bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Three Sample Preparation Techniques for Determination of Organic Bromide and Chloride in Halogenated Lipids by X-Ray Fluorescence Spectroscopy
Authors: Conacher Henry B S , Chadha Rajinder K , Lacroix Gladys 
Published: February 2020

Abstract
Three sample preparation techniques—thin-film, solution, and cellulose pellet—were applied to the determination of bromide in brominated lipids by X-ray fluorescence spectroscopy. Using brominated vegetable oils of known bromide content it was demonstrated that the thin-film technique could result in erroneously high bromide contents, which could also vary with the amount of oil applied, depending on the solvent used. As solutions in hexane, slightly high bromide contents were observed at high concentrations. With the cellulose pellets, bromide contents similar to known values were observed. It was concluded that the cellulose pellet procedure, although more time consuming, and less convenient for ready recovery of sample, was the most suitable for organic bromide determination. Similar results were indicated for chlorinated oils.
Evaluation of Milko-Tester Minor for Determining Fat in Milk
Authors: Shipe Frank W , Senyk Gary F 
Published: February 2020

Abstract
The Milko-Tester Minor was tested to determine if it conformed to recommended AOAC performance specifications. Results were compared with those from the Babcock method and other approved instruments. Results indicated that the MT Minor conformed to the specifications for transfer errors, linear response, and homogenizer efficiency. In addition, 3 MT Minors, 1 Milko-Tester Automatic, 2 Model 300 Milk-Scans, and the Babcock method were used to determine 15 individual cow milks and 15 bulk milks in triplicate. Standard deviations of triplicates were 0.035 and 0.024 (av. for MT Minors), 0.015 and 0.013 (Automatic), 0.030 and 0.012 (av. for Milko-Scans), and 0.039 and 0.038% (Babcock) for individual and bulk milks, respectively. Standard deviations of differences between instrument and Babcock results were within recommended limits with the 3 MT Minors, averaging 0.070 and 0.042% on individual and bulk milks, respectively. Analysts and MT Minors instrumental variations were studied by having 3 analysts operate each of 3 MT Minors independently to test 12 samples. Range of average fat content was 4.290–4.312% for analysts and 4.292–4.311% for instruments.
Improved Ammonium Molybdate Method for Thin Layer Chromatographic Detection of Organophosphate Residues
Authors: Murty A Satyanarayana , Rajabhushanam B Roosevelt , Christopher K , Ramani A Venkata 
Published: February 2020

Abstract
An improved ammonium molybdate method for detecting organophosphate residues on thin layer chromatographic (TLC) plates is described. After development, the plates are heated at 110°C for 2 h and the resultant inorganic phosphate is reacted with ammonium molybdate to form phosphomolybdate which is then reduced to a blue complex by ascorbic acid. Quantities as low as 0.1–0.2 μg residues could be detected on TLC plates by this method.
Automated Analysis of Soil Extracts for Phosphorus, Potassium, Calcium, and Magnesium
Authors: Flannery Roy L , Markus Denes K 
Published: February 2020

Abstract
An automated method is described for determining P in double acid (0.05N HCI + 0.025N H2SO4) and Bray P1 (0.025N HCI + 0.03N NH4F) soil extracts and K, Ca, and Mg in double acid and 1N ammonium acetate soil extracts. Comparisons are made between double acid and Bray P1 soil extraction methods for removal of P from a Freehold sandy loam soil that had been differentially fertilized with P fertilizers. Comparisons are also made between the double acid and ammonium acetate soil extraction methods for removal of K, Ca, and Mg from the same soil that had been differentially fertilized and limed with K fertilizers and pulverized–dolomitic limestone, respectively. Comparisons are made between automated and atomic absorption determinations of K, Ca, and Mg in standard solutions and double acid and ammonium acetate soil extracts. Bray P1 soil extractant removed 30–73% more P than did the double acid soil extractant from Freehold sandy loam soil. Ammonium acetate extractant removed about 25% more K from soil than did the double acid extractant. Double acid soil extractant removed more Ca from the soil than did ammonium acetate extractant, particularly at high soil Ca levels. Greater amounts of Ca were found in both types of soil extracts by the automated than by atomic absorption techniques. Double acid extractant removed more Mg from soil than did ammonium acetate extractant. The 2 instrumentation methods produced similar results for Mg and K analyses of both soil extract types.
Nitrogen Specific Ion Electrodes for Soil, Plant, and Water Analysis
Authors: Mills Harry A 
Published: February 2020

Abstract
The nitrate specific ion electrode and the ammonia and nitrogen dioxide gas-sensing combination electrodes offer simple methods of analyses of plants, soils, and water. The nitrate electrode measures activity of the nitrate ion in solution and is susceptible to interfering ions, particularly Cl. Considerable discrepancies exist in the literature concerning nitrate extracting solutions and buffering solutions used to eliminate interferences with the nitrate electrode. An evaluation of ionic strength adjusters, used to alleviate fluctuating ionic background interferences, indicates (NH4)2SO4 produces consistent results without adversely affecting life of the nitrate electrode. Ammonia electrode determination of total nitrogen in soil, plant, and water samples is a rapid method that eliminates the time-consuming distillation-titration step. The nitrogen dioxide electrode is relatively new and little information is available concerning methodology and its potential problems.
Automated Turbidimetric Determination of Sulfate Sulfur in Soils and Fertilizers and Total Sulfur in Plant Tissues
Authors: Wall Larry L , Gehrke Charles W , Suzuki Jun 
Published: February 2020

Abstract
An automated turbidimetric method has been developed for the rapid and accurate determination of sulfate. The method is practical and useful for accurately measuring total sulfur in plant tissues, and extractable sulfate in soils and fertilizers. The principle of intermittent reagent addition is used, which eliminates drift and sensitivity changes caused by coating of BaSO4 on tubing and cell walls. Also, the appropriate chemistry is used to minimize coating and interactions of the wash with the sample at a sampling rate of 30/h. The sensitivity of the method is excellent with a working range of 0–15 ppm sulfur for soils. For plant and fertilizer digests, the sample solutions are diluted to 0–35 ppm S. The precision as determined by repeated analysis of a soil sample extract was 0.58% relative standard deviation (RSD) with a mean of 9.26 μg extractable sulfate sulfur. On another soil sample, using a different extractant and extraction procedure, the RSD was 0.64%, mean of 9.29 μg/g. Multiple automated sulfur analyses on a plant tissue digest resulted in an RSD of 0.41% for a sample containing 0.21% S. The average recovery of sulfate sulfur on 5 Magruder Fertilizer Check Samples by the automated turbidimetric method was 100.6%, range of 99.8 to 101.4%, as compared to gravimetric analysis. The automated turbidimetric method for sulfate has excellent precision and sensitivity in plant tissue and soil analyses where gravimetric BaSO4 assays are not practical. The method is rapid, precise, and accurate for analysis of sulfate sulfur in fertilizers.
Rapid Method for Analysis of Aflatoxin M1 in Dairy Products
Authors: Fukayama Mark , Winterlin Wray , Hsieh Dennis P H 
Published: February 2020

Abstract
Four methods for determining aflatoxin M1 levels in fluid milk were compared in a search for a simple, routine analytical procedure. Each method was tested with samples spiked at levels of 0, 0.1, 0.5, and 1.0 ppb. The 3 quantitative methods were comparable in sensitivity (0.1 ng/mL) and recoveries (80–90%). A new method, a commercially available extraction column that contains an inert hydrophilic matrix to permit extraction of dairy products, is described. The milk is adsorbed on the column and aflatoxin M1 is eluted with chloroform-acetone (9 + 1). The extract is further purified on a small silica gel collumn and aflatoxin M1 is determined by TLC. This method was simpler and shorter, and was equally sensitive and reproducible in determining aflatoxin M1 in spiked and naturally contaminated fluid milk samples and in spiked nonfat powdered, condensed, and evaporated milk.
Thin Layer Chromatographic Determination of Aflatoxins in Dry Ginger Root and Ginger Oleoresin
Authors: Trucksess Mary W , Stoloff Leonard 
Published: February 2020

Abstract
A method for determining aflatoxins in dry ginger root and ginger oleoresin, using 1-dimensional thin layer chromatography (TLC) for the determinative step, has been developed. The key cleanup steps that permit this change from the 2-dimensional TLC previously required are partitioning of the extract with carbon tetrachloride and use of an improved eluting system for the silica gel adsorption column. Recoveries of aflatoxins B1, B2, G1, and G2 added to samples of ground ginger were 82, 101, 106, and 110%, respectively; recoveries of these aflatoxins added to ginger oleoresin were 75, 100, 93, and 125%, respectively. The method is applicable to fish meal and a number of mixed feeds.
Rapid HPLC Determination of Hydroxymethylfurfural in Tomato Paste
Authors: Allen Bradford H , Chin Henry B 
Published: February 2020

Abstract
A procedure is presented for the rapid determination of hydroxymethylfurfural in tomato paste. The clear serum obtained from the ultracentrifugation of tomato paste is analyzed by high pressure liquid chromatography using a reverse phase LiChrosorb C8 column, an ultraviolet detector operated at 284 nm, and isocratic elution with water.
High Pressure Liquid Chromatographic Determination of Vitamin D3 in Mineral Feed Premixes
Authors: Lein Dennis G , Campbell Harold M , Cohen Huguette 
Published: February 2020

Abstract
A simple and rapid quantitative method is described for determining the presence and amount of vitamin D3 (cholecalciferol) in mineral feed premixes by high pressure liquid chromatography. The samples were extracted with dichloromethane–pentane–methanol (46+46+8) after treatment with ammonium hydroxide, cleaned up by silica Sep-pak, and analyzed by normal phase high pressure liquid chromatography: 10 μm LiChrosorb NH2 column, hexane-isopropanol (98+2) mobile phase, ultraviolet detection at 254 nm. Recoveries were better than 95% in the range 25 000–100 000 IU/kg.
Spectrophotometric Determination of Urea in Urine Stains on Foods and Containers
Authors: Goo Reginald K S , Kanai Hiromitsu , Inouye Veronica , Wakatsuki Helen 
Published: February 2020

Abstract
Urea is extracted from rodent urine-contaminated material with hot acetone. After the extract is evaporated to dryness, aqueous urease solution is added to produce ammonia and carbon dioxide. A blue product, indophenol, is formed by the reaction of ammonia with phenol in the presence of hypochlorite. Absorbance is maximum at 625 nm. Presence of urea is easily detected at 4 μg. Detection of urine contamination in various materials is compared with detection by the AOAC urease– H2PtCL6 test.
High Performance Liquid Chromatographic Determination of Phenothiazine Residues in Sheep Tissues
Authors: Blackman Graeme L , Ho Ah Chai , Jozsa Alex , Kelly John D 
Published: February 2020

Abstract
A high performance liquid chromatographic (HPLC) technique is described for the determination of residue levels of the anthelmintic drug phenothiazine in sheep tissues. Phenothiazine was administered to sheep which were slaughtered after withholding periods of 24, 48, and 72 h. Residues of phenothiazine were then extracted from tissue samples by homogenization in methanol. The HPLC analysis of the extracts involved separation on a 10 μm silica column using a mobile phase of 0.3% n-propanol in cyclohexane. The lower limit of detection by ultraviolet absorption at 254 nm was 0.05 ppm
Some Parameters Affecting Hydride Generation From Arsenic(V) for Atomic Absorption Spectrophotometry
Authors: Liddle John R , Brooks Robert R , Reeves Roger D 
Published: February 2020

Abstract
The atomic absorption signals obtained from the reduction of arsenic(V) by sodium borohydride solution are strongly dependent on a number of parameters which are examined in this paper. If the arsine produced by sodium borohydride reduction is condensed in a cold trap and then released suddenly, the atomic absorption peak is larger and more reproducible. The procedure is more satisfactory if the borohydride solution is added to the reaction mixture in small aliquots. Peak height depends on the total volume of the reaction mixture and on the carrier gas flow rate. Peak height is also a function of the time elapsed after addition of the final aliquot of borohydride, and increases as the interval between successive aliquots is increased. Optimum conditions established were: initial volume of reaction mixture, 30 mL; 12 mL 3% NaBH4 solution added in 2 mL aliquots at 30 s intervals; carrier gas flow 1.25 L/ min; 60 s time lapse from last addition of borohydride until removal of the cold trap. Under these conditions, linear absorbance-concentration curves were obtained for 0.05–3.0 μg arsenic, with a relative standard deviation of 4.2% at the 2 %g level.
Simple Colorimetric Method for Determination of Acetaminophen
Authors: Sane Ramesh T , Kamat Sudhir S 
Published: February 2020

Abstract
A simple colorimetric method for the determination of acetaminophen is described. The method is based on the measurement of a crimson complex formed when acetaminophen is treated with 10% sodium hydroxide solution at elevated temperature. Compounds such as phenacetin, aspirin, caffeine, oxyphenbutazone, barbiturates, hydantoins, and dextropropoxyphen which are present in various formulations containing acetaminophen do not interfere. The method is sensitive to concentrations as low as 25 μg acetaminophen/mL.
Spectrophotometric Estimation of Cinnamic and Benzoic Acids in Balsam Tolu and Benzoin
Authors: Saleh Mohamed R I , Habib Abdel-Azim M , El-Shaer Nagwa 
Published: February 2020

Abstract
In a previous work, a difference spectrophotometric method was developed for quantitating benzoic and cinnamic acids, in the presence of resin acids. In the present work, the technique was adapted for estimating the individual balsamic acids in balsam tolu and benzoin. A procedure for determining purity of the balsamic acids fraction, recovered after alternative purification steps, was studied. Thus we developed an assay procedure relevant to both balsams. Results by the proposed method, the BPC method, and a literature spectrophotometric method are compared.
Analysis of Potato Glycoalkaloids by Gas-Liquid Chromatography of Alkaloid Components
Authors: King Russell R 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method has been developed for the analysis of potato glycoalkaloids by direct determination of the alkaloid components isolated by hydrolysis with IN ethanolic HCl. Recoveries of solanidine from potato tubers and foliage fortified with solanine over a range approximately 0.5 to 5 times the glycoalkaloid originally present averaged greater than 95%, and the lower limit of sensitivity was 0.25 mg/100 g using a nitrogen-phosphorus detector. A means of distinguishing solanidine and demissidine by formation of their respective 3β-trifluoroacetates with trifluoroacetic anhydride (TFAA) is demonstrated.
Argon Plasma Emission Spectrometric Determination of Molybdenum in Mixed Fertilizer
Authors: Woodis Terry C , Holmes John H , Ardis Jimmie D , Johnson Frank J 
Published: February 2020

Abstract
A method is described for the determination of molybdenum in fertilizers by argon plasma emission spectrometry. The sample is acid digested, potassium is added to standards to prevent enhancement, and emission intensities at 313.26 nm are compared. Results compared to a dithiol colorimetric procedure show no difference at the 95% confidence level.
Determination of Ammoniacal Nitirogen in the Presence of Urea
Authors: Viswanathan T S , Nagarajan M , Haribabu B 
Published: February 2020

Abstract
There is no approved AOAC procedure for determining ammoniacal nitrogen in the presence of urea, which is required for the quality control of urea-ammonium phosphate-based fertilizers. A comparative study has been made of various methods available for this estimation. We found that the automated spectrophotometric method, the ion selective electrode method, and the reduced pressure distillation method all furnish results of comparable precision and accuracy. The MgO distillation method, even though not recommended for the above type of sample, still yields results of satisfactory accuracy when certain precautions are taken.
Extraction Efficiencies for Pesticides in Crops: 14C-Benomyl Extraction from Mustard Greens and Radishes
Authors: Wheeler Willis B , Thompson Neal P , Andrade Pio , Krause Richard T 
Published: February 2020

Abstract
14C-labeled benomyl [methyl l-(butylcarbamoyl)-2-benzimidazolecarbamate] suspended in a commercial benomyl formulation was sprayed on mustard greens and radishes. At 3 intervals after application, the crops were extracted with methanol, acetonitrile, or acetone. Crops were either blended and leached or repetitively blended followed by Soxhlet extraction. Essentially all olF the extractable radioactivity was removed by blending. The 14C was more difficult to extract from radishes than from mustard greens as time increased. Respective percentages of 14C extracted at 1, 7, and 14 days were 99, 98, and 97 jFrom mustard greens and 96, 88, and 79 from radishes. Methanol exhibited the highest extraction efficiency, and the blend-Soxhlet process was better than the blend-leach process. Thin layer ihromatography of the organic-soluble extracts indicated that the majority of 14C was recovered as methyl 2-benzimidazole carbamate (MBC), a breakdown product of benomyl. Acid hydrolysis of the extracted tissues released 30–50% of the residual 14C.
Gas Chromatographic Determination of Fluridone Aquatic Herbicide and Its Major Metabolite in Fish
Authors: West Sheldon D , Burger Robert O 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method is described for determining residues of the aquatic herbicide fluridone (l-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(lH)-pyridinone) and its major metabolite (l-methyl-3-(4-hydroxypherayl)-5-[3-(trifluoromethyl)phenyl]-4(lH)-pyridinone) in fish. Both compounds are extracted from fish tissue with methanol, and the extracts are subjected to acidic hydrolysis to release conjugated forms of fluridone and the metabolite. After purification by liquid-liquid partitioning, sample extracts are reacted with methyl iodide to methylate the metabolite, and then both fluridone and the metabolite are brominated with phosphorus tribromide. After purification by Florisil column chromatography, the derivatives are separated and measured by electron capture GLC. The method is capable of determining approximately 0.01 ppm of both compounds in fish, and recoveries have averaged 84±14.7% for fluridone and 83±13.4% far the metabolite.
Analytical Methods for Sulfonamides in Foods and Feeds. I. Review of Methodology
Authors: Horwitz William 
Published: February 2020

Abstract
Sulfonamides are an important class of antibacterial compounds used in veterinary practice and animal production. A number of specific compounds are approved for use in certain species under limitations requiring withdrawal long enough to eliminate the residues from edible tissues. In most cases, the legal tolerance is 0.1 ppm. This residue is measured in regulatory laboratories by a modified Bratton-Marshall procedure of solvent extraction, transfer to an acid solution, removal of potentially interfering amines by extraction from basic solution, diazotization of the sulfonamide in a reacidified solution, and spectrophotometric measurement of the developed color. The tissue metabolites of the sulfonamides are usually the parent compound and the N4-acetyl derivative, which is hydrolyzed to the parent compound by evaporation of the extracting solvent in the presence of acid.
The only collaborative studies which have been performed on methods for veterinary sulfonamides involve their determination as additives to feeds at levels of the order of magnitude of 100 ppm. Recoveries (94-103%) are satisfactory for the collaborative studies available. The reproducibility coefficient of variation of 5% is satisfactory for sulfaquinoxaline, sulfaguanidine, sulfanitran, and sulfamethazine; the 13% coefficient of variation for sulfadimethoxine is not satisfactory, indicating that the method for this compound needs improvement.
No collaborative studies have been performed on tissue residue methods. Therefore the between-laboratory variability and the susceptibility to outliers of the method used to enforce residue tolerances are unknown. Based upon within-laboratory studies, however, it appears that all of the diazotization-based methods are being operated close to their limit of reliable determination, a poor analytical practice.
Current methodological approaches utilize gas chromatography, high pressure liquid chromatography, and even gas chromatography-mass spectrometry with an isotopically labeled internal standard. None of these proposed methods have yet reached the stage of collaborative studies for either feeds or tissues.
In this discussion of analytical methods for sulfonamides, an introductory section covering the regulatory aspects and chemical properties of sulfonamides is followed by three main sections: first, general problems, including sampling and sample preparation, extraction, protein precipitation, cleanup, emulsions, color reactions, confirmation of identity, interferences, and sulfonamide metabolites; second, collaboratively studied methods of analysis, including methods for feeds, concentrates and premixes, and tissues, and statistical parameters; and last, other available analytical methods, including methods in the Food Additives Analytical Manual, validation studies for New Animal Drug Applications, the Tishler method, methods for sulfonamides as contaminants in feeds, methods involving chromatography, polarography, and automation, and prospective methods.
Improved Method for Confirmation of Identity of Aflatoxins B1 and M1 in Dairy Products and Animal Tissue Extracts
Authors: Egmond Hans P Van , Stubblefield Robert D 
Published: February 2020

Abstract
A method is described for confirming the identity of aflatoxins B1 and M1 in dairy products and liver extracts on a thin layer plate. Extracts and standards containing aflatoxins B1 and M1 are spotted on 10 × 10 cm plates, which are developed 2-dimensionally in mixtures of isopropanol-acetone-chloroform. After the first development, trifluoroacetic acidhexane (1 + 4) is sprayed on that part of the plate containing the separated extract components and the undeveloped standard spots of B1 and M1, and the plate is heated 6-8 min at 75°C. Then the plate is developed in a second direction, and the reaction products of B1 and M1 with trifluoroacetic acid from the extract are compared with the same derivatives of the respective standards. The method has been used successfully on extracts of milk, cheese, and liver containing 0.1 ng B1 or M1/g and can be completed in 35-45 min.