bluuebunny/crossref_metadata_2025_split huggingface dataset:
Volatile Compositional Differences Between Cultivars of Black Pepper (Piper nigrum)
Authors: Russell Gerald F , Else Joanne 
Published: February 2020

Abstract
Computer-generated chromatographic profiles are used to determine whether statistically valid chromatographic differences could be established between Lampong and Sarawak cultivars of Piper nigrum. The solvent is separated on a column of uncoated glass beads; the effluent is then passed through a capillary column coated with SF-96(50). Computer programs were written, and stored data were used to plot simulated chromatograms in a 3-dimensional, topological display where differences were readily discernible.
Gas Chromatographic Determination of Diethylstilbestrol Residues in Animal Tissues
Authors: Coffin David E , Pilon Jean-Claude 
Published: February 2020

Abstract
A procedure is described for the determination of diethylstilbestrol residues in various tissues of beef, chicken, and lamb. This involves acetone extraction of the tissue, HCl hydrolysis, liquid-liquid partition between CHCl3 and aqueous acidic and alkaline solutions, formation of diethylstilbestrol trifluoroacetates, elution of the trifluoroacetates from a Chromosorb W column, and electron capture gas chromatographic detection and measurement of the diethylstilbestrol trifluoroacetates. Recoveries of diethylstilbestrol obtained from a variety of animal tissue samples spiked at 2–10 ppb levels were 70–110%.
Atomic Absorption Spectrophotometric Determination of Aluminum in Pharmaceuticals
Authors: Karkhanis Pramod P , Anfinsen Jon R 
Published: February 2020

Abstract
A simple, sensitive, and rapid atomic absorption spectrophotometric method for aluminum in pharmaceutical preparations is described. No interference from other ingredients has been experienced in utilizing this technique. The reproducibility of the method has been reported for a lotion containing lipid base. The results of the determination of aluminum in 3 different commercial products are presented. This method, because of its simplicity and sensitivity, provides a distinct advantage over methods previously reported in the literature.
Chromatographic-UV Spectrophotometric Determination of Menadione in Tablets
Authors: Bathalter William H , Levine Joseph 
Published: February 2020

Abstract
A chromatographic-UV spectrophotometric method for the determination of menadione in tablets, utilizing the conversion of menadione to menadione sodium bisulfite, has been developed. The sample is treated with sodium bisulfite and the resultant menadione sodium bisulfite is analyzed by the method of Johnson. A column prewash with CHCl3 removes impurities or degradation products present in the original menadione sample. The menadione is then eluted with an ammonia-saturated CHCl3 solution. The method worked equally well on coated and uncoated tablets and it has the advantage of determining only the amount of menadione and not degradation products present in the sample.
Comparison of Automatic and Manual Turbidimetric Analyses of Tylosin in Feeds with the Plate Method
Authors: Ragheb Hussein S , Breunig H Latham , Scroggs Robert E 
Published: February 2020

Abstract
Two laboratories participated in a comparison of a manual turbidimetric assay with the AUTOTURB® System and the AOAC method of analysis of tylosin in 4 feed samples. Results showed no significant difference between the 2 turbidimetric assays. When the AOAC method was considered, the difference between laboratories was significant. On an overall basis the turbidimetric methods were significantly higher than the plate method. The relative standard deviation was higher (6.72%) for the plate assay versus turbidimetric assay (4.5%). The mean recovery in both laboratories was significantly less than the labeled amount of tylosin by all 3 methods.
Determination of Ammoniacal Nitrogen in the Presence of Urea with an Ammonia Electrode
Authors: Woodis T C , Cummings James M 
Published: February 2020

Abstract
A recently introduced commercial electrode is shown to be suitable for the determination of ammoniacal nitrogen in the presence of urea. The results compare favorably with those of the reduced pressure distillation method. Standard deviations for the electrode method and the reduced pressure distillation method for ammoniacal nitrogen in urea ammonium phosphate are 0.12 and 0.09%, respectively.
Dry Ashing Technique for the Determination of Arsenic in Marine Fish
Authors: Leblanc Patrick J , Jackson Adrian L 
Published: February 2020

Abstract
A dry ashing procedure, followed by the silver diethyldithiocarbamate colorimetric determination of arsenic in marine fish, is presented. The sample is first homogenized and a portion is pre-ashed with magnesium nitrate, using infrared heat, followed by ashing in a 500°C muffle furnace. The residue is dissolved in HCl and the arsenic is reduced by means of zinc and HCl to arsine, which is complexed with AgDDC and determined colorimetrically at 535 nm. At temperatures of 460°C and above, efficient ashing was obtained. The effect of various volumes of ashing aid (50% magnesium nitrate) was also studied. Maximum recovery and precision were obtained when a minimum of 8 ml 50% magnesium nitrate was used. Standard recoveries of inorganic arsenic added to NBS orchard leaves and a sample of dry marine fish tissue gave values of 91–98%. Analyses of a number of standard NBS orchard leaves and marine fish As-1 and As-2 gave coefficients of variation of 7.0, 6.0, and 8.1%, respectively. Results from dry ashing and wet digestion of a number of species of marine fish were not comparable. Levels of arsenic found in different species of marine fish ranged from &lt;0.4 to 27.0 μg As/g wet weight. Crabs were found to contain elevated amounts of arsenic.
Collaborative Study of the Foss Milko-Tester Method for Measuring Fat in Milk
Authors: Shipe W Frank , Senyk G F 
Published: February 2020

Abstract
In a third collaborative study, the Milkotester was compared with the Babcock method in 9 laboratories. In addition, 3 laboratories analyzed the samples by an ether extraction method. The standard deviations for these methods were +0.018, +0.032, and +0.044%, respectively. These deviations are based on triplicate determinations on 5 samples by each of the laboratories. The average values for all samples were 3.99, 3.96, and 3.88% for the Milko-tester, Babcock, and ether extraction methods, respectively. The standard deviation of differences between the Milko-tester and Babcock for all 9 laboratories was +0.077%.
Infrared Analysis of Carbaryl Insecticide: Modification of the Extraction Procedure to Accommodate Liquid Suspension Formulations
Authors: McDermott William H 
Published: February 2020

Abstract
The extraction procedure for the official first action infrared analysis for carbaryl in formulations, 6.206–6.208, has been modified by the addition of anhydrous granular sodium sulfate to make the method applicable to liquid suspension formulations of carbaryl. A limited collaborative study of the modified method yielded a standard deviation of ±1% at the 40% level and a coefficient of variation of ±2%. The modification has been adopted as official first action.
Preparation of 14C-Labeled Aflatoxin B1
Authors: Schoenhard Grant L , Sinnhuber Russell O , Lee Donald J 
Published: February 2020

Abstract
A successful method to obtain 14C-labeled aflatoxin B1 from Aspergillus parasiticus ATCC 15517 was developed. The nitrogen-free resting culture contained mycelia from a 72 hr primary culture, 0.02M glucose, 0.005M (1 mCi/mmole) acetate-1-14C, salts, and trace metals. It was incubated 12 hr at 30°C. Aflatoxin B1-14C was isolated from chloroform extracts of the resting culture by column chromatography on silica gel H eluted under pressure with a continuous gradient of chloroform to chloroform-methanol (98+2). The ultraviolet spectrum of the 14C-labeled aflatoxin was examined. The ratios of the absorbances at 220/265 and 362/265 nm compared to established values and a reference standard were used as criteria of chemical purity. Label integrity was verified by chromatography, hydrogenation to the tetrahydrodeoxoaflatoxin B1, and conversion to the hemiacetal and the epimeric acetates. After purification, 1.37 mg 14C-labeled aflatoxin B1 of specific activity 744 μCi/mmole was obtained from 2 mCi acetate-1-14C of specific activity 1 mCi/mmole.
Semiautomated Colorimetric Determination of Methenamine and Methenamine Mandelate in Tablets
Authors: Dow Matthew L 
Published: February 2020

Abstract
A semiautomated chromotropic acid colorimetric procedure was collaboratively studied by 6 laboratories, both as a composite assay and as an individual tablet assay method. Results agreed well with the USP and NF methods. The coefficients of variation ranged from 0.54 to 2.48%. The method has been adopted as official first action for the analysis of coated and uncoated tablets of methenamine mandelate, methenamine, and methenamine with sodium biphosphate.
Separation of dl-2-(3-Phenoxyphenyl) propionic Acid (Fenoprofen) From Its Intermediates by Thin Layer Chromatography
Authors: Bishara Rafik H 
Published: February 2020

Abstract
Fenoprofen and its synthetic intermediates are resolved on silica gel F254 TLC plates developed with chloroform-acetic acid (98+2). The interrelationship between the chemical constitution and the Rf values is discussed. The lower limit of detecting the intermediates in Fenoprofen raw material is 1%.
Minicomputer—Automatic Analysis System for Pharmaceuticals
Authors: Alber Larry L , Overton Mack W , Smith Donald E 
Published: February 2020

Abstract
Software has been developed for reduction of automatic analyzer data both for on-line and off-line modes, using a PDP-12 minicomputer with 8K core memory, magnetic tape and disk storage, a multiplexer and 16 channel 10-bit analog-to-digital converter, and a cathode ray tube. The on-line system performs data-logging onto magnetic tape of 16 instruments asynchronously, displaying any 2 analog-to-digital conversion channels on the cathode ray tube in real-time. Spectrophotometers are interfaced to the computer, using economically constructed operational amplifier circuits. Data reduction is aided by a hardware floating-point processor, using an 8-point least-squares fitting algorithm to digitally smooth the data array and determine each peak maximum. Computer results of 3 different systems operating simultaneously are compared to values obtained manually. The off-line system was written using FOCAL-12 conversational language and will accept digital values by Teletype, peak detector paper punch, or TWX; the latter makes the program available to other laboratories through the Federal Telecommunications TWX System.
Determination of Propoxyphene and Aspirin in Combinations
Authors: Cunningham Catherine G , Barkan Susan 
Published: February 2020

Abstract
Propoxyphene is assayed by a partition chromatographic method in which it is eluted as the ion pair with CHCl3 from a sulfamic acid-Celite column and determined spectrophotometrically. Napsylate anion present in some formulations is retained on a NaHCO3-Celite trap column.
Collaborative Study of a Spectrophotometric Method for the Determination of Dienestrol in Pharmaceuticals
Authors: Graham Joseph H 
Published: February 2020

Abstract
A highly specific, sensitive, and rapid method for the determination of dienestrol was studied by 13 collaborators. Dienestrol is separated from excipient matter, degradation products, and other drugs present by column partition chromatography, converted to a substituted indene by acid-induced isomerization, and determined by ultraviolet spectrophotometry. Standard deviations obtained for the 4 samples used in the study, containing approximately 0.1 and 0.5 mg dienestrol, ranged from 1.81 to 3.04. The most critical step in the method is the use of suitable ether. This method has been adopted as official first action.
Collaborative Study of the Method for the Analysis of Trisulfapyrimidine Preparations by Thin Layer Chromatography
Authors: Brunner Charlotte A 
Published: February 2020

Abstract
The TLC method for trisulfapyrimidine preparations reported earlier has been collaboratively studied. Fifteen collaborators reported results for total trisulfapyrimidine as well as individual results for sulfadiazine, sulfamerazine, and sulfamethazine for 3 samples (commercial composite, commercial suspension, and simulated tablet mix). The coefficients of variance for the total sulfur content of the 3 samples were 1.65, 1.25, and 1.55. For the determination of the individual sulfur components, the coefficients of variance ranged from 0.76 to 1.66. The method has been adopted as official first action.
Uncombined Intermediates in FD&C Red No. 40
Authors: Marmion Daniel M 
Published: February 2020

Abstract
The results of a collaborative study are reported. Nine collaborators from industry and government analyzed 3 samples each. The intermediates were separated from FD&C Red No. 40 and from each other on a cellulose column, using 40 and 20% aqueous ammonium sulfate as eluants, and were quantitated by UV spectrometry. Cresidinesulfonic acid, Schaeffer’s salt, and 6,6′-oxybis(2-naphthalenesulfonic acid) were recovered at an average level of 99.7%. Between-laboratory standard deviations ranged from 0.007 to 0.072% when the intermediates were present at levels of 0.03 to 1.00%. The method has been adopted as official first action.
Oxytetracycline Residues in Milk Following Intramammary Infusion
Authors: Katz Stanley E , Fassbender Carol A , Hackett Arthur J , Mitchell Ralph G 
Published: February 2020

Abstract
An intramammary infusion of Oxytetracycline was used to study the potential of residues occurring in milk from a recommended usage program. Residues from the treated quarters persisted as long as 5.5 days. Residues in milk from the rear quarters disappeared in 3.5–4.5 days; residues in the milk from the front quarters persisted 5.0–5.5 days. In any case, residues persisted longer than an interval consistent with the recommended 4 day withdrawal period. Residues in the milk of the untreated quarters appeared to arise from transfer via the circulatory system and not from septal transfer.
Factors Relating to Completeness of Solvent Extraction of Dieldrin from Milk
Authors: Ang Catharina Y W , Dugan Leroy R 
Published: February 2020

Abstract
Milk containing added dieldrin was separated into 2 lipid fractions by differential solvent extraction. Fraction 1 was extracted with nonpolar hydrocarbon solvents and Fraction 2 with the same solvent system after mixing with sodium oxalate and ethanol. Three solvent systems were compared. Dieldrin concentrations in Fraction 1 of all 3 solvent systems were much higher than in Fraction 2 on a fat basis. Less than 50% of the dieldrin was recovered in Fraction 1, probably because of the low recovery of hydrocarbon solvents from fluid milk or factors that depressed the separation of solvents from milk. Factors possibly involved were the adsorption of solvents and pesticide to the hydrophobic groups of membrane proteins and/or serum proteins or the penetration of solvents and pesticide into the fat globules of milk.
Comparative Extraction of Chlorinated Hydrocarbon Insecticides from Soils 20 Years After Treatment
Authors: Nash Ralph G , Harris William G , Ensor Peter D , Woolson Edwin A 
Published: February 2020

Abstract
Three methods, shake, Soxhlet, and column, were compared for efficiency of extraction of certain chlorinated hydrocarbon insecticides from a Congaree sandy loam soil which had been treated 20 years earlier. Column extraction had a tendency to be less efficient than the other 2 methods, but statistically there were no differences in extraction efficiencies among the 3 methods for aldrin, dieldrin, heptachlor, chlordane, isodrin, endrin, toxaphene, or Dilan and their residue products. However, shake extraction was significantly more efficient for the BHC isomers than Soxhlet extraction and the latter was significantly more efficient than column extraction.
Calculation of Turbidimetric Microbiological Vitamin Assay Results, Using an APL/360 Computer Program
Authors: Brolund Gregory V , Haskins Ethelbert W , Hudson George A 
Published: February 2020

Abstract
An APL-360 computer program is described for the calculation of results from microbiological vitamin assays. The results are compared to manual calculations specified in official AOAC methods. This comparison shows the validity of the computer program for these calculations.
Modified Rapid Screening Method for Aflatoxin in Corn
Authors: Shannon Gail M , Stubblefield Robert D , Shotwell Odette L 
Published: February 2020

Abstract
A rapid screening method for detecting aflatoxin in cottonseed products was investigated to determine if it was applicable to corn. Other aflatoxin-extracting solvents and protein-precipitating agents were tried with white and yellow corn. When acetone-water (85+15) and a saturated solution of ammonium sulfate were substituted for acetonitrile-water (80+20) and lead acetate in the cottonseed method, fewer interferences and more compact fluorescent zones were observed on the developed minicolumns. The modified method for corn was applicable to samples containing 10 ppb or more aflatoxin.
Dry Ashing Method for the Determination of Total Arsenic in Animal Tissues: Collaborative Study
Authors: George Glenn M , Frahm Larry J , McDonnell J Patrick 
Published: February 2020

Abstract
The method described for the determination of total arsenic in animal tissue is sensitive to levels of 0.1 ppm. Tissue samples are dry-ashed in the presence of magnesium oxide and magnesium nitrate and the arsenic is determined colorimetrically with silver diethyldithiocarbamate. The arsenic content in the tissue is determined from standard curves prepared for each tissue, thereby correcting for losses during the ashing step. The average recovery for 8 collaborators was 98.8% for poultry tissue and 103.4% for swine tissue with an average overall coefficient of variation of 8.31% for the entire study. This method has been adopted as official first action.
Collaborative Study of Three Screening Methods for Aflatoxin in Corn
Authors: Shotwell Odette L , Stubblefield Robert D 
Published: February 2020

Abstract
The 3 rapid screening methods studied all involved chromatography of partially purified extracts on minicolumns. In one method acetonitrile-water is used to extract aflatoxin from corn and a lead acetate precipitation removes impurities from the extracts. The second method specifies acetone-water as the extracting solvent and ammonium sulfate as the precipitant. The third method is based on acetone-water as the extracting solvent and ferric gel as the precipitant. The most sensitive method was the ferric gel precipitation, which could detect 5 ppb aflatoxin, but it was very time-consuming. The most satisfactory method (timewise) used the ammonium sulfate and had a sensitivity of 10 ppb. This method also led to the best differentiation between levels of aflatoxin. These 2 methods have been adopted as official first action.
New Collaborative Study of a Zincon Ion Exchange Method for the Quantitative Determination of Zinc in Fertilizer
Authors: Pracht Louis E , Jones Clyde E 
Published: February 2020

Abstract
A collaborative study was performed with 8 Magruder samples to evaluate a new zincon colorimetric method, an alternative to 2.137. The previous zincon method was modified, but the basic principle remains: 0.5N HCl retains a stable Zn(II) chloro-complex ion on an anion exchange resin but not interfering cations; 0.005N HCl elutes the Zn(II) ion which is determined colorimetrically in the presence of the indicator, zincon. Overall estimate of precision, Sr = 0.033, is similar to Sr = 0.030 for atomic absorption. Sb values (0.074 at 0.05%, 0.035 at 0.25%, and 0.054 at 1%) compare favorably with atomic absorption Sb values (0.072 at 0.05%, 0.036 at 0.25%, and 0.063 at 1%). F- and t-test results at the 95% confidence level indicate systematic error by both methods but do not discern a difference in the true value each method can measure. Average single sample values agree better with Magruder grand averages than corresponding averages by atomic absorption. While applicable to samples containing 0.05% zinc and higher, the method is quite time consuming when samples are low in zinc and have high iron—zinc ratios. This method has been adopted as official first action.
Collaborative Study of the Determination of Water-Insoluble Nitrogen in Fertilizers
Authors: Katz Stanley E , Fassbender Carol A 
Published: February 2020

Abstract
Three procedures for water-insoluble nitrogen in fertilizers were collaboratively studied; the extraction method; the water-insoluble nitrogen method, 2.064; and the slow-release nitrogen method, 2.072. The extraction method and 2.064 gave comparable results for water-insoluble nitrogen, with similar degrees of repeatability. Method 2.072 yielded values which did not consistently agree with either the extraction method under study or 2.064. In addition, 2.072 yielded results with variances between laboratories that were unexpectedly high. The extraction method has been adopted as official first action. It is recommended that 2.064 remain official first action, and that 2.072 be repealed, first action.
Effects of Solvent Composition on the Partition of Barbiturates
Authors: Doyle Thomas D , Proctor Joseph B 
Published: February 2020

Abstract
The distribution of 5 common barbiturates between water and various mixed organic phases was studied in detail. It was shown that ether gave uniformly higher extraction constants than chloroform; dilution of these solvents with isooctane resulted in rapid, nonlinear decreases in extraction; these variations can be approximately described by an exponential equation. A uniform sequence of extractability was found, in decreasing order: secobarbital, pentobarbital, amobarbital, butabarbital, phenobarbital. Partition was independent of barbiturate concentration but varied with pH as expected by simple ionization considerations; these facts indicate that extraction of monomeric free barbiturate was the only important process. A large temperature effect was found for secobarbital. The results obtained are discussed in relation to the known partition chromatographic behavior of barbiturates.
Collaborative Study of an Atomic Absorption Method for the Determination of Lead and Cadmium Extracted from Glazed Ceramic Surfaces
Authors: Krinitz Benjamin , Franco Vincent 
Published: February 2020

Abstract
A method for the determination of lead extracted from glazed ceramic surfaces was adapted from the German standard procedure and extended to include extractable cadmium. Studies comparing a 0.5 hr exposure to 4% acetic acid at room temperature (22±2°C) with a 24 hr exposure under the same conditions indicated that the longer exposure gave higher, asymptotic values for extracted metal. In the collaborative study, 7 samples of the 24 hr leach solution containing lead, one of these also containing cadmium, were sent to 13 collaborators for analysis by atomic absorption. The results show that the method is precise and accurate. The average relative standard deviation for lead was 5.2%, and for cadmium, 3.9%, with average recoveries of 101% for both metals. The method has been adopted as official first action.