bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Cry9C Protein in Processed Foods Made with StarLink™ Corn
Authors: Diaz Carmen , Fernandez Cecilia , McDonald Regina , Yeung Jupiter M 
Published: February 2020

Abstract
StarLink™ (Aventis CropScience US) hybrid corn has been genetically modified to contain a pesticidal protein, Cry9C, which makes it more resistant than traditional varieties to certain types of corn insect pests. Unlike other varieties of genetically engineered corn, the U.S. Environmental Protection Agency authorized the use of StarLink corn for animal feed and industrial use only, not for human consumption. However, some Cry9C-containing corn was mistakenly or inadvertently comingled with yellow corn intended for human food use. Because corn containing the Cry9C construct was not approved for human use, the U.S. Food and Drug Administration considers food containing it to be adulterated. Consequently, this regulatory violation resulted in hundreds of recalls of corn-based products, such as taco shells, containing cry9C DNA. Detecting the novel protein in StarLink corn is an emerging issue; therefore, there is no standardized or established analytical method for detecting Cry9C protein in processed foods. We developed a procedure for quantitation of Cry9C protein, with validation data, in processed food matrixes with a limit of quantitation at 1.7 ng/g (ppb), using a commercial polyclonal antibody-based Cry9C kit that was intended for corn grain samples. Intra- and interassay coefficients of variation were 2.8 and 11.8%, respectively. Mean recoveries were 73 and 85% at 2 and 5 ng/g Cry9C fortifications, respectively, for 19 control non-StarLink corn-based matrixes. Our data demonstrate only 0–0.5% of Cry9C protein survived the processing of tortilla chips and soft tortillas made from 100% StarLink corn, resulting in levels from below the detection limit to 45 ppb.
Determination of Vegetal Proteins in Milk Powder by Sodium Dodecyl Sulfate–Capillary Gel Electrophoresis: Interlaboratory Study
Authors: Manso María A , Cattaneo Tiziana Maria , Barzaghi Stefania , Olieman Cornelis , López-Fandiño Rosina ,   Collaborators:, Leaver J , Otte J , S�nchez A , Svenning C , Tirelli A , Vegarud G 
Published: February 2020

Abstract
An interlaboratory study, with the participation of 8 laboratories, was conducted to evaluate a sodium dodecyl sulfate–capillary gel electrophoresis method for determination of adulteration of milk powder with soy and pea proteins. Calibration standards (0–8%, w/w, soy and pea protein in total protein) and adulterated skim milk powders (0–5%, w/w, soy and pea proteins in total protein) were produced. Vegetal proteins were determined after removal of milk proteins by pretreatment of the samples with tetraborate–EDTA buffer, pH 8.3. Repeatability standard deviations ranged from 9 to 15% and reproducibility standard deviations ranged from 25 to 30% in the samples containing 5% vegetal protein in total protein.
Comparison of Five Extraction Methods for Determination of Incurred and Added Pesticides in Dietary Composites
Authors: Rosenblum Laura , Garris Sherry T , Morgan Jeffrey N 
Published: February 2020

Abstract
The National Exposure Research Laboratory of the U.S. Environmental Protection Agency conducts research to measure exposure of individuals to chemical pollutants through the diet. In support of this research, methods are being evaluated for the determination of pesticides in dietary composite samples. In the present study, Soxhlet, blender, microwave-assisted, pressurized fluid, and supercritical fluid extraction methods were compared for the determination of incurred and added pesticides in 4 dietary composites, which varied in fat and water content. Incurred pesticides were chlorothalonil, chlorpyrifos, DDE, dicloran, dieldrin, endosulfan I, malathion, cis- and trans-permethrin, and trifluralin. Added pesticides were α- and γ-chlordane, hexachlorobenzene, and fonofos. Concentrations of the individual pesticides were between 0.2 and 20 ng/g composite. All 5 methods tested could extract pesticides from dietary composites. Most incurred pesticides were recovered from the dietary composites within the range of 59–140% of expected values. Recoveries of added pesticides were between 60 and 130%. Microwave-assisted extraction led to significantly higher concentrations of 7 pesticides. Blender extraction yielded significantly higher concentrations of chlorothalonil and fonofos. Water content was a significant factor in the recovery of chlorothalonil, and fat content was a significant factor in the recovery of fonofos. In designing an exposure study, the selection of the extraction method would be determined by number of samples to be extracted, analyte stability, and cost.
Novel Chromatographic Separation and Carbon Solid-Phase Extraction of Acetanilide Herbicide Degradation Products
Authors: Shoemaker Jody A 
Published: February 2020

Abstract
One acetamide and 5 acetanilide herbicides are currently registered for use in the United States. Over the past several years, ethanesulfonic acid (ESA) and oxanilic acid (OA) degradation products of these acetanilide/acetamide herbicides have been found in U.S. ground waters and surface waters. Alachlor ESA and other acetanilide degradation products are listed on the U.S. Environmental Protection Agency's (EPA) 1998 Drinking Water Contaminant Candidate List. Consequently, EPA is interested in obtaining national occurrence data for these contaminants in drinking water. EPA currently does not have a method for determining these acetanilide degradation products in drinking water; therefore, a research method is being developed using liquid chromatography/negative ion electrospray/mass spectrometry with solid-phase extraction (SPE). A novel chromatographic separation of the acetochlor/alachlor ESA and OA structural isomers was developed which uses an ammonium acetate–methanol gradient combined with heating the analytical column to 70°C. Twelve acetanilide degradates were extracted by SPE from 100 mL water samples using carbon cartridges with mean recoveries &gt;90% and relative standard deviations ≤16%.
Interlaboratory Study of a Multiresidue Gas Chromatographic Method for Determination of Organochlorine and Pyrethroid Pesticides and Polychlorobiphenyls in Milk, Fish, Eggs, and Beef Fat
Authors: Bordet François , Inthavong Dary , Fremy Jean-Marc ,   Collaborators:, Aspe D , Durand T , Ducher M , Fontayne N , Grignon E , Herbreteau C , Hulot S , Le Bigot C , Marengue E , Martin V , Ranneaud S , Sartre L , Vouillon B 
Published: February 2020

Abstract
An interlaboratory study was conducted to validate a gas chromatographic (GC) method for determination of 21 organochlorine pesticides, 6 pyrethroid pesticides, and 7 polychlorobiphenyl (PCB) congeners in milk, beef fat, fish, and eggs. The method was performed at low contamination levels, which represent relevant contents in food, and is an extension of the European standard (method NF-EN-1528, Parts 1–4). It enlarges the applicable scope of the reference EN method to pyrethroid pesticides and proposes the use of solid-phase extraction (SPE) as a cleanup procedure. Cryogenic extraction was made, and SPE cleanup was performed with 2 successive SPE cartridges: C18 and Florisil®. After injection of the purified extract onto a GC column, residues were measured by electron capture detection. Food samples (liquid milk, beef fat, mixed fish, and mixed eggs) were prepared, tested for homogeneity, and sent to 17 laboratories in France. Test portions were spiked with 27 pesticides and 7 PCBs at levels from 26 to 45, 4 to 27, 31 to 67, and 19 to 127 ng/g into milk, eggs, fish, and fat, respectively. Based on results for spiked samples, the relative standard deviation for repeatability ranged from 1.5 to 6.8% in milk, 3 to 39% in eggs, 4.5 to 12.2% in fish, and 7 to 13% in fat. The relative standard deviation for reproducibility ranged from 33 to 50% in milk, 29 to 59% in eggs, 31 to 57% in fish, and 30 to 62% in fat. This method showed acceptable intra- and interlaboratory precision data, as corroborated by HORRAT values at low levels of pesticide and PCB contamination. The statistical evaluation of the results was performed according to the International Organization for Standardization (ISO; ISO 3534 standard) and 5725-2 Guideline.
Application of Thermal Desorption to the Development of a Gas Chromatographic/Mass Spectrometric Method for the Determination of Toluene, Chlorinated Aromatic Hydrocarbons, and 2,3,7,8-Tetrachlorodibenzo-p-Dioxin in Combustion Emissions
Authors: Donaldson John D , Grimes Susan M , Mehta Lina , Jafari Ahmad J 
Published: February 2020

Abstract
A fast and accurate analytical method, which uses commercially available adsorbents (Tenax TA, Carbotrap B and C, and Carbosieve S-III), was developed for the sampling and determination of aromatic hydrocarbons, chloroaromatic compounds, and 2,3,7,8-tetrachlorodibenzo-p-dioxin. The breakthrough volume data show that Carbotrap C has a good capacity for compounds of high molecular weight, whereas Carbosieve S-III and Tenax TA are efficient for volatile compounds. The organic components are thermally desorbed and transferred to a gas chromatograph/mass spectrometer. Importantly, thermal desorption avoids conventional solvent extraction procedures and also allows reuse of adsorbent tubes. Preliminary results for recovery of analytes from tubes packed with single adsorbent prove that a single-adsorbent bed is not capable of sampling a wide range of compounds. The best method to obtain the desired collection and desorption properties is to use adsorbent tubes containing several different materials. The results of optimization studies are summarized.
Determination of Percentage of RoundUp Ready® Soya in Soya Flour Using Real-Time Polymerase Chain Reaction: Interlaboratory Study
Authors: Hird Heather , Powell Joanne , Johnson Mari-Louise , Oehlschlager Sarah ,   Collaborators:, Anklam E , Buchno M , Bulkmans C , van Duijn G , Foth M , Gachet E , Garrett S , Harris N , Lake R , Moebes A , Moreno C , Popping B , Rentsch J , Sang K , Taesan K , Wiseman G 
Published: February 2020

Abstract
An interlaboratory study was conducted to evaluate a method for determination of the percentage of RoundUp Ready® (RR) soya in soya flour using Taqman® technology. The method included DNA extraction from the test portion with cetyltrimethylammonium bromide buffer followed by chloroform extraction and Wizard® resin cleanup steps. The DNA was then assayed with primer and probe sets specific for lectin as the endogenous control and the RR insert as the target. The percentage of RR soya in the soya fraction of the sample was calculated by using a matrix-matched standard curve. Ten samples of split-level blind duplicates were sent to 22 laboratories in 12 countries worldwide. Test portions contained 0, 0.5, 0.7, 1.6, 2, and 3.9% (w/w) RR soya prepared gravimetrically from commercially available RR standard reference materials. Based on the results for test materials, the relative standard deviation for repeatability (RSDr) for the method ranged from 9.3 to 19.3% and, for reproducibility (RSDR), ranged from 20.3 to 33.7%.
Simultaneous Determination of Zilpaterol and Other Beta Agonists in Calf Eye by Gas Chromatography/Tandem Mass Spectrometry
Authors: Bocca Beatrice , Fiori Maurizio , Cartoni Claudia , Brambilla Gianfranco 
Published: February 2020

Abstract
Adrenergic drugs for growth promotion have been outlawed in European meat production; however, molecules such as Ractopamine and Zilpaterol are licensed for feeding swine and cattle in the United States, Mexico, and South Africa. Analysis of bovine retinal extracts has recently shown considerable extension in the detection period following withdrawal. Previous studies demonstrated that residual concentrations of Clenbuterol and related substances in retinal tissue were &gt;100 ng/g at day 50 of withdrawal. A method was developed to identify and simultaneously quantify Clenbuterol-like substances with anilinic moieties and drugs with phenolic and catecholic moieties, such as Ractopamine and Zilpaterol, in retinal tissue. The method was validated according to SANCO/1805/2000. After extraction in 0.1N HCl, samples were cleaned up on C18 non-endcapped solid-phase extraction columns and analyzed as trimethylchlorosilane derivatives by gas chromatography/tandem mass spectrometry, electron impact mode. At concentrations of agonists between 62.5 and 250.0 ng/g in bovine retina, mean recoveries ranged from 85.3 to 94.8%, repeatability was &lt;9.6%, and within-laboratory reproducibility was &lt;10.5%. The decision limits (CCα) were within the range of 66.3–70.4 ng/g, and the detection capability (CCβ) varied from 73.9 to 79.8 ng/g. Results are discussed in terms of a multiresidue approach to improve reliability of the monitoring strategy.
Determination of Total Fat in Milk- and Soy-Based Infant Formula Powder by Supercritical Fluid Extraction: PVM 2:2002
Authors: LaCroix Denis E , Wolf Wayne R , LaCroix Denis E , Wolf Wayne R , Myer Leslie J D , Calabraro Ron 
Published: February 2020

Abstract
Commercially available simple benchtop systems using CO2 supercritical fluid extraction (SFE) eliminate expensive organic solvent disposal problems and offer potential to meet a demand for rapid, accurate high-volume gravimetric determinations of total fat content of infant formula powders. A Data Quality Objectives (DQOs) approach was used to evaluate the performance characteristics of instrumental SFE extraction for determination of total gravimetric fat in infant formula. The established DQOs included the following: Accuracy.—Correct values were obtained for a suitable reference material, SRM 1846 Infant Formula [National Institute of Standards and Technology (NIST), Gaithersburg, MD]. Ruggedness.—Variables were defined as (1) extraction time (35 min optimum); (2) ratio of sample size to diatomaceous earth support material (1 g sample/2 g support); (3) ratio of distilled water to alcohol (50% isopropanol optimum for both milk- and soy-based infant formula samples); (4) extraction flow rate was 3–3.5 mL/min optimum. Precision.—Relative standard deviations of multiple determinations fell within the Horwitz limits of acceptability of ≤2.8% at the level of analyte determined (0.34–2.5% obtained). Scope of applicability.—Includes milk- and soy-based infant formula powders. Research data were obtained by use of a commercially available fat analyzer. Samples of the SRM, 2 commercial milk-based and 3 commercial soy-based infant formula products were distributed to 2 additional collaborating laboratories. Very good agreement was obtained among the submitting and collaborating laboratories for these samples. The use of clearly defined DQOs to establish method performance characteristics, along with the commercially available reference material, provided the mechanism for verification and validation of analytical methodology.
Concentration of Sodium Ion as the Determining Factor for the Association of Dansyl Amino Acids with the Teicoplanin Molecule in Reversed-Phase Liquid Chromatography
Authors: Ismaili Lhassane , Truong Tong Than , André Claire , Thomassin Mireille , Mozer Jean-Louis , Robert Jean-Francois , Xicluna Alain , Refouvelet Bernard , Millet Joelle , Nicod Laurence , Guillaume Yves-Claude 
Published: February 2020

Abstract
The mechanism of the binding of D,L dansyl amino acids to teicoplanin was investigated. Na+ was used as an indicator of the interactions between the solutes and teicoplanin. The number (n) of sodium ions, Na+, excluded from the soluteteicoplanin interface when analyte transfer occurred was determined. A thermodynamic study and enthalpy–entropy compensation were performed to further explore the interaction mechanism. From these results, it was shown that teicoplanin was balanced between 2 conformational states characterized by distinct enantioselective properties. This approach indicates that liquid chromatography (LC) is a useful tool to extract physicochemical and molecular information from retention data. Thus, LC can be used as a complementary technique with the conventional techniques of molecular interaction analysis.
Determination of Fleroxacin in Pure and Tablet Forms by Liquid Chromatography and Derivative UV-Spectrophotometry
Authors: Kowalczuk Dorota , Hopkała Hanna 
Published: February 2020

Abstract
Derivative UV-spectrophotometric and liquid chromatographic (LC) methods for fleroxacin determination were validated. In the spectrophotometric assay, first-, second-, third-, and fourth-order measurements were applied with the use of peak–zero and peak–peak techniques. The linear correlation between amplitude of the peak and concentration of the examined drug ranged from 2.0 to 12.0 μg/mL. An isocratic LC analysis was performed on a Purospher ODS column with an acidic mobile phase containing tetrabutylammonium hydroxide. Measurements were made at a wavelength of 285 nm with 4-aminobenzoic acid (PABA) as internal standard. The calibration curve was linear (r = 0.9999) in the studied range of concentration (1.0–10.0 μg/mL). The accuracy (mean recovery, about 100%), precision (relative standard deviation &lt;1%), selectivity, and sensitivity of the elaborated methods were satisfactory.
Modification of Enrichment Protocols for TECRA Listeria Visual Immunoassay Method 995.22: Collaborative Study
Authors: Hughes Denise , Dailianis Angela , Duncan Louise , Briggs Julie , McKintyre Deborah A , Silbernagel Karen ,   Collaborators:, Anderson G , Anderson J , Bannach B , Barratt C , Booyens C , Briggs J , Brooks R , Bryant D , Burnie A , Carver C , Chambers D , Chong J , Clarke D , Coates E , Comontofski G , Deiss K , Destro C , Dillon J , Duncan L , Dundas M , Dymond N , Dziedziczak D , Eglezos S , Gasanov U , Gebler J , Graham T , Haley E , Johnson L , Kurien S , Maczuga J , Matera J , Matthew K , Munyard S , Ramine A , Reed J , Remes A , Subasinghe N , Tan A , Tan J , Tatum M , Taylor M , Torrance H , Twohy C , Vialpando M , Watts K 
Published: February 2020

Abstract
A collaborative study was conducted to validate new enrichment methods for the TECRA Listeria Visual Immunoassay (TLVIA). These new methods incorporate a newly formulated medium, TECRA Listeria Enrichment Broth, which does not contain the highly toxic antifungal agent, cycloheximide. The new procedures will provide an alternative to the enrichment procedures described in AOAC Method 995.22. Three food types (raw ground beef, lettuce, and ice cream) were analyzed in the United States, and 2 food types (cooked turkey and cooked fish fillets) were analyzed in Australasia. Thirty collaborators participated in the study, 16 in Australasia and 14 in the United States. With the exception of one batch of ground beef, comparison of the proportion of positive test portions (p ≥ 0.05) showed no significant difference between the TLVIA and the reference method for the 5 foods at 3 inoculation levels. For the one batch of naturally contaminated raw ground beef, the TLVIA gave significantly more confirmed positive results than the reference method.
Determination of Immunoglobulin G in Bovine Colostrum and Milk by Direct Biosensor SPR-Immunoassay
Authors: Indyk Harvey E , Filonzi Enrico L 
Published: February 2020

Abstract
An automated biosensor surface-plasmon resonance-based assay was developed for the determination of immunoglobulin G (IgG) in bovine milk and colostrum with either goat or rabbit antibovine IgG or protein G used as detecting molecule. The method is configured as a direct and nonlabeled immunoassay, with quantitation against an authentic IgG calibrant. Whole colostrum or milk is prepared for analysis by dilution into buffer. Analysis conditions, including ligand immobilization, flowrate, contact time, and regeneration, were optimized, and nonspecific binding was evaluated. Performance parameters included working range of 15–10 000 ng/mL, method detection limit of 0.08 mg/mL, overall instrument response reproducibility relative standard deviation (RSDR) of 0.47%, mean between-run RSDR of 10.5% for colostrum, and surface stability over 200 analyses. The proposed method was compared with independent alternative methods. The technique was applied to the measurement of IgG content during early lactation transition from colostrum to milk, as well as in consumer milk, colostrum, and hyperimmune milk powders.
Comparative Tests To Improve the Gas Chromatographic Analysis of Chlorobornanes in Fish Samples
Authors: Boer Jacob de , Leonards Pim E G , Klungsoyr Jarle , McHugh Brendan , Nixon Eugene , McGovern Evin , Rimkus Gerhard G 
Published: February 2020

Abstract
A comparison was made between electron capture negative ionization quadrupole mass spectrometry (ECNI-MS) and electron capture detection (ECD) with regard to repeatability and reproducibility for the gas chromatographic (GC) analysis of toxaphene congeners [chlorobornanes (CHBs)]. The tests, including standard solutions and several cleaned fish extracts, showed larger relative standard deviations (RSDs) for the repeatability of ECNI-MS but no differences in the reproducibility of the 2 techniques. The sensitivity of the GC-ECNI-MS was considerably better than that of GC/ECD. Four stepwise-designed comparative tests were also conducted on GC analysis, cleanup, and the complete method. The results showed that, according to the current state-of-the-art, coefficients of variation for the between-laboratory performance were not &lt;20% and were usually between 20 and 30%. In spite of separation problems, e.g., for CHB 26, which cannot be separated into a single-component peak, a 95% methyl 5% phenyl polysiloxane (CP Sil 8) column was preferred to more polar columns for the analysis of CHBs 26, 40, 41, 44, 50, and 62. CHB 62 was more difficult to determine than CHB 26 and 50. Addition of the CHBs 40, 41, and 44 to the standard set of 3 chlorobornanes (26, 50, and 62) resulted in more separation problems. A 3-step cleanup method was recommended.
Screening Method for Detecting Cross-Contamination Residues of Tiamulin in Swine Feeds
Authors: Rodríguez-Comesaña Mirian , Cancho-Grande Beatriz , Simal-Gándara Jesús 
Published: February 2020

Abstract
A method was developed for the determination of tiamulin (TML), 14-deoxy-14-[(2-diethylaminoethyl)- mercaptoacetoxy]mutilin hydrogen fumarate, a semisynthetic derivative of the naturally occurring antibiotic pleuromutilin produced by the fungus Pleurotus mutilis. This drug, with high activity against Gram-positive bacteria, some Gram-negative bacteria, and several strains of mycoplasms is administered to animals in food, drinking water, or by injection; however, its chemical structure causes problems in analysis of feeds. Although the molecule is charged below pH 8, at-tempts to analyze TML-containing extracts on ion-exchange columns or other polar stationary phases have failed. Additionally, TML shows no fluorescence activity and only poor UV activity. The present method consists of organic solvent extraction followed by liquid chromatography with UV detection. A low wavelength (208 nm) was used for detection. Limits of detection and quantitation, as well as data for recovery and repeatability obtained during characterization of the method, are described. The applicability of the optimized method was tested by analyzing commercial blank feeds processed after TML-medicated feeds.