bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Chromatographic Determination of Nicarbazin in Feed
Authors: Hurlbut Jeffrey A , Nightengale Cyril T , Burkepile Roger G 
Published: February 2020

Abstract
A liquid chromatographic method was developed for the determination of nicarbazin (4,4'-dinitrocarbanilide.2-hydroxy-4,6-dimethylpyrimidine) in chicken feed. Ground feed was extracted with hot dimethylformamide, filtered, and then cleaned up on an alumina column. The nicarbazin was eluted from the column with ethanol and quantitated using a reverse phase C-18 column, with a methanol-water mobile phase and ultraviolet detection at 344 nm. Recoveries at a typical use level of 100 μg/g feed averaged 98% with a standard deviation of 3%. Samples fortified at levels as low as 0.1 μg/g were analyzed with 92% recovery. The detection limit is 1 ng, and the response is linear between 4 and 1000 ng. Feed additives in combination with nicarbazin do not interfere with recovery.
Thin Layer Chromatographic Determination of Sterigmatocystin in Cheese
Authors: Francis Octave J , Ware George M , Carman Allens , Kuan Shia S 
Published: February 2020

Abstract
A one-dimensional thin layer chromatographic method has been developed for determining sterigmatocystin in cheese. Cheese is extracted with acetonitrile—4% KC1 (85 + 15). A simplified liquid-liquid partition cleanup is used, and the sample extract is passed through a cupric carbonate column for final purification. Sterigmatocystin is visualized by spraying the plate with aluminum chloride. The fluorescence of the : spot is enhanced 10-fold by additional plate spraying with a silicone- ' ether mixture, enabling sterigmatocystin detection and quantitation at 2 land5 μg/kg, respectively. Average recoveries were 88.3 and 86.4% at the 10 and 25 μg/kg levels, respectively.
Assessment of Extraction Procedures in the Analysis of Naturally Contaminated Grain Products for Deoxynivalenol (Vomitoxin)
Authors: Trenholm, Locksley H , Warner Robert M , Prelusky Dan B 
Published: February 2020

Abstract
A comparison of 2 extraction solvent systems (acetonitrile-water, 21 + 4 and methanol-water, 1 + 1) and 3 mixing apparatus (high-speed blender, wrist-action shaker, and mechanical stirrer) was carried out for different extraction time periods. Methods were evaluated using uncontaminated corn spiked with pure deoxynivalenol (DON), fieldinoculated (Fusarium graminearum) corn, and uncontaminated and naturally infected wheat in swine diets. After sample extraction, aliquots were passed through alumina-charcoal cleanup columns, evaporated to dryness, dissolved in 8% aqueous methanol, and injected onto the liquid chromatograph. Results confirm published reports of recoveries from DON-spiked samples; however, longer extraction times (&lt; 120 min) were required for naturally contaminated samples. Use of the high-speed blender resulted in faster extractions, but in our laboratory more samples could be more conveniently extracted simultaneously with the wrist-action shaker or mechanical stirrer. Less carryover (co-extraction) of interfering contaminants was observed when acetonitrile-water was used vs methanol-water. Results emphasize the importance of careful evaluation of extraction procedures with not only spiked samples but also naturally contaminated samples to establish extraction times required for maximum deoxynivalenol recoveries.
pH-Induced Difference, Spectrophotometric Assay of Tetracycline and Oxytetracycline
Authors: Wahbi Abdel-Aziz M , Barary Magda , Mahgoub Hoda , Elsayed M Abdel-Hady 
Published: February 2020

Abstract
The △D1 method is based on the measurement of the quotient of the first order spectrum displacement effect induced by a pH change as a function of tetracycline-oxytetracycline concentration. The linear relationship of such variables with negligible intercept values permits the assay of these drugs in commercial capsule preparations, with good accuracy and reproducibility. The assay results were compared with other spectrophotometric methods: Amax, △A, and D1,
Polarographic Determination and Aqueous Potentiometric Titration of Cimetidine in Tablets
Authors: SÁnchez-PÉrez Ambrosio , HernÁndez-MÉndez, JesÚs , Fuentes De Frutos JosÉ E 
Published: February 2020

Abstract
A method is described which uses the direct current (dc) polarographic behavior of cimetidine in a strong acid solution to determine this compound. The diffusional characteristics of the reduction wave of cimetidine in 1M HC1 (about —0.8 V vs SCE) are shown, and their analytical usefulness was studied. This polarographic method was used to determine cimetidine in standard solutions ranging from 4 to 80 |xg/ mL with a coefficient of variation of 1.3%, and was further applied to the determination of cimetidine in tablets. The results obtained by the dc polarographic method agree with those obtained by an aqueous potentiometric titration of cimetidine with HCI04 and estimation of the end point by the Gran graphic method
Gas Chromatographic Determination of Formaldehyde in Coffee Via Thiazolidine Derivative
Authors: Hayashi Tateki , Reece Clayton A , Shibamoto Takayuki 
Published: February 2020

Abstract
Thiazolidine formed from trace quantities of formaldehyde in an aqueous solution containing cysteamine at pH 8 was extracted with chloroform and subsequently analyzed by a gas chromatograph equipped with a fused silica capillary column and a thermionic nitrogen-phosphorus specific detector. Recoveries of formaldehyde from the aqueous solutions at levels lower than 1 ppm were slightly over 100%. Quantitative analysis of formaldehyde in commercial brewed and instant coffees showed 3.4-4.5 ppm in the brewed and 10-16.3 ppm in the instant coffee.
Indirect Spectrophotometric Method for Determining Epicillin
Authors: Núñez-Vergara Luis J , Roa Alejandro , Squella Juan Arturo , González-Barbagelata Renato V 
Published: February 2020

Abstract
A new UV spectrophotometric assay for determination of epicillin in capsules and plasma is reported. The method is based on the absorptivity of a degradation product obtained from the acidic hydrolysis of the antibiotic. The isolation, identification, individual capsule assays, composite assay, and recovery studies are described. Also, the proposed method is compared with a dc polarographic assay in plasma.
Cranberry Juice Composition
Authors: Hong Victor , Wrolstad Ronald E 
Published: February 2020

Abstract
Eight samples of cranberries (Vaccinium macrocarpon) representing the major varieties and principal commercial growing regions in the United States were processed into juice. Four of the 8 samples were concentrated to 50° Brix. Liquid chromatography (LC) was used to determine nonvolatile organic acid, anthocyanidin pigment, and sugar profiles. Ultraviolet-visible spectral methods were used to determine anthocyanin concentration, polymeric color, and percent polymeric color. Other data presented include stable isotope carbon ratios, degree Brix, pH, and Hunter color parameters. These data are presented to serve as an authentic data base for use in detection of adulterated cranberry juice.
Determination of Diagnostic Levels of Arsenic in Animal Tissue: Collaborative Study
Authors: Hunter R Tracy ,   Collaborators:, D’Andrea G H , Audette R J , Colvin B , George G , Gerlach M , Jain A V , Reagor J , Roof J E , Stahr H M , Tipton B , Weaver P , Willard J 
Published: February 2020

Abstract
The method chosen for this collaborative study is a modification of the AOAC method for As residues, 41.009-41.012. The tissue is dry-ashed overnight at 500°C, and then dissolved in dilute HCl. The solution is diluted and an aliquot is reacted with zinc metal to evolve arsine gas. The gas is trapped in AgDDC solution and As is quantitated at 540 nm. Nine collaborating laboratories performed single analyses on 4 blind duplicate pairs of bovine liver samples which were spiked at 0, 4.3, 10.8, or 21.6 mg As/kg liver. A National Bureau of Standards control (SRM 1566 Oyster Tissue, 13.4 ± 1.9 mg As/kg) and a 1000 mg As/L standard were also submitted to the collaborators. Intralaboratory coefficients of variation ranged from 7.7 to 17.8%; interlaboratory coefficients of variation ranged from 10.9 to 19.0%. The method has been adopted official first action.
Optimum Methanol Concentration and Solvent/Peanut Ratio for Extraction of Aflatoxin from Raw Peanuts by Modified AOAC Method II
Authors: Whitaker Thomas B , Dickens James W , Giesbrecht Francis G 
Published: February 2020

Abstract
The amount of aflatoxin extracted from raw peanuts by using the waterslurry modification of AOAC Method II was determined for 49 different combinations of methanol concentration and solvent/peanut ratio. Results indicate that the amount of anatoxins B1 and B2 extracted from raw peanuts is a function of both methanol concentration and solvent/peanut ratio, and a cubic equation was developed, using regression techniques, to describe the combined effects. From the functional relationship, the predicted methanol concentration and solvent/peanut ratio that extracts the most aflatoxin Bt was computed to be 60.0% and 10.8 mL solvent/g peanuts, respectively. This combination extracted 12.1% more aflatoxin than did AOAC Method II.
Methods of Sample Preparation for Detecting Alkaline Phosphatase in Casein: Collaborative Study
Authors: Murthy Gopala K , Peeler James T ,   Collaborators:, Bassett L , Dickerson B , Dombroski P , McFall D , Marchetti D , Neal D , Reese D 
Published: February 2020

Abstract
A collaborative study was conducted in which 2 different sample preparation techniques were used to determine alkaline phosphatase in casein by the rapid colorimetric test. Seven collaborators tested 10 unknown casein products containing different amounts of residual phosphatase. Results indicated that the phosphatase contents of casein prepared by the 2 methods were not significantly different. The collaborators correctly analyzed 100% of the test samples that were ground and 98 % of the test samples that were unground. The alternative rapid sample preparation method has been adopted official first action.
CuSO4-TiO2 as Kjeldahl Digestion Catalyst in Manual Determination of Crude Protein in Animal Feeds
Authors: Kane Peter F 
Published: February 2020

Abstract
The official AOAC manual Kjeldahl methods for determining crude protein in animal feeds have several disadvantages. For the HgO catalyst method, there are environmental concerns and a lengthy digestion. For the CuS04 catalyst method, the digestion period is shorter, but still 90 min. A different catalyst combination, CuS04-Ti02, makes 40 min digestion feasible. Comparison of these catalysts on a group of representative feeds resulted in a mean difference, Cu-Ti minus HgO, of 0.034% protein. Standard deviation of the differences was 0.36. A Student’s t-test showed no significant difference. The method will be collaboratively studied.
Hydrophobic Grid Membrane Filter Method for Aerobic Plate Count in Foods: Collaborative Study
Authors: Entis Phyllis ,   Collaborators:, Allen J , Bhatnagar A , Brouwer A , Catherwood K , Chrunyk P , Comar P , Cook S , Coulter R , Creighton J , Currie A , Elliott P , Fawcett J A , Haines G , Hall P A , Harrell F M , Harris K , Hopkins K , Jones D , Joy J , Lam J , Lammerding A M , Langford M , Levine D , Myers J , Nelson T , Nielsen P K , Nolan D A , Park M , Pearson C , Pettipas R , Prychitko S , Pryor B M , Rauch W , Reaves L A , Roberts B , Szabo R , Talbot L , Taylor C , Toms S , Wagner C , White S , Wilson P 
Published: February 2020

Abstract
Twenty-one laboratories participated in a collaborative study to validate a hydrophobic grid membrane filter (HGMF) method for aerobic plate count by comparing its performance against the AOAC/APHA pour plate method. Raw milk, raw poultry, whole egg powder, flours, and spices were included in the study. Counts obtained by the HGMF and pour plate methods did not differ significantly, except in the case of whole egg powder, for which the HGMF method produced significantly higher counts. The hydrophobic grid membrane filter method for aerobic plate count in foods has been adopted official first action.
Liquid Chromatographic Determination of Dicofol in Kelthane Formulations: Collaborative Study
Authors: Rothman Alan M ,   Collaborators:, Ausari A , Bennett O O , Blusiewicz E J , Christensen A , Cohen M , Diuguid J , Gentry G M , Grimes G , Harder D , Hitos P , Hodgins W E , Pavel K , Poulsen H H , Rowe N , Sanchez-Rasero F , Stroh S 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was used to determine p,p'- and o,p'-isomers of dicofol AI (active ingredient) in Kelthane® EC and MF formulations. Samples are dissolved in methanol and AI components and impurities are separated on a high resolution C8 column in series with a short C18 guard column, with a methanol-water-acetic acid mobile phase. Cleaned samples are directly injected into the LC system and are monitored at 254 nm. Twelve collaborators submitted results on 5 samples. Using 95% confidence criteria, the average total standard deviation of the total AI across all samples was 2.82%. The method has been adopted official first action.
Nonaqueous Reverse Phase Liquid Chromatographic System for Separation and Quantitation of Provitamins A
Authors: Quackenbush Forrest W , Smallidge Robert L 
Published: February 2020

Abstract
A reverse phase liquid chromatographic (LC) system has been developed for separating the main naturally occurring carotenoids that have provitamin A activity. The system produces baseline separation of β-carotene, α-carotene, and β-cryptoxanthin (β,β-carotene-3-ol, 472- 70-8) from biologically inactive zeinoxanthin (β, ∊-carotene-3-ol, 24480- 38-4) and from a pigment believed to be α-cryptoxanthin (β,∊-carotene- 3'-ol). Some m-isomers are also separated. These separations are obtained on a C-18 column, isocratically, with methanol-chloroform eluant. For quantitation, peak areas from detection at 475 nm are compared with that of an internal standard, l-(phenylazo)-2-naphthalenol (842-07-9), which elutes prior to the provitamins. Provitamin amounts are calculated from absorbance ratios. Prior to LC, esters are saponified, and interfering pigments are removed from ester-free extracts by adsorption on magnesia.
Halogenated Phenols in Water at Forty Canadian Potable Water Treatment Facilities
Authors: Sithole Bishop B , Williams David T 
Published: February 2020

Abstract
Samples of raw and treated water were collected once in each of 3 seasons at 40 potable water treatment plants across Canada and were analyzed for phenol and 33 halogenated phenolic compounds including chlorophenols, bromophenols, bromochlorophenols, and chloroguaiacols. Eighteen of the compounds were not found at any treatment plant; phenol and each of the remaining halogenated phenols were found in at least 1 sample. Pentachlorophenol was the only halogenated phenolic compound found in more than 20% of the raw water samples in the fall and winter samples at levels up to 53 ng/L with mean values of 1.9 and 2.8 ng/L, respectively. No halogenated phenols were detected in raw water summer samples. The halogenated phenols found most frequently in treated water samples were 4-chloro-, 2,4-dichloro-, 2,4,6- trichloro-, and bromodichlorophenols. Mean values were less than 15 ng/L and maximum values seldom exceeded 100 ng/L. Most of the positive values for the treated water samples were found at 8 of the 40 treatment plants but no correlations could be found between halogenated phenol levels and raw water type, treatment process, or chemical dosages.
Graphite Furnace Atomic Absorption Spectrophotometric Determination of 4-Hydroxy-3-Nitrobenzene Arsonic Acid in Finished Animal Feed: Collaborative Study
Authors: George Glenn M , Fra Larry J ,   Collaborators:, Aten C F , Bestianich J , Boucher J , Carr M R , Creekmur R , Hartlieb P , Herald C S , Hunter R T , Kuervers T , Leipzig C , Miller C , Moore E J , Shick L , Sullivan D M , Walton J C 
Published: February 2020

Abstract
Eight laboratories participated in a collaborative study of an atomic absorption spectrophotometric (AAS) method for determination of 4- hydroxy-3-nitrobenzene arsonic acid (roxarsone), which is administered in animal feed at levels of 25-50 ppm as a growth stimulant. The drug is extracted from feed by using aqueous 1% ammonium carbonate solution. Undissolved feed particles are allowed to settle, and then a diluted aliquot of the feed extract is analyzed for total arsenic by AAS using a graphite furnace for sample atomization. Collaborators performed single analyses on 18 samples which were randomly numbered blind duplicate pairs of a complete poultry ration fortified with roxarsone at concentrations from 22.5 to 55.0 ppm. Statistical evaluation of the collaborative data showed satisfactory method performance. Overall mean recovery of roxarsone was 100.4% and the overall relative standard deviation was 6.2%. The method has been adopted official first action.
Gas Chromatographic Determination of Deoxynivalenol in Wheat with Electron Capture Detection: Collaborative Study
Authors: Ware George M , Francis Octave J , Carman Allen S , Kuan Shia S ,   Collaborators:, Bennett G , Carter L , Gaba D , James T , Lyon S , Nowak G , Richelieu M , Routh J , Tarter E , Thorpe C 
Published: February 2020

Abstract
Ten laboratories participated in a collaborative study of a method for the determination of deoxynivalenol in wheat by gas chromatography with electron capture detection. Each laboratory analyzed 6 samples in duplicate. Each collaborator received samples spiked at the 100.3, 501.3, and 1002.6 ng/g levels; a control sample; and 2 naturally contaminated samples. The average recovery (outliers excluded) for the spiked samples was 92.2%. The mean repeatability and reproducibility, respectively, were 32.2 and 41.3% for the spiked samples and 30.9 and 47.6% for the naturally contaminated samples. The method was adopted official first action.
Micro-Kjeldahl Analysis Using 40-Tube Block Digestor and Steam Distillation
Authors: Campbell Duncan C 
Published: February 2020

Abstract
A steam distillation unit was developed for use with a 40-tube block digestor (25 x 290 mm tubes). Initial digestion for 10 min with sufficient H2SO4 alone avoids frothing. A K2SO4/HgO mixture is then added and the digestion is continued. Use of condenser tubes and a fan to cool condensers and the tops of digestion tubes allows the use of high block temperatures (450°C) and long digestion times (1.5 h) with little loss of acid. The steam distillation unit incorporates a large head which contains the steam/sample solution mixture during distillation. The large distillation head allows the acid and base solutions to be sufficiently dilute to avoid a violent reaction when mixed. Distillation was 99.9% complete about 2.2 min after distillate appeared in the condenser. To demonstrate the use of the apparatus, rapeseed (Brassica napus cv. Altex) was ground and forty 0.5 g samples were analyzed giving the following results: mean 23.34%, SD 0.07, CV 0.005%, min. 23.17%, max. 23.46%, range 0.29%. Complete digestion and recovery rate were indicated for nicotinic acid by recovery of 99.9-100.0% of the nitrogen.
Rapid Methods for Determination of Meat Composition
Authors: Mcneal Jon E 
Published: February 2020

Abstract
Rapid analytical procedures are needed to determine the total protein, moisture, and fat content of meat and poultry products. During the past 5 years, the U.S. Department of Agriculture (USDA) has been studying various methods involving instrumentation that test for these constituents either in combination or separately. The studies are initiated on request of the Department or the instrumentation manufacturer and are conducted at the manufacturers' facilities using 2 sets of samples preanalyzed by conventional means. One set, with values, is used for calibration purposes, the other set is tested as unknown samples. The resultant data are evaluated statistically vs the conventional test results. Most studies show the usefulness of these rapid tests for product quality control, but some fall short of regulatory requirements because of unacceptable bias or variability. Typical within-product standard deviations obtained in rapid methods instrumentation tests have ranged from 0.47 to 0.67 for percent total protein, 0.73 to 1.71 for moisture, and 0.41 to 1.14 for fat. For conventional methods, the acceptable USDA performance criteria for repeatability are standard deviations of less than 0.24 for protein, 0.46 for moisture, and 0.63 for fat. Improvements in instrumentation are being made and studies continue.
Detection of Beef and Poultry by Serological Field Screening Tests (ORBIT and PROFIT):
Collaborative Study
Authors: Cutrufelli Mark E , Mageau Richard P , Schwab Bernard , Johnston Ralph W 
Published: February 2020

Abstract
Ten laboratories each analyzed 30 raw meat and raw meat product samples in a collaborative study of the ORBIT (overnight rapid bovine identification test) and PROFIT (poultry rapid overnight field identification test) serological field screening tests for the detection of beef and poultry. Versatility of the tests was shown in the analysis of whole tissue, ground, or emulsified raw meat products. Both tests were demonstrated to be reliable and were capable of detecting adulterants present at the 10% level. The method has been adopted official first actio
A New, Rapid, High-Sensitivity Analysis of Amino Acids in Food Type Samples
Authors: Bidlingmeyer Brian A , Cohen Steven A , Tarvin Thomas L , Frost Beverly 
Published: February 2020

Abstract
A new approach to the analysis of free amino acids and amino acids from hydrolyzed foods is described. The method is based on reaction of the free amino acids with phenylisothiocyanate to form stable derivatives which are subsequently separated by liquid chromatography. Sample preparation procedures are described and results are compared with conventional ion exchange results. Reproducibility of the new method has been determined on a typical food type sample.
Multiresidue Method for Determining Substituted Urea Herbicides in Foods by Liquid Chromatography
Authors: Luchtefeld Ronald G 
Published: February 2020

Abstract
A method is described for determining substituted urea herbicides in foods. The residues are extracted from the product with methanol, and the food coextractives are removed by using solvent partitioning and Florisil column chromatography. The extract is analyzed using liquid chromatography with postcolumn photodegradation, chemical derivatization with orthophthalaldehyde, and spectrofluorometry. Recoveries were determined by spiking 8 different food products with 6 phenylureas—chlorbromuron, chloroxuron, diuron, fluometuron, linuron, and metobromuron—at 0.05 and 0.5 ppm. Three determinations were made at each level for each product. Average recovery at 0.05 ppm was 95% (with a standard deviation of 7.9%), and at 0.5 ppm, 98% (with a standard deviation of 6.9%).
Listeria monocytogenes—A Current Dilemma
Authors: Wehr Michael H 
Published: February 2020

Abstract
Since 1985, Listeria monocytogenes has gone from being an organism known to only a handful of microbiologists to being a fully recognized food-borne pathogen of concern. With nearly unprecedented speed and vigor, food processors, particularly in the dairy industry, and regulatory agencies have reacted in concert to resolve unanswered questions about Listeria so as to assure the safety of the food supply. This report summarizes what has been learned and what is being done