bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of heat treatment on properties of SD251-PH1 composite produced by additive SLM technology
Authors: Bricín David , Jansa Zdeněk , Somr Josef , Elmanová Andrea , Kříž Antonín
Published: February 2020

This study evaluates how heat treatment affects the structure and properties of the engineered composite material SD251-PH1. This material was formed by mixing two powder blends in a weight ratio of 90 wt. % WC-Co powder SD251 with 10 wt. % of a PH1 precipitation hardening powder of the stainless steel. Samples were prepared from this mixture on an SLM additive device. The printed samples were then divided into groups. Some of them were left in the initial state and the rest were used for heat treatment based on the standard AMS 5659. Light and electron microscopy metallographic analysis together with X-ray diffraction analysis were then used to evaluate structural and phase changes in the prototype samples. The main attention was paid to changes in the phase composition of the samples. In addition, changes in the size and shape of the pores and tungsten carbide (WC) grains were studied. The metallographic analysis was supplemented by an evaluation of the changes in their mechanical properties and wear resistance. Vickers hardness measurements and the ball on disc test were used for this purpose. The experiments showed that the selected heat treatment processes precipitated new structural phases which differed from the original sample structure in terms of shape, size, chemical composition, and mechanical properties.
Why the moral equality account of the hypocrite’s lack of standing to blame fails
Authors: Lippert-Rasmussen Kasper
Published: February 2020

It is commonly believed that blamees can dismiss hypocritical blame on the ground that the hypocrite has no standing to blame their target. Many believe that the feature of hypocritical blame that undermines standing to blame is that it involves an implicit denial of the moral equality of persons. After all, the hypocrite treats herself better than her blamee for no good reason. In the light of the complement to hypocrites and a comparison of hypocritical and non-hypocritical blamers subscribing to hierarchical moral norms, I show why we must reject the moral equality account of the hypocrite’s lack of standing to blame.
Global Needs-Assessment for a Postgraduate Program on Nonsurgical Facial Aesthetics
Authors: Kumar Narendra , Rahman Eqram
Published: February 2020

Background

Standardizing training and education in nonsurgical facial aesthetic procedures during residency training has long been challenging because majority of the procedures are performed outside the usual teaching hospital settings. Several areas of refinement have been suggested and an increased need for more hands-on training identified in the available literature. Despite the growing demand for nonsurgical facial aesthetics (NSFA), it is yet to be fully integrated into standard postgraduate medical or surgical curriculum.

Objectives

The objective of this study was to explore the current state and the need for medical education and training of aesthetic clinicians across specialties in a formal postgraduate curriculum.

Methods

A mixed-method, cross-sectional, online research was conducted among physicians involved in training and practicing NSFA between July 2018 and December 2018. Focus group discussion was conducted to ensure the face and content validity of the survey items.

Results

The total responses collected in the trainer’s group was 179 and 496 in the trainee’s group. The majority of trainers (95%) and trainees (93.8%) across specialties expressed their opinion for the need of a standard postgraduate course in NSFA. Moreover, more than 55% of them felt that 12 months, with a work-based, blended learning approach, would be most suitable for training and education.

Conclusions

The survey results have underlined the need for specialized training in NSFA to enable clinicians to pursue independent practice with confidence. The authors recommend the inclusion of evidence-based postgraduate programs on NSFA in higher academic institutions as per their educational curriculum.
Weather stochasticity and alternative reproductive tactics in Northern chamois, Rupicapra rupicapra
Authors: Corlatti Luca , Bassano Bruno , Lovari Sandro
Published: February 2020

In polygynous ungulates, male breeding success is often achieved through alternative reproductive tactics (ARTs). The maintenance of ARTs in this taxon is largely explained by condition-dependent selection, a decision rule in which individuals switch their breeding behaviour on the basis of internal factors such as ageing (status-dependent selection), or external factors such as weather conditions during the rut (environment-dependent selection). In some species, however, ARTs are fixed during the mating season, and other forms of selective pressures rather than environment-dependent selection may contribute to the evolutionary maintenance of male types within populations. Assuming female vicinity as a proxy of mating opportunity, we explored the effect of snow depth variations on the elevational overlap between females, and territorial and non-territorial male chamois, Rupicapra rupicapra, in three consecutive rutting seasons. In snow-free periods, females overlapped with non-territorial males, but not with territorial ones. With increasing snow depth, females and territorial males progressively occupied similar elevations. Our results suggest that snow cover variations may impose changes in the spatial distribution of males and females. In turn, weather stochasticity over multiple ruts, rather than within-rut environment-dependent selection, may impose variations in mating opportunities of ARTs, possibly contributing to the coexistence of different phenotypes within populations.
Stock assessment and management of cephalopods: advances and challenges for short-lived fishery resources
Authors: Arkhipkin Alexander I , Hendrickson Lisa C , Payá Ignacio , Pierce Graham J , Roa-Ureta Ruben H , Robin Jean-Paul , Winter Andreas
Published: February 2020

Cephalopods have become an important global food source, but their sustainable management is challenged by unique life history characteristics associated with short lifespans and semelparous reproduction, high natural mortality rates, rapid and often nonasymptotic growth, and complex population structures. Weak stock-recruitment relationships together with the time-consuming work required for age validation and high-volume annual age determinations make traditional age-based modelling impractical. We propose that the best method for cephalopod assessment involves innovative depletion models, fitted with in-season data on catch numbers and fishing effort, to produce realistic estimates of stock biomass. A “fast lane” assessment approach is suggested that includes high-frequency data collection for separate, in-season stock assessments of each cohort to ensure sustainable exploitation of these short-lived resources. However, most cephalopod fisheries are data-poor and/or lack the infrastructure and resources needed to apply depletion methods; therefore, we also present alternative assessment methods that have been recently applied worldwide. We also offer suggestions for further research on the remaining challenges of cephalopod stock assessment and management.
Reduced growth in Baltic Sea cod may be due to mild hypoxia
Authors: Brander Keith
Published: February 2020

Daily food consumption by small Baltic Sea cod has declined in recent decades, resulting in reduced growth and biomass. Declining oxygen may cause lower production of benthic prey for small cod, but an alternative explanation presented here is that the mildly hypoxic conditions that small cod experience reduces their rate of digestion and hence food consumption. Better information about the distribution and behaviour of small cod and their metabolic response to low oxygen levels is required.
A second-order asymptotic model for Rayleigh waves on a linearly elastic half plane
Authors: Wootton Peter T , Kaplunov Julius , Prikazchikov Danila
Published: February 2020

We derive a second-order correction to an existing leading-order model for surface waves in linear elasticity. The same hyperbolic–elliptic equation form is obtained with a correction term added to the surface boundary condition. The validity of the correction term is shown by re-examining problems which the leading-order model has been applied to previously, namely a harmonic forcing, a moving point load and a periodic array of compressional resonators.
Characterization of viral rebounds on dual etravirine/raltegravir maintenance therapy (ANRS-163 ETRAL trial)
Authors: Soulie Cathia , Assoumou Lambert , Abdi Basma , Sayon Sophie , Nguyen Thuy , Valantin Marc-Antoine , Beniguel Lydie , Ferre Virginie , Alloui Chakib , Montes Brigitte , Avettand-Fenoel Véronique , Delaugerre Constance , Descamps Diane , Martinez Esteban , Reynes Jacques , Peytavin Gilles , Costagliola Dominique , Katlama Christine , Calvez Vincent , Marcelin Anne-Geneviève ,   the ANRS-163 ETRAL study group, Bernard Louis , Bottero Julie , Bouchaud Olivier , Chidiac Christian , Duvivier Claudine , Goujard Cécile , del Mar Gutiérrez Maria , Martinez Esteban , Molina Jean-Michel , Morlat Philippe , Naqvi Alissa , Podzamczer Daniel , Poizot-Martin Isabelle , Raffi François , Reynes Jacques , Salmon-Céron Dominique , Simon Anne , Valantin Marc-Antoine , Weiss Laurence , Yazdanpanah Yazdan
Published: February 2020

Background

The ANRS-163 ETRAL trial, a switch study to an etravirine 200 mg/raltegravir 400 mg twice-daily regimen in 165 patients with HIV-1 infection, showed durable efficacy until Week 96. The aim of this work was to investigate in detail the virological rebounds (VRs), defined as at least one plasma HIV viral load (VL) >50 copies/mL.

Methods

Quantification of HIV-DNA level was assessed at baseline, Week 48 and Week 96 (n = 157). VLs were measured in seminal plasma at Week 48 (n = 26). Genotypic resistance testing by ultra-deep sequencing (UDS) for reverse transcriptase (RT) and integrase regions was performed at baseline and at the time of VR.

Results

In this study, 19 patients experienced VR, with 2 patients having virological failure (VF; two consecutive VLs >50 copies/mL). For the first patient with VF, UDS detected minority resistant variants only in RT (K103N, 9.6%; Y181C, 4.9%) at baseline. Some RT variants became dominant at VF (K101E, 86.3%; Y181C, 100.0%; G190A, 100.0%) and others emerged in integrase (Y143C, 2.4%; Q148R, 6.2%; N155H, 18.8%). For the second patient with VF, neither RT nor integrase mutations were detected at baseline and VF. Median HIV-DNA level was similar at baseline, Week 48 and Week 96 (2.17, 2.06 and 2.11 log10 copies/106 cells, respectively). Only one patient had a detectable seminal HIV VL (505 copies/mL).

Conclusions

The dual etravirine/raltegravir regimen as maintenance therapy was effective and the emergence of mutations in cases of VF was similar to that seen in other dual-regimen studies. No HIV-DNA level modification was evidenced by Week 96.
Ethopabate in Feeds
Authors: Szalkowski C P
Published: February 2020

Collaborative study was made of a method for determining ethopabate, a coccidiostat used in conjunction with amprolium. The method involves: (a) complete extraction of ethopabate from the feed by chloroform; (b) removal of most interfering substances from the chloroform extract by washing with diluted hydrochloric acid; (c) conversion of the extracted ethopabate to free amine by controlled acid hydrolysis; (d) diazotization and coupling of the free amine; (e) extraction of colored complex with ra-butanol and measurment at 555 mμ. Unmedicated commercial poultry feeds assayed by this method showed an apparent ethopabate content of 0.2—0.4 ppm. These same feeds were blended with a premix of ethopabate at levels of 4 ppm and 125 ppm amprolium. The recoveries obtained ranged from 96 to 105%. This assay method is suitable for the determination of ethopabate down to levels of 2 ppm, and is recommended for adoption as official, first action.
Determination of Nicotine in Feeds
Authors: Root David E
Published: February 2020

Nicotine, used in medicated animal feed in combination with phenothiazine, dibutyl tin dilaurate, and 2,2'-dihydroxy-5,5’-dichlorophenyl methane, has been successfully isolated from these compounds and the feed interferences and cleaned up by extraction with 0.5% NaOH, steam distillation f r om this basic solution, and extraction from the aqueous phase with chloroform. The nicotine is then partitioned into 0.05iV HC1, and determined by ultraviolet spectrophotometry. A collaborative study yielded 9 0% over-all recoveries, and the method is recommended for adoption as official, first action.
Collaborative Study of the Infrared Method for DDVP in Pesticide Formulations
Authors: Mitchell L E
Published: February 2020

A collaborative study was conducted to evaluate an infrared method for determining the DDVP content of four commercially available formulations: 0.5% sugar bait, 4 1b/gallon emulsible concentrate, 0.5% spray solution, and 1.0% cattle spray. A chloroform extraction procedure and a chloroform dilution procedure gave reproducible results for sugar bait and emulsible concentrate samples, respectively. Two procedures, acetonitrile and solvent compensation, were tried for the lowconcentration hydrocarbon solutions. Neither procedure gave completely satisfactory results and further study is needed.
Rapid Method for MCP in Soil by Electron Affinity Determination of 2-Chloroethyl Ester
Authors: Gutermann Walter H , Lisk Doxald J
Published: February 2020

In developing a rapid method for MCP in soil, it was found that MCP had to be esterified with 2-chloroethanol to increase its response to electron affinity detection. The method is sensitive to about 0.5 ppm MCP; recoveries of 1 and 2 ppm from soil were 79 and 83% and 103 and 107%, respectively. MCP could not be detected in MCPB-treated soil.
Dextrose Determination in Honey: A Rapid Photometric Determination
Authors: White Jonathan W
Published: February 2020

The granulating tendency of honey may be predicted by the dextrose-water ratio. The reducing disaccharides in honey complicate the determination of dextrose by routine procedures. True glucose can be determined in honey with a glucose oxidase reagent in which the contaminant alpha-glucosidase activity is inhibited. Accuracy and precision of the method are comparable with those of the selective adsorption procedure, and it is more suitable for routine control use.
Total Solids in Processed Vegetables
Authors: Lamb Frank C
Published: February 2020

A method was developed for total solids in processed vegetable products, involving diluting with diatomaceous earth, predrying by any of three procedures, and final drying in vacuo for 2 hours at 69-71°. The new method was found to give lower results than the official method on all products tested except pork and beans and baked beans. In a collaborative study by 17 analysts in 9 laboratories, the new method was slightly more precise than the official method, but its main advantage was in providing greater flexibility in sample size and predrying conditions, and in requiring less time for an analysis. The major sources of error in both methods appeared to be deficiencies in the vacuum ovens used and lack of skill of the individual analysts.
Revision of the AOAC Sediment Test for Milk
Authors: Joiner Curtis R
Published: February 2020

A modified procedure, 36.009 (e), for sifting materials used to prepare fine sediment standards was adopted in 1959 to promote uniformity. Later work showed that the appearance of the standards was altered by the change. The more rigid conditions of sifting produced more uniform particle size, with fewer particles in a given weight of sediment. Sifting freshly dried, still warm materials in 25— 50 g batches gave uniform results. When these materials were sifted for a double 5 minute period on a nested No. 140 over a No. 230 sieve, the "on 230" fractions satisfactorily matched standards prepared and presented in 1953. However, the new standards were improved by adding to the sediment mixture 10% of materials passing a No. 120 but retained on a No. 140 sieve. Sediment tests of bulk tank milk are commonly made by filtering 1-pint mixed samples through a 0.40" diameter area instead of the usual 1⅛" diameter area. Standards 0.40" in diameter are used to judge these tests. Two methods are commonly used to grade both sizes of standards: "to the line," and to the nearest standard disk. It is recommended that a collaborative study be made of the procedure, with these changes incorporated for more uniformity.
A Chemically Defined Medium for Disinfectant Testing
Authors: Pelczar Michael J
Published: February 2020

A synthetic broth has been developed as a culture medium for use in disinfectant testing procedures, 5.001— 5.005. Collaborative testing of the Wright- Mundy medium revealed satisfactory performance, and the medium is recommended for adoption as official, first action, as an alternative medium for disinfectant testing.
Chromatographic Detection of Flavor Additives in Vanilla Extract
Authors: Kahan S , Fitelson J
Published: February 2020

Two chromatographic methods, one a thin-layer technique and the other paper chromatography, were developed for five flavoring additives and submitted to collaborative study. The thinlayer method gave good results and proved to be a rapid and sensitive test. However, some of the features of the method required further study to improve the identification of the separated spots. A better test for coumarin and another solvent giving greater separation between the ethyl vanillin and veratraldehyde spots were developed. The modified method has been recommended for adoption as official, first action. Some analysts attained good results with the paper chromatographic test; others, even experienced analysts, got poor results. Some of the difficulty was traced to variations in composition of reagents, but the method needs further study to standardize conditions. This method was not recommended for adoption. The proposed chromatographic thin-layer method offers a rapid means of detecting ethyl vanillin, veratraldehyde (methyl vanillin), coumarin, piperonal (heliotropin), and vanitrope (propenyl guaethol).
Organic Acids in Vanilla Extract
Authors: Fitelson J
Published: February 2020

Further collaborative studies were made of the gradient elution and paper chromatographic methods for organic acids in vanilla extract, both adopted as official, first action in 1962. The gradient elution method was studied by six collaborators on three samples. All six detected the presence of added foreign acid. The paper chromatographic method was studied by 16 collaborators on four unknown samples and one reference standard vanilla. Results were very good. It is recommended that both methods be made official, final action.
Hydrocarbon Propellants in Self-Pressurized Containers
Authors: Keppel George E
Published: February 2020

A study was undertaken to determine whether the present official flammability tests for self-pressurized containers or aerosols are suitable for those containing hydrocarbon propellants. Fifty aerosols, five containing hydrocarbon propellants, were examined by the official methods for flammability (flame projection and flash point tests), and by other tests. Official tests detected the extremely flammable component in only one of the five highly flammable samples, a paint preparation. Of 24 samples examined for propellant identity, 5 contained hydrocarbon propellants, 10 contained hydrocarbon and fluorocarbon mixtures, and the remaining 9 contained fluorocarbons only. The present official flammability tests are not entirely suitable for self-pressurized containers with flammable propellants, and studies on flammable substances in pressurized containers should be continued.
Free Water in Fertilizers by Karl Fischer Titration
Authors: Caro Joseph H
Published: February 2020

A method is proposed for free water in fertilizer, which involves extraction with p-dioxane and titration of the extract with Karl Fischer reagent. Preliminary tests established the most suitable experimental conditions and showed p-dioxane to be the most feasible extractant for fertilizers. In comparison with the official vacuum desiccation method, Karl Fischer extraction-titration gave results for water averaging 0.22% lower on 11 test materials. Because of the inherent positive error of weight loss methods, the lower values are considered to be reasonable.
The Metabolism and Persistence of Systox, Diazinon, and Phosdrin on Field-Sprayed Lettuce
Authors: Coffin D E , Mckinley W P
Published: February 2020

Three organophosphate pesticides (Systox, Diazinon, and Phosdrin) were applied individually to field plots of lettuce. Samples were removed at various times after spraying and examined for residues and metabolites of the pesticides

The two isomers of Systox rapidly disappeared from the lettuce, but two toxic metabolites were formed and persisted up to 2 weeks after spraying. No metabolites were discovered on lettuce which had been sprayed with Phosdrin or Diazinon. Residues of Phosdrin had decreased to less than 0.1 ppm 3 days after spraying. Residues of Diazinon were less than 0.1 ppm at 10 days and were present at detectable levels 14 days after spraying.
Cleanup Method for Electron Capture Determination of Endrin in Fatty Vegetables
Authors: Albert Richard A
Published: February 2020

A method has been developed in which a KOH-Celite column is used instead of the longer saponification method for cleanup of vegetables, reducing the time of analysis by about 2 hours. The method involves fewer sample transfers, thereby increasing the per cent recovery. Good results were obtained with samples of carrots, onions, collards, and broccoli.
Artificial Flavors in Blended Oils: Detection of Ethyl Butyrate by Gas Chromatography
Authors: Ratay A F
Published: February 2020

A procedure is described for detecting ethyl butyrate in olive oil and other vegetable oils. Volatiles are isolated from the oil by steam distillation, and the distillate is extracted with methylene chloride. The ethyl butyrate in the solution is determined by gas chromatography at a column temperature of 100 °C in a thermal conductivity cell on a 6’ × 1/4” i.d. stainless steel column, packed with 2 0% diethylene glycol succinate polyester on 60—80 mesh, acidwashed Chromosorb W. The method detects 0.001% or less of ethyl butyrate in olive oil and other vegetable oils. Recoveries from known olive oil blends were 66–100%.
A Comparison of the Quinoline Molybdate and the Volumetric Method for Total Phosphorus in Food and Food Products
Authors: Whitley Voyce P
Published: February 2020

The quinoline molybdate method for total phosphorus in food and food products was compared with the volumetric method for total phosphorus, 2.020. Values obtained by both methods were in good agreement. Small amounts of tin interfered with the phosphorus de-termination in fruits and juices; HBr added to the ash prior to HC1 extraction yielded a tin-bromine compound that could easily be removed at low temperatures. Studies will be continued to determine the effect of acid concentration on the phosphorus recovery.
Determination of Compounds Related to Vanillin in Vanilla Extracts
Authors: Smith D Morison
Published: February 2020

A method has been developed for the estimation of the quantities of vanillic acid, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde in vanilla extracts. This method separates these compounds from each other and from vanillin by two-dimensional paper chromatography. An estimate of the quantity of each of these compounds is obtained by measuring the area of the colored spot produced on reacting the compounds with chromogenic reagents. The vanillin content was also determined by two different methods. Vanilla planifolia was found to have an unidentified phenolic component not present in V. tahitensis. The Tahiti vanillas contained over twice as much p-hydroxybenzoic acid as any other vanilla extracts.
Quantitative Infrared Determination of the Isomers of Ethylbenzylaniline Sulfonic Acid
Authors: Wilson Clifton H , Dolinsky Meyer
Published: February 2020

A simple analytical procedure is described for determining the three isomers of N-ethyl-N-phenyl benzylamine sulfonic acid. The sulfonic acids are converted to their LA-2 resin salts, dissolved in carbon disulfide, and analyzed by infrared spectrophotometry.
Microbiological Assay of Low Chlortetracycline Concentrations in Animal Feeds
Authors: Abbey Anthony , Hewel David B
Published: February 2020

Satisfactory microbiological values were obtained for animal feeds containing low levels of cblortetracycline (CTC), 5.0–40g CTC/ton. Results were comparable when calculated against both compensating CTC standard curves prepared from blank feed extracts and laboratory-inactivated CTC feed extracts. The inactivation of CTC in animal feed extracts by 5.25% sodium hypochlorite solution and heat was investigated, and it appeared to offer a convenient alternative for preparing compensating CTC standard curves.
Qualitative Determination of Sulfa Drugs in Medicated Feeds by Thin-Layer Chromatography
Authors: Alexander Leland R , Stanley Eugene R
Published: February 2020

Sulfacetamide, sulfadiazine, sulfaquinoxaline, sulfamerazine, sulfamethoxypyridazine, sulfamethazine, and sulfanilamide are extracted from a medicated feed with acetone. The acetone is evaporated, the residue is taken up in basic solution, and the interfering material is extracted from the basic solution with chloroform. The basic solution is then made acidic and evaporated to dryness. The sulfas are extracted from the residue with acetone, separated, and identified by thin-layer chromatography. Methanol-chloroform (3 + 7) is used as mobile solvent; an acidic solution of dimethylaminobenzaldehyde in ethanol is used as the chromogenic agent. The method easily detects and identifies 1 μg of the individual sulfas.
Ethopabate in Feeds
Authors: Szalkowski C R
Published: February 2020

A collaborative study was completed on a method for the determination of ethopabate. Ethopabate is extracted from the feed with 50% methanol at room temperature, and separated from amines by chloroform extraction. The chloroform extract is washed with sodium carbonate solution to remove interfering drugs, if present. Chloroform is removed by evaporation, and the ethopabate residue is hydrolyzed with HCI to the free amine, which is diazotized and coupled. The colored compound is extracted and measured at 555 mμ against pure reference standard ethopabate. Unmedicated commercial poultry feeds showed an apparent ethopabate content of 0.2–0.5 ppm. Recoveries from these same feeds after medication with ethopabate ranged from 96 to 105%. This assay method is suitable for determining ethopabate down to 2 ppm and is recommended for adoption as official, first action, for all levels of ethopabate.
Spectrophotometric Determination of Thiabendazole in Feeds
Authors: Szalkowski C R , Kanora J
Published: February 2020

An improved method has been developed for thiabendazole in feeds. Thiabendazole is extracted from the feed with 0.2N HCl in 50% methanol; interfering substances are removed by making the extract alkaline and extracting into chloroform. The thiabendazole is re-extracted with dilute HCl; the solution is reduced with zinc dust in the presence of p-phenylenediamine to form a hydrogen sulfide complex. After subsequent oxidation with ferric solution to form a thiazine dye, the dye is extracted into n-butanol and measured at 605 mμ. More than 30 commercial unmedicated cattle and swine feeds show an apparent thiabendazole content of 0.00006–0.00044%. Recoveries on feeds made to contain 0.0025–10.0% thiabendazole ranged from 97.6 to 106.6%, with a coefficient of variation of 2.44%. In studies of 30 other drugs added to feeds, only nithiazide, Enheptin, and sulfathiazole interfere. Many variables involved in the color development were studied. The method gives the most accurate and reproducible results on solutions containing 0.2–2.0 μg thiabendazole/ml.
Further Studies on the Yeast and Enzyme Methods for Determining Lactose in Meat Products Containing Corn Sirup
Authors: Hankin Lester , Wickroski Alphonse F
Published: February 2020

Further comparative studies were conducted on lactose determination in meat products by the enzyme method and the AOAC yeast method. Inflated values for lactose in meat products result from the AOAC yeast method on meat samples containing corn sirup solids and nonfat dry milk. Quantitative data indicate that maltose is primarily responsible for the high values, and that dextrin interference is slight. The average difference between the yeast and enzyme methods for commercial samples declaring both corn sirup and nonfat dry milk was 0.27% lactose. The enzyme method appears useful for determining lactose in meat products containing corn sirup.
Infrared Assay for Santonin in Tablets
Authors: Biesemeyer Mae E
Published: February 2020

A quantitative infrared procedure for the determination of santonin and/or santonin in combination with calomel in tablets has been studied collaboratively. Santonin is extracted with CHCl3 from an ammoniacal aqueous phase and evaporated to dryness. The residue is dissolved in CS2 and baseline absorbances are determined relative to CS2 at a maximum of 9.75μ, with the baseline between minima of 9.6 and 9.95μ. This method was adopted as official, first action.
Separation and Identification of Sodium Salts of Acetic, Propionic, Butyric, and Valeric Acids by Paper Chromatography
Authors: Young James A , Schwartzman George , Melton Anna L
Published: February 2020

A method has been developed to confirm the identity of volatile fatty acids after they have been steam distilled, separated by a silicic acid column, and titrated with NaOH. The method works equally well for the detection of propionates in bread products. This paper reports a second collaborative study with a modified mobile solvent: two volumes of acetone added to equal volumes of n-butanol, tertiary butanol, and concentrated NH3. This solvent system gives a more distinct separation of the acid spots, the spots remain stable longer, and the time required for the paper to develop is reduced to 2.5 hours. Six laboratories and eight collaborators participated in the study. The method was adopted as official, first action for identifying the sodium salts of the C2–C5 acids and as a qualitative test for propionates in bread products.
Studies on an In Vitro Method for Determining Tuberculocidal Activity With Disinfectants
Authors: Ortenzio L F
Published: February 2020

An in vitro method for determining tuberculocidal activity of disinfectants, composed of a presumptive procedure using Mycobacterium smegmatis with a 12-day incubation period and a confirmative procedure using Mycobacterium tuberculosis with a 60-day incubation period, is given in detail. Collaborative results on the confirmative procedure by seven laboratories establish a reasonable degree of precision and show clearly that this part of the test is capable of detecting possible errors in the analysis of data developed in the presumptive part of the method. The method is recommended for adoption as official, first action.
Determination of Residual Germicidal Activity in Swimming Pool Water
Authors: Ortenzio L F
Published: February 2020

Collaborative results on the standard test for the efficiency of germicides in disinfecting swimming pool water (This Journal, 47, 541 (1964)) showed a reasonable degree of precision. Variations in the standard sodium hypochlorite solution and unknown sample are discussed. The method is recommended for adoption as official, first action.
Rapid Procedure for Carbaryl Residues: Modification of the Official Colorimetric Method
Authors: Benson Walter R , Finocchiaro Josephine M
Published: February 2020

A modification of the official colorimetric method for carbaryl eliminates the need for special equipment and shortens the time of analysis. Recoveries from eight crops at about 10 ppm levels ranged from 84 to 106%. Crop blanks, except for cabbage, averaged about 0.2 ppm.
Qualitative Determination of Syringaldehyde and Dihydroconiferyl Alcohol in Maple Sirup
Authors: Underwood J C , Filipic V J
Published: February 2020

The combined amount of syringaldehyde and dihydroconiferyl alcohol in maple sirup was determined by extracting the sirup with methylene chloride, isolating the compounds by GLC (SE-30 column), and comparing the height of the single peak representing the two compounds with a standard of syringaldehyde. The procedure accounts for 97–98% of the SA-DHCA in the sirup with a standard deviation of ± 4% of the value obtained. Two samples of sirup were found to contain 5 and 8 ppm SA-DHCA.
Antioxidants (BHA and BHT) in Breakfast Cereals
Authors: Takahashi David M
Published: February 2020

Antioxidants (BHA and BHT) in different types of breakfast cereals were studied by argon ionization gas chromatography. Samples containing antioxidants were packed into the column, and antioxidants were eluted with redistilled petroleum ether. EIuates were concentrated under N2 and injected into a Barber-Colman Model 10 gas chromatograph. Recoveries ranged from about 92 to 110%. Results obtained by steam distillation-colorimetry methods were erratic. Colorimetric procedures were not free from interferences and could lead to highly erroneous results at the lower ppm levels. The gas chromatographic method is faster, simpler, and more accurate. Collaborative studies on corn and rice ready-to-eat breakfast cereals are recommended.
The EDTA Titration of Calcium and Magnesium
Authors: Steagall Edward F
Published: February 2020

A method is proposed for the EDTA titration of calcium and/or magnesium in pharmaceutical preparations. Five samples simulating these products were analyzed collaboratively by eight analysts in six laboratories. The new method was found to be as precise as, and far less time-consuming than, the present official procedures. The results were easily reproducible by the analyst and the agreement between laboratories was quite good as evidenced by low standard deviations.
Organic Compounds in FD&C Blue No. 1
Authors: Schumacher Robert J
Published: February 2020

Studies show that ethylbenzylaniline sulfonic acid is not present in FD&C Blue No. 1, but that N-ethyl-N-(3-suIfobenzyI)-sulfanilic acid and ortho-, meta-, and parasulfobenzaldehydes are present. The method described is suitable for determination of ESBSA and total sulfobenzaldehydes.
Infrared Techniques Useful in Residue Chemistry
Authors: Blinn Roger C
Published: February 2020

Although infrared spectrophotometry is suitable for the measurement and identification of pesticides and their metabolic products because of its inherent characterizing properties, only recently have techniques and instrumentation become adequate for the difficult requirements of residue chemistry. This paper describes techniques which have been successful for the quantitative measurement and qualitative characterization of micro-quantities of pesticide residues. Because of the nature of residue problems, microtechniques are essential for the successful use of infrared spectrophotometry; these techniques strictly limit the permissible amount of contamination from substrate, reagent, atmosphere, handling, etc. Such techniques are described as well as amounts of material required for reliable infrared data. Quantitative measurements are most reliably made as solutions in long energypath cells, whereas qualitative characterization is best accomplished as micro pellets. Detailed procedures for each of these techniques are described.
Thin Layer Chromatography for Pesticide Residue Analysis
Authors: Kovacs Martin F
Published: February 2020

Thin layer chromatography is a simple, rapid, sensitive, and versatile semiquantitative method which is readily applied to pesticide residue analysis. Its greatest value in residue analysis is as a confirmatory method used in conjunction with gas-liquid chromatography. A new solvent system and micro slide technique for the rapid detection of nanogram quantities of many chlorinated pesticide residues are described.
Paraffins of Cigar Smoke
Authors: Osman S , Barsox J , Dooley C J
Published: February 2020

Column chromatography was used to isolate a fraction from cigar smoke condensate containing a homologous series of normal paraffinic hydrocarbons; the individual hydrocarbons were separated by gas-liquid chromatography and characterized by their infrared spectra, mass spectra, and gas chromatographic behavior. Those compounds identified include the normal paraffins from dodecane to pentacosane. This fraction was isolated from the smoke condensates of four cigar types containing unblended filler tobacco that varied considerably in smoking characteristics. Qualitatively, the four types were identical, but quantitative differences were observed.
Improved Procedure for the Colorimetric Determination of Sulfamethazine in Feeds Containing Aureo SP-250®
Authors: Berg T R , Penrod J Q , Blaylock L G
Published: February 2020

The procedure provided by the manufacturer for the colorimetric determination of sulfamethazine in feeds uses a hot alkaline extraction. This extract is difficult to handle because many feeds form a gel and solubilized protein when heated in the presence of an alkaline solution. Centrifugation does not readily separate these solids. An extraction method utilizing a cold alkaline extraction and a double centrifugation has been developed which yields an extract that can be readily carried through the remaining steps of the analysis. Average recoveries were 104% at the 0.01% level and 106% at the 0.05% level of sulfamethazine.

In addition, a separate study was conducted to determine whether penicillin or aureomycin interfere with the analysis for sulfamethazine. The data indicate that there is no interference.
Chromatographic, Spectrometric, and Irradiation Behavior of Five Carbamate Insecticides
Authors: Eberle D O , Gunther F A
Published: February 2020

A comparison of different analytical techniques for the detection and determination of microgram quantities of five carbamate insecticides is presented: carbaryl, Dimetilan, Isolan, Pyrolan, and Zectran. The insecticides were separated by thin-layer and gas chromatography are quantitatively characterized through combination of these techniques with fluorescence, infrared and ultraviolet spectrometry, and oscillographic polarography. The chemical courses resulting from the influence of natural sunlight and short-wavelength ultraviolet radiation on carbamate insecticides were followed by means of these microanalytical, instrumental methods and are briefly discussed.
Collaborative Study of the Application of Electrometric Titration Techniques in the Volumetric Ammonium Molybdate Method for Phosphorus
Authors: Hoffman W M
Published: February 2020

Results are given on a collaborative study for total phosphorus in which the volumetric ammonium molybdate method (both conventional and formaldehyde titration techniques) was compared with the gravimetric quinoline molybdate method. The conventional titration procedure exhibits a slight positive bias and lacks good precision. The HCHO titration procedure appears as accurate as the quinoline method, but its accuracy is enhanced by the use of a recovery factor. Its precision is better than the other titration procedure but not as good as the quinoline molybdate method. Neither procedure is recommended for adoption as official, first action.
Automatic Flame Photometric Determination of Potassium in Fertilizers. A. Elimination of Anion Exchange Cleanup. B. Using Direct Available P2O5 Extract
Authors: Ussary James P , Gehrke Charles W
Published: February 2020

Three primary standard grade potassium salts, eight Magruder check samples, and 18 commercial fertilizer samples were analyzed by three methods. Primary standards gave an average recovery of 100.0% and an average range of 0.21% K20. Magruder check samples averaged 0.09% K20 higher by the modified flame photometric method than the grand averages of the STPB results on the respective Magruder reports. The modified flame photometric method averaged 0.02% K20 lower than the official flame photometric method and 0.11% K20 higher than the official STPB method on 18 commercial fertilizer samples. The automatic flame photometric method, without anion exchange cleanup, is rapid enough for routine analysis and is as accurate and precise as the AOAC official methods. The method was also applied to the direct available P205 extract. Results on three primary grade potassium salts, seven Magruder check samples, and 13 commercial fertilizer samples were as accurate and precise as the official STPB method.
Activation Analysis of Drugs
Authors: Schlesinger H L , Pro M J , Hoffman C M , Cohan M
Published: February 2020

Activation analysis has been employed to compare and determine the source of manufacture of drugs. The irradiations were carried out with the DASA-TRIGA1 and Naval Research Laboratory nuclear reactors,2 and the induced radionuclides were identified by nondestructive gamma-ray spectrometry. The results show that the technique can be a useful tool for the identification of trace elements which serve to characterize drugs.
Assay of Ascorbic Acid in Pharmaceuticals: A Modified Colorimetric Procedure Using p-Nitroaniline
Authors: Weeks Cora E , Deutsch Mike J
Published: February 2020

The colorimetric procedure by Schmall has been modified by use of diazotized p-nitroaniline as the chromogenic reagent for assaying microgram quantities of ascorbic acid. The volumes have been adjusted so that the entire procedure is conducted in test tubes. Folic acid, choline, inositol, biotin, calcium pantothenate, nicotinic acid and amide, B6 compounds, and ferrous sulfate did not interfere; the thiazole moiety of thiamine gave negligible interference, while the pyrimidine moiety had no effect. The method is not applicable in the presence of p-aminobenzoic acid or cysteine. The results by the p-nitroaniline method were 98–103% of the ascorbic acid found by the dichlorophenol-indophenol method, while the iV-bromosuccinimide method gave 98–105% of the acid as determined by the dye titration.
Extraction of Aflatoxin from Peanut Products by Dialysis
Authors: Jayaraman A , Sreenivasamurthy V , Parpia H A B
Published: February 2020

The dialysis with aqueous methanol of aflatoxin in natural materials has been examined. With the use of aqueous methanol of decreasing strength every two hours, high toxin values are obtained as compared with those obtained by a Soxhlet extraction with methanol. This is possibly because of partial destruction of the toxin by heating in the Soxhlet extraction.
Estimation of Fatty Acid Composition by Gas Chromatography Using Peak Heights and Retention Time
Authors: Bartlet John C , Iverson John L
Published: February 2020

In isothermal gas chromatography, the peak widths have been demonstrated to be a linear function of retention time. For most quantitative purposes, the product of the retention time and peak height can be used for area measurement. Statistical comparison of results obtained by this procedure and by triangulation demonstrate its validity.
Aflatoxin Determination in Seed Meal
Authors: Chen Shui-Chin , Friedman Leo
Published: February 2020

An assay method for aflatoxin B1 in seed meals with a sensitivity limit of <0.02 ppb is described. The sample is extracted with aqueous methanol in a Waring Blendor. The extract is purified by lead acetate precipitation, followed by partition chromatography on Celite, and assayed by comparison of fluorescence intensity with aflatoxin B1 standards on silica gel G-HR thin layer chromatograms. This method successfully eliminates potential interference from a “new blue spot” found in cottonseed meal extracts.
Sugars in Plants: A Preliminary Report on the Use of EDTA in the Munson-Walker Sugar Method
Authors: Potter Earl F , Long Marion C
Published: February 2020

Preliminary studies were conducted on the use of EDTA in the Munson-Walker method for sugar analysis. The method requires less time and attention when the reduced copper is titrated with EDTA instead of sodium thiosulfate. Studies will be continued.
Test for the Determination of Starch in Meat Food Products (Applicable for Estimation of Cereal in Sausages)
Authors: Glover W , Kirschenbaum H , Caldwell A
Published: February 2020

A method has been developed for determining starch in meat food products in which simple sugars are extracted from meat food products with hot 80% ethanol while starch remains. The starch residue is solublized with dilute perchloric acid, readily forms a colored derivative when heated with anthrone-sulfuric acid reagent, and is measured at 630 mμ. It was not necessary to prepare a standard dextrose curve daily. The anthrone-sulfuric acid reagent is good for 3–4 days if kept near 0.0°C.
Nitrodan in Feeds
Authors: Bloom Donald , Gehrt A J
Published: February 2020

The anthelmintic, nitrodan, 3-methyl-5(p-nitrophenyl-azo) rhodanine, is extracted from the feed with dimethyl for mamide: ethanol (1 + 1). The intensely absorbing purple solution formed is separated from the residue by suction filtration through a sintered glass funnel. The filtrate is transferred to a volumetric flask, a small amount of NaOH is added, and the solution is brought to volume, Absorbance is measured at 575 mμ, and the amount of nitrodan present is calculated from a standard curve of known concentrations.
Fatty Acid Composition of White Mustard Seed Oil by Urea Fractionation and Gas-Liquid Chromatography
Authors: Iverson John L
Published: February 2020

The detection of C20 to C26 polyunsaturated fatty acids in a Cruciferae seed oil (white mustard) is possible when these methyl esters are concentrated by urea fractionation. The detection and estimation of fatty acids present in trace amounts (< 0.1%) was simplified by quantitative removal of other fatty acids with similar gas chromatographic retention times. Odd and even chain length di- and tri-unsaturated fatty acids were tentatively identified in white mustard seed oil. A tetraenoic acid, presumably arachidonic acid, was tentatively identified for the first time in a plant lipid of the highest evolutionary level, i.e., angiospermae. More easily extracted “free” lipids have a significantly different fatty acid composition than the more difficult to extract “bound” lipids.
Residues in Eggs from Low Level Feeding of Five Chlorinated Hydrocarbon Insecticides to Hens
Authors: Cummings J G , Zee K T , Turner V , Quinn F , Cook R E
Published: February 2020

Sixty laying hens were carried for 20 weeks in a study designed to show the residue levels in eggs from birds maintained on feed containing 0.05, 0.15, or 0.45 ppm of lindane, heptachlor epoxide, dieldrin, endrin, and DDT in combination, and to show the rate of decline of residues in eggs during a one month withdrawal period. A rapid method for analysis of eggs based on electron capture gas chromatography and the one-step Florisil cleanup of Stemp and coworkers is described. Dieldrin and heptachlor epoxide showed the greatest propensity for storage in eggs, followed in order by endrin, p,p′-DDT, and lindane. There was a significant increase of DDE in eggs from birds fed DDT. Only lindane residues returned to the background level within the one-month withdrawal period.