bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Rapid Gas-Liquid Chromatographic Method for the Multidetermination of Antioxidants in Fats, Oils, and Dried Food Products
Authors: Kline David A , Joe Frank L , Fazio Thomas 
Published: February 2020

Abstract
A rapid quantitative method for determining 8 antioxidants in various food products is described. Two procedures are employed. The first involves the use of a glass wool precolumn to separate 3(2)-tert-butyl-4-hydroxyanisole, 3,5-di -tert - butyl - 4 - hydroxytoluene, 4 - hydroxymethyl- 2,6-di-tert-butylphenol, and mono-tertbutylhydroquinone (TBHQ) from nonvolatile residues resulting from direct injection of diluted sample or sample extracts into the gasliquid chromatographic (GLC) column. In the second procedure, the antioxidants TBHQ, 3,3'- thiodipropionic acid, n-propyl gallate, 2,4,5- trihydroxybutyrophenone, and nordihydroguaiaretic acid are isolated from food products by extraction with 70% ethanol. The antioxidant residues are then converted to trimethylsilyl derivatives, and determined by GLC, using a flame ionization detector. Recoveries of all 8 antioxidants from 28 food samples fortified at either 10 or 100 ppm ranged from 70 to 105%.
Improved Microbiological Assay for Penicillin Residues in Tissues and Stability of Residues Under Cooking Procedures
Authors: Katz Stanley E , Fassbender Carol A , Depaolis Anneli M , Rosen Joseph D 
Published: February 2020

Abstract
The microbiological assay for penicillin residues was improved by using centrifugation to remove physical barriers to diffusion, a small buffer/meat extraction ratio, and a more sensitive 2-layer assay system. Recoveries from muscle, kidney, and liver tissues ranged between 70.1 and 86.7% with measurable levels of 0.03- 0.05 unit/g. By comparison, the Food and Drugsuggested methodology yielded recoveries of 45.9-54.0% and levels of detectability of 0.08- 0.10 unit/g. Cooking of hamburger, steaks, and pork chops indicated that procaine penicillin withstood cooking conditions, and significant levels of the original activity remained.
pH-Induced Difference Spectrophotometric Assay of Acetazolamide, Hydrochlorothiazide, and Furosemide
Authors: Abdine Hassan , Abdel-Hady Elsayed M , Elsayed Yousry M 
Published: February 2020

Abstract
On the basis of pH-induced spectral changes for acetazolamide, hydrochlorothiazide, and furosemide, 3 different spectrophotometric methods are described. The methods were successfully applied to the assay of these drugs in different pharmaceutical formulations (tablets and ampoules). The accuracy of the analysis is increased by using the suggested methods as compared with conventional spectrophotometry.
Measurement of the Bioavailability of Iron, Using the Rat Hemoglobin Repletion Test
Authors: Fritz James C , Pla Gwendolyn W , Harrison Bertha N , Clark Geneva A , Smith Edythe A 
Published: February 2020

Abstract
Variations in the AOAC official first action rat hemoglobin repletion test for iron were studied. These changes included (1) use of a simplified basal diet to eliminate ingredients which sometimes contribute too much iron; (2) increased fortification of the basal diet with vitamin E, pantothenic acid, and pyridoxine; (3) increased dietary copper; (4) variations in the carbohydrate source in the basal diet; (5) changes in the length of the depletion and repletion periods; and (6) comparison of prophylactic and curative procedures. The changes yielded results comparable to those obtained with the present official method. Further study may reveal that the depletion period can be shortened or eliminated. To fully meet the rat's vitamin requirements, increased levels of vitamin E, pantothenic acid, and pyridoxine are recommended. It is further recommended that the present method remain in official first action status, and that study be continued.
Problems in the Recovery and Identification of Yersinia from Food
Authors: Mehlman Ira J , Aulisio Calvin C G , Sanders Arvey C 
Published: February 2020

Abstract
Y. enterocolitica and Y. pseudotuberculosis are emerging foodborne pathogens. Phosphatesaline enrichment of food homogenates at 4°C required about 2 weeks for retrieval of yersinia when present at 10,000/g. Modification by inclusion of 1% sorbitol and 0.15% bile salts increased sensitivity 10-fold and extended the recovery period. MacConkey was superior to bismuth-sulfite, Salmonella-Shigella, Hektoen, and Levine EMB agars for isolation. Incubation at 26°C was more satisfactory for recovery and characterization than 37°C. Isolates were first screened in TSI, mannitol, and lysine which eliminated 75% of interfering cultures. Of 25 biochemicals evaluated, urea, arginine, motility (at 26 and 37C°), and phenylalanine were most useful for confirmation. Cultures isolated from foods were classified into 2 groups (1) giving negative reactions in citrate, raffinose, melibiose, and gelatin; and (2) giving positive reactions in the above biochemicals. The former resembled classical European strains of Y. enterocolitica. The latter were more frequently recovered and designated Y. enterocolitica-like bacteria.
Fecal Coliform Methods for Examination of Sea Water: Interlaboratory Evaluation of Split Sample Analysis
Authors: Miescier John J , Carr Virgil E , Musselman John F , Furfari Santo A 
Published: February 2020

Abstract
An interlaboratory study was conducted to compare the effectiveness of the following 3 multiple-tube fermentation methods for determining the most probable number (MPN) of Escherichia coli in a split artificial sea water sample: ( 1 ) the 72-hr standard methods procedure of the American Public Health Association, (2) a 24-hr elevated-temperature test using A-l medium, and (3) a 24-hr elevated temperature test modified to include an initial 3-hr resuscitation period using A-l medium. The capability of the laboratories to perform the 3 test procedures was also compared. Split sample replicates with low, medium, and high levels of E. coli were examined in 18 laboratories in the United States and Canada. Data indicate that the laboratories performed each test with equal capability, and all 3 procedures were equally effective in enumerating the strain of E. coli used in this investigation. By virtue of its homogeneity and stability, the split sample served as an appropriate specimen for this study and could probably be used as a proficiency test specimen for evaluating laboratory analyst performance in the bacteriological examination of sea water.
Gas-Liquid Chromatography of Aqueous-Alcohol Solutions for Insecticide Residue Analysis
Authors: Sans Walter W 
Published: February 2020

Abstract
Injection of water-methanol solutions of insecticides into a gas-liquid chromatograph, equipped with alkali flame ionization and electron capture detectors, is a simplified, cost-saving technique for obtaining analytical data since the most economical solvents are used and time spent on extraction is eliminated. The procedure has been used to obtain water-solubility values for 20 insecticides ranging from 0.09 ppm (iodofenfos) to 4000 ppm (disulfoton sulfoxide) and for determining equilibrium concentrations of insecticides in clay-water suspensions. The usefulness of this technique is limited by the sensitivity of the gas chromatographic system which may require concentration of the extracts, and the stability of the compound in an aqueous system.
Gas-Liquid Chromatographic Determination of Selenium in Biological Materials, Using 4-Bromo- and 4-Chloro-1,2-Diaminobenzene as Derivatizing Reagents
Authors: Bycroft Brian M , Clegg Donald E 
Published: February 2020

Abstract
A method is described for the gas-liquid chromatographic determination of traces of selenium in marine biological materials. The method is based on the reaction of Se(IV) with bromo- and chloro-substituted 1,2-diaminobenzenes. The benzoselenadiazoles so formed are sensitive to electron capture detection. The sample is digested in a nitric-perchloric acid mixture and selenium is reduced to the IV oxidation state. Different aliquots of the digest solution are reacted with either 4-bromo- or 4-chloro-l,2-diaminobenzene to quantitatively form the corresponding 2,1,3-benzoseIenadiazole. Recovery of added selenite to a fish meal sample was 95% for the bromo derivative and 101% for the chloro derivative. Different portions of a well mixed fish meal sample were analyzed in independent laboratories by the fluorometric method and by atomic absorption spectrophotometry (hydride generation). The following mean values (μg/g) were found: present method 1.89, fluorometric method 1.91, atomic absorption method 2.1. The lower limit of detection for the method described was 13 ng, using the bromo derivative, and 27 ng, using the chloro derivative.
Spectrofluorometric Determination of Atropine-Hyoscyamine in Tablets and Powders
Authors: Cieri Ugo R 
Published: February 2020

Abstract
A method is presented for determining atropine-hyoscyamine alkaloids in tablets and powders by spcetrofluorometry. The sample is first shaken with 0.1N H2S04 solution; then an aliquot containing about 0.1 mg alkaloid is transferred to a separatory funnel, made basic with NaOH solution, and extracted with CHC13. The extract is added to a Celite-0.2N H2S04 column and the eluate is discarded. The alkaloids are then eluted from the column with ammoniacal CHCI3 and the eluate is evaporated to dryness. The residue is dissolved in CHC13, eosin Y solution is added, and the solution is mixed. Aliquots of a reference solution of atropine are similarly treated and a blank is prepared from CHCI3 and eosin Y solution. All solutions are scanned with a recording spectrofluorometer in the emission mode from 440 to 700 nm and the excitation set at 475 nm. The emission peaks near 550 nm are used for quantitative estimation of the alkaloids. The method cannot generally be used in the presence of other organic bases but is applicable in the presence of barbiturates.
Spectrophotometric Determination of Carboxin in Formulations After Extraction and Thin Layer Chromatographic Separation
Authors: Handa Swadesh K 
Published: February 2020

Abstract
Carboxin (5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxanilide) is extracted from formulations with chloroform. The extract is subjected to thin layer chromatography and the carboxin zone is scraped from the developed plate. Carboxin is then eluted from the adsorbent with chloroform and determined spectrophotometrically at 300 nm. Recoveries from laboratory-prepared formulations were 97-98%.
Rapid Screening Method for Alkaline Phosphatase Activity in Cheese: Collaborative Study
Authors: Kleyn Dick H 
Published: February 2020

Abstract
The method developed for determining alkaline phosphatase activity in cheese, in which phenolphthalein monophosphate is used as the substrate, was collaboratively studied. A 7.5% butanol extract of cheese is reacted with phenolphthalein monophosphate; phenolphthalein is released and yields a red solution that is compared visually with a standard (s) prepared from the same extract. Seven collaborators analyzed 8 samples of cheese, in duplicate, by the screening method and Scharer I method. Of the 208 observations returned, only 4 were incorrect. The alkaline phosphatase method has been adopted as official first action.
Comparison of Sample Preparation Procedures for Colorimetric Analysis of Nitrite in Frankfurters
Authors: Nicholas Fiddler Rosemary , Fox Jay B 
Published: February 2020

Abstract
Three groups of methods for analyzing nitrite in meat are compared. All methods consist of a sequence of steps, grouped according to initial extraction procedures. In Croup 1, the sample is treated with borate followed by HgCl2 or Carrez I, and then Carrez II. In Group 2, the sample is diluted with water, heated at 80°C, and analyzed immediately (AOAC) or after addition of either Na2CO3 and FeCl3 or HgCl2. In Group 3, the sample is made alkaline with NH4C1 buffer and then treated with one of the following: activated carbon plus Carrez I and II, alumina cream, or A1K(S04)2. At each step when the method involved the addition of a chemical, supernates and precipitates (if formed) were analyzed for nitrite by Griess reagent both before and after AOAC digestion. The normally discarded precipitates formed after addition of HgCl2 and Carrez I and II contained bound nitrite that could be detected by AOAC analysis. Except in the AOAC method, HgCl2 improved nitrite analysis. Results by AOAC analysis were 3 to 300% higher than those determined after addition of any chemical or combination of chemicals. Spiked meat samples could not be used in comparing nitrite analysis methods because results were misleading. Acid meat samples, such as fermented sausages, required neutralization before AOAC analysis.
Liquid Chromatography with Fluorescence Detection of Lasalocid Sodium in Feeds and Premixes
Authors: Osadca Modest , Araujo Mercedes 
Published: February 2020

Abstract
Lasalocid sodium is extracted directly from feeds and premixes with the mobile phase solution, an aliquot is chromatographed, and the concentration (peak height) of lasalocid sodium is measured by high pressure liquid chromatography with fluorescence detection. Chromatography and detection are completed in about 7 min. The results agree well with those found by the official AOAC fluorometric method, 42.A08-42.A13. The method offers an alternative to the AOAC method and has the capability of processing almost twice as many samples. The average recovery of 4 levels (0.0008, 0.0040, 0.0080, and 0.0120%) of lasalocid sodium from feeds is 100%. Replicate assays of typical poultry mashes and pellets containing about 0.0080% lasalocid sodium yielded coefficients of variation of 2.68—3.35%.
Microbiological Method for Assaying Lincomycin in Animal Feed: Collaborative Study
Authors: Neff A William , Thomas Richard W 
Published: February 2020

Abstract
A microbiological assay for determining lincomycin in swine feed, supplement, and a vitamin- mineral premix was studied collaboratively in 16 laboratories. The design of the study involved a complete feed, feed supplement, and a vitamin-mineral premix covering a range of fortification from 20 to 80 g/ton and 80 to 2600 g/ton. Two methods of sample preparation were used depending on the concentration of lincomycin in the sample. Statistical evaluation of the results from the 2 methods indicated that 10 and 11 collaborators, respectively, had mean recoveries which were not significantly different from one another. Ten laboratories obtained a mean recovery of 112.2% (range 102.3-123.5%) for the lower level, and 11 laboratories obtained a mean recovery of 104.4% (range 100.0-107.7%) for the higher level. The method has been adopted as official first action.
Sodium Cobaltinitrite as a Reagent for Determining Some Phenolic Drugs
Authors: Wahbi Abdel-Aziz M , Abdine Hassan , Korany Mohamed , Abdel-Hay Mohamed H 
Published: February 2020

Abstract
Dichlorophen, oxyphenbutazone, phenazone, methyldopa, isoprenaline sulfate, and salbutamol sulfate are reacted with sodium cobaltinitrite in aqueous acetic acid. The yellow color is measured at 365, 320, 320, 330, 425, and 325 nm in aqueous acetic acid, respectively, and at 445, 380, 375, 345, 325, and 412 nm in sodium hydroxide, respectively. The reaction product is extractable with CHC13, with a maximum absorption at 370 nm for dichlorophen, 355 nm for phenazone, and 325 nm for oxyphenbutazone. The method is applied to the determination of these drugs in tablet form. The results obtained are reasonably reproducible with a coefficient of variation less than 2%.
Determination of Germanium, Arsenic, Tin, Selenium, and Antimony by Plasma Emission Spectrometry with Hydride Generation and Chromatographic Separation
Authors: Fricke Fred L , Robbins Wayne D , Caruso Joseph A 
Published: February 2020

Abstract
A semiautomated hydride generation device was coupled to a microwave-induced Ar/He plasma which is used with a 0.5 m monochromator. This coupling necessitated the use of a condensation tube and a Chromosorb 102 column to separate the analyte species from hydrogen produced during the generation reaction, and also to separate the analytes from condensed contaminants which cause spectral background interference. Data reported for Ge, As, Se, Sn, and Sb are detection limits in the ppb range and linear dynamic ranges which extend to 3 orders of magnitude. Precision of results ranges from 2.9 to 8.8%. Chromatographic characteristics of the elemental hydrides on 1, 3, and 6 ft columns are also reported. This system or portions of it can be used to substantially decrease both time and quantities of reagents needed for analysis in both simultaneous and sequential experiments in either emission spectroscopy or atomic absorption spectrometry.
Rapid Screening Field Test for Detecting Cadmium and Lead Extracted from Glazed Ceramic Dinnerware: Collaborative Study
Authors: Krinitz Benjamin 
Published: February 2020

Abstract
A test intended for field screening glazed ceramic dinnerware for acid-extractable cadmium and lead was subjected to collaborative study. The test, a modification of the classical dithizone procedure, requires no instrumentation. Ninety samples were field-tested for lead and then analyzed by the 24 hr official method; of 63 negative field tests, 48 had no lead after 24 hr, and each of the other 15 contained &lt;0.7 ppm. Of 60 samples field tested for cadmium, 45 gave negative field tests; of these, 30 showed no cadmium by the 24 hr test, and 15 showed ≤0.09 ppm. All 15 laboratories participating in the study were able to detect a color change at 0.05 μg Cd and 0.3 μg Pb/ml 4% acetic acid. The method has been adopted as interim official first action.
Isomer Specific Assay of Ester and Salt Formulations of 2,4-Dichlorophenoxyacetic Acid by High Pressure Liquid Chromatography: Collaborative Study
Authors: Stevens Timothy S , Skelly Norman E , Grorud Robert B 
Published: February 2020

Abstract
A high pressure liquid chromatographic (HPLC) assay of ester and salt formulations of 2,4-D has been collaboratively studied. The method is specific for 2,4-D isomer and resolves all known impurities from 2,4-D and the internal standard p-bromophenol. In situ saponification, at room temperature, is performed by adding a combined saponification-internal standard solution to ester products. The same saponification- internal standard solution is added to amine salts and the analytical standard. The injected aqueous potassium salt solution of 2,4-D is then converted to the acid form by an acidic buffered mobile solvent of 20% acetonitrile in water. Optimum chromatography is attained by a mobile solvent pH of 2.95 in a reverse phase microparticulate column, by ion suppression. Each of the 9 collaborators received 3 different ester and 2 different amine formulations of 2,4-D. The coefficients of variation of 2,4-D acid equivalent ranged from 1.22 to 1.59%. The method has been adopted as official first action.
Banminth and a Common Fragment Assay
Authors: Figdor Sanford K , Von Wittenau M Schach , Lynch Martin J 
Published: February 2020

Abstract
The metabolism of the anthelmintic pyrantel, Banminth™ (trans-l-methyl-l,4,5,6-tetrahydro- 2-[2-(2-thienyl)vinyl]pyrimidine) is characterized by extensive transformations. Evidence derived from excreted metabolites indicated nearly total destruction of the thiophene ring. The tetrahydropyrimidine moiety was less extensively degraded since the basic skeleton, iV-methylpropanediamine, was obtained after hydrolysis. In addition, some of the pyrantel radioactivity was degraded to small fragments and re-incorporated into normal tissue constituents since liver amino acids gave 14C02 after ninhydrin treatment. Attempts to develop a tissue residue assay involved the difficult task of distinguishing drug-related front tissue re-incorporated radioactivity in the parts per million range. An approach to choosing a marker residue was to select a feature common to the metabolites present in tissues, chemically liberate that entity, and designate it the marker residue. The tetrahydropyrimidine portion of pyrantel offered such an opportunity since N-methylpropanediamine was readily liberated by hydrolysis. It was demonstrated that approximately half of the radioactivity in long-term tissues was associated with N-methylpropanediamine and that the remainder of tissue radioactivity was re-incorporated label. Thus, for assay purposes, the hydrolysis of tissue followed by the quantitation of N-methylpropanediamine served as a useful procedure that permitted monitoring a number of drug-related residues which still contain the diamine moiety.
Comparison of Two Rapid Test Procedures with the Standard EC Test for Recovery of Fecal Coliform Bacteria from Shellfish-Growing Waters
Authors: Hunt Daniel A , Springer Janet 
Published: February 2020

Abstract
A study was conducted to compare recovery and enumeration capability of two 24-hr multitube fermentation tests with the standard EC test for fecal coliform levels in shellfish-growing waters. The 2 tests were the A-1 test developed by Andrews and Presnell, specifying 24-hr incubation in A-1 medium at 44.5CC; and a modification of the A-1 test requiring a 3-hr resuscitation at 35°C before incubation at 44.5°C for 21 hr. Fifteen State, Federal, and Provincial laboratories examined 10 routine shellfish-growing area samples per month in parallel by the 3 methods for 1 year. IMViC tests (indole, methyl red, Voges-Proskauer, and citrate) were conducted on all gas-positive tubes. The modified A-1 test recovered higher levels of fecal coliforms than the A-1 test. Although there were seasonal and geographic variations in recovery and enumeration by the modified A-1 test, overall there was good correlation of the modified A-1 test with the EC test. Both the A-1 and modified A-1 tests were more specific for Escherichia coli than the EC test. Results of the study indicate that the 24-hr modified A-1 test can be used as an alternative test for the standard 72-hr EC test as an adjunct to the sanitary survey for the classification and control of shellfish-growing area waters.
Improved Colorimetric Method for Determining Nitrate and Nitrite in Foods
Authors: Sen Nrisinha P , Donaldson Barbara 
Published: February 2020

Abstract
A method is described for determining nitrate and nitrite in cured meat products, cheeses, and vegetables. The nitrite is determined colorimetrically by diazotization of sulfanilic acid and subsequent coupling with N-(l-naphthyl)-ethylenediamine. The concentration of nitrate plus nitrite is determined similarly but after reduction of the nitrate to nitrite on a cadmium column. The difference of the 2 values is a measure of the nitrate concentration. The main improvements are replacing the Griess reagent, which contains a carcinogen, with a mixture of sulfanilic acid and N-(l-naphthyl)- ethylenediamine, providing for adjustment of pH of the sample suspension during extraction and digestion by heating, and maintaining constant pH by controlled addition of buffers and acids during color development. The method was successfully applied to the analysis of 15 samples of meat products, 23 cheeses, and 6 different vegetables. The average recovery of sodium nitrite added at levels ranging from 10 to 30 ppm was 9 5% and recovery of sodium nitrate added at levels from 30 to 400 ppm was 9 4% (corrected for cadmium column efficiency).