samples by Using Polyoxyethylene Surfactants and Liquid Chromatography with Photodiode Array Detection
Authors: Santana C Mahugo , Ferrera Z Sosa , Rodríguez J J Santana 
Published: February 2020

Abstract
Methodology based on the cloud-point phenomenon was applied to the comparative study of 3 different polyoxyethylene nonionic surfactants in order to extract and preconcentrate a group of phenolic derivatives in water samples; these phenolic compounds, which were determined by liquid chromatography with UV detection, included 11 pollutants given priority by the U.S. Environmental Protection Agency. The optimum conditions for the extraction and preconcentration of phenolic compounds were established for each surfactant. The surfactant that gave the best extraction and preconcentration of the analytes under study was polyoxyethylene 6 lauryl ether (C12E6) with detection limits of &lt;3.5 μg/L for all the phenolic compounds tested. The method was applied to seawater and depurated wastewater samples.
Speciation and Bioavailability of Selenium in Yeast-Based Intervention Agents Used in Cancer Chemoprevention Studies
Authors: Larsen Erik H , Hansen Marianne , Paulin Helge , Moesgaard Sven , Reid Mary , Rayman Margaret 
Published: February 2020

Abstract
This study investigated the speciation and bioavailability of selenium in yeast-based intervention agents from multiple manufacturers from several time points. Sources of selenized yeast included Nutrition 21 (San Diego, CA), which supplied the Nutritional Prevention of Cancer (NPC) Trial from 1981–1996; Cypress Systems (Fresno, CA; 1997–1999); and Pharma Nord (Vejle, Denmark; 1999–2000), which supplied the Prevention of Cancer by Intervention by Selenium (PRECISE) Trial pilot studies. The low-molecular-selenium species were liberated from the samples by proteolytic hydrolysis followed by separation by ion exchange liquid chromatography and detection by inductively coupled plasma-mass spectrometry. The results for the NPC tablets showed that selenomethionine, together with 3 unidentified selenium compounds, were predominant in the sample hydrolysates. The relative amounts of the 4 selenium species varied (p &lt; 0.05) among several of the 7 tablet batches used during the course of the NPC Trial. In comparison, 5 batches of more recently produced selenized yeasts, which were used as a source of selenium in the PRECISE and other trials, contained less of the unknown compounds and more selenomethionine at 54–60% of the total selenium in the yeasts. One batch of yeast, however (from 1985), which originated from the same producer as the yeast used in the NPC tablets, contained only 27% of selenium in the sample as selenomethionine. Human subjects receiving 200 μg selenium/day in the UK PRECISE Pilot Trial showed a higher concentration (p &lt; 0.01) and higher increase from baseline in plasma selenium than did the same dosage used in the NPC Trial. Differences in intake, speciation, or bioavailability of selenium from the yeast-based supplements in the population groups studied may explain this. Furthermore, the selenium concentration in whole blood from the Danish PRECISE Pilot Trial was higher (p &lt; 0.001) than that obtained with synthetic L-selenomethionine in a comparable group of Danes, both groups having been treated with 300 μg selenium/day.
Qualitative Method for Determination of Aflatoxin B1 in Nuts
Authors: Trullols Esther , Ruisánchez Itziar , Rius F Xavier , Ódena Marta , Feliu M Teresa 
Published: February 2020

Abstract
The proper characterization of a commercial qualitative method for determining aflatoxin B1 in some nuts is described. A qualitative method that provides binary responses of the yes/no type means that the performance parameters have been properly adapted and defined. Performance characteristics such as the cut-off limit, the detection limit, sensitivity, specificity, false-positive and negative rates, and the unreliability or uncertainty region are defined and then estimated by means of the performance characteristic curves. The commercial test kit showed the cut-off limit at 1.6 ng/g, with a sensitivity rate of 95% and a false-negative rate of zero. A modification can be performed to shift the cut-off to 2.0 ng/g, keeping the same values for the sensitivity and false-negative rate.
Methods for Analysis of Conjugated Linoleic Acids and trans-18:1 Isomers in Dairy Fats by Using a Combination of Gas Chromatography, Silver-Ion Thin-Layer Chromatography/Gas Chromatography, and Silver-Ion Liquid Chromatography
Authors: Cruz-Hernandez Cristina , Deng Zeyuan , Zhou Jianqiang , Hill Arthur R , Yurawecz Martin P , Delmonte Pierluigi , Mossoba Magdi M , Dugan Michael E R , Kramer John K G 
Published: February 2020

Abstract
Conjugated linoleic acids (CLA) are octadecadienoic acids (18:2) that have a conjugated double-bond system. Interest in these compounds has expanded since CLA were found to be associated with a number of physiological and pathological responses such as cancer, metastases, atherosclerosis, diabetes, immunity, and body fat/protein composition. The main sources of these conjugated fatty acids are dairy fats. Rumen bacteria convert polyunsaturated fatty acids, especially linoleic and linolenic acids, to CLA and numerous trans- containing mono- and diunsaturated fatty acids. It has been established that an additional route of CLA synthesis in ruminants and monogastric animals, including humans, occurs via Δ9 desaturation of the trans-18:1 isomers. To date, a total of 6 positional CLA isomers have been found in dairy fats, each occurring in 4 geometric forms (cis,trans; trans,cis; cis,cis; and trans,trans) for a total of 24. All of these CLA isomers can be resolved only by a combination of gas chromatography (GC), using 100 m highly polar capillary columns, and silver-ion liquid chromatography, using 3 of these 25 cm columns in series. Complete analysis of all the trans-18:1 isomers requires prior isolation of trans monoenes by silver-ion thin-layer chromatography (TLC), followed by GC analysis using the same 100 m capillary columns operated at low temperatures starting from 120°C. These analytical techniques are required to assess the purity of commercial CLA preparations, because their purity will affect the interpretation of any physiological and/or biochemical response obtained. Prior assessment of CLA preparations by TLC is also recommended to determine the presence of any other impurities. The availability of pure CLA isomers will permit the evaluation and analysis of individual CLA isomers for their nutritional and biological activity in model systems, animals, and humans. These techniques are also essential to evaluate dairy fats for their content of specific CLA isomers and to help design experimental diets to increase the level of the desired CLA isomers in dairy fats. These improved techniques are further required to evaluate the CLA profile in monogastric animals fed commercial CLA preparations for CLA enrichment of animal products. This is particularly important because absorption and metabolism will alter the ingested-CLA profile in the animal fed.
Instrumental Factors Influencing Absorption Measurements for Fluid Food Color Determination
Authors: Montes Cristina , Campos Joaquín , Pons Alicia , Heredia Francisco J 
Published: February 2020

Abstract
The differences in color coordinates obtained from the use of different spectral features in the calculation are studied. Seven groups of food (olive oil, vanilla milkshake, brandy, honey, grape juice, vinegar, and orange juice) and an anthocyanin petunidin solution (natural pigment present in several vegetables) with different pH values were selected. Tristimulus values were calculated by considering the different sources of errors (truncation, abridgement, or different bandwidths). Results obtained were corrected by using the methods recommended (see References). These methods of abridgment work well in general, although in some circumstances (20 nm bandwidth or larger), specific spectral weighting functions have to be used to obtain a negligible error. Therefore, it is interesting to know how much difference can be expected from those factors in order to avoid confusion between color differences attributable to instruments and those attributable to actual color changes.
Applications and Uses of Resistant Starch
Authors: Brown Ian L 
Published: February 2020

Abstract
For the past 30 years there has been a steady increase in our knowledge of the sources, uses and physiological effects of resistant starch. However, it has only been in the past decade that the use of ingredients with a high resistant starch content has occurred in foods, initially in Australia but now throughout the world. Foods containing these resistant starch-rich ingredients include not only staple foods, such as bread and breakfast cereals, but also foods designed for those with special physiological or medical needs, such as celiac sensitivity and ulcerative colitis, or for individuals who are seeking to manage energy intake and control weight. Resistant starch has other benefits when compared with traditional sources of dietary fiber in that the preparation and design of foods with additional health benefits have the appearance, taste, and texture characteristics that encourage people to consume these “better for you” foods. As our knowledge of the range of physiological effects that occur through the consumption of resistant starch increases, more applications will be found for their inclusion in an expanding range of foods around the world.
Determination of Residues of Quaternary Ammonium Disinfectants in Food Products by Liquid Chromatography-Tandem Mass Spectrometry
Authors: van Bruijnsvoort Michel , Rooselaar Joop , Stern Alfred G , Jonker Klaas M 
Published: February 2020

Abstract
A liquid chromatography-tandem mass spectrometry method has been developed for the determination of residues of alkylbenzyldimethyl-ammonium, didecyldimethylammonium, didodecyldimethylammonium, and benzyldodecyl-hydroxyethylammonium compounds in various food matrixes. These quaternary ammonium compounds (QAs) are used in the food industry as disinfectants. According to the Dutch Food Law, the total mass (expressed as cetyltrimethyl-ammonium chloride) of QAs in food products shall not exceed the legislative limit of 0.5 mg/kg. Samples were extracted by a simple salting-out procedure, using acetonitrile and sodium chloride; about 100 samples could be prepared and analyzed daily. Special care had to be taken to thoroughly homogenize samples and to avoid the use of contaminated labware. The method was validated by a procedure in compliance with EU Directive 2002/657. From the matrixes of ice cream and minced meat, recoveries of more than 95% with a relative standard deviation of about 3% were obtained by 3 different analysts (n = 54). Detection limits were in the low μg/kg range. The decision limit (CCα) was determined to be 0.55 mg/kg. Dairy and meat products, collected in The Netherlands, were analyzed (761 samples). In 1% of the meat samples, 2% of the ice cream and milkshake samples, and 24% of the whipped cream samples, the Dutch legislative limit was exceeded. Over 2000 injections could be performed on a single column without deterioration of the peak shapes or recoveries.
Preparation and Certification of Zearalenone Mass Concentration of Two Low-Level Maize Reference Materials
Authors: Krska Rudolf , Josephs Ralf D , Pettersson Hans , MacDonald Susan 
Published: February 2020

Abstract
The contamination of maize by fungi, especially by Fusarium species, is a worldwide problem. One of the most prevalent Fusarium mycotoxins frequently found on European maize is zearalenone (ZON), which has been implicated in a range of human and animal diseases. It shows remarkable estrogenic properties and can cause severe infertility problems in farm animals. Currently, 9 countries have set maximum tolerable levels for ZON in food, ranging from 0 to 1000 μg/kg. This paper describes the preparation of 2 maize reference materials (BCR-716 very low level ZON and BCR-717 low level ZON) and the certification of their individual ZON contents (mass concentration and mass fraction). Uncertainties were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement and include uncertainties that are due to possible inhomogeneity and instability. Finally, BCR-716 was certified at a level of &lt;5 μg/kg and BCR-717 at a level of 83 μ/kg with an expanded uncertainty (k = 2) of 9 μg/kg.
Development of a Solid-Phase Extraction Method for Determination of Pheophorbide a and Pyropheophorbide a in Health Foods by Liquid Chromatography
Authors: Oshima Harumi , Ueno Eiji , Saito Isao , Matsumoto Hiroshi 
Published: February 2020

Abstract
A simple solid-phase extraction (SPE) method was developed for the liquid chromatography (LC) determination of pheophorbide (Phor) a and pyropheophorbide (Pyro) a in health foods such as chlorella, spirulina, etc. The food sample was extracted with 85% (v/v) acetone. The extract was acidified with hydrochloric acid and loaded on a C18 cartridge. After washing with water, Phor a and Pyro a were eluted with the LC mobile phase. Phor a and Pyro a were separated by isocratic reversed-phase LC and quantitated by fluorescence detection. The recoveries for spiked samples of chlorella and the extract were 87.1–102.0%. Commercial health foods (chlorella, spirulina, aloe, kale, Jews mallow, and green tea leaves) were analyzed using the SPE method. The values found for Phor a and Pyro a ranged from 2 to 788 μg/g and from &lt;1 to 24 μg/g, respectively. There was no significant difference between the SPE method and the official method in Japan (spectrophotometry after liquid–liquid extraction). The advantages of the SPE method are the short extraction times, lack of emulsions, and reduced consumption of organic solvents compared with the official method in Japan. The SPE method is considered to be useful for the screening of Phor a and Pyro a in health foods.
Determination of Maduramicin in Feedingstuffs and Premixtures by Liquid Chromatography: Development, Validation, and Interlaboratory Study
Authors: Jong Jacob De , Stoisser Bernd , Wagner Karl , Tomassen Marinka , Driessen Jaap , Hofmann Peter , Putzka Hans-Artur ,   Collaborators:, Antalick J P , Cowles J , Felgueiras I , Hofmann P , Johannsen F H , Putzka H A , Stepinska A , Stoisser; B , Thalmann A , van der Kamp H J , van Schalm K 
Published: February 2020

Abstract
A reversed-phase liquid chromatography method for determination of maduramicin in feedingstuffs and premixtures was developed, validated, and interlaboratory studied. The extraction solvent was methanol. Maduramicin was detected at 520 nm after postcolumn derivatization with vanillin.