bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interlaboratory Evaluation of the AOAC Method and the A-l Procedure for Recovery of Fecal Coliforms from Foods
Authors: Andrews Wallace H , Wilson Clyde R , Poelma Paul L , Bullock Linda K , Mcclure Foster D , Gentile Dorothy E 
Published: February 2020

Abstract
An interlaboratory evaluation was made of the 96 h AOAC method and the 24 h A-l procedure for the enumeration of fecal coliforms in samples of yellow corn meal, rye flour, mung beans, raw ground beef, and raw oyster homogenate. Results indicated that the efficiency of the A-l procedure, measured in terms of recovery of fecal coliforms, and the reproducibility of that recovery were dependent on the particular food being analyzed. Accordingly, until its efficiency can be more fully demonstrated, the A-l procedure is recommended only as a screening procedure for fecal coliforms in foods.
Temperature-Programmed Gas Chromatographic Determination of Polychlorinated and Polybrominated Biphenyls in Serum
Authors: Needham Larry L , Burse Virlyn W , Price Harold A 
Published: February 2020

Abstract
An analytical method was developed to quantitate polychlorinated and polybrominated biphenyls (PCBs and PBBs, respectively) in human serum. The method includes denaturation of the proteins in serum, extraction, adsorption chromatography, and gas chromatography with electron capture detection. The coefficients of variation for determining the in vivo bound PCBs and PBBs ranged from 11.7 to 29.8% and 7.1 to 14.0%, respectively. The method is capable of measuring 10 ng PCBs and PBBs/mL in 4 mL serum.
Liquid Scintillation Counting of 14C for Differentiation of Synthetic Ethanol from Ethanol of Fermentation
Authors: Martin Glenn E , Noakes John E , Alfonso Felipe C , Figert Donald M 
Published: February 2020

Abstract
Samples containing ethanol are fractionated on a column so that the resultant ethanol content is &gt;93%. Determination of 14C by liquid scintillation counting on the ethanol fraction differentiates ethanol produced by fermentation from synthetic ethanol produced from fossil fuel sources. Twenty-seven samples were fractionated and analyzed for the 14C isotope. Six samples were synthetic ethanol derived from ethylene gas (direct and indirect process), and yielded a mean value for 14C isotope of 0.167 dpm/g carbon with a standard deviation (SD) of 0.066 dpm/g carbon (disintegrations per minute per gram of carbon). The remaining samples were ethanol derived from the fermentation of natural materials, such as corn, pear, sugar cane, grape, cherry, and blackberry, and yielded a mean value for 14C isotope of 16.11 dpm/g carbon with an SD of 1.27. The 14C values for specific mixtures of a synthetic and a natural ethanol compare favorably with the analytical values obtained by this procedure.
Colorimetric Method for Determination of Ethanol in Presence of Methanol
Authors: Sane Ramesh T , Kamat Sudhir S , Pandit Amulya D 
Published: February 2020

Abstract
A method is described for the determination of ethanol in the presence of methanol without pre-separation. The sample is oxidized to give acetaldehyde and formaldehyde. 2-Thiobarbituric acid reagent is added and selectively forms a pink adduct with acetaldehyde, but not with formaldehyde. The method is sensitive, obeys Beer’s law in the concentration range 18–80 μg/mL, and has an advantage over other methods because it does not detect any “apparent normal value” of alcohol in blood.
Simultaneous Electron Capture Detection of Chlorpyrifos and Its Major Metabolite, 3,5,6-Trichloro-2-Pyridinol, after Gel Permeation Chromatography
Authors: Guinivan Richard A , Thompson Neal P , Bardalaye Promode C 
Published: February 2020

Abstract
Preparative gel permeation chromatography of ethyl acetate extracts of Southern Pea vines precedes the simultaneous quantitation by electron capture gas chromatography of chlorpyrifos [0,0-diethyl O- (3,5,6-trichloro-2-pyridyl)-phosphorothioate] and its major metabolite 3,5,6-trichloro-2-pyridinol, which is analyzed as its iV,0-bis(trimethylsilyl)acetamide derivative. The dark green extract of a pea vine sample (spiked with both the pesticide and its metabolite) is concentrated and chromatographed on a Bio-Beads S-X3 column. Fractions are monitored for cleanup effectiveness by measuring the absorbance at 490 nm and also by gas chromatographic analysis for chlorpyrifos and 3,5,6-trichloro-2-pyridinol recovery. Results showed that the pesticide and its metabolite are separated from the bulk of optically absorbent compounds. Recoveries from 25 g spiked pea vine samples, cleaned up on the Bio-Beads column, are 100% at levels of 0.2 ppm (5 μg) and above, and 62% at levels ranging from 0.01 (0.25 μg) to 0.2 ppm. This analytical procedure provides a fast, sensitive method for simultaneous quantitation of these compounds which were previously determined by 2 separate procedures.
Extraction of Aquatic Herbicide Fluridone from Water and Determination by High Pressure Liquid Chromatography
Authors: West Sheldon D , Day Edgar W 
Published: February 2020

Abstract
Fluridone is extracted from water onto a Sep-Pak C18 cartridge, and then eluted with a small volume of methanol. Fluridone is concentrated and then is measured by reverse phase high pressure liquid chromatography with UV detection at 254 nm. The method is sensitive to approximately 0.001 ppm and has resulted in recoveries averaging 103.1 ± 19.4,94.8 ± 5.9, and 93.5 ± 8.5% for control water fortified with 0.001, 0.010, and 0.100 ppm (μg/mL) fluridone, respectively.
High Performance Liquid Chromatographic Determination of Cyanuric Acid in Human Urine and Pool Water
Authors: Briggle Thomas V , Allen Larry M , Duncan Robert C , Pfaffenberger Carl D 
Published: February 2020

Abstract
A reverse phase high performance liquid chromatographic (HPLC) assay for the quantitative determination of cyanuric acid (CA) in urine and water is described. For purification, samples are passed through a pre-activated reverse phase C18 column. The effluent is dried by lyophilization, and the residue is reconstituted in hexane-washed water and then passed through a prewashed Dowex-1 column. The effluent is again dried by lyophilization, and the dry residue is extracted with hot dioxane. The solution is cooled to ambient temperature and centrifuged. The supernatant liquid is removed, dried under a nitrogen steam, and dissolved in water for final extraction by reverse phase chromatography. This effluent is dried, dissolved in the sodium phosphate monohydrate in methanol (pH 7.0) mobile phase, and injected into a pre-equilibrated chromatographic system. An external standard is used for quantification by peak height comparison. A sample of HPLC column effluent is collected, dried, dissolved in methanol, and used for mass spectrometric confirmation by a solid probe insert procedure. Average combined recovery determined at 1.0, 5.0 and 10.0 μg CA/mL is 103 ± 3% with an average coefficient of variation of 8.6%. Standard deviations for the 3 concentration levels are 0.04, 0.58, and 0.76, respectively, with average precisions of 4.28, 10.92, and 7.61%. The limits of detection are approximately 0.05 μg/mL for urine and 0.1 μg/mL for swimming pool water. Recorder response to CA is linear over the concentration range 1-10 μg/mL.
Gas Chromatographic/Mass Spectrometric Study of Isoequilin A
Authors: Roman Robin , Yates Claire H , Millar John F , Vandenheuvel William J A 
Published: February 2020

Abstract
Isoequilin A, which is produced by the acid-induced isomerization of equilin, has been resolved into 3 major components by gas chromatography. Tentative identification of the 3 compounds was made by using combined gas chromatography/mass spectroscopy. One of these compounds, identified as 8-dehydroestrone, closely resembled a component previously identified in pregnant mares’ urine.
Atomic Absorption Spectrometric Determination of Tin in Canned Foods Using Nitric Acid-Hydrochloric Acid Digestion and Nitrous Oxide-Acetylene Flame
Authors: Dabeka Robert W , Mckenzie Arthur D 
Published: February 2020

Abstract
Foods (5-40 g) are digested sequentially with HNO3 and HC1, diluted to 100 mL, and filtered, and tin is determined by atomic absorption using an N2O-C2H2 flame. Synthetic standards in 10% HC1 are used. A positive interference by potassium is compensated by adding 100 µg potassium/mL to both standards and samples. Recoveries for 17 foods spiked with tin at levels between 40 and 500 µg/g ranged from 85 to 110% with a mean of 101%. Results agreed well with a solvent extraction atomic absorption method and a direct X-ray fluorescence method.
Simple Paper and Micro Thin Layer Chromatographic Method for Separation and Detection of Mercuric Chloride, Copper Sulfate, Cadmium Sulfate, and Silver Nitrate in Fresh Water
Authors: Devi Yalavarthy Prameela , Kumar Nanguneri V Nanda 
Published: February 2020

Abstract
Simple concentration techniques are described for delecting heavy metals in water. Copper sulfate and cadmium sulfate are precipitated with alkaline' phosphate buffer (pH 8.2); mercuric chloride and silver nitrate are concentrated through evaporation. Compounds redissolved in citric acid are suitable for paper and micro thin layer chromatographic-enzymatic separation by a 0.1% NaCl solvent system. The heavy metal compounds can be detected by horse liver acetone powder succinate dehydrogenase inhibition, using 2-(4-iodophenyl-3-(4-nitrophenyl)-5-phenyltetrazolium chloride (INT)-sodium succinate-N-methyl phenazonium methosulfate mixture as the chromogenic reagent. Microgram amounts of Cu, Ag, Hg, and Cd can be separated and identified by using this method.
Microwave Oven Drying in the Gravimetric Phosphorus Method
Authors: Melton James R , Hoover William L 
Published: February 2020

Abstract
The gravimetric quinolinium molybdophosphate method for determining P2O5 in fertilizers, AOAC 2.026–2.028, has been modified to permit the precipitate to be dried in a microwave oven rather than a conventional drying oven. After the yellow quinolinium molybdophosphate precipitate is formed, cleaned up, and washed, it is placed in a microwave oven at 600 watts until dry. The quantity of precipitate remaining after microwave drying was equal to that obtained by drying according to AOAC 2.028 for several fertilizer samples. A distinct advantage of the described method is that the yellow precipitate will not char with reasonably excessive drying. Also, much less energy is expended with the microwave oven than with the drying oven.
Data Handler/Controller System with Application to P2O5 and K2O in Fertilizers
Authors: Kane Peter F , Bennett Brian R , Gulik Stefan 
Published: February 2020

Abstract
An automated data handler/controller system performs 2 main functions: As a data handler, it finds peak maxima, does standard curve fitting, performs peak height correction for drift, gain, and carryover, and does limited calculation of results with a printed record. It may also control modules of an analyzer system to allow both manual operation and completely automatic, unattended startup, operation, and shutdown. Such a system has 2 main advantages, and one disadvantage. The automatic control features extend the useful operational hours, and the data handling features make possible a level of sophistication above manual treatment of the data, with no computer expertise required. To achieve these ends, however, the flexibility that comes with control over software modification has been sacrificed. The ability to correct peak heights for drift, gain, and, particularly, carryover, allows a wider range of standards and/or faster sampling rates. In the phosphorus method, it was possible to eliminate much labor-intensive aliquoting of extracted samples by using a broader range of standards. Alternatively, if desired, the sampling rate could be increased from 40 to 60 per hour. With computer-corrected peak heights, either alternative is still more precise than the usual method without correction. For the potassium method, the maximum concentration is limited by the detector of the flame photometer and therefore the standard range cannot be significantly expanded. However, dramatic increases in sampling rate are possible with peak height correction. Data indicate that sampling rates can be increased from the usual 40–50 per hour up to 90 or possibly 120 per hour, with equivalent precision.
Systematic Identification of Antioxidants in Lards, Shortenings, and Vegetable Oils by Thin Layer Chromatography
Authors: Peteghem Carlos H Van , Dekeyser Diana A 
Published: February 2020

Abstract
A simple and reliable method is described for rapid identification of ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene, ethoxyquin, gallates (lauryl, octyl, propyl), nordihydroguaiaretic acid, 3,3’-thiodipropionic acid, tocopherol, t-butylhydroquinone, and 2,4,5-trihydroxybutyrophenone in lards, shortenings, and vegetable oils. The antioxidants are extracted with 95% methanol, concentrated under vacuum at ≤45°C, and analyzed by thin layer chromatography. Three elution solvents, 2 adsorbent types, 2 visualization sprays, and UV viewing at 254 and 366 nm are used. Sunflower and corn oil samples, fortified with 100 ppm antioxidant, were analyzed to establish the validity of the method.
High Pressure Liquid Chromatographic Determination and Fluorescence Detection of Aflatoxins in Corn and Dairy Feeds
Authors: Cohen Huguette , Lapointe Michel 
Published: February 2020

Abstract
A high pressure liquid chromatographic (HPLC) method is described for the determination of aflatoxins B1, B2, G1, and G2 in animal feeds at levels as low as 2.5 ppb. Samples are extracted with acetonitrile-water and initially purified by using a Sep-Pak silica cartridge. The aflatoxins are then reacted with trifluoroacetic acid and acetonitrile-water (1 + 1). After filtration, the aflatoxins are completely resolved on a 10 μm C18 column using a radial compression separation system with an acetonitrile-water solvent system. Aflatoxins G2a, B2a, G2, and B2 were reported in less than 30 min, using fluorescence detection. The method was successfully applied to samples at levels of 20-2.5 ppb added aflatoxins with recoveries in the range of 82-99%.
Citrus Artifact Interference in Aflatoxin M1 Determination in Milk
Authors: Price Ralph L , Jorgensen Karen V , Billotte Michael 
Published: February 2020

Abstract
Dried citrus waste was fed to dairy cows, their milk was extracted, and aflatoxin M1 was quantitated by using both high pressure liquid chromatography (HPLC) and thin layer chromatography (TLC). Results indicate that a compound from the citrus waste, which is excreted into the milk, interferes with the HPLC determination of aflatoxin M1 in milk and causes a false positive test. This interference can be overcome by using TLC with proper selection of developing solvents.
Multicomponent Analysis of Meat Products
Authors: Bjarnø Ole-Christian 
Published: February 2020

Abstract
A new method for rapid multicomponent analysis of meat products is reported. The sample is homogenized, and then dispersed by treatment with an alkaline aqueous solution combined with mechanical subdivision. Constituents are determined by infrared transmission spectrophotometry in the fundamental IR absorption bands. It is possible to measure protein, fat, and carbohydrate in about 5 min with an accuracy and precision comparable to that of well established standard methods, and no expensive or dangerous chemicals are used.
Ion Pairing High Pressure Liquid Chromatographic Determination of Amaranth in Licorice Products
Authors: Hurst William J , Mckim James M , Martin Robert A 
Published: February 2020

Abstract
A high pressure liquid chromatographic method is described for the determination of amaranth (FD&C Red No. 2; Red No. 2) in licorice products. The Red No. 2 is extracted with a basic buffer solution, cleaned up on a Sep-Pak column, chromatographed on a reverse phase column in the ion pairing mode, and detected at 254 nm. The procedure is time-conservative with accurate and precise results. Recovery data ranged from 93 to 104%, and coefficients of variation were less than 4% for standards and samples.
Polarographic Analytical Study of Oxyphenbutazone
Authors: Ellaithy Moustafa M , El-Tarras M Fayez , Amer Sawsan M 
Published: February 2020

Abstract
The polarographic behavior of the widely used anti-inflammatory agent, oxyphenbutazone, was studied. It is determined polarographically by conversion to the nitroso derivative characterized by a cathodic, irreversible, diffusion-controlled wave. The method is applied to the determination of 2.5-10 mg/100 mL of oxyphenbutazone, with an accuracy of 99.9 ± 1.38%. By differential pulse polarographic analysis, as little as 10 ppm oxyphenbutazone can be determined with an accuracy of 99.70 ± 0.99% in pure powder and in some pharmaceutical formulations.
Colorimetric Determination of Certain Phenol Derivatives in Pharmaceutical Preparations
Authors: Hassan Sayed M , Walash Mohammed I , El-Sayed Sanaa M , Abou Ouf Abdel Malek 
Published: February 2020

Abstract
Simple colorimetric methods are reported for determining both acetaminophen and oxyphenbutazone. These methods are based on coupling between the phenolic compound and the diazonium salts of both sulfanilic acid and p-nitroaniline; the optimum conditions for the reactions were carefully studied. For acetaminophen, the reaction products with diazosulfanilic acid and diazo-p-nitroaniline show maximum absorbance at 480 and 425 nm, respectively. The mean percentage recoveries for authentic samples were 99.5 ± 1.1 and 100.6 ± 0.66, respectively (P = 0.05). For oxyphenbutazone, the obtained colors showed maxima at 385 nm with diazosulfanilic acid and 490 nm with diazo-p-nitroaniline reactions. The mean percentage recoveries for authentic samples were 99.8 ± 0.27 and 100.1 ± 0.57, respectively (P = 0.05). The proposed methods were successfully applied to the analysis of commercial preparations; results were statistically compared with those of other methods.
Determination and Confirmation of N-Nitrosodimethylamine in Beer
Authors: Andrzejewski Denis , Havery Donald C , Fazio Thomas 
Published: February 2020

Abstract
A qualitative method has been developed for the confirmation of N-nitrosodimethylamine (NDMA) in beer by capillary gas chromatography-mass spectrometry (GC/MS) from full mass scans after quantitation, using a gas chromatograph interfaced to a thermal energy analyzer (GC/TEA). The GC/MS method has a lower limit of confirmation of 5 ppb. In a survey of 22 imported and 42 domestic beers, NDMA was found in 60 samples by GC/TEA at levels up to 7.7 ppb, and was confirmed by GC/MS in 5 samples.
Gravimetric Determination of Ethoxylated Mono- and Diglycerides in Bread
Authors: Lawrence James F , Iyengar Jagannath R , Conacher Harry B S 
Published: February 2020

Abstract
A gravimetric method is described for the quantitative determination of ethoxylated mono- and diglycerides (EMGs) in bread at levels as low 0.42% (dry sample). The air-dried pulverized samples are Soxhlet-extracted 22 h with an azeotropic mixture of n-propanol-water. The contents are evaporated to dryness, and then treated with 5% HCl in methanol to trans-esterify the fatty acids present which are then removed by petroleum ether extraction. The EMGs are subsequently precipitated from aqueous solution with phosphomolybdic acid in the presence of barium ions. The precipitate is weighed and compared with known amounts of standard carried through the same procedure.
Fast Cleanup of Difficult Substrates for Determination of Fenitrothion and Some Derivatives
Authors: Haché Patrick , Marquette René , Volpé Gilles , Mallet Victorin N 
Published: February 2020

Abstract
A simple method is described for the fast recovery of fenitrothion, an organophosphorus insecticide, from soil, chicken liver, urine, clams, and pine needles. The substrate is homogenized with acetonitrile or methanol, diluted with water, and passed through a column containing Amberlite XAD-7. Fenitrothion is recovered quantitatively by eluting with 4 portions of 25 mL ethyl acetate. After evaporation, the compound is determined quantitatively by gas-liquid chromatography with a flame photometric detector. The procedure is also suitable for some derivatives of fenitrothion, namely, fenitrooxon and S-methylfenitrothion. As low as 0.05 ppm of the parent compound may be determined.
Sulfur Oxidation in Fertilizers using Nitric-Perchloric Acid
Authors: Melton James R , Hoover William L , Koska Janice , Anderson Wendy H 
Published: February 2020

Abstract
AOAC 2.160-2.161 is inadequate for determining total sulfur in fertilizers. The bromine-nitric acid combination does not oxidize all reduced forms of sulfur to sulfate; consequently, some findings are biased low. A perchloric-nitric acid mixture was used as the oxidizing mixture, and recovery of sulfur from 3 standards was complete. Also, quantitative results on fertilizer samples compared favorably with a potassium permanganate-nitric acid procedure that has been successfully used in the authors’ laboratory for about 16 years. The described method is recommended for determining all forms of sulfur found in fertilizers except elemental sulfur. A procedure is described for determining elemental sulfur.
Titrimetric Method With Ion Selective Electrode for Determination of Acetylenic Hypnotics
Authors: Rizk Mohamed S , Walash Mohamed I , El-Brashy Amina 
Published: February 2020

Abstract
An ion selective electrode has been used for indirect titrimetric assay of ethchlorvynol, ethinamate, and meparfynol carbamate. These acetylenic hypnotics form silver acetylide in the presence of excess silver. Excess silver is determined potentiometrically with standardized iodide solution and an iodide selective electrode. With this technique, 0.10-20 mg drug was determined with 95.7 ± 1.3-110.8 ± 5.9% accuracy. The procedure has been successfully applied to different pharmaceutical dosage forms.
Rapid Dry Column Method for Determination of N-Nitrosopyrrolidine in Fried Bacon
Authors: Pensabene John W , Miller Arthur J , Greenfield Earl L , Fiddler Walter 
Published: February 2020

Abstract
A rapid method has been developed for the determination of N-nitrosopyrrolidine (NPYR) in fried bacon at less than the 1 ppb level. Ground fried bacon is mixed with anhydrous sodium sulfate and Celite by using a glass mortar and pestle. This dry mixture is then added to a chromatographic column containing a layer of acid-Celite. The column is washed with pentane-dichloromethane, and the nitrosamines are eluted with pure dichloromethane. The eluate is concentrated, and the nitrosamines are quantitated by using a gas chromatograph interfaced with a thermal energy analyzer. Recovery of the nitrosamine internal standard, N-nitrosoazetidine, added at the 10 ppb level, was over 90%. The results obtained by this method are in good agreement with the mineral oil distillation procedure currently used in the FSIS monitoring program. Because 25 samples can be analyzed per day per person, this simple screening procedure offers advantages over other methods.