bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyses of Fat-Soluble Vitamins, XIV. Collaborative Study of the Determination of Vitamin D in Multivitamin Preparations
Authors: Mulder Frits J , De Vries Ellen J , Borsje Ben
Published: February 2020

The colorimetric assay for the determination of vitamin D (4000—50,000 international units (IU)/g) in multivitamin preparations has been collaboratively studied. The method is based on the same principle as the official method for the determination of vitamin D in concentrates, i.e., elimination of trans-isomers of vitamin D resins. The method includes the following steps: saponification and extraction (isolation of unsaponifiable material), phosphate-treated alumina column chromatography (elimination of tocopherols and vitamin A decomposition products), partition chromatography with polyethylene glycol 600 and Celite (separation of vitamin D fraction from vitamin A alcohol), adsorption chromatography on Florex (elimination of vitamin A decomposition products and small amounts of polyethylene glycol 600), maleic anhydride addition reaction (elimination of trans-isomers of vitamin D resins), and colorimetric determination at 2 wavelengths with and without acetic anhydride (an inhibitor for the color reaction of vitamin D and antimony trichloride). The mean result of 4 laboratories for 8 different samples, expressed as per cent of the known amount of vitamin D added, was 95.8% with a coefficient of variation of 10.5%. Considering the complexity of the method, the collaborative results were reasonable. The method has been adopted as official first action.
Chelate Extraction and Flame Atomic Absorption Spectrometric Determination of Nanogram Amounts of Manganese in Blood and Animal Tissue
Authors: Shearer Duncan A , Cloutier Richard O , Hidiroglou Michael
Published: February 2020

A method for the determination of manganese in blood and animal tissue has been developed involving wet digestion of the sample by perchloric and nitric acids, complexing with sodium diethyldithiocarbamate, and extracting with methyl isobutyl ketone at pH 6.7. The methyl isobutyl ketone is removed, and the residue is dissolved in 0.05N HCl in acetone-water (9+1) and is aspirated into an air-acetylene flame of an atomic absorption spectrometer. The limit of detectability is about 10 ng Mn/ml in the solution aspirated or 2 ng Mn/ml in bovine blood for a 20 ml sample.
Microbiological Assay of Thiopeptin in Broiler Rations
Authors: Takano Norio , Nomura Kimiko , Arakawa Akira
Published: February 2020

A microbiological assay method is described for the determination of thiopeptin in poultry feeds. Feed samples are extracted with acetone-water (9+1). Interfering substances are compensated for by extracting standard solutions from antibiotic-free feed. Microbiological activity is measured on monolayer agar plates by the paper disk diffusion method with Acholeplasma laitllaivii A. Concentrations are calculated from the responses to high and low levels of the unknown and the standard. A mean recovery of 96% was obtained from samples prepared by fortifying basal feeds in the laboratory with thiopeptin at concentrations ranging from 0.6 to 2.0 mg/kg shortly before extraction. The average recovery rate was 93% in feed samples prepared by 5 feed manufacturers with thiopeptin concentrations ranging from 0.6 to 2.5 g/ton.
Gas-Liquid Chromatographic Determination of Diflubenzuron (Dimilin) in Water as Its Trifluoroacetyl Derivative
Authors: Worobey Brian L , Webster G R Barrie
Published: February 2020

A new gas-liquid chromatographic (GLC) procedure has been developed for the analysis of diflubenzuron, 1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl) urea, in pond water. The residues from fortified pond water were extracted with ethyl acetate, derivatized, and cleaned up on a mini Florisil column. The diflubenzuron was determined by GLC as its N,N′-di(trifluoroacetyl) derivative, using electron capture detection. A 50% full scale deflection was obtained with 0.03 ng injected. Recoveries from fortified unfiltered pond water were 65.7, 72.8, 82.0, and 90.8% at the 0.020, 0.059, 0.197, and 0.788 mg/L (ppm) levels, respectively. Recoveries from fortified filtered pond water were 94.1 and 89.3% at the 0.020 and 0.060 mg/L levels, respectively. It is postulated that diflubenzuron is immobilized by adsorption, for example, to particulate organic matter in the pond water because recovery data from unfiltered water followed the linear form of the Freundlich equation.
Automated Analytical System for Phenols Incorporated into Screening Method Suitable for Determination of 2-Methyl-4-chlorophenoxyacetic Acid and/or 2,4-Dichlorophenoxyacetic Acid Herbicide Residues in Water
Authors: Ott Daniel E , Friestad Hakon O
Published: February 2020

2-Methyl-4-chlorophenoxyacetic acid (MCPA) and 2,4-dichlorophenoxyacetie acid (2,4-D) are extracted from water with methylene chloride and are degraded when heated in the presence of pyridine hydrochloride to their corresponding phenols which are determined automatically with a modified distillation-colorimetric analyzer system. The method has been evaluated primarily with surface water samples collected from areas of known MCPA applications. The lower limit of detection of MCPA is about 50 µg/L water. Response for 2,4-D is almost identical to that for MCPA at equal concentrations. Comparative responses to other potential responding phenoxy acid herbicides have not been determined. MCPA results from this method for several water samples compared favorably with results from a gas chromatographic method. The scntiautontated colorimetric method can be applied to water samples of unknown history as a screening method in which case a significant, positive recorder response, suitably corrected for free phenol response as suggested herein, indicates probability of presence of one or more of the responding herbicides. The sample would then need to be examined by other, more definitive means.
Thin Layer Chromatographic Detection of Carum bulbocastanum Koch in Carum carvi Linn
Authors: Sen Asit R , Sardar Pranab K , Sengupta Pratima
Published: February 2020

A rapid thin layer chromatographic method has been developed to detect Carum bulbocastanum Koch in Carum carvi Linn. The volatile essential oils are developed on silica gel G plates, using benzene-petroleum ether and visualized by 2,4-dinitrophenylhydrazine spray. This procedure can also differentiate mixtures of the 2 seeds.
Analysis of Polychlorinated Biphenyls by Carbon-13 Nuclear Magnetic Resonance Spectroscopy
Authors: Levy George C , Hewitt James M
Published: February 2020

A technique is presented for the analysis of polychlorinated biphenyl mixtures by assigning 13C resonances to the observed peaks and matching these shifts to the shifts of known individual polychlorinated biphenyls. The technique has not proved to be as useful for heavily chlorinated mixtures.
Micro-Determination of p-Hydroxybenzoic Esters in Pharmaceuticals and Cosmetics
Authors: Weisenberg Emil , Gershon Baruch , Schoenberg Judith
Published: February 2020

A rapid and specific method is described for the determination of microamounts of methyl, propyl, and butyl p-hydroxybenzoic esters (parabens) in pharmaceuticals and cosmetics. The method involves the direct extraction of parabens into benzene or chloroform followed by derivatization with phosphorochloridate. The diethyl phosphate ester derivatives are cleaned up on a Florisil minicolumn and finally measured by gas-liquid chromatography on 5% OV-210 on Gas-Chrom Q. A flame photometric detector or a KCl thermionic detector may be used. The concentration response was linear up to 40 ng parabens. The reproducibility and margin of error were tested with fortified samples. This method may be applied to the estimation of other phenol derivatives.
Field Desorption Mass Spectrometry of Mycotoxins and Mycotoxin Mixtures, and Its Application as a Screening Technique for Foodstuffs
Authors: Sphon James A , Dreifuss Peter A , Schulten Hans-Rolf
Published: February 2020

The field desorption mass spectra of a variety of mycotoxins have been studied. These include the 4 aflatoxins B1, B2, G1; and G2, rubratoxin B, T-2 toxin, and zearalenone, as well as mixtures of these mycotoxins. The spectra of all of the mycotoxins exhibited molecular ions [M]+. Under the conditions employed, only rubratoxin B exhibited major fragmentation. The field desorption technique has been applied to the analysis of both spiked and naturally contaminated extracts of foodstuffs. The potential of the method as an analytical screening technique for the presence of mycotoxins has been evaluated.
Gas-Liquid Chromatographic Determination of m-Phenoxybenzyl cis, trans-(±)-3-(2,2-Dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate in Aqueous Formulations
Authors: Simonaitis Richard A , Cail R Spencer , Zehner James M , Bry Roy E
Published: February 2020

A simple and rapid gas-liquid chromatographic (GLC) method was developed for the analysis of aqueous solutions of FMC 33297 (m-phenoxybenzyl cis,trans-(±)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate). The compound is extracted from aqueous solution with benzene and cleaned up by liquid chromatography. The sample extracts are analyzed by GLC with a flame ionization detector and quantitated by comparing integrator counts of extracts with those of standards. Recoveries of FMC 33297 were 90—100%. The method has good precision (the standard deviation for 4 determinations of a 0.002394% formulation was 6 × 10−6) and is sensitive to 0.00004% active ingredient by weight.
Trace Analysis of Zearalenone and/or Zearalanol in Animal Chow by High Pressure Liquid Chromatography and Gas-Liquid Chromatography
Authors: Holder Claude L , Nony Charles R , Bowman Malcolm C
Published: February 2020

An analytical method is described for determining residues of the estrogens zearalenone and/or zearalanol in animal chow at levels as low as 10 ppb. The chow is extracted with methanol and cleaned up by a 3-step procedure employing a Sephadex LH-20 column, liquid-liquid partitioning at pH 13 and 8.3, and a silica gel column. Residues of the 2 compounds, separated on silica gel, are assayed by using high pressure liquid chromatography with ultraviolet detection. Additional data are also included concerning p-values of the compounds in several solvent systems, Rf values from thin layer chromatography with 9 solvent systems, solubilities in 3 solvents, and a procedure for preparing their pentafluoropropionyl derivatives for analysis by electron capture gas-liquid chromatography.
Detection of Low-Level Carbadox Residues in Animal Feeds by High Pressure Liquid Chromatography
Authors: Luchtefeld Ronald G
Published: February 2020

The high pressure liquid chromatographic (HPLC) method is capable of detecting from 1 to 0.024 ppm methyl 3-(2-quinoxalinyl-methylene) carhazate-Nl,N4-dioxido (carbadox). Carbadox is extracted from the feed with 2% NH4OH in acetone, passed through a liquid-liquid partition, subjected to HPLC, and detected by using a 365 nm detector. No feed materials or other active drug ingredients produced false positive results.
Modified Sutter’s Arginine Dihydrolase Medium for Pseudomonas Speciation
Authors: Cary Sylvia G
Published: February 2020

Sutter’s arginine dihydrolase medium has been modified to obtain maximum yields of arginine dihydrolase. Bromothymol blue is the indicator for alkalinity in Sutter’s medium. By adding glucose and lowering the pH of the medium, more positive reactions were obtained in 24 hr as well as a sharper color contrast to the base medium which facilitated reading the reactions. The modified Sutter’s medium was included in the routine biochemical schema for speciation of pseudomonads isolated from cosmetic products. Of the 706 strains belonging to the 5 species isolated from cosmetic products, only one false negative reaction was obtained with a strain of Pseudomonas putida. The medium was also used for the biochemical characterization of 122 Pseudomonas sp. isolates.
An Improved Cooked Meat Medium for the Detection of Clostridium botulinum
Authors: Quagliaro Daniel A
Published: February 2020

A new medium composed of cooked meat and fluid thioglycolate broth was tested with 20 proteolytic and 11 saccharolytic strains of Clostridium botulinum. All of the proteolytic strains produced a black ring at the surface of the broth, presumably due to hydrogen sulfide production, while the saccharolytic strains produced white opaque rings. Since the black ring is formed rapidly and is easily seen, the new medium may be useful for the rapid identification of proteolysis in unknown isolates. Growth and toxin production were better in the new medium than in the usual cooked meat medium or in cooked meat medium plus 0.5% glucose. These results suggest that the new medium will be useful in facilitating identification of C. botulinum.
Gas-Solid Chromatographic Confirmation of Vinyl Chloride Levels in Oils and Vinegars by using Electrolytic Conductivity Detection
Authors: Page B Denis , O’Grady Ronald
Published: February 2020

A gas-solid chromatographic headspace method has been developed for the quantitative confirmation of vinyl chloride (VC) in oils and vinegars. The method, based on the electrolytic conductivity detector, permits quantitative confirmation of VC residues as low as 0.05 and 0.02 ppm for oil and vinegar, respectively. A number of samples were analyzed by using a previously reported flame ionization method and the proposed technique. The results by using the latter technique averaged 5% lower.
Aflatoxin and Zearalenone Occurrence in Dry-Milled Corn Products
Authors: Stoloff Leonard , Dalrymple Barbara
Published: February 2020

Eighty-two com dry-milling establishments in 20 States were surveyed concerning control practices for preventing the use of corn contaminated with aflatoxin or zearalenone. Prime products and by-products from each establishment were analyzed for these mycotoxins to determine whether a correlation exists between control practices and product contamination. No zearalenone was detected in any product; there was little awareness of the potential for contamination with this mycotoxin. No correlation was found between control practices and aflatoxin contamination encountered, but there was a positive correlation between aflatoxin contamination and the geographical source of the corn. Reported experimental findings in regard to the distribution of aflatoxin between prime product and by-product were generally corroborated.
Gas-Liquid Chromatographic Determination of Solvents in Commercial Nail Lacquer Preparations
Authors: Stutsman Martin J
Published: February 2020

A gas-liquid chromatographic (GLC) method has been developed for the determination of 5 solvents (butanol, butyl acetate, ethyl acetate, 2-propanol, and toluene) and camphor in commercial nail lacquer preparations. Resins and pigments are first precipitated from the solvents by dilution with isooctane. n-Propyl acetate is then added as an internal standard to the isooctane solution of solvents and the mixture is analyzed by temperature-programmed GLC. Analyses at 3 concentration levels (4, 20, and 40%) with 4 determinations at each level gave good recoveries.
Ultraviolet Determination of Chlordimeform in Cattle Dipping Baths and Sprays
Authors: Machin Michael V , Dingle John H P
Published: February 2020

A simple and reliable method has been developed for determining chlordimeform. A preliminary cleanup converts chlordimeform to its hydrochloride and removes ultraviolet-absorbing impurities. The aqueous acid phase containing chlordimeform. HCl is diluted and passed through a silica gel column. The column effluent is used as the reference solution and a portion not eluted through silica gel is used as the sample solution in the spectrophotometer. The absorbance at 240 nm is measured, and chlordimeform concentration is determined from the calibration graph. The method applied to solutions of acaricides gives good results in the range of 0.02–0.06% w/v chlordimeform; higher concentrations may be determined by appropriate dilutions.
Gas Chromatographic Determination of Residual Methylene Chloride and Trichloroethylene in Decaffeinated Instant and Ground Coffee with Electrolytic Conductivity and Electron Capture Detection
Authors: Page B Denis , Charbonneau Claudette F
Published: February 2020

A method is described for the quantitative determination of residual methylene chloride (MC) and trichloroethylene (TCE) in decaffeinated instant and ground roasted coffees. The residual solvents were isolated by a closed system vacuum distillation technique with toluene as a carrier solvent, chromatographed on Chromosorb 102, detected by both electron capture and electrolytic conductivity detectors, and quantitated by comparison with an internal standard. Average recoveries of MC from instant and ground coffees spiked at 1, 10, and 25 ppm were 100.0 (88-113), 93.2 (92-95), and 97.7% (94-102%); and for TCE, 97.2 (92-101), 96.2 (95-99), and 96.5% (92-100%), respectively. The results from both detectors are compared. At lower attenuations, levels less than 1 ppm can be readily measured. The procedure developed was applied to domestic and imported coffee samples.
Collaborative Study of Gas-Liquid Chromatographic Method for Determining Fluometuron
Authors: Hofberg Arthur H , Heinrichs Lee C , Barringer V Michael , Tin Maung , Gentry Gene A
Published: February 2020

A gas-liquid chromatographic (GLC) method for determining fluometuron in a wettable powder formulation containing about 80% active ingredient was collaboratively studied using a matched pair scheme. The samples were dissolved in chloroform containing diethyl phthalate as an internal standard, derivatized with trifluoroacetic anhydride, and chromatographed on OV-3, using a flame ionization detector. Analyses of the 2 samples by 14 collaborators, using peak height measurements, showed the following results: 0.99% overall coefficient of variation, 1.08% coefficient of variation for the random error, and no evidence of systematic error. The validity of these results was verified by a concurrent collaborative effort using high pressure liquid chromatography. Analyses of the 2 samples by 8 collaborators, using peak height measurements, showed a 1.17 standard deviation of the total for liquid chromatography vs. 0.76 standard deviation of the total for GLC. The averages for Sample A and Sample B by liquid chromatography showed a relative difference of 0.19 and 0.00%, respectively, when compared with the results by the GLC method. The GLC method has been adopted as official first action.
Comparison of Semiautomated and Manual Methods for the Determination of Thiamine in Baby Cereals and Infant and Dietary Formulas
Authors: Ribbron Wallace M , Stevenson Kenneth E , Kirk James R
Published: February 2020

Using a semiautomated method, the mean thiamine content of specific products ranged from 88 to 101% and 83 to 93% for baby cereals and infant and dietary formulas, respectively, of those obtained with the AOAC manual method. The best results were obtained when data for the semiautomated method were calculated from a standard curve obtained by using thiamine solutions which had been digested and hydrolyzed along with the samples.
Aflatoxins in Egyptian Foodstuffs
Authors: Girgis Amir N , El-Shbrif Safinaz , Rofael Nazmy , Nesheim Stanley
Published: February 2020

Six samples each of wheat, corn, lentils, beans, fenugreek, peanuts, and cottonseed cake from various areas of Egypt were analyzed for aflatoxins both at the time of collection and after 12 months’ storage. Aflatoxin was found at low levels (3 to 12 ppb total aflatoxins in 14 of 42 samples, as follows: 1 sample each of corn, lentils, and beans; 2 peanut samples; 3 fenugreek samples ; and 6 cottonseed cake samples. None of the samples contained aflatoxins above 11.7 ppb.
Aflatoxin in Tunisian Aleppo Pine Nuts
Authors: Boutrif Ezzeddine , Jemmali Mongi , Pohland Albert E , Campbell Alfred D
Published: February 2020

Twenty-six of 50 Aleppo pine nut samples collected throughout Tunisia showed relatively high levels of contamination by aflatoxin. Some samples contained as much as 2000 ppb aflatoxin B1, and very few contained less than 100 ppb. Total aflatoxins as high as 7550 ppb were found. A traditional pudding, widely consumed in Tunisia, which was prepared from contaminated nuts still contained more than 80% of the aflatoxin originally present in the nuts.
Survey of 1975 Wheat and Soybeans for Aflatoxin, Zearalenone, and Ochratoxin
Authors: Shotwell Odette L , Goulden Marion L , Bennett Glenn A , Plattner Ronald D , Hesseltine Clifford W
Published: February 2020

Wheat samples (102 lots) were collected from Virginia, North Carolina, southeastern Missouri, southern Illinois, and Kentucky. Soybean samples (180 lots) were collected from Virginia, Illinois, Iowa, Minnesota, Nebraska, Alabama, Arkansas, and Texas. Samples of both commodities were analyzed for zearalenone, aflatoxin, and ochratoxin by the Eppley method. None of the 3 mycotoxins was detected in soybeans. Aflatoxins and ochratoxin A were not detected in wheat, but zearalenone was detected in 19 of 42 samples collected in Virginia. Half of the Virginia samples were collected because they were mold-damaged. Zearalenone levels ranged from 0.36 to 11.05 ppm; the identity of the zearalenone was confirmed by gas-liquid chromatography and mass spectroscopy. Gibberella zea infection (6–60%) was detected in all of the zearalenone-positive samples; 6–60% of the kernels in the samples tested contained G. zea.
Methods for Determining Free Amino Nitrogen in Wort and Beer and Viscosity of Wort and Beer
Authors: West Dwight B
Published: February 2020

The American Society of Brewing Chemists (ASBC) has released new methods for the determination of free amino nitrogen in wort and beer and for viscosity of wort and beer. The 4 procedures have been collaboratively tested by ASBC and the European Brewing Convention and adopted as official by both organizations. The free amino nitrogen methods use ninhydrin in the colorimetric reaction. The viscosity procedures measure flow times of the test materials against water. The methods have been adopted as official first action.
Semiautomated Method for Simultaneous Determination of Phosphorus, Calcium, and Crude Protein in Animal Feeds
Authors: Hambleton Larry G
Published: February 2020

A semiautomated method was developed for the simultaneous determination of phosphorus, calcium, and crude protein in animal feeds. Samples are digested with a block digestor, diluted to volume, and analyzed at the rate of 40 samples/hr. Protein is determined by the official AOAC method, by measuring the absorbance of an ammonia-salicylate complex at 660 nm. Phosphorus and calcium are determined by measuring the absorbances of the molybdovanadophosphate and calcium-cresolphthalein complexes at 420 and 570 nm, respectively. Samples are weighed according to the amount of protein they contain. Over 90% of the mixed animal feed samples analyzed for phosphorus and calcium fall within the range of the instrument; provisions are made for single determinations on those samples that fall outside the specified ranges. Results correlate well for the semiautomated method and official AOAC methods on mixed feed check samples and NBS Standard Reference Orchard Leaves.
Collaborative Study of an Assay for Progestational Steroids in Individual Contraceptive Tablets
Authors: Wu John Y P
Published: February 2020

A single tablet assay method has been developed for determining norethindrone, norethynodrel, and norgestrel in commercial contraceptive tablets. The steroid is separated from the tablet constituents on a diatomaceous earth column, the chloroform eluate is reacted with isonicotinic acid hydrazide, and the steroid is determined by colorimetry. Norethynodrel is isomerized to a conjugated ketosteroid before the colorimetric determination. Fourteen laboratories collaboratively tested the method. The average recoveries in 3 brands of tablets were as follows: 102.6% for the sample labeled as containing 0.35 mg norethindrone/tablet, 99.4% for the 2.5 mg norethynodrel/tablet, and 98.2% for the 0.5 mg norgestrel/tablet. The assay method has been adopted as official first action.
Spectrophotometric Determination of Diphenhydramine. HCl in Pharmaceutical Preparations
Authors: Maghssoudi Rostam H , Fawzi Ahmad B , Moosavi Meerkalaiee Majd Aldeen N
Published: February 2020

A new Spectrophotometric method has been developed for determining diphenhydramine. HCl, based on solvent extraction into chloroform of the complex formed with bromocresol green. The complex solution in chloroform showed maximum absorption at 415 nm and obeyed Beer’s law over the concentration range of 3.0–12.0 μg/ml. The molar absorptivity of the complex was 2.02 × 104. Complex formation and extraction was complete and quantitative over the pH range from 2 to 5. The ratio of diphenhydramine to bromocresol green was 1:1. Excipients, coloring matter, flavoring agents, and other substances likely to be present in diphenhydramine preparations do not interfere in the determination. Direct determinations in tablet, capsule, sirup, and lotion preparations were carried out satisfactorily, and the average recovery was 100±1.0%.
Gas-Liquid Chromatography of Picogram Quantities of Pyrethroid Insecticides
Authors: Chapman Ralph A , Simmons Herbert S
Published: February 2020

A gas-liquid chromatographic method is described for 4 newly developed pyrethroid insecticides: 3-phenoxybenzyl(±)-cis,trans-3-(2,2-dichlorovinyl)-2,2- dimethylcyclopropanecarboxylate, (±)-α-cyano-3-phenoxybenzyl(±)-2,2,3,3-tetramethylcyclopropanecarboxylate, (±)-α-cyano-3-phenoxybenzyl(±)-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, and (±)-α-cyano-3-phenoxybenzyl (±)-2-(4-chlorophenyl)-3-methylbutyrate. The compounds were stable and separated at 230°C on columns of 5% OV-101 on Gas-Chrom Q. All are strongly electron-capturing, allowing quantitation at the 20 pg level with a 63Ni electron capture detector.
Evaluation of Electrolytic Conductivity Detection for Gas-Liquid Chromatographic Screening of Some Organonitrogen Herbicides and Fungicides in Foods
Authors: Lawrence James F , McLeod Harry A
Published: February 2020

Electrolytic conductivity detection for the gas-liquid chromatographic (GLC) screening of 15 organonitrogen herbicides and fungicides was investigated. Spiked samples of crop material were extracted with acetone and the filtered sample extracts were partitioned with methylene chloride-petroleum ether (1+1) followed by second and third extractions with methylene chloride. The combined organic extracts were evaporated to dryness and the residues were dissolved in hexane for cleanup on a 2% deactivated Fiorisil column. The pesticide fractions were determined directly by GLC. All pesticides could be detected at 0.1 ppm in the foods studied.
Column Chromatographic Analysis of Barbiturates in Their Dosage Forms. IV. Combinations with Parabens
Authors: Barkan Susan , Doyle Thomas D
Published: February 2020

The nature of the alkaline hydrolysis of some barbiturates in combinations with parabens (p-hydroxybenzoates) was studied with controlled variables, including temperature, viscosity, and concentrations of sodium hydroxide, barbiturate, and parabens. The kinetic studies showed that parabens could be completely hydrolyzed in strong base at 40°C in 1 hr, while the barbiturate remained intact and was readily isolated by partition chromatography. Based on the theoretical results, a partition chromatographic procedure for butabarbital with parabens was devised. Standard recoveries averaged 100.7 % with a standard deviation of 0.89. Kinetic data indicate that the hydrolysis of parabens could also be applied to analyze combinations with amo-, seco-, and pentobarbitals. Phenobarbital and parabens are readily separated by partition chromatographic methods without prior hydrolysis of the parabens. The low extraction constant for phenobarbital allowed its retention on a column against relatively strong solvents while the intact parabens are eluted. A slightly modified method was applied to the separation of phenobarbital from parabens. Standard recoveries average 99.9% with a standard deviation of 0.69.
Extraction and Gas-Liquid Chromatographic Determination of Hexachlorophene from Several Plant Tissues
Authors: Van Auken Oscar W , Hulse Michael
Published: February 2020

Conditions are described for extraction, cleanup, derivatization, detection, and quantitation of hexachlorophene (HCP) residues from several types of plant material. Wet plant tissue was homogenized and extracted with ethyl ether, dried, and methylated with excess diazomethane. Samples were precleaned by column chromatography on silica gel with benzene-petroleum ether (1 + 1), and then 1–10 μI concentrated sample was chromatographed on a 6′ column of 3% SE-30 on 80–100 mesh Gas-Chrom Q. The detection limit for the electron capture detector was <0.1 ng dimethoxyhexachlorophene and 1 ppb HCP in plant tissue. Recoveries (%) of 11–610 pph HCP added to tissue averaged 94.3 for tomatoes, 86.4 for green peppers, 92.6 for cucumbers, 93.3 for green beans, 93.7 for peanut hay, and 91.6 for peanut shells.
Gas-Liquid Chromatographic Method for Determining Ethylenethiourea in Potatoes, Spinach, Applesauce, and Milk: Collaborative Study
Authors: Onley John H
Published: February 2020

Eight laboratories collaboratively tested a gas-liquid chromatographic method for determining ethylenethiourea (ETU) in potatoes, spinach, applesauce, and milk. In the determinative step, ETU is converted to the S-butyl derivative (2-n-butylmercapto-2-imidazoline) which is detected by a flame photometric detector, sulfur mode. For unknown fortification levels of 0.06, 0.12, and 0.30 ppm, the collaborators reported an overall average recovery range of 85–97% in the various commodities. The method has been adopted as interim official first action.
Spectrophotometric Determination of Some Preservatives in Milk
Authors: Wahbi Abdel-Aziz M , Abdine Hassan , Blaih Salah M
Published: February 2020

Benzoic acid, propyl p-hydroxybenzoate, and sorbic acid in milk have been determined by using the corresponding first derivative curves of absorption spectra of clarified milk samples. The ΔA/Δλ curves were computed and the concentration of each preservative was calculated using 1 point, 2 points, and/or 3 points. In all cases, the percentage error was within 2.4%.
Scanning Electron Microscopic Study of Adult Stored Product Beetle Mandibles
Authors: Kvenberg John E
Published: February 2020

Adult stored product beetle mandibles were used as a subject for this scanning electron microscopic study. A total of 34 species are represented. Discussion is organized taxonomically by family, and comparisons are made between species where possible. Established terminology for morphological processes has been applied to all characteristics of mandibles reported in earlier literature ; however, several new terms have been added in an attempt to better describe specific attributes of a species.
High Pressure Liquid Chromatographic Analysis of Food for Folates
Authors: Clifford Carolyn K , Clifford Andrew J
Published: February 2020

The multiplicity of naturally occurring chemical forms of folates and the lack of technology to measure these forms individually stimulated the application of high pressure liquid chromatographic procedures to the separation and quantitation of these compounds. Optimum conditions for separating a mixture of tetrahydrofolic acid (THF), N5-methyltetrahydrafolic acid (N5-CH3-THF), dihydrofolic acid (DHF), and folic acid (FA) were established for a pellicular strong anion exchange resin (0.01 × 300 cm) and a potassium chloride gradient in phosphate buffer at pH 7.5, 40°C, flowing at 15.2 ml/hr. The order of elution was THF, N5-CH3-THF, DHF, and FA. The coefficients of variation for standard peak area responses ranged from 5 to 8%, and for retention times from 1.3 to 1.8%. Separations were dependent on the substitution on the pteridine portion of the molecule and were independent of the number of glutamic acid residues. Compounds were completely separated in less than 75 min. The smallest amount of folic acid which could be measured reliably was 0.035 nmole/10 μl placed on the column. Peak area response to each folate increased linearly to at least 0.21 nmole/10 μl. The relative contribution of each of the 4 folates to the total folate content of a number of fruit juices and foods differed markedly and may be related to the relative availability of folate from these sources.
Polarographic Determination of Robenidine Residues in Chicken Tissues, Eggs, Litter, Soil, and Plant Tissue
Authors: Smith John E , Pasarela N Robert , Wyckoff John C
Published: February 2020

Polarographic residue methods have been developed for determining robenidine (Robenz), 1,3-bis[(p-chlorobenzylidene)amino]. guanidine monohydrochloride, in chicken tissues, eggs, litter, soil, and plants. The compound is extracted from chicken fat, skin, muscle, liver, and eggs with ethyl acetate; from blood with acetone; from plant tissue, litter, and kidney with acidic acetone; and from soil with basic methanol. After extraction by high-speed blending or overnight shaking, the extract is cleaned up by evaporation, solvent partition, and/or elution from CG-50 ion exchange resin. Robenidine is quantitated by differential cathode ray polarography, using acidic aqueous methanol or acetic acid (1+1) supporting electrolyte. Recoveries ranged from 64 to 125% with an average overall recovery of 90%. The validated sensitivity is 0.1 ppm for chicken tissues, soil, and plants, 0.01 ppm for eggs, and 1 ppm for litter.
High Pressure Liquid Chromatographic Determination of Saccharin in Alcoholic Products
Authors: Tenenbaum Milton , Martin Glenn E
Published: February 2020

After preliminary cleanup, sodium saccharin can be quantitatively determined in wines and proprietary drugs by using high pressure liquid chromatography. The preliminary cleanup removes materials that cause column deterioration, loss of baseline stability, and interfering peaks. The average experimental error found in analyses of 6 wines for sodium saccharin content was 2.3% and the standard deviation was 0.01. In the analysis of 10 cough medicines and vitamin preparations, the difference between declared and experimental values for sodium saccharin averaged 5.7%. The recovery for the extraction process ranged from 97.8 to 101.6%.
Comparison of Methods for Determining Probenecid in Tablets and Flavored Oral Suspensions Containing Ampicillin
Authors: Vollmer Paul J , Chastonay Richard , Haneke Carol , Kantor Nathan , Blyth Robert
Published: February 2020

Several methods for quantitating probenecid were compared: USP XIX method for probenecid in tablets, a modified USP extraction method for probenecid in tablets, a new column extraction method for probenecid in tablets and oral suspensions containing ampicillin, and a high pressure liquid chromatographic (HPLC) method for probenecid in tablets and oral suspensions containing antibiotics. The first 3 methods were satisfactory for probenecid in bulks and tablets but proved unsatisfactory for oral suspensions containing flavors. The flavors gave positive interference for probenecid in oral suspensions. The HPLC method, although more time-consuming, separated probenecid from excipients, thus eliminating positive interference from flavors.
Quantitative Gas-Liquid Chromatographic Method for Sodium Fluoroacetate
Authors: Stahr Henry M
Published: February 2020

The original gas-liquid chromatographic method for determining sodium fluoroacetate, 1080, involving the preparation of the methyl ester, has been modified for quantitative application to biological tissue, food, and bait samples. Changes include increasing the sample size to 20 g, increasing the esterification reaction time to 20 hr, and increasing the amount of ethyl ether extractant to 120 ml. With these modifications, recoveries of radiolabeled 1080 averaged 85%.
The effect of reproductive loss on the performance of a research flock
Authors: Shorten Paul R , Edwards Sara J , Juengel Jenny L
Published: February 2020

The reproductive performance of a sheep flock is dependent on a multitude of complex interacting factors. Achieving optimal flock performance requires knowledge of the reproductive steps and how these are linked and related to available measurements of the state and performance of the flock. The goal was to use previously collected data from a research flock that had undergone selection for fecundity (11,369 lambing records), to model the key reproductive steps affecting flock reproductive performance. The model was used to investigate how changes in liveweight, age, ovulation rate, number of fetuses at midpregnancy, number of lambs born, and birthweight affect the number of lambs weaned and the weaning weight of each lamb in this flock. The data available from the research flock were used to parameterize models of each reproductive step and assess the role of ewe age and premating liveweight on each reproductive step. These models were then linked together as a simulation tool to assess the role of different parameters on flock reproductive performance, which was defined as the total weight of lambs weaned per ewe exposed to the ram. Flock elasticities were calculated that characterize the relative importance of the effect of average premating ewe liveweight (0.81), average ovulation rate (0.33), variance in ovulation rate (−0.095), embryo survival (0.72), lamb survival (1.03), conception failure (0.35), and average ewe age (0.056) on the total kilograms of lamb liveweight at weaning per ewe exposed to the ram. The largest elasticity for lamb survival indicated that a 1% increase in lamb survival is expected to have a 1.03% increase in the total kilograms of lamb liveweight at weaning per ewe exposed to the ram in this flock. Assuming similar costs, interventions to increase lamb survival for this flock will provide the largest increase in the total kilograms of lamb liveweight at weaning per ewe exposed to the ram, which is a key metric of flock performance.
Influence of sodium chlorate, ferulic acid, and essential oils on Escherichia coli and porcine fecal microbiota
Authors: Arzola-Alvarez Claudio , Hume Michael E , Anderson Robin C , Latham Elizabeth A , Ruiz-Barrera Oscar , Castillo-Castillo Yamicela , Olivas-Palacios Ana Luisa , Felix-Portillo Monserrath , Armendariz-Rivas Ruth L , Arzola-Rubio Alejandro , Ontiveros-Magadan Marina , Bautista-Martínez Yuridia , Salinas-Chavira Jaime
Published: February 2020

The influence of sodium chlorate (SC), ferulic acid (FA), and essential oils (EO) was examined on the survivability of two porcine diarrhetic enterotoxigenic Escherichia coli (ETEC) strains (F18 and K88) and populations of porcine fecal bacteria. Fecal bacterial populations were examined by denaturing gradient gel electrophoresis (DGGE) and identification by 16S gene sequencing. The treatments were control (no additives), 10 mM SC, 2.5 mg FA /mL, a 1.5% vol/vol solution of an EO mixture as well as mixtures of EO + SC, EO + FA, and FA + SC at each of the aforementioned concentrations. EO were a commercial blend of oregano oil and cinnamon oil with water and citric acid. Freshly collected porcine feces in half-strength Mueller Hinton broth was inoculated with E. coli F18 (Trial 1) or E. coli K88 (Trial 2). The fecal-E. coli suspensions were transferred to crimp top tubes preloaded with the treatment compounds. Quantitative enumeration was at 0, 6, and 24 h. All treatments reduced (P < 0.05) the counts of E. coli F18 at 6 and 24 h. With the exception of similarity coefficient (%SC), all the other treatments reduced (P < 0.05) the K88 counts at 24 h. The most effective treatments to reduce the F18 and K88 CFU numbers were those containing EO. Results of DGGE revealed that Dice percentage similarity coefficients (%SC) of bacterial profiles among treatment groups varied from 81.3% to 100%SC. The results of gene sequencing showed that, except for SC at 24 h, all the other treatments reduced the counts of the family Enterobacteriaceae, while Lactobacillaceae and Ruminococcaceae increased and Clostridiaceae decreased in all treatments. In conclusion, all treatments were effective in reducing the ETEC, but EO mixture was the most effective. The porcine microbial communities may be influenced by the studied treatments.
Compulsive collectors
Authors: Krakus Anna
Published: February 2020

Oscar-winning film director Andrzej Wajda (1929–2016) was an avid collector of all information relating to himself and his film-making. In 1978 he made a documentary film about a fellow collector, Ludwig Zimmerer (1924–1987), who accumulated thousands of paintings and objects of Polish folk art. This article tells the stories of these two men and their collections. I suggest that an investigation into the lives and times of Wajda and Zimmerer can shed new light on the psychological processes that inform collecting. Rather than dismissing the compulsion to collect as a product of neurosis, as some previous interpretations have done, I argue here that we should read it as a productive and compensatory method for curing addictions.
Evaluating Treatment Tolerability in Cancer Clinical Trials Using the Toxicity Index
Authors: Gresham Gillian , Diniz Márcio A , Razaee Zahra S , Luu Michael , Kim Sungjin , Hays Ron D , Piantadosi Steven , Tighiouart Mourad , Yothers Greg , Ganz Patricia A , Rogatko André
Published: February 2020

Background

The National Cancer Institute Moonshot research initiative calls for improvements in the analysis and reporting of treatment toxicity to advise key stakeholders on treatment tolerability and inform regulatory and clinical decision making. This study illustrates alternative approaches to toxicity evaluation using the National Surgical Adjuvant Breast and Bowel Project R-04 clinical trial as an example.

Methods

National Surgical Adjuvant Breast and Bowel Project R-04 was a neoadjuvant chemoradiation trial in stage II–III rectal cancer patients. A 2 x 2 factorial design was used to evaluate whether the addition of oxaliplatin (Oxa) to 5-fluorouracil (5FU) or capecitabine (Cape) with radiation therapy improved local-regional tumor control. The toxicity index (TI), which accounts for the frequency and severity of toxicities, was compared across treatments using multivariable probabilistic index models, where Pr A < B indicates the probability that higher values of TI were observed for A when compared with B. Baseline age, sex, performance status, body mass index, surgery type, and stage were evaluated as independent risk factors.

Results

A total of 4560 toxicities from 1558 patients were analyzed. Results from adjusted probabilistic index models indicate that oxaliplatin-containing regimens had statistically significant (P < .001) probability (Pr) for higher TI compared with regimens without oxaliplatin (Pr 5FU < 5FU + Oxa = 0.619, 95% confidence interval [CI] = 0.560 to 0.674; Pr 5FU < Cape + Oxa = 0.627, 95% CI = 0.568 to 0.682; Pr Cape < 5FU + Oxa = 0.587, 95% 0.527 to 0.644; and Pr Cape < Cape + Oxa = 0.596, 95% 0.536 to 0.653). When compared with other existing toxicity analysis methods, TI provided greater power to detect differences between treatments.

Conclusions

This article uses standard data collected in a cancer clinical trial to introduce descriptive and analytic methods that account for the additional burden of multiple toxicities. These methods may provide a more accurate description of a patient’s treatment experience that could lead to individualized dosing for better toxicity control. Future research will evaluate the generalizability of these findings in trials with similar drugs.
Public Capacity, Plural Forms of Collaboration, and the Performance of Public Initiatives: A Configurational Approach
Authors: Lazzarini Sergio G , Pongeluppe Leandro S , Ito Nobuiuki C , Oliveira Felippe de Medeiros , Ovanessoff Armen
Published: February 2020

We assess conditions that explain plural forms of public and private action using a comparative study of 24 public initiatives in Brazil, India, and South Africa. Measuring performance as evidence of positive outcomes to their target populations, we compare cases of high and low performance. Our configurational approach examines combinations of conditions leading to positive outcomes: public operational capacity, diverse collaborations nurtured by public units (with for-profit firms, with nonprofit organizations, and with other units in the public bureaucracy), and stakeholder orientation (permeability to multiple sources of input to design and adjust the project). We apply fuzzy set qualitative comparative analysis to unveil configurations consistent with high performance. Our configurational analysis reveals two distinct paths to high performance. A path with higher private engagement involves concurrent collaborations with for-profit and nonprofit actors, whereas an alternative path with higher internal (public) engagement relies on collaborations within the public bureaucracy complemented by high permeability to inputs from multiple stakeholders. Our results also confirm that strong public capacity is necessary in all high-performance configurations. An important implication is that externalization and multiple forms of collaboration are not substitutes for weak governments. Furthermore, our configurational perspective contributes to the literature by operationalizing a multiple-actor, multiple-logic perspective describing alternative paths to high performance.
Fumarase-deficient uterine leiomyoma: a case of a rare entity and surgical innovation
Authors: Lee Hong , Shafiezadeh Saman , Singh Rajeev
Published: February 2020

We report a case of a 47-year-old female, with strong preoperative clinical and radiological suspicious of uterine leiomyosarcoma who underwent a total abdominal hysterectomy. Despite the final histology concluded as benign uterine leiomyoma, the loss of fumarate hydratase expression of the same specimen still put her at risk of having hereditary leiomyomatosis and renal cell carcinoma syndrome. Intraoperatively, an obstetric vacuum cup was used for uterine manipulation to avoid breaching of the uterine serosa.
Molecular genetic analyses of abiotic stress responses during plant reproductive development
Authors: Ma Xinwei , Su Zhao , Ma Hong
Published: February 2020

Plant responses to abiotic stresses during vegetative growth have been extensively studied for many years. Daily environmental fluctuations can have dramatic effects on plant vegetative growth at multiple levels, resulting in molecular, cellular, physiological, and morphological changes. Plants are even more sensitive to environmental changes during reproductive stages. However, much less is known about how plants respond to abiotic stresses during reproduction. Fortunately, recent advances in this field have begun to provide clues about these important processes, which promise further understanding and a potential contribution to maximize crop yield under adverse environments. Here we summarize information from several plants, focusing on the possible mechanisms that plants use to cope with different types of abiotic stresses during reproductive development, and present a tentative molecular portrait of plant acclimation during reproductive stages. Additionally, we discuss strategies that plants use to balance between survival and productivity, with some comparison among different plants that have adapted to distinct environments.