bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Long-Life Radiocesiums Cs-134 and Cs-137 in Food by γ-Ray Spectrometry: Interlaboratory Study
Authors: Beuaars Paul R , van Duk Remmelt , Geertsen Jos A M , Nootenboom Hans 
Published: February 2020

Abstract
A gamma-ray spectrometric method for the determination of cesium-134 and cesium-137 in food was studied collaboratively in 13 laboratories, using 8 samples (including 4 blind duplicates) consisting of heather honey, milk, and mixed dried herbs. Low resolution, shielded Tl-activated Nal scintillation detectors were used to measure Cs-137 in the photon energy range 516 to 714 keV and Cs-134 in the range 716 to 880 keV. Results were generally acceptable and no outliers were identified for any sample results. The method worked well in the absence of “fresh” fission products. The method was less appropriate for radiocesium determinations where the activity concentration was &lt;100 Bq/kg at a counting time of 900 s or where the Cs-137/Cs-134 activity-ratio was larger than 10. The accuracy of mean measurements of both isotopes (relative to reference measurements made in one laboratory using a high resolution GeLi detector) was in the range of 98 to 103%. For all samples analyzed, the repeatability relative standard deviation (RSDr) values varied from 4.3 to 11.7% for 2 Cs-134 levels ranging from 121 to 337 Bq/kg and from 2.0 to 7.3% for 4 Cs-137 levels ranging from 210 to 1130 Bq/kg, whereas the reproducibility relative standard deviation (RSDR) values for these levels ranged from 10.7 to 14.9% for Cs-134 and from 4.1 to 7.4% for Cs-137.
Liquid Chromatographic Analysis of Sucrose Polyester in Salad Dressing by Evaporative Light-Scattering Mass Detection
Authors: Chase G William , Akoh Casuvmr C , Eitenmiller Ronald R 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for analysis of sucrose polyester (SPE) in salad dressings. SPE is separated from acylglycerols by gel permeation chromatography. The elution time window for SPE was determined with an evaporative light-scattering mass detector. The SPE fraction is collected and quantitated by C18 reversed-phase chromatography with a ternary gradient. The gradient consists initially of 45.5% methylene chloride, 52.5% acetonitrile, and 2.0% isopropyl alcohol. After 5 min, the ratios change to 98.0% methylene chloride and 2.0% isopropyl alcohol and remain unchanged for the next 6 min. The gradient then reverts back to initial conditions and is ready for another injection after a total run time of 17 min. Sucrose octaacetate was used as an internal standard to simplify quantitation. The mean (n = 3) recovery of SPE was 92.4 ± 2.6%. Reversed-phase LC precision was determined by performing 6 replicate analyses of Italian dressing. The mean recovery ± standard deviation and coefficient of variation were 261 ± 9.5 mg SPE/g and 3.6%, respectively.
Quantitation of Cyfluthrin in Liquid and Solid Formulations by Reversed-Phase Liquid Chromatography: Collaborative Study
Authors: Harbin Donald N 
Published: February 2020

Abstract
A liquid chromatographic (LC) method has been developed for quantitation of cyfluthrin (Baythroid®, Tempo®) in liquid and solid formulations. Cyfluthrin is a synthetic pyrethroid insecticide. Samples are dissolved in acetonitrile and analyzed by reversedphase LC with decanophenone as an internal standard. Seventeen laboratories from 7 countries participated in a collaborative study of the method. Each collaborator was provided with reference standard, internal standard, and matched pair samples of Tempo 20 wettable powder, Tempo 2 emulsifiable concentrate, and Tempo 2 flowable liquid formulations. Collaborators were instructed to use peak area measurements for quantitation. Relative standard deviations for reproducibility (RSDR) were 0.78,0.98, and 2.32, respectively. The LC method for determination of cyfluthrin in pesticide formulations has been adopted first action by AOAC INTERNATIONAL.
Determination of Ractopamine Hydrochloride in Swine and Turkey Tissues by Liquid Chromatography with Coulometric Detection
Authors: Turberg Michael P , Macy Thomas D , Lewis Jerry J , Coleman Mark R 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for determination of ractopamine hydrochloride (LY031537) in swine and turkey tissues. Liver, kidney, muscle, and fat samples were homogenized in methanol. An aliquot of the extract was evaporated, diluted with water, and buffered to pH 10.5 ± 0.5 with sodium carbonate to convert ractopamine hydrochloride to a free base. The free base was extracted from the buffered sample with ethyl acetate. The extract was further purified on a Bond Elut acid-washed silica solid-phase extraction cartridge. After converting the free base back to the salt form with pH 4.5 buffer, analytical separation and quantitation of ractopamine hydrochloride was performed on an IBM C18 column with coulometric detection at +600 mV. The limit of detection of the method was approximately 0.5 ppb as determined in swine liver. Overall recovery levels ranged between 75 and 100% for samples of liver, kidney, muscle, and fat fortified at 1 to 100 ppb. The coefficients of variation ranged from 2 to 18% for samples fortified at 1 to 100 ppb.
Simultaneous Determination of Multiple Tetracycline Residues in Milk by Metal Chelate Affinity Chromatography: Collaborative Study
Authors: Carson Mary C , Breslyn Wayne ,   Collaborators:, Carmany J , Cross S , Farrington W H , Hahn A , Jaworski J , Lansdon P , Li M , Pearson D , Polli R , Shepherd E , Singh D , Sundlof S , Tieso T , Wagner R , Wentworth J , Wilson B 
Published: February 2020

Abstract
To meet federal and state regulatory needs, a liquid chromatographic (LC) method with ultraviolet (UV) detection was developed for determination of 7 tetracyclines at 30 ng/mL in milk. Raw milk samples are defatted, acidified, and centrifuged to remove proteins, and tetracyclines are specifically absorbed from the milk by chelation with metal ions bound to small Chelating Sepharose Fast Flow columns. Tetracyclines are removed from these columns with EDTA-containing buffer, and extracts are further cleaned by ultrafiltration. Finally, extracts are concentrated and analyzed simultane ously by using on-line concentration. This method was validated in a collaborative study that involved 11 laboratories, including the authors’ laboratory. Each laboratory was asked to prepare and analyze known control and fortified milk samples, as well as 18 coded blind samples. Eight laboratories completed all analyses. Average interlaboratory recoveries for the known fortified samples ranged from 59% (methacycline at 15 ng/mL) to 78% (oxytetracy cline at 60 ng/mL). Average recovery for each of 7 residues at 30 ng/mL were between 60 and 110%, meeting single-residue guidelines for accuracy set by the U.S. Food and Drug Administration. Reproducibility relative standard deviation (RSDR) for the known fortified samples varied from 11 to 39%, with 6 of 7 residues at the 30 ng/mL level having RSDR values at or below 20%. Seven of 8 laboratories correctly identified blind control milk samples and all 28 residues present in blind samples. The metal chelate affinity—LC method for determination of multiple tetracycline residues in milk has been adopted first action by AOAC INTERNATIONAL.
Determination of D-Malic Acid in Apple Juice by Liquid Chromatography: Collaborative Study
Authors: Eisele Thomas A ,   Collaborators:, Adadevoh K , Anderson G , Brause A , Briesmeister D , Burke J , Cherix G , Ellis C , Hendricks S , Ho C T , Huang C J , Iuliano T , Kline L , Knapp C , Krueger D , Terwel L 
Published: February 2020

Abstract
Eleven laboratories collaboratively studied a liquid chromatographic (LC) method for determination of D-malic acid in apple juice. The mobile phase consisted of 16 mM L-valine and 8 mM copper acetate adjusted to pH 5.5 with NaOH. The UV detector was set at 330 nm, and a single reversed-phase LC column was used. Seven paired samples containing various amounts of D-malic acid ranging from 0 to 188 mg/100 mL of 12 Brix pasteurized apple juice were tested by each collaborator. Repeatability and reproducibility coefficients of variation ranged from 1.0 to 3.5% and 7.7 to 11.7%, respectively, within the range of 26 to 188 mg D-malic acid/100 mL of 12 Brix apple juice. The collabora tive study results demonstrated that the method could quantitate the economic adulteration of ap ple juice with DL-malic acid at lower levels than those reported with previous methods. The LC method for determination of D-malic acid in apple juice has been adopted first action by AOAC INTERNATIONAL.
Liquid Chromatographic Assay of Tylosin in Animal Feeds
Authors: Houglum Joel E , Tasler Mary K 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for the assay of tylosin (tylosin A, tylosin B, and tylosin-urea adduct [TUA]) in animal feeds at approximately 4-200 g/ton. Samples are extracted with an equal mixture of methanol and 0.1 M pH 8 phosphate buffer. An acidic alumina column cleanup step is used prior to reversed-phase LC. Determination is accomplished with UV detection at 280 nm. A15 cm C8 column is used for sample concentration. Elution is performed at 1.5 mL/min with a gradient containing an increasing methanol concentration with 0.5% acetic acid and tetramethylammonium chloride (5 g/L) as the aqueous portion. Baseline separation of tylosin B, TUA, and tylosin A is achieved with retention times of approximately 7.4, 9.3, and 10.7 min, respectively. Conversion factors of 1.0 and 1.2 are used to convert peak areas of tylosin B and TUA, respectively, to tylosin A equivalent as an alternative to standards being used for these components of some feeds. The precision of the procedure ranged from a coefficient of variation (CV) of 1.6% for tylosin A at 94 g/ton to a CV of 11.3% for TUA at 10 g/ton. The average percent recovery of spiked feed extracts was100.4-102.2% for the 3 tylosin components. A correlation with the microbiological assay is presented for 12 feeds, 1 premix, and 1 injectable tylosin product.
Determination of Amoxicillin in Catfish and Salmon Tissues by Liquid Chromatography with Precolumn Formaldehyde Derivatization
Authors: Ang Catharina Y W , Luo Wenhong , Hansen Eugene B , Freemana James P , Thompson Harold C 
Published: February 2020

Abstract
A liquid chromatographic (LC) method with fluorescence detection was developed for analysis of amoxicillin in catfish and salmon tissues. The tissue was extracted with phosphate buffer (pH 4.5), followed by trichloroacetic acid (TCA) precipitation of proteins and solid-phase (C18) extraction. Trace amounts of nonpolar interfering substances present after solid-phase extraction were removed by ether liquid-liquid extraction. The extract was reacted with formaldehyde and TCA at 100°C for 30 min. A fluorescent derivative was extracted with ether, concentrated, and analyzed by reversed phase LC with fluorescence detection. Average recoveries of amoxicillin spiked at 2.5-20 ppb were &gt;80% for catfish and &gt;75% for salmon muscle tissue, with coefficients of variation of &lt;6%. Limits of detection (LOD) and quantitation (LOQ) for catfish tissue were 0.5 and 1.2 ppb, respectively. LOD and LOQ for salmon muscle tissue were 0.8 and 2.0 ppb, respectively.
Determination of Benzocaine in Rainbow Trout Plasma
Authors: Bernardy Jeff A , Coleman Kathleen S , Stehly Guy R , Gingerich William H 
Published: February 2020

Abstract
A liquid chromatographic method is described for analysis of benzocaine (BZ), a proposed fish anesthetic, in rainbow trout plasma. Mean recoveries of BZ from plasma samples fortified at 44–10 100 ng/mL were 96–100%. The method detection limit is 10 ng/mL, and the limit of quantitation is 37 ng/mL. Acetylation of BZ occurs in whole blood after storage at room temperature (i.e., 21 °C) for 10 min. However, no acetylation of BZ was detected in plasma samples held at room temperature for 4 h. Mean method precision for plasma samples with incurred BZ residue is similar to that for fortified samples in the same concentration range (relative standard deviations of 0.9 and 1.2%, respectively).
Liquid Chromatographic Determination of Fumonisins B1, B2, and B3 in Corn: AOAC–IUPAC Collaborative Study
Authors: Sydenham Eric W , Shephard Gordon S , Thiel Pieter G , Stockenström Sonja , Snijman Petra W , Van Schalkwyk Dirk J ,   Collaborators:, Castegnaro M , Kamimura H , Lauren D R , Miller J D , Nawaz S , Pascale M , Pittet A , Savard M E , Schillack V R , Scudamore K , Sizoo E A , Smith W A , Stack M E , Ueno Y , Viljoen C C , Visconti A , van der Westhuizen L 
Published: February 2020

Abstract
A liquid chromatographic (LC) method for simultaneous determination of fumonisins B1 (FB1), B2 (FB2), and B3 (FB3) in corn was subjected to a collaborative study involving 12 participants from 10 countries, in which the accuracy and reproducibility characteristics of the method were established. Mean analyte recoveries from corn ranged from 81.1 to 84.2% for FB1 (at a spiking range of 500 to 8000 ng/g), from 75.9 to 81.9% for FB2 (at a spiking range of 200 to 3200 ng/g), and from 75.8 to 86.8% for FB3 (at a spiking range of 100 to 1600 ng/g). The valid data were statistically evaluated after exclusion of outliers. Relative standard deviations for within-laboratory repeatability ranged from 5.8 to 13.2% for FB1, from 7.2 to 17.5% for FB2, and from 8.0 to 17.2% for FB3. Relative standard deviations for between-laboratory reproducibility varied from 13.9 to 22.2% for FB1, from 15.8 to 26.7% for FB2, and from 19.5 to 24.9% for FB3. HORRAT ratios, calculated for the individual toxin analogues, ranged from 0.75 to 1.73. The LC method for determination of fumonisins B1, B2, and B3 in corn (at concentrations of 800–12800 ng total fumonisins/g) has been adopted by AOAC INTERNATIONAL.
Gas Chromatographic Determination of Propionic Acid and Sorbic Acid Contents of Rye Bread: Interlaboratory Study
Authors: Beljaars Paul R , Van Dijk Remmelt , Verheuen Peter J J , Anderegg Marcia J P T ,   Collaborators:, Bos H , van Dijk R , van Drunen G , van Ede K , Hoekstra A , Huijbregtse P A , Koopmans H , Koot Y , Ottink S , Rondags T M M , Schakel D 
Published: February 2020

Abstract
An interlaboratory study of the gas chromatographic (GC) determination of propionic acid and sorbic acid in rye bread was conducted. Homogenized test portions were extracted with a diethyl ether-phosphoric acid solution. Extracts were analyzed by capillary GC with flame ionization detection. Valeric acid and heptanoic acid were used as internal standards for propionic acid and sorbic acid, respectively. Six rye bread samples (3 blind duplicates) with propionic acid and sorbic acid at 3 concentration levels varying from 0.09 to 0.41% (w/w) were analyzed singly according to the proposed procedure by 11 laboratories. For all samples analyzed, repeatability relative standard deviations varied from 3.4 to 3.9% for propionic acid and from 1.7 to 3.0% for sorbic acid. Reproducibility relative standard deviations ranged from 5.0 to 8.0% for propionic acid and from 5.1 to 5.9% for sorbic acid. Average calculated recoveries from rye bread prepared from spiked dough were 100-101% for propionic acid and 101-106% for sorbic acid for 3 concentration levels.
Liquid Chromatographic Determination of Tocopherols and Tocotrienols in Margarine, Infant Foods, and Vegetables
Authors: Konings Erik J M , Roomans Harry H S , Beljaars Paul R 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was developed for determination of tocopherols and tocotrienols in foods. Tocopherols and tocotrienols were released after saponification of test portions for 40 min at 80°C, followed by extraction with hexane-ethyl acetate. After evaporation of the organic solvents, the extract was injected into the LC system. Separation of individual tocopherols and tocotrienols was satisfactory. Some interferences were encountered from tocomoneols, tocodienols, 2-tert-butyl-4-hydroxyanisole (BHA), 2,6-di-tert-butyl-4-methylphenol, (BHT), and plastochromanol-8. The response of the LC system was linear over a range of 0-10 μg/mL for tocopherols and tocotrienols. The detection limit for these compounds was 0.1 μg/mL. Repeatabilty relative standard deviation values for tocopherols and tocotrienols in margarine, infant formula, and broccoli (concentration range, 0.11-22 mg/100 g) varied from 1.3 to 6.4%. Recoveries ranged from 91 to 105%.
Comparison of Babcock and Ether Extraction Methods for Determination of Fat Content of Cream: Collaborative Study
Authors: Lynch Joanna M , Barbano David M , Fleming J Richard 
Published: February 2020

Abstract
A modified Mojonnier ether extraction method for determination of the fat content of cream was developed based on the method for milk (AOAC Official Method 989.05). The cream Babcock method (AOAC Official Method 920.111 B-C) was modified to harmonize with the milk Babcock method (AOAC Official Method 989.04) and to clarify procedural details. Using the AOAC collaborative study format, 10 laboratories tested 9 pairs of blind duplicate heat-treated cream samples with a fat range of 30-45% using both methods. The statistical performance (invalid and outlier data removed) was as follows: mean % fat = 37.932, sr = 0.125, sR = 0.151, RSDr = 0.330, RSDR = 0.398, r = 0.354, and R = 0.427 for the ether extraction method. For the Babcock method, mean % fat = 38.209, sr = 0.209, SR = 0.272, RSDr = 0.548, RSDR = 0.712, r = 0.592, and R = 0.769. Average test results for fat from the Babcock method were 0.277% (absolute fat) greater than for the Mojonnier ether extraction method. The difference between methods, as a percentage of the average fat content of the samples, was 0.73%. This agrees with differences observed between the 2 methods for milk when 10 to 17 laboratories tested 7 milk samples in blind duplicate at bimonthly intervals over a 4-year period (average difference 0.029% fat, 0.78% as a percentage of average fat content). The Mojonnier ether extraction and Babcock methods for fat in cream have been adopted by AOAC INTERNATIONAL. The new Babcock method replaced the AOAC Official Method 920.111 B-C.
Simultaneous Determination of 2,4-D, Dicamba, and Mecoprop in Soil Leachates by Gas Chromatography with Electron Capture Detection
Authors: Hong Moo-Ki , Kim Myung-Chul , Smith Albert E 
Published: February 2020

Abstract
Capillary gas chromatography (GC) with electron capture detection (ECD) and mass selective detection (MSD) was used for simultaneous determination of 2,4-dichlorophenoxyacetic acid (2,4-D), 3,6-dichloro-2-methoxybenzoic acid (dicamba), and (±)2-(4-chloro-2-methylphenoxy)propanoicacid (mecoprop) extracted from soil leachates. The 2,2,2-trif luoroethanol (TFE) esters of the acid analytes were synthesized by using H2SO4 as the catalyst. Efficiency of derivatization and instrumental molecular response were compared for herbicides methylated with boron trifluoride-methanol (14%, w/v), H2S04-methanol (33%, v/v), and diazomethane. The molecular integrity of TFE-2,4-D, TFE-dicamba, and TFE-mecoprop in the mixture was confirmed by GC-MSD. The TFE-esterification efficiency was maximized by adjusting the volume of H2SO4, the reaction time, and the reaction temperature. Optimal efficiency for the herbicide mixture was obtained by adding 1 m└ H2SO4 and 1 m└ TFE to the dried extract and allowing the reaction to proceed at 22�C for 8 h or by adding 0.5 m└ H2SO4 and 1 m└ TFE at 60°C for 120 min. Maximum esterification efficiency required an increased temperature and a decreased reaction time. The sensitivity of GC-ECD was about 2-20 times greater in determining TFE esters than in determining methyl ester derivatives. The herbicides were extracted simultaneously from soil leachates previously spiked with the analytes and esterified to TFE derivatives. Herbicide recovery, peak resolution, and detector sensitivity were excellent without column cleanup procedures.
Determination of Organochlorine Pesticide and Polychlorinated Biphenyl Residues in Fatty Fish by Tandem Solid-Phase Extraction Cleanup
Authors: Schenck Frank J , Calderon Lori , Podhorniak Lynda V 
Published: February 2020

Abstract
A rapid, multiresidue solid-phase extraction (SPE) technique for determination of organochlorine pesticide and polychlorinated biphenyl (PCB) residues in nonfatty fish was modified for use with fatty fish. In the modified procedures, samples are extracted with acetonitrile, and the extract is cleaned up with both C18 and Florisil SPE columns. Residues are determined by gas chromatography with electron capture detection. The original method was modified for use with fatty fish by reducing the amount of tissue extracted and by using an improved Florisil SPE cleanup. Recovery data are presented for 24 fortified organochlorine pesticide residues (0.12 ppm) and 3 fortified PCB residues (0.80 ppm) from flounder, bluefish, and shad samples, which contained 0.8,5.4, and 22.6% fat, respectively. For the 3 types of fish, recoveries of 23 of 24 fortified organochlorine pesticide residues ranged from 55 to 129%, and recoveries of 3 fortified PCB residues ranged from 55 to 104%. There were no significant differences in recovery based on fish species and/or fat content for the majority of residues studied. This SPE method and the official AOAC method yielded comparable results for fish containing incurred organochlorine residues.
Sources of Error in Vitamin A Analysis
Authors: Thiex Nancy , Smallidge Robert , Beine Robert 
Published: February 2020

Abstract
Potential sources of error in analysis of vitamin A in animal feed and pet food are discussed. Errors arising during sample handling and preparation and those due to standards, calibration, sample size, hydrolysis, extraction, evaporation, detection, equipment calibration, and isomerization are addressed. Quality control practices are recommended, and safety considerations are outlined. A summary of systematic and random errors is provided.
Rapid Quantitative Screening Assay of Trace Benzimidazole Residues in Milk by Liquid Chromatography
Authors: Fletouris Dimitrios , Botsoglou Nickos , Psomas Ioannis , Mantis Antonios 
Published: February 2020

Abstract
A simple, rapid, and sensitive liquid chromatographic (LC) assay for quantitative screening of albendazole 2-aminosulfone, albendazole sulfoxide, oxibendazole, oxfendazole, albendazole sulfone, p-hydroxyfenbendazole, albendazole, mebendazole, fenbendazole sulfone, and fenbendazole residues in milk was developed. Samples are made basic (pH 10) and extracted with ethyl acetate. Extracts are partitioned with water, evaporated to dryness, reconstituted with mobile phase, and analyzed isocratically by ion-pair reversed-phase LC at 292 nm. Overall recoveries ranged from 79 to 100%. Linearity was excellent in the fortification range examined (5.3–200 ng/mL). Precision data, based on within- and between-days variations, suggested an overall relative standard deviation of 2.0 to 5.8%. The method was successfully used to quantitate albendazole and fenbendazole and metabolites in milk from 2 drug-treated dairy cows.
Detection of DSP-Toxins, Okadaic Acid, and Dinophysis Toxin-1 in Shellfish by Serine/Threonine Protein Phosphatase Assay
Authors: Honkanen Richard E , Mowdy Don E , Dickey Robert W 
Published: February 2020

Abstract
A relatively rapid protein phosphatase-based assay was developed for detecting okadaic acid in extracts of shellfish, using oysters (Crassostrea virginica) as a model. The assay has good sensitivity, detecting okadaic acid in crude methanolic extracts of oysters at ≥4 ng/mL (≥0.1 ng/assay). Assay accuracy for detecting toxic shellfish was validated through a series of spike recovery experiments. In more than 320 assessments, all oysters containing toxic amounts of okadaic acid (≥0.2 μg/g) were detected. Results of analysis of the same extract by phosphatase assay and liquid chromatography gave very high correlation.