bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Biphenyl in Citrus Fruits by Thin Layer Chromatography and Ultraviolet Spectrophotometry
Authors: Corneliussen Paul E 
Published: February 2020

Abstract
A rapid method for determining biphenyl in citrus fruits has been developed and was studied collaboratively. Biphenyl is separated from fruit tissue by steam liquidliquid extraction. The ra-heptane extract is subjected to preparative thin layer chromatography (TLC) on plates coated with silica gel containing phosphors for ready visibility of the biphenyl spots under UV light. The spots are removed from the plate and extracted with alcohol for spectrophotometric measurement at 248 mμ. The TLC cleanup adds specificity to the method; o-phenylphenol, if present, does not interfere and crop blanks are insignificant. The average of 36 recoveries (12 each at abovit 100, 50, and 10 ppm) was 96.7% with a mean deviation of 10.7%. It is recommended that the method be adopted as official, first action.
Determination of Starch and Soluble Carbohydrates. I. Development of Method for Grains, Stock Feeds, Cereal Foods, Fruits, and Vegetables
Authors: Friedemann Theodore E , Witt Norman F , Neighbors Bonnie W 
Published: February 2020

Abstract
Starch is determined in samples containing not &gt; 400 rag available carbohydrate by the following procedure: The fat is extracted with isopropanol, the solution is diluted to 70% alcohol concentration, NaCl and Celite are added, and the soluble sugars are extracted. Starch is hydrolyzed with Rhozyme-S, the solution is clarified with Zn(OH)2 , and the reducing sugar content is determined by reduction of potassium ferricyanide. Maltose and other soluble saccharides are present in the 70% isopropanol extract. The solubility of enzymatically hydrolyzable oligosaccharides, minus maltose, of three commercial soluble starches and three commercial dextrins in 0 - 7 0% isopropanol-1 % NaCl was determined. In 70% isopropanol, the respective solubilities of the hydrolyzable oligosaccharides were as follows: starches—0.4, 3.4, and 0.5%; dextrins—4.9, 3.3, and 6.1%. In 40% isopropanol, the respective solubilities were 12.7, 9.8, and 62.3% of the starches and 92.3, 88.2, and 89.4% of the dextrins. Although the soluble starches and dextrins were water-soluble, they contained up to 9.5% (6.5% average) oligosaccharides that were not hydrolyzable by enzyme but were hydrolyzable by l.OA' HCl. Use of 40% isopropanol is recommended for extraction of oligosaccharides of low DP (dextrins, maltose, etc.) and determination of the insoluble oligosaccharides of relatively high DP. Retrogradation of starch and its prevention during the analysis is discussed. Starch and soluble sugars were determined in 21 samples of grains and breakfast cereals and in 12 samples of roughages.
Analysis of Limestone
Authors: Rexroad Paul R 
Published: February 2020

Abstract
Results from six limestone samples show that 15—20% more of the sample passes through a No. 40 sieve by wet sieving than by dry sieving when the agglomerates are not broken up for dry sieving. Excessive clay found in the additional material represents 1—3% of the sample. It is recommended that study be continued on method 1.002 with emphasis on breaking up the agglomerates or that a wet sieving method be adopted as official, first action.
Direct Fluorescent Detection of Organothiophosphorus Pesticides and Some of Their Sulfur-containing Breakdown Products After Thin Layer Chromatography
Authors: Ragab Mohamed Tawfik H 
Published: February 2020

Abstract
A rapid, simple, convenient, and widely applicable method for the direct fluorescent detection of organothiophosphorus pesticides and some postulated breakdown products of these compounds is presented. The coinpounds were spotted on thin layer chromatographic sheets, developed in ethyl acetate :nhexane, and made visible by exposure to bromine vapor followed by spraying with ferric chloride and 2-(o-hydroxy phenyl) benzoxazole. Of the 47 compounds tested, 32 compounds produced fluorescent blue spots vinder longwave ultraviolet light; these consisted of 25 organothiophosphorus pesticides, 5 sulfur-containing breakdown products, and phosphoric and hypophosphorous acids. A superimposed Congo red spray destroyed the fluorescence and resulted in dark blue spots against a red backgrovind. The sensitivity of this method is in the range of 0.2 to 5.0 μg, depending on the specific compound.
Determination of Bitterness of Olives
Authors: Cohen S , Lifshitz A , Samish Z 
Published: February 2020

Abstract
An objective analytical method for the estimation of bitterness of fresh and fermented olives has been developed. Results of the bitterness estimation by the proposed method were in good agreement with organoleptic tests performed concomitantly. The method is based on the extraction with acetone of a bitter constituent from the olive, adsorption of possible interfering materials on gelatin and alumina, and spectrophotometric determination of the resulting bitter solution.
Temperature-Programmed Gas Chromatography of 20 Phosphorus-Containing Insecticides on 4 Different Columns and Its Application to the Analysis of Milk and Corn Silage
Authors: Bowman M C , Beroza Morton 
Published: February 2020

Abstract
Relative retention times and conditions for the gas chromatography of 20 phosphorus- containing insecticides on 4 column packings, DC-200, QF-1, DC-710, and stabilized DEGS, have been determined. With temperature programming, it is possible to analyze compounds of widely differing volatilities in a single run with good sensitivity and a large saving in time. Compounds were detected with the flame photometric detector of Brody and Chaney in both the phosphorus- and sulfur-sensing modes and were identified in milk and corn silage at levels as low as 0.01 ppm. Recoveries of the insecticides from corn silage exceeded 90% and more often were better than 95%; those from milk were at least 80% and usually were above 90%. The gas chromatography in a single multicomponent analysis required from 12 to 28 minutes. The procedure shows promise for identification or multicomponent analysis of phosphorus- and sulfur-containing pesticides as well as for the monitoring of foodstuffs and forage for these pesticides
Gravimetric Procedure for the Quantitation and Identification of Polysorbate 80 in Pickle Products
Authors: Barcklow Patricia 
Published: February 2020

Abstract
A qualitative and quantitative gravimetric procedure for Polysorbate 80 in pickle products involves acid hydrolysis of the comminuted sample, saponification, extraction of the glycol portion of the molecule with chloroform, and removal of interfering fatty acids with petroleum ether. The glycol is finally precipitated with silicotungstic acid, determined gravimetrically, and identified by infrared spectroscopy. Recoveries from commercially prepared pickle relish and dill pickles containing 0.01 to 0.02% Polysorbate 80 ranged from 80 to 98.5%
Rapid Ammonium Citrate Extraction Method for
Determination of Available Phosphorus
Authors: Guerrant Gordon O , Hunter J D , Mcbride C H 
Published: February 2020

Abstract
Available phosphorus has been determined in fertilizers by a quick extraction method useful for screening or quality control purposes. Samples were extracted in a Gooch crucible with a jet of 65 °C neutral ammonium citrate in 10—20 mill. A single direct determination of available phosphorus was made by the alkalimetric quimociac method, modified for speed and for use in high citrate concentrations. The results compare favorably in accviracy to the gravimetric quimociac results reported on 20 Magruder check fertilizer samples
Excretion of Cyclamate in the Rat
Authors: Sonders Robert C , Wiegand R G , Netwal J C 
Published: February 2020

Abstract
The utility of the gas chromatographic procedure for cyclamate has been confirmed. 14C-cyclamate was traced through the procedure to determine distribution at each step. The recovery of dietary cyclamate in excreta of the rat was found to be complete, in contrast to an earlier report Complete recovery was obtained by gas chromatographic analysis of fed cyclamate as well as by isotope recovery of a trace dose of i ^C-cyclamate. Sifting of cyclamate to the bottom of the food containers could account for the low excretion data previously reported
Assay of Rauwolfia serpentina
Authors: Kunze Frieda M , Barkan Susan , Banes Daniel 
Published: February 2020

Abstract
The lengthy NF XII assay for Rauwolfia serpentina products can be considerably shortened by faster extraction procedures. In the proposed method, Rauwolfia root is homogenized for 10 min with alcoholsulfuric acid, and the evaporation of solvents in the chromogenic step has been eliminated. This modification requires only 3 hr and results are in good agreement with the official method. A collaborative study is planned.
Mass Spectral Identification of Some Hallucinogenic Drugs
Authors: Bellman Sander W 
Published: February 2020

Abstract
A general method is given for the mass spectral identification of some hallucinogenic drugs. The fragmentation patterns observed in the spectra are discussed. Three groups of hallucinogens have been studied: lysergic acid amides, methoxy substituted phenylalkylamines, and tryptamine derivatives. Similarities in the fragmentation patterns of the members of each group are observed. The fragmentation patterns described can be used to identify hallucinogenic drugs even in the presence of low molecular-weight impurities.
Determination of Isoproterenol in Deteriorated Inhalations
and Injections
Authors: Welsh Llewellyn H , Sammul Oscar R 
Published: February 2020

Abstract
Isoproterenol forms an ether-soluble ion pair with di-(2-ethylhexyI) phosphoric acid, while the sulfonic acid produced by the reaction with bisulfite antioxidant in aqueous dosage forms does not. This fact and the use of partition chromatography form the basis of a convenient method for determining isoproterenol in inhalation and injection preparations. Of 22 such commercial solutions, ranging in age from 4 to 28 months, analyzed by this method, 14 showed isoproterenol losses of 10 to 62%. Standard recovery experiments indicate the method should be useful in the quantitative determination of a number of drugs structurally related to isoproterenol
Selection of Partition Chromatographic Systems from
Distribution Diagrams: Determination of Dextromethorphan in Cough Sirups
Authors: Doyle Thomas D , Levine Joseph 
Published: February 2020

Abstract
Ionization and extraction constants for dextromethorphan and 14 other alkoids are given. By constructing the logarithmic distribution diagrams for mixtures of these compounds, Celite partition chromatographic systems can easily be selected for their separation; both free base and ionpair extraction provide useful systems. A general procedure for the isolation of dextromethorphan from any of those alkoids with which it is currently formulated is presented; the results of analyses of standard samples and of commercial sirups are given. Some other separations do not appear to be feasible. However, the distribution diagrams clearly show the reasons for this fact
Automated Spectrophotometric Method for Nitrogen in
Fertilizers
Authors: Gehrke Charles W , Kaiser Floyd E , Ussary James P 
Published: February 2020

Abstract
An automated spectrophotometric method utilizing the Technicon Autoanalyzer has been developed to determine nitrogen in fertilizer digestates in the range from 5 to 15 ppm nitrogen at a rate of 40 analyses per hour. NH4 is determined by reacting it with phenol and hypochlorite in an alkaline medium to form a blue compound closely related to indole phenol. Optimum reagent concentrations for the colored reaction were determined, and several ions were investigated to determine if they interfere with the reaction. Comparison of results obtained by the automated method and the comprehensive nitrogen method in primary standard grade NH4SO4 and KN03, Magruder check samples, and several commercial fertilizers show that the automated method is accurate and precise. The automated method results in considerable saving of analytical time, especially in laboratories analyzing large numbers of samples
Variation of Florisil Activity: Simple Method for
Measuring Adsorbent Capacity and Its Use in Standardizing Florisil Columns
Authors: Mills Paul A 
Published: February 2020

Abstract
Sodium sulfate content was found to be the principal cause of variation of adsorbancy between batches of Florisil. A rapid method was developed for determining the adsorptive capacity of Florisil based on the absorption of lauric acid from hexane solution. An excess of lauric acid is used and the amount not adsorbed is measured by alkali titration. Lauric acid adsorbed (mg/g Florisil) is used to calculate, by simple proportion, equivalent quantities of Florisil from batches having different adsorptive capacities.
Distribution of Radioactivity in Milk Resulting from
Oral Administration of 14C—Labeled Carbarl
Authors: Baron R L , Palmer Nancy J , Ross R , Doherty J , Jacobson W C 
Published: February 2020

Abstract
Carbonyl-1 'C-labeled carbaryl administered orally to a lactating cow at a dose of 3.05 mg/kg resulted in the appearance of radiolabeled materials in milk. About 1% of the administered dose of 14C was recovered in the whole milk with a maximum concentration of 2.6 ppm carbaryl equivalents found in 9 hr. Radiometric assay of the milk fat showed a maximum level of 4.1 ppm carbaryl equivalents. Analysis of the skim milk by thin layer chromatographic assay failed to show the presence of carbaryl
Estimation of Chlorinated Pesticide Residues in Animal and
Vegetable Oils
Authors: Singh J , Lanthier J D 
Published: February 2020

Abstract
A procedure for the determination of chlorinated pesticide residues in cottonseed oil, hydrogenated marine oil, seal oil, butter oil, and processed beef tallow is described. The oil is spread in the form of a thin film over a large surface area provided by Celite 545. The pesticides are extracted from the oil-coated Celite with 80% aqueous acetonitrile, partitioned into Skellysolve F, and cleaned up on a basic alumina (activity III) column. Gas chromatography with an electron capture detector is used for qualitative and quantitative estimations. The average recovery of six commonly used chlorinated pesticides (aldrin, dieldrin, heptachlor, heptachlor epoxide, lindane, and p,p'-DDT) at levels of 0.1 and 0.25 ppm ranged from 82 to 106%.
Structure of Klein's Metabolites of Aldrin and of Dieldrin
Authors: Damico Joseph N , Chen Jo-Yun T , Costello Catherine E , Haenni Edward O 
Published: February 2020

Abstract
Certain predominant unknown metabolites of aldrin and of dieldrin, previously reported in the urine of rats on diets containing these pesticides, have been characterized by mass, infrared, and Raman spectrometric examination. By interpretation of all the evidence adduced, the structure of the isomeric metabolites of aldrin and dieldrin. respectively, could be postulated. The metabolites appear to be almost identical, the minor spectrometric differences being attributed to possible alternative exo- or endo-orientations of an epoxide ring.
Automatic Recording of the Molecular Sieve Effects of Sephadex, Using Liquid Chromatograph with the Thermal Detector
Authors: Nagasawa Kakuma 
Published: February 2020

Abstract
Ethylene glycol and its oligomers can be separated by chromatography on Sephadex, using a thermionic detector. The fractionation is then recorded automatically. The separation with the thermal detector is reproducible and has a sensitivity of 0.01 to O.lilf ethylene glycol.
Mass Spectra of Some Carbamates and Related Ureas. II
Authors: Benson W R , Damico J N 
Published: February 2020

Abstract
Mass spectral data for fourteen carbamates, live dithiocarbamates, one thiocarbamate, and eight phenylureas are given with some interpretations. Among the compounds examined were some sulfur-containing aliphatic oxime carbamates; these lost the sulfur moieties more easily than the methyl isocyanate moiety. In the aryl IV-methylcarbamate series, the CH3NCO moiety appears to be lost most easily, as it is in pyrolysis. When l-(2-chlorophenyI)-3- methylurea is fragmented, unexpectedly the [HNC0]+ ion is found in high relative abundance. However, the remaining ureas undergo fragmentation in a manner similar to their related carbamates. Although the two ethylene bisdithiocarbamates give essentially identical fragmentation patterns, the spectra of the other four thio- and dithiocarbamates show sufficient differences so that they may be distinguished from one another.
Rapid Method for the Extraction of Light Filth from Paprika
Authors: Thrasher Joel J , Brickey Paris M 
Published: February 2020

Abstract
A rapid extraction method has been developed for the separation of light filth from paprika; in the method, paprika is defatted with a surfactant, wet sieved, and floated with n-heptane from 60 % alcohol and Tween 80-Versene mixture. Collaborative results by the method gave 8.7 and 16.1% increased recovery of insect fragments and rodent hairs, respectively. The method is recommended for adoption as official, first action.
Fluorodensitometric Measurement of Aflatoxin Thin Layer Chromatograms
Authors: Beckwith A C , Stoloff Leonard 
Published: February 2020

Abstract
The precision limit of visual comparison procedures used in aflatoxin assay methods can be no better than ± 2 0 % for a single observation and, under operating conditions, it is probably close to ± 2 8 % . Fluorodensitometric procedures described in the literature can improve this precision to ± 9% for the average of multiple observations. A possible source of inaccuracy in the published densitometric procedures is pointed out and a method using internal standards to avoid the inaccuracy is presented. Tested with spiked extracts of "clean" peanut butter, the procedure gave an average 101 ± 3% recovery of added aflatoxin B1 and 89 ± 6% recovery of aflatoxin B2 with a precision for individual assays equal to the precisions reported for the other procedures. The major source of error was shown by elimination to reside in the thin layer chromatography and aflatoxin instability.
Improved Method for Determination of Extractable Color in Capsicum Spices
Authors: Rosebrook D D , Bolze C C , barney J E 
Published: February 2020

Abstract
The variables that affect the determination of extractable color in paprika and other capsicums by the official ASTA method were examined in a preliminary study. As a result, an improved method was devised and tested in a statistical program involving four types of paprika, four extraction times, two sample weights, and two filtration techniques. The improved method permits analysis in 4 hours.
Estimation of Residues of Uracil Herbicides by Gas Chromatography After Evaporative Co-distillation
Authors: Gutenmann W H , Lisk D J 
Published: February 2020

Abstract
A gas chromatographic method has been developed for estimation of residues of uracil herbicides. The method involves sample extraction by blending with ethyl acetate, isolation of the herbicides by evaporative co-distillation, and electron affinity detection following chromatography on a Ucon Polar column. The procedure has been used to recover 0.04—0.4 ppm of bromacil added to soil and 0.5—1.0 ppm of terbacil added to alfalfa.
Isolation and Concentration of Traces of Lead with Strontium Sulfate
Authors: Flann Bruce C , Bartlet John C 
Published: February 2020

Abstract
Lead in trace quantities is co-precipitated as the sulfate with milligram quantities of strontium carrier, using dilute sulfuric acid. The precipitate is separated from the excess sulfate by centrifuging and is then converted to the carbonate by agitation with ammonium carbonate solution. The carbonate precipitate is separated, dissolved in a slight excess of hydrochloric acid, and then freed of carbon dioxide. The solution, buffered to a pH of 8.8, is immediately extracted with a solution of dithizone in chloroform, and the lead is determined spectrophotometrically. Recoveries are approximately 100% and moderate quantities of the following ions do not interfere: Cd; Co (II) ; Cu (II) ; Fe (II); Fe (II); Mn (II); Hg (II) ; Ni (II) ; Ag (I) ; and Zn. Cyanide buffer is not required, all the chemistry is done in the same centrifuge tube, and many samples can be analyzed simultaneously, using readily available equipment
Identification of Commercially Used Fish Found in the Pacific by Disk Electrophoresis
Authors: Chu Rod 
Published: February 2020

Abstract
Identification of fish by disk electrophoresis was studied. Five fish of the sole family yielded electrophoretograms sufficiently dissimilar to identify them properly. The members of the rock family, with the exception of two of the eight species investigated, could not be distinguished on the basis of their electrophoretograms. However, a fish could be characterized as being either a rock or a sole. Two other species had characteristic profiles. These results indicate that the disk electrophoresis method can be utilized with limited success for the identification of these fish.
Colorimetric Determination of Nitrates and Nitrites in Feeds
Authors: Schall E D , Hatcher D W 
Published: February 2020

Abstract
A method for determining nitrates and nitrites in feeds was developed and studied collaboratively. The partially clarified sample solution was passed over a cadmium column to reduce the nitrate to nitrite; nitrite was then determined colorimetrically. The method was applicable to microgram levels. Collaborative results were good, and the method is recommended for adoption as official, first action.
Uric Acid as an Index of Insect Infestation in Flour
Authors: Sen N P 
Published: February 2020

Abstract
The sensitivity of the enzymatic-ultraviolet method for determining uric acid in flour has been improved by modifying the method of extraction. Uric acid is extracted from flour with methanol containing LiOH, and after evaporation of methanol, viric acid in the extract is measured enzymically. Uric acid can now be detected at a level of 50—60 μg/100 g of flour. This method has been used to determine the amount of uric acid and the rate of its excretion by larvae, pupae, and adults of the insect Tribolium castaneum Herbst. Although the rate of excretion of uric acid/mg body weight for the larvae was higher than that of adults, the larvae were found to contain less uric acid than the adults and the pupae in their whole-body homogenates. Preliminary results indicate good correlation between the insect fragment counts and uric acid levels in flours manufactured from naturally infested wheat.
Determination of Cesium-137 and Related Sampling Problems of Dairy Cattle Feeds, 1962-1967
Authors: Ward G M , Johnson J E , Whelan D L 
Published: February 2020

Abstract
Samples of feeds fed to dairy cattle on the university farm were analyzed from 1962 to 1967 for fallout 137Cs by means of gamma-ray spectrometry. Maximum levels were observed in first-cutting alfalfa hay in 1963 (3600 pc/kg).Second and third cuttings each year were lower by factors of two to six. Levels declined each year after 1963 to barely detectable levels in mid-1967. Pasture forage or green-cut alfalfa contained concentrations of 137Cs similar to hay with the same seasonal and yearly patterns. Corn silage contained levels similar to later cuttings of hay. Grain mixes contained levels which were lower than forages by a factor of 10 in 1962-1963 but approached equal levels in subsequent years. The results indicated that sampling was much more important than radiation counting in explaining variation between sampling. The levels of 137Cs found in the feeds was readily explained in terms of observed patterns of fallout during this period.