bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collaborative Study of the Rat Hemoglobin Repletion Test for Bioavailability of Iron
Authors: Fritz James C , Pla Gwendolyn W , Harrison Bertha N , Clark Geneva A 
Published: February 2020

Abstract
A collaborative study of the hemoglobin repletion test was conducted with male weanling rats. The rats were depleted for 4 weeks on a low-iron casein based diet. They were then divided into 13 comparable groups of at least 8 animals each. One group continued on the basal diet. Three groups were given different levels of each of 4 samples. Sample 1 was FeS04.7H20, used as the reference standard. Samples 2 and 3 were from the same lot of electrolytically reduced iron separated into fractions of different particle size by nitrogen elutriation, and were 7—10 and 27—40 /tm, respectively. Sample 4 was a mixture of several lots of food grade ferric orthophosphate. After 2 weeks on the test diets, individual blood samples were drawn for hemoglobin determinations. The data were analyzed by the parallel lines technique, and relative biological values, vs. FeS04 = 100, together with 95% confidence limits were calculated. The relative biological values were as follows: reduced iron, 7—10 /mi = 63.5 ± 10.9; reduced iron, 27— 40 /im = 3 7 . 9 ± 1 2 . 2 ; ferric orthophosphate = 44.5±4.8. This revised method for measuring bioavailability of iron has been adopted as official first action to replace the original method, 39.A15-39.A17.
Manual Microbiological Turbidimetric Analysis of Chlortetracycline in Feeds
Authors: Ragheb Hussein S , Cummings Anne M 
Published: February 2020

Abstract
The turbidimetric log-probability plots of chlortetracycline HCl (CTC-HCl) showed the same dosage-response slope for Staphylococcus aureus, Streptococcus faecalis, and Bacillus cereus. The slope was different for Klebsiella pneumoniae and Salmonella gallinarum. In Penassay broth at pH 7.0, S. aureus appeared to be the most suitable organism for turbidimetric assay of CTC-HCl in feeds. The useful range was between 0.04-0.14 μg CTC-HCl. Two commercial unmedicated feeds (A and B) were each fortified at finished feed levels by addition of premixes containing CTC-HCl alone or in combination with penicillin and sulfamethazine. CTC-HCl recovery from feed A was 97.5— 107.2% turbidimetrically and 99.5-123.2% by the AOAC method, 38.179-38.182. Comparable results for feed B were 87.1-93.3% (turbidimetric) and 99.4-108.3% (AOAC). For both feeds, the overall coefficient of variation was higher (9.5-23.9%) for the manual turbidimetric assay than for the plate assay (5.5— 6.0%). Comparison of the 2 methods for analysis of premix samples showed essentially the same CTC-HCl recovery and comparable precision. The main advantage of the manual turbidimetric method over the plate assay is that results can be obtained within the same day of analysis.
Hexachlorophene in Cosmetics by Partition Chromatography and Ultraviolet Spectrophotometry
Authors: Wilson Clifton H 
Published: February 2020

Abstract
Five samples at 3 levels of hexachlorophene concentration were analyzed by 6 collaborators. Results show recoveries of 79—103% for samples containing from 1 to 10 mg hexachlorophene. The standard deviation varied from 0.039 to 0.33 and the coefficient of variance ranged from 1.55 to 9.77%. The method has been adopted as official first action.
Collaborative Study of a Chromatographic Method for Determination of Patulin in Apple Juice
Authors: Scott Peter M 
Published: February 2020

Abstract
Collaborators in 20 laboratories studied a method for the determination of patulin in apple juice. The collaborators mixed patulin solutions with the apple juice to obtain 9 spiked samples (of which 2 were blanks) and 1 practice sample. After column chromatography of the apple juice extract, patulin was estimated visually by thin layer chromatography, using 3-methyl-2-benzothiazolinone hydrazone.HCl as the spray reagent. Mean recoveries of patulin ranged from 69.8 to 98.3% for 3 contamination levels. The method has been adopted as official first action for the determination of patulin in apple juice.
Spectrophotometric Assay of Karathane Technical and Karathane Formulations
Authors: Black Ronald F , Kurtz C P , Baum Harry 
Published: February 2020

Abstract
A spectrophotometry procedure for the determination of total dinitrooctylphenols and dinitrooctylphenyl crotonates in Karathane Technical (dinocap) and Karathane formulations has been collaboratively studied. The sample is dissolved in petroleum ether; the total mono- and dinitrooctylphenols are then selectively extracted with aqueous sodium hydroxide solution and examined photometrically at 410 nm. The dinitrooctylphenyl crotonates are hydrolyzed in aqueous pyridine solution and measured photometrically at 442 nm. Five collaborators analyzed Karathane Technical, Karathane LC, and Karathane WD in duplicate on each of 2 days. Statistical analysis indicates that between- laboratory precision, s, of the dinitrooctylphenyl crotonate determination, excluding outliers, was 2.05, 0.71, and 0.79% absolute at the 76, 38, and 18% assay levels, respectively. The precision of the dinitrooctylphenol determination on the same sample series was s = 0.071% at the 2.3% concentration level, 0.18% at the 1.88% level, and 0.457% at the 2.20% level, respectively. It is recommended that another collaborative study be conducted with an increased number of collaborators, incorporating changes in the procedure suggested by the collaborators.
Collaborative Study of the Extraction of Light Filth from Canned Whole Shrimp
Authors: Dent Russell G 
Published: February 2020

Abstract
The method developed utilizes a washing technique for shrimp larger than 1", followed by an acid digestion with mineral oil as the flotation liquid. In the case of the smaller shrimp, the washing step is eliminated. A Corning percolator is used for trapping; the percolator is drained in 2—3 stages. Average recoveries from 6 collaborators were 73.6% for rodent hairs (20 added) and 91.9% for fly setae (20 added). The proposed method has been adopted as official first action.
Detection of Synthetic Vanillin in Vanilla Extracts by Isotopic Analysis
Authors: Bricout Jacques , Fontes Jean-Charles , Merlivat Liliane 
Published: February 2020

Abstract
The isotopic composition of vanillin was investigated in order to distinguish synthetic wood lignin vanillin and natural vanilla-extracted vanillin. Natural vanillin is enriched in deuterium and carbon-13 as compared to synthetic vanillin. This enrichment probably results from differences in the synthetic pathways of this compound. In particular, carbon isotope fractionation is associated with photosynthesis; this fractionation lowers the 13C/12C ratio by about 20 0/00, relative to atmospheric carbon dioxide, for the Calvin cycle in photosynthetic carbon dioxide fixation, which occurs in trees. The fractionation factor is even lower, about 13 0/00, for the orchid Vanilla planifolia Andrews in which the Crassulacean acid metabolic pathway probably operates.
Structure of Alkaline Hydrolysis Products of Neostigmine Methylsulfate and Neostigmine Bromide
Authors: Kling Rita E 
Published: February 2020

Abstract
The nuclear magnetic resonance spectra of the alkaline hydrolysis products of neostigmine bromide and neostigmine methylsulfate confirm that the products are m-hydroxyphenyltrimethylammonium salts and not 3-dimethylaminophenol as mentioned in early literature. Ultraviolet, infrared, and elemental analysis data are also presented in the quaternary structure confirmation of the alkaline hydrolysis product of neostigmine bromide.
Determination of Propoxyphene Hydrochloride, Aspirin, Phenacetin, and Caffeine in Combination
Authors: Cunningham Catherine G , Barkan Susan 
Published: February 2020

Abstract
The title compounds are isolated by partition chromatography, using a new procedure combining the classical assay for aspirin-phenacetincaflfeine with the previously reported method for propoxyphene, in which the active principle is eluted as the sulfamate ion pair. All 4 components are determined spectrophotometrically. Results are given for standard and commercial preparations.
Determination of Steroid Phosphates in Formulations of Creams, Ointments, and Solutions by Blue Tetrazolium Reduction
Authors: Van Dame Halver C 
Published: February 2020

Abstract
A collaborative study has been completed on a method for the determination of steroid phosphates in creams, ointments, and solutions. The steroid is almost completely separated from interfering materials such as oils, fats, and waxes found in pharmaceuticals by using a hydrolysis step in which the steroid phosphate is hydrolyzed to the alcohol by an alkaline phosphatase enzyme. After the interfering materials are removed, the steroid is quantitatively measured by the blue tetrazolium reaction. Results from 10 collaborators for 3 samples each of dexamethasone phosphate cream, dexamethasone ophthalmic ointment, and dexamethasone phosphate solution for injection were 100.0, 98.1, and 101.2% recovery, respectively; the corresponding coefficients of variation were 3.31, 3.08, and 2.57. The method has been adopted as official first action.
Determination of Prednisolone Sodium Phosphate by Ion-Pair Extraction
Authors: Kaplan Gilbert B , Levine Joseph 
Published: February 2020

Abstract
Prednisolone sodium phosphate cannot be extracted as such from aqueous solutions because of its polar characteristics. It can be extracted as its ion pair, using a relatively high molecular weight aliphatic amine as counter ion. Liquid formulations of prednisolone sodium phosphate are rapidly assayed by incorporating the sample as immobile phase in a partition chromatographic column. Prewash with suitable organic solvents removes extractable adjuvants; the phosphate ester is eluted with a solution of trihexylamine hydrochloride in methylene chloride. The ester is extracted from the eluate with sodium hydroxide solution, and measured by ultraviolet spectrophotometry.
Collaborative Study of an Ion Exchange Method for the Chromatographic Separation of Mixtures Containing Expectorants, Sympathomimetic Amines, Antihistamines, or Phenothiazine in Pharmaceuticals
Authors: Smith Donald J 
Published: February 2020

Abstract
An ion exchange chromatographic method has been applied to the determination of 9 drugs in various dosage forms, alone or in combination: chlorpheniramine maleate, codeine phosphate, dextromethorphan. HBr, glyceryl guaiacolate, phenylephrine. HCI, phenylpropanolamine . HCI, potassium guaiacolsulfonate, promethazine. HO, and pyrilamine maleate. Nitrogenous bases are separated from the excipients by retention on a sulfonated polystyrene resin column. These basic compounds are eluted from the column with the appropriate concentration of HCI and are determined by ultraviolet (UV) absorption. The organic acids are retained on the quaternary ammonium anion resin. The acidic compounds are eluted from the columns with the appropriate concentration of HQ and determined by UV absorption. Average recoveries and standard deviations for the 9 drug ingredients in 3 simulated combinations ranged from a low of 93.2±4.03% (phenylpropanolamine . HCI) to a high of 98.8±4.8% (codeine phosphate), for 6 unknown samples per collaborator. Comparable values were reported for 2 commercial sirups collaboratively studied. The method has been adopted as official first action for the following compounds: (a) promethazine . HCI, phenylephrine. HCI or phenylpropanolamine. HCI (except in tablets or powders), and potassium guaiacolsulfonate; (b) promethazine. HCI codeine phosphate, and potassium guaiacolsulfonate; (c) phenylephrine. HCI or phenylpropanolamine. HQ (except in tablets or powders), dextromethorphan.HBr (except in sirups), potassium guaiacolsulfonate, and pyrilamine maleate; and (d) phenylephrine. HCI or phenylpropanolamine. HCI (except in tablets or powders), dextromethorphan. HBr (except in sirups), glyceryl guaiacolate, and pyrilamine maleate.
Colorimetric Determination of Ethinyl Estradiol in Oral Contraceptive Formulations
Authors: Wu John Y P 
Published: February 2020

Abstract
Ethinyl estradiol in oral contraceptive formulations is separated from the sample on a chromatographic column prior to color formation with methanol-sulfuric acid reagent directly in the chloroform-isooctane eluate. Collaborative results on 3 commercial tablet samples averaged 93.93, 98.69, and 98.50% of label claim. The standard deviations and coefficients of variation were 2.61, 2.39, and 2.82, and 2.77, 2.43, and 2.86%, respectively. The method has been adopted as official first action.
Sodium Contamination by Filter Paper
Authors: Ali Mohammad W , Kalra Yash P 
Published: February 2020

Abstract
During the analysis of small samples of peats, the concentration of sodium in the blank solutions was observed to be high in relation to that found in the sample solutions. Sodium contamination by filter paper was suspected and confirmed. For accurate measurement of low sodium concentrations in peat samples, the filter paper should be washed with dilute hydrochloric acid before the acid solution of the ash is filtered.
Collaborative Study of Two Analytical Methods for the Analysis of Formothion Formulations
Authors: Sauer Horst H , Bosshardt Hans P 
Published: February 2020

Abstract
The 2 methods collaboratively studied were a gas-liquid chromatographic (GLC) method, using either a flame photometric or a flame ionization detector, a column packed with 3% OV-225 on 80-100 mesh Chromosorb W (HP), and an internal standard; and a paper chromatographic (PC/C) method in which the chromatographed spot is combusted and the formothion content is determined colorimetrically as phosphorus. Four samples of formothion, 50% technical solution, 25 and 33% emulsifiable concentrates, and 70% ultralow volume formulation, were studied. Collaborative results for the GLC method (5 collaborators for 3 samples and 7 collaborators for 1 sample) were satisfactory, with standard deviations ranging from 0.57 to 1.42. PC/C values (3 collaborators) were higher but still satisfactory, with standard deviations ranging from 1.50 to 5.22. Both methods have been adopted as full CIPAC methods, with the GLC method as the reference method. The GLC method has been adopted as official first action by the AOAC.
Automated Method for Determining Direct Available P2O5 in Fertilizers
Authors: Wall Larry L , Gehrke Charles W 
Published: February 2020

Abstract
In the automated method for the analysis of direct available and total P205 in fertilizers, a heating bath is used to destroy ammonium citrate and colored material and for hydrolysis of non-orthophosphates. The heating bath was maintained at 98°C and contained a 40' time delay coil, providing 15 min digestion. Improvements on the method for the automated digestion of citrate extracts of fertilizer included decreasing the reagent and sample flow rates by factors of 2 to 5. All of the citrate in those samples containing the highest levels of citrate was not destroyed; however, the slight effect of the remaining citrate could be eliminated by changing the concentration of the molybdovanadate reagent. No difficulty was encountered with the hydrolysis of non-orthophosphates. With this analytical system, steady state conditions were reached at a sampling rate of 40 samples/hr and with a 4 : 1 sample-to-wash ratio. Repeated analyses were made on 9 samples, and the accuracy and precision of results obtained by the automated method compared very well with data by the official AOAC gravimetric method.
Further Survey of Cured Meat Products for Volatile N-Nitrosamines
Authors: Panalaks Thavil , Iyengar Jagannath R , Donaldson Barbara A , Miles Walter F , Sen Nrisinha P 
Published: February 2020

Abstract
Eighty samples of various kinds of cured meat products were analyzed for volatile nitrosamines. Nitrosopyrrolidine (NPy) was determined by using thin layer chromatography and simple dialkylnitrosamines were measured by using a gas-liquid chromatographic (GLC) method with a Coulson electrolytic conductivity detector (pyrolytic mode). Seventeen samples contained 13–105 ppb NPy; 29 samples contained 2–35 ppb dimethylnitrosamine (DMN) ; 9 samples contained 2-25 ppb diethylnitrosamine (DEN). In a few cases the identities of NPy, DMN, and DEN were confirmed by GLC-mass spectrometry.
Comparison of Two Analytical Methods for Penicillin Residues in Milk
Authors: Katz Stanley E , Fassbender Carol A , Hackett Arthur J , Mitchell Ralph G 
Published: February 2020

Abstract
Two microbiological assay procedures for penicillin residues were compared for the analysis of milk from a lactating cow treated experimentally for mastitis. There was very little difference between procedures when penicillin levels were above 1 unit/ml; below 1 unit/ml the centrifuge procedure gave consistently higher concentrations than those found by using an FDA-suggested procedure in which the milk was assayed directly without centrifugation. The ratio of results between the centrifuge and FDA-suggested procedures ranged from 1.10 to 1.67 for levels below 1 unit /ml. When the centrifuge procedure was used, residues were found 12–36 hr longer than could be detected with the FDA-suggested methodology.
Collaborative Study of Methods for the Determination and Chemical Confirmation of Aflatoxin M1 in Dairy Products
Authors: Stubblefield Robert D , Shannon Gail M 
Published: February 2020

Abstract
An international collaborative study involving 19 collaborators was conducted to test methods for the determination and chemical confirmation of aflatoxin M1 in dairy products. For the quantitative method, collaborators assayed samples of liquid and powdered milk, cheese, and butter containing low levels of M1. Statistical results indicated that sensitivity and precision of this method were comparable to other AOAC methods for aflatoxin M1. Impurities were present in blue cheese extracts that tended to interfere with thin layer chromatography. Analysis of liquid milk samples from different areas revealed that some milk extracts may require column chromatography. For the chemical confirmatory method, collaborators prepared acetate and hemiacetal derivatives of M1 in extracts of liquid milk and colby cheese. A sensitivity limit of 30 ng M1 was apparent for the method, and most collaborators easily identified the derivatives. As a result of this collaboration, both methods have been adopted as official first action methods.
Analysis of Penicillic Acid by Gas-Liquid Chromatography
Authors: Thorpe Charles W , Johnson Robert L 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method is described for the analysis of the mycotoxin penicillic acid in corn, dried beans, and apple juice. The samples are extracted with ethyl acetate and the penicillic acid is isolated by liquidliquid extraction, followed by elution from a 3 g silica gel column with hexane-ethyl acetate. Penicillic acid is determined by GLC of the trifluoroacetate derivative, using a 6' column containing OV-101 and an electron capture detector. Penicillic acid can be detected at the 4 μg/kg level with recoveries of added penicillic acid greater than 80%. Confirmation may be obtained by gas chromatography-mass spectrometry. Analysis of 20 commercial corn samples originating from several Midwest counties with potential mold problems showed that penicillic acid was present in 7 samples at levels ranging from 5 to 230 μg/kg. Penicillic acid was found in 5 of 20 commercial samples of dried beans at levels of from 11 to 179 μg/kg.
Collaborative Study of AOAC Methods I and III for the Determination of Aflatoxins in Peanut Butter
Authors: Stack Michael E 
Published: February 2020

Abstract
A collaborative study was designed and carried out to test the accuracy and precision, at low levels of contamination, of AOAC methods I, 26.015-26.020, and III, 26.026-26.030, for the determination of anatoxins in peanut butter. Ten test samples and 1 practice sample of each peanut butter were analyzed by each method. Two test samples were naturally contaminated with about 2 μg aflatoxin B1/kg. The 8 spiked samples (duplicate samples for each level) had 0, 2, 4, and 8 μg B1 added/kg and B2 was added at one-fourth the B1 level. The 7 collaborators were instructed to analyze the samples according to methods I and III except for minor modifications necessary to handle the low level of aflatoxins in the sample extracts and to quantitate the aflatoxin content both visually and densitometrically. The results of this study indicate that the analysts were able to determine the aflatoxins in the 2–10 μg/kg range with either method although method I gave better accuracy and precision and had less interferences than method III.
Review of Gas-Liquid Chromatography of Marihuana
Authors: Parker James M , Stembal Brian L 
Published: February 2020

Abstract
Gas-liquid chromatographic (GLC) methods used in the separation, identification, and quantification of Cannabis components are reviewed. Glass columns packed with 3% OV-17 offer better separation of tetrahydrocannabinol isomers and greater sensitivity. GLC identification of new Cannabis constituents, preparation of trimethylsilyl ether derivatives of known cannabinoids, and preparation of pure standards from Cannabis samples are discussed along with problems in cannabinoid quantification. Use of a 6' × ¼" glass column packed with 3% OV-17 on 100–120 mesh Gas-Chrom Q is suggested for GLC separation of Cannabis components.
Fluorometric Determination and Thin Layer Chromatographic Identification of Diethylstilbestrol in Beef Liver
Authors: Ponder Carl 
Published: February 2020

Abstract
Diethylstilbestrol (DES) and its monoglucuronide conjugate (DES-G) are extracted from homogenized beef liver by blending with acetonitrile containing triethylamine sulfate. An alkaline solution saturated with sodium chloride extracts DES and DES-G from the acetonitrile. The alkaline extract is acidified with sulfuric acid, triethylamine is added, and DES and DESG are extracted with 1-heptanol. DES is cleaved from DES-G by refluxing the 1-heptanol extract after adding ammonium chloride and monobasic ammonium phosphate. Solvent partitioning is used to isolate the DES, which is irradiated in a buffer solution with ultraviolet light to form the phenanthrenedione derivative. The dione is converted to the phenanthrenediol derivative in an acidified bisulfite solution. The diol derivative is isolated by solvent partitioning and determined fluorometrically in methanol. Thin layer chromatography is used for confirmation of DES. Recovery on 5 samples spiked with DES-G equivalent to 1, 2, and 4 ppb DES ranged from 82.5 to 104%.
Thin Layer Chromatographic Determination of Subsidiary Dyes in D&C Red No. 19 and D&C Red No. 37
Authors: Bell Sandra 
Published: February 2020

Abstract
A thin layer chromatographic method is presented by which triethylrhodamine and other lower ethylated subsidiary colors are separated from D&C Red No. 19 and D&C Red No. 37. After removal from the plate, subsidiary dyes are extracted from silica gel C adsorbent and quantitated spectrophotometrically. Recoveries of 1, 2, and 5% of added triethylrhodamine ranged from 89 to 1 0 3% for D&C Red No. 19 and from 85 to 1 0 2% for D&C Red No. 37.
Atomic Absorption Determination of Lead in Apples
Authors: Markus John R 
Published: February 2020

Abstract
Two studies have been conducted on the analysis of apples for lead by atomic absorption spectrophotometry using the official first action method, 25.B01–25.B05. Sixteen laboratories participated in each study. Recoveries ranged from 92.6 to 110% (101.6% average) in the first study. A second study, in which procedural modifications were made, showed recoveries ranging from 91.2 to 109.7%, with an average of 100.0%. Coefficients of variation for the first and second studies were 5.19 and 4.94%, respectively. On the basis of the second study, procedural modifications have been incorporated into the 12th Edition of Official Methods of Analysis.