bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Vegetal Proteins in Milk Powder by Enzyme-Linked Immunosorbent Assay: Interlaboratory Study
Authors: Sánchez Lourdes , Pérez María D , Puyol Pilar , Calvo Miguel , Brett Gary ,   Collaborators:, Cattaneo T M P , Haasnoot W , López-Fandiño R , Manso M A , Mata L , Razquín P , Sánchez A , Svenning C , Vegarud G E 
Published: February 2020

Abstract
Eight laboratories participated in a collaborative study to evaluate an enzyme-linked immunosorbent assay (ELISA) to determine soy, pea, and wheat proteins in pasteurized or ultra-high temperature (UHT) milk powders. To perform this assay, polyclonal antibodies for soy, pea, and wheat proteins were obtained from rabbit sera. Collaborators received calibration standards composed of milk powder containing 0–8% (w/w) vegetal protein in total protein and blind test samples containing approximately 1, 2, and 5% (w/w) vegetal protein. An indirect competitive ELISA was performed with a kit prepared by a participating laboratory; the kit contained plates coated with soy, pea, or wheat proteins, the corresponding specific antisera, enzyme-labeled second antibody, and substrate solution. Test samples and calibrants were extracted with phosphate-buffered saline, pH 7.4, containing 0.05% Tween and assayed with the ELISA kits. The degree of adulteration was affected by the type of heat treatment applied to the samples. The estimated percentage of vegetal protein addition was close to the theoretical value for pasteurized samples but much lower for UHT samples. For pasteurized samples, intralaboratory relative standard deviations ranged from 5 to 22% and interlaboratory relative standard deviations ranged from 14 to 34%.
On-Line Preconcentration and Determination of Cadmium in Honey Using Knotted Reactor Coupled to Flow Injection-Flame Atomic Absorption Spectrometry
Authors: Orsi Ricardo Fernández , Wuilloud Rodolfo G , Wuilloud Jorgelina C A de , Olsina Roberto A , Martinez Luis D 
Published: February 2020

Abstract
An on-line cadmium preconcentration and determination system implemented with flame atomic absorption spectrometry (FAAS) associated with flow injection was studied. Cadmium was retained as Cd-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol Cd-(5-Br-PADAP) complex, pH 9.3. The Cd complex was removed from the knotted reactor (KR) with ethanol. A total enhancement factor of 140 was obtained with respect to FAAS (40 for KR and 3.5 due to the use of ethanol) with preconcentration time of 120 s. The detection limit value for preconcentration of 1 g sample was 0.5 ng/g. The repeatability for 10 replicate determinations at 5.0 ng/g Cd level was 3.5% relative standard deviation, calculated from peak heights obtained. The calibration graph using the preconcentration system for Cd was linear with a correlation coefficient of 0.9990 at levels near the detection limits to at least 2000 ng/g. The method was successfully applied to determination of total Cd in honey samples.
Determination of Isoflavones in Ready-to-Feed Soy-Based Infant Formula
Authors: Johns Paul , Dowlati Lobat , Wargo Wayne 
Published: February 2020

Abstract
An alkaline hydrolysis/liquid chromatography (LC) method was developed for determination of isoflavones in ready-to-feed soy-based infant formula. The method consists of a 15 min methanol extraction, 10 min alkaline hydrolysis, HCl neutralization, gravity filtration, aqueous dilution, and 50 min LC analysis with UV detection at 262 and 250 nm to quantify 6 isoflavone analytes: daidzin, glycitin, genistin, daidzein, glycitein, and genistein. The concentration averages for 10 commercial batches (μg aglycone/g formula) were daidzein, 6.12 ± 1.23; glycitein, 1.19 ± 0.16; genistein, 12.8 ± 2.35; and total, 20.1 ± 3.61. Validation experiments demonstrated extraction completion and analyte stability to alkaline hydrolysis. Spike recoveries ranged from 97.6 to 104.1%, and a series of accuracy assessments showed that isoflavone concentration determined by the method was within 5% of the true value. The relative standard deviation values for repeatability ranged from 0.4 to 2.2% (n = 10), and from 0.3 to 2.7% (n = 4) for intermediate precision. Isoflavone peak purity was verified by comparing sample and standard peak area ratios (262/250 nm). The limits of detection and quantitation (μg/g formula) ranged from 0.02 to 0.05 and 0.08 to 0.18 μg/g, respectively. The difference between our concentrations and those reported by others in 1995–1998 is attributable to the well-established seasonal variation in soybean isoflavone levels. Although the method was applied exclusively to ready-to-feed formula in the present study, it is equally suitable for powder and concentrated liquid infant formulas.
Determination of Cholecalciferol (Vitamin D3) in Selected Foods by Liquid Chromatography: NMKL Collaborative Study
Authors: Staffas Anders , Nyman Arne ,   Collaborators:, Ask K , Hermansson E , Jacobsen J S , Jakobsen J , Mattila P , Smidt Olsen G , Schüep W 
Published: February 2020

Abstract
Results are presented from an NMKL (Nordic Committee on Food Analysis) collaborative study of a method for the determination of cholecalciferol (vitamin D3) in foods. The method is based on the addition of an internal standard (vitamin D2), followed by saponification and extraction with n-heptane. The fraction that contains vitamin D2/D3 is separated by preparative normal-phase liquid chromatography (LC), and the analytes are determined by reversed-phase LC with UV detection at 265 nm. The method was tested by 8 participating laboratories. In this study 6 different matrixes were analyzed for cholecalciferol content: milk, liquid infant formula (gruel), cooking oil, margarine, infant formula, and fish oil. The contents varied from 0.4 to 12 μg/100 g. Three matrixes (milk, gruel, and margarine) were fortified with vitamin D3. In the other matrixes, vitamin D3 was added at 3 different levels at the Swedish National Food Administration. The milk was analyzed as a blind duplicate, whereas the other matrixes were analyzed as split-level pairs. The recoveries from the samples with vitamin D3 added varied from 93 to 102%. The repeatability relative standard deviation (RSDr) values for accepted results varied between 2.2% (fish oil) and 7.4% (cooking oil), whereas the reproducibility relative standard deviation (RSDR) values varied between 6.8% (margarine) and 24% (cooking oil).
Alternative AOAC Sporicidal Test Carrier for Evaluating Peracetic Acid-Based Sterilants (Modification of AOAC Official Method 966.04)
Authors: McDonnell Gerald 
Published: February 2020

Abstract
Dacron suture loops were demonstrated to be inert, consistent carriers in the presence of peracetic acid-based sterilants, whereas black silk sutures had a variable preparation process and interacted with peracetic acid. In addition, Dacron suture loops provided comparable spore loading to black silk suture loops and an HCl resistance of ≥2 min. These results indicate that black silk suture loops are not appropriate carriers for assessing peracetic acid-based sterilants, and Dacron loops are an acceptable alternative. This finding is consistent with the Office of Science and Technology Laboratory (Center for Devices and Radiological Health) study which determined that “polyester suture material is a viable alternative to silk for the AOAC sporicidal test for liquid disinfectants.”
Determination of Ephedrine Alkaloids in Dietary Supplements and Botanicals by Liquid Chromatography/Tandem Mass Spectrometry: Collaborative Study
Authors: Trujillo William A , Sorenson Wendy R ,   Collaborators:, Laurensen J , Luo G , McClanahan R , Perez R , Roper C , Kotello S , Schwind B , Shevchuk C , Suen E , Sullivan D 
Published: February 2020

Abstract
An interlaboratory study was conducted to evaluate the accuracy and precision of a method for ephedrine-type alkaloids [i.e., norephedrine (NE), norpseudoephedrine (NPE), ephedrine (E), pseudoephedrine (PE), methylephedrine (ME), and methylpseudoephedrine (MPE)] in dietary supplements and botanicals. The amount of ephedrine-type alkaloids present was determined using liquid chromatography with tandem mass selective detection. The samples were diluted to reflect a concentration of 0.0200 to 1.00 μg/mL for each alkaloid. An internal standard was added and the alkaloids were separated using a 5 μm phenyl LC column with an ammonium acetate, glacial acetic acid, acetonitrile, and water mobile phase. Eight blind duplicates of dietary supplements or botanicals were analyzed by 10 collaborators. Included was a negative control, ephedra nevadensis, and negative controls fortified at 2 different levels with each of the 6 ephedrine-type alkaloids. The spike levels were approximately 100 and 1000 μg/g for NE, 100 and 600 μg/g for NPE, 6500 and 65 000 μg/g for E, 1000 and 10 000 μg/g for PE, 300 and 3000 μg/g for ME, and 100 and 1000 μg/g for MPE. On the basis of the accuracy and precision results for this interlaboratory study, it is recommended that this method be adopted Official First Action for the determination of 6 different individual ephedrine-type alkaloids in dietary supplements and botanicals.
Purity Assessment of Crystalline Zearalenone
Authors: Krska Rudolf , Welzig Elvira , Josephs Ralf D , Kandler Wolfgang , Pettersson Hans , MacDonald Susan , Charlton Adrian , Brereton Paul , Hametner Christian , Berner Diana , Zöllner Peter 
Published: February 2020

Abstract
Commercially available solid zearalenone (ZON) to be used as a certified liquid calibrant (BCR-699) in a project funded by the European Commission within the Standard Measurement and Testing program was characterized and its purity determined. The degree of purity of the ZON was examined by UV spectrophotometer, liquid chromatography (LC) with diode array and fluorescence detection, 1H and 13C-NMR spectrometry, LC–mass spectrometry (LC/MS/MS), ion chromatography (IC), and differential scanning calorimetry (DSC). The diagrams obtained from DSC analysis and the UV spectrum showed no detectable impurities. Likewise, no impurities were observed by LC analysis with both diode array and fluorescence detection. IC determination revealed negligible contamination of ZON with chloride of 0.020 ± 0.005% and nitrate of 0.016 ± 0.006%. Zearalanone (ZAN) was identified as one of 2 minor (0.2%) impurities by LC/MS/MS. The 1H-NMR measurements revealed an additional peak, which has not been previously reported in the literature. It could be identified as part of the ZON spectrum as the signal arising from the phenolic proton attached to C4'. The manufacturer states an additional contamination with 0.2% methylene chloride, which could be confirmed to an extent of 0.1% by 1H-NMR. Minor impurities, whose structures remain unknown, were discovered at 3.5 and &lt;1 ppm. Total percentage of impurities based on NMR measurement was estimated not to exceed 1%. A purity of 99.5% with a tolerance of ±0.5% was finally attributed to the ZON studied in this project.
Crude Fat, Hexanes Extraction, in Feed, Cereal Grain, and Forage (Randall/Soxtec/Submersion Method): Collaborative Study
Authors: Thiex Nancy J , Anderson Shirley , Gildemeister Bryan ,   Collaborators:, Adcock W , Boedigheimer J , Bogren E , Coffin R , Conway K , DeBaker A , Frankenius E , Gramse M , Hogan P , Knese T , MacDonald J , M�ller J , Royle R , Russell M , Shafiee F , Shreve B , Sieh J , Spann M , Töpler E , Watts M 
Published: February 2020

Abstract
A method for determining crude fat in animal feed, cereal grain, and forage (plant tissue) was collaboratively studied. Crude fat was extracted from the animal feed, cereal grain, or forage material with hexanes by the Randall method, also called the Soxtec method or the submersion method. The use of hexanes provides for an alternative to diethyl ether for fat extractions. The proposed submersion method considerably decreases the extraction time required to complete a batch of samples compared to Soxhlet. The increase in throughput is very desirable in the quest for faster turnaround times and the greater efficiency in the use of labor. In addition, this method provides for reclamation of the solvent as a step of the method. The submersion method for fat extraction was previously studied for meat and meat products and was accepted as AOAC Official Method 991.36. Fourteen blind samples were sent to 14 collaborators in the United States, Sweden, Canada, and Germany. The within-laboratory relative standard deviation (repeatability) ranged from 1.23 to 5.80% for crude fat. Among-laboratory (including within) relative standard deviation (reproducibility) ranged from 1.88 to 14.1%. The method is recommended for Official First Action.
Determination of Tetracycline Antibiotics in Salmon Muscle by Liquid Chromatography Using Post-Column Derivatization with Fluorescence Detection
Authors: Pena Angelina L , Lino Celeste M , Silveira M Irene N 
Published: February 2020

Abstract
A simple and accurate cleanup procedure using polymeric sorbent was developed for the determination of oxytetracycline (OTC) and tetracycline (TC) residues in salmon muscle. It was applied to the analysis of 20 salmon samples during a month period. The OTC and TC residues were extracted with ethylenediaminetetracetic acid (EDTA)–McIlvaine buffer acidified at pH 4.0 and cleaned up by solid-phase extraction with a polymeric sorbent. The advantages of the polymeric sorbent over the silica-based sorbent in the cleanup of salmon muscle samples are described. A liquid chromatographic method with post-column derivatization and fluorescence detection is proposed because of its sensitivity and specificity. The average recoveries of OTC and TC from muscle salmon tissue fortified at 50, 100, and 200 μg/kg levels, ranged from 83.9 to 93.4% with a coefficient of variation between 4.09 and 5.80%. The limit of quantitation for OTC and TC in salmon muscle was 50 μg/kg.
Photostimulated Luminescence Detection of Irradiated Shellfish: International Interlaboratory Trial
Authors: Sanderson David C W , Carmichael Lorna A , Fisk Saffron ,   Collaborators:, Brown P , Burton Y , Nootenboom H , Pinnioja S , Schreiber G A , Wagner U 
Published: February 2020

Abstract
An interlaboratory trial was conducted to validate photostimulated luminescence (PSL) detection of irradiated shellfish. Five species of shellfish (Nephrops norvegicus, mussels, black tiger prawns, brown shrimps, and king scallops) were presented blind as nonirradiated and irradiated to 0.5 and 2.5 kGy. Precharacterization analysis of each product and treatment was performed on both whole (including shell) and intestinal samples. The results for whole samples (including shell) confirmed that the method was able to distinguish between nonirradiated and irradiated samples, regardless of dose. Intestinal data have identified that the method is dependent on the quantity and sensitivity of grits present within the intestinal tract, which can be assessed using calibration by normalization to 1 kGy. Five laboratories returned both initial screening and calibrated data and sample classification. All laboratories correctly identified all irradiated products using the screening criteria. There were no false positives. The results confirm the validity of the PSL method for shellfish, which has been adopted as a European standard method and by the Codex Alimentarius Commission. Calibration is required where only intestinal material is available. For whole samples with shell, screening alone is sufficient.
Multilaboratory Validation of a Method To Confirm Chloramphenicol in Shrimp and Crabmeat by Liquid Chromatography-Tandem Mass Spectrometry
Authors: Hammack Walter , Carson Mary C , Neuhaus Barbara K , Hurlbut Jeffrey A , Nochetto Cristina , Stuart James S , Brown Amy , Kilpatrick Donna , Youngs Kristl , Ferbos Krystle , Heller David N 
Published: February 2020

Abstract
An existing method for chloramphenicol (CAP) determination in shrimp using a gas chromatograph with electron capture detector was adapted for confirmation of CAP with a liquid chromatograph interfaced to a triple quadrupole mass spectrometer. CAP residues are extracted from tissue with ethyl acetate, isolated via liquid–liquid extraction, and concentrated by evaporation. Extracts are chromatographed by using a reversed-phased column and analyzed by electrospray negative mode tandem mass spectrometry. Four product ions (m/z 152, 176, 194, and 257) of precursor m/z 321 were monitored. Moving from gas chromatography to liquid chromatography–tandem mass spectrometry improved the sensitivity of the method greatly, enabling reliable confirmation of CAP residues at 0.3 μg/kg (ppb). The method meets confirmation criteria recommended by the U.S. Food and Drug Administration and 4-point identification criteria established by the European Union. With slight modifications to accommodate different equipment, the method was validated in 3 laboratories.
Determination of Ochratoxin A in Currants, Raisins, Sultanas, Mixed Dried Fruit, and Dried Figs by Immunoaffinity Column Cleanup with Liquid Chromatography: Interlaboratory Study
Authors: MacDonald Susan J , Anderson Sharron , Brereton Paul , Wood Roger ,   Collaborators:, Barrett G , Brodie C , Burdaspal P A , Conley D , Cooper J , Darroch J , Donnelly C , Embrey N , Ennion R A , Felguerias I , Griffin J , Kitching M , Knight S , Lanham J , Legarda T M , Lenartowicz P , Luis E , Lundie J C , Möller T , Norwood D , Novo R , Nyberg M , O’Donnell C , Panzarini G , Pascale M , Patel S , Paulsch W , Payne N , Rawcliffe P , Reid K , Rizzo A , Rothin A , Saari L , Stangroom S G , Swanson W , Sweet P , Thomas T , Trani R , Turpin E , van Egmond H P , Walker M , Watkins J D , Williams C 
Published: February 2020

Abstract
An interlaboratory study was performed on behalf of the Food Standards Agency to evaluate the effectiveness of an affinity column cleanup liquid chromatographic (LC) method for the determination of ochratoxin A in a variety of dried fruit at European regulatory limits. To ensure homogeneity before analysis, laboratory samples are normally slurried with water in the ratio of 5 parts fruit to 4 parts water, and test materials in this form were used in the study. The test portion was extracted with acidified methanol. The extract was filtered, diluted with phosphate-buffered saline, and applied to an affinity column. The column was washed and ochratoxin A was eluted with methanol. Ochratoxin A was quantified by reversed-phase LC. The use of post-column pH shift to enhance the fluorescence of ochratoxin A by the addition of 1.1M ammonia solution to the column eluant is optional. Determination was by fluorescence. Currants, sultanas, raisins, figs, and mixed fruit (comprising dried pineapple, papaya, sultanas, prunes, dates, and banana chips), both naturally contaminated and blank (very low level), were sent to 24 collaborators in 7 European countries. Participants were asked to spike test portions of all test samples at a level equivalent to 5 ng/g ochra toxin A. Average recoveries ranged from 69 to 74%. Based on results for 5 naturally contaminated test samples (blind duplicates) the relative standard deviation for repeatability (RSDr) ranged from 4.9 to 8.7%, and the relative standard deviation for reproducibility (RSDR)rangedfrom14to28%. The method showed acceptable within-and be-tween-laboratory precision for all 5 matrixes, as evidenced by HORRAT values &lt;1.3.
Development of the Analytical Methods and Reference Materials Program for Dietary Supplements at The National Institutes of Health
Authors: Saldanha Leila G , Betz Joseph M , Coates Paul M 
Published: February 2020

Abstract
The need for validated analytical methods and reference materials to identify and measure constituents in dietary supplements is essential. Such methods allow for the documentation that products meet manufacturer's specifications and contain what their labels declare. In March 2003, the U.S. Food and Drug Administration issued a proposed rule that would establish specific current good manufacturing practices for dietary supplements. This proposed rule requires that companies create a quality control unit to set specifications and ensure compliance with these specifications using scientifically valid procedures. This report provides insights and lessons learned from 3 meetings the Office of Dietary Supplements (ODS) at the National Institutes of Health helped organize. These meetings were structured to (1) educate individuals about the importance and need for validated analytical methods and reference materials to identify and quantify constituents of dietary supplements; (2) identify resources required to fulfill this need; and (3) serve as a platform to obtain input from interested parties to help frame the research agenda for the Dietary Supplements Methods and Reference Materials Program within ODS. Stakeholder's opinions and views expressed at these 3 meetings are outlined in this report.
Identification and Quantification of Major Species of Arsenic in Rice
Authors: D'Amato Marilena , Forte Giovanni , Caroli Sergio 
Published: February 2020

Abstract
A study was undertaken to develop a method for the chemical speciation of As in rice on the basis of current knowledge in this field for use in preparing a certified reference material (CRM). Samples of the Arborio rice variety were ground to a fine powder, which was extracted under sonication with a water–methanol mixture (1 + 1, v/v). The resulting solutions were injected into a high-performance liquid chromatograph combined on-line with a quadrupole inductively coupled plasma–mass spectrometer. This hyphenated system allowed for the quantification of As species in one analytical step. Four forms of As were detected: inorganic As (III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), and inorganic As (V) at concentrations of 88.2 ± 7.1, 50.8 ± 5.0, 15.2 ± 1.7, and 51.2 ± 3.5 ng/g, respectively. The concentration of total As was 211 ± 7 ng/g. The limits of detection (3σ criterion) and the quantitation (10σ criterion) were, respectively, as follows (in ng/g): As (III), 0.095 and 0.320; As (V), 0.082 and 0.273; MMA, 0.110 and 0.367; and DMA, 0.145 and 0.480. Ten hours were needed for the extraction procedure, 6 h for the evaporation, and 30 min for quantification of the analytes. This investigation was performed in the frame of a European Commission Project on the feasibility of CRMs for As and Se species.
Rapid Forensic Selected Reaction Monitoring Liquid Chromatography/Mass Spectrometry Determination of Ionophore Antibiotics Found at Toxic Levels in Animal Feeds
Authors: Ebel Joseph G , Wachs Timothy , Henion Jack D 
Published: February 2020

Abstract
A rapid, accurate, and selective method was developed for the forensic determination of ionophore antibiotics in animal feeds. A simple extraction procedure and liquid chromatography/tandem mass spectrometry (LC/MS/MS) in the selected reaction monitoring (SRM) mode were used for rapid identification and confirmation of monensin and lasalocid in feed samples and for quantitation of monensin. Extracts from a homogenous portion of ground feeds were prepared using liquid–solid extraction and liquid–liquid extraction techniques. Feed extracts were further purified by a simple defatting and solvent wash step and then concentrated to dryness. Feed extract residues were reconstituted in 1 mL LC mobile phase and a 2 μL aliquot injected into the SRM LC/MS system. The latter system used a C18, 100 × 2.0 mm, LC column coupled to a PE-Sciex API 2000 tandem triple quadrupole mass spectrometer equipped with a TurboIonSpray LC/MS interface. Feed samples were extracted and analyzed for the determination of monensin and lasalocid within a couple of hours. Control feed samples fortified with monensin at concentrations from 50 ppb to 5 ppm provided a linear response and calibration curve across this range with a correlation coefficient of 0.996.