bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectrophotometric Determination of Methomyl Residues in Selected Vegetables, Crains, and Soil
Authors: Rangaswamy Jois R , Prakash Shimoga R , Vijayashankar Yadathora N 
Published: February 2020

Abstract
Methomyl (S-methyl-N-[(methylcarbamoyl) oxy] thioacetimidate) is converted to oxime and hydroxylamine by alkali and acid treatment, respectively. Hydroxylamine is oxidized with iodine in the presence of sulfanilic acid to yield p-diazoniumbenzenesulfonic acid which is coupled with α-naphthylamine to form a crimson p-benzenesulfonic acid-azo-α-naphthylamine with an absorption maximum at 520 nm. The relationship between absorbance and concentration of methomyl is linear in the range 0.5–10 μg. The method is sensitive and specific; 0.625 ppm methomyl can be determined in a 40 g sample of selected vegetables, grains, and soil.
Interlaboratory Quality Control Study of the Analysis of Water for Pesticides
Authors: Aspila Keijo I , Carron John M , Chau Alfred S Y 
Published: February 2020

Abstract
An interlaboratory quality control study was conducted to provide information to 5 participating Canadian laboratories on their capability in analyzing natural waters for 10 pesticides. The study was designed to identify the quality of each laboratory’s working standards for 15 organochlorine pesticides, and the accuracy and precision of each laboratory’s analytical procedures. Fifteen samples were provided, of which 3 were standards prepared for direct injection into an electron capture gas chromatograph. Instructions were provided to use these 3 standards for quantitating the pesticide content (8–150 ng/L) in 5 pairs of 1 L water samples. These paired samples contained 10 organochlorine pesticides approaching natural levels. Results of the study indicated that participants were fairly precise and achieved the designed ratio 1.5 for concentrations in the paired samples.
Fluorometric Determination of Histamine in Tuna: Development of Method
Authors: Staruszkiewicz Walter F , Waldron Ellen M , Bond John F 
Published: February 2020

Abstract
Tuna extracts are treated with an anion exchange resin to remove interfering materials, histamine is derivatized with o-phthalaldehyde, and the fluorescence of the resulting compound is measured fluorometrically. Replicate analyses of acceptable and decomposed tuna packed in oil or water agreed within 1 mg at a level of 10 mg/100 g and within 12 mg at a level of 100 mg/100 g. Recoveries of histamine added to fish were &gt;90 and &gt;83% at levels of 10 and 100 mg/100 g, respectively. The new method is more rapid and specific and is simpler than previous methods because no liquid-liquid extractions or chromatographic separations of histamine are required. The sensitivity of the method allows quantitation of &lt;10 mg histamine/100 g sample. The accuracy and precision of the fluorometric method are comparable to those of the official AOAC colorimetric method.
Determination of Dimethylpolysiloxane in Instant Coffee
Authors: Kacprzak Jurgen L 
Published: February 2020

Abstract
A method is described for determining dimethylpolysiloxane in instant coffee. The siloxane is extracted with chloroform in a Soxhlet apparatus and then converted to silica which is estimated by a heteropoly blue method. The method is interference-free, and 5 μg dimethylpolysiloxane can be easily detected.
Gas-Liquid Chromatographic Determination of Fluchloralin in Formulations
Authors: Grimes Gregory S 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method has been developed that is precise, rapid, simple, and specific for fluchloralin in emulsifiable liquid formulation. Sample and reference standard are weighed, internal standard solution is added, and an aliquot of the mixture is injected onto the chromatographic column. Fluchloralin gives a sharp symmetrical peak at about 5.4 min. The internal standard has a broader symmetrical peak at about 6.9 min. The relative standard deviation for 21 consecutive injections of the standard solution was 0.3773%. The method was compared with the official GLC method, 6.210–6.215, for the structurally similar trifluralin. Fluchloralin gave a sharp symmetrical peak at about 8.5 min; the internal standard had a sharp symmetrical peak at about 9.2 min. The relative standard deviation of 21 consecutive injections of reference standard solution was 0.6988%. Comparison of the variances of the 2 methods by the F-test at the 99% confidence level showed that the proposed method demonstrated substantially better precision.
Nonaqueous Copper Colorimetric and Silver Titrimetric Methods for Determining Malathion in Technical Grade Malathion and Malathion Formulations from Domestic and Foreign Sources: Interlaboratory Study
Authors: Stiles Alan R , Miles James W , Wayne Richard S , Newton Ladene H 
Published: February 2020

Abstract
The nonaqueous copper colorimetric and the silver titrimetric methods for determining malathion were studied. Samples of technical grade malathion and emulsifiable concentrates from 4 countries and samples of water-dispersible powders from 3 countries were used in the study. Nineteen participants in 15 laboratories representing 11 countries took part in the study. The precision obtained within laboratories was excellent. Agreement between laboratories was also quite good with coefficients of variation ranging from 1.05 to 5.31 for the silver method and from 0.65 to 3.52 for the copper method. Results by both methods were high when compared with results obtained by gas-liquid chromatography. This was particularly true for poor quality samples.
Filter Flame Photometer for Determination of Boron in Plants
Authors: Pickett Edward E , Franklin Michael L 
Published: February 2020

Abstract
A filter photometer employing a manually tilted interference filter provides intensity readings at a maximum and adjacent minimum in the BO2 emission spectrum in the air-hydrogen flame, thus eliminating the need for a separate background intensity reading. Diol chelate-extracted boron of plant samples measured by this flame method is compared with that measured by fluoroborate-methylene blue colorimetry.
Rapid High Pressure Liquid Chromatographic Determination of Carbohydrates in Milk Chocolate Products
Authors: Hurst W Jeffrey , Martin Robert A 
Published: February 2020

Abstract
A high pressure liquid chromatographic method is described for determining 4 carbohydrates in milk chocolate products. The carbohydrates are extracted with water, chromatographed on a small particle packing with acetonitrile-water (80+20) mobile phase, and quantitated by a refractive index detector and digital integrator. The relationship between peak area and concentration was linear. Retention times and peak areas were reproducible. This procedure was successfully applied to several milk chocolate samples and is rapid and more accurate and precise than the official methods.
Comparison of Official AOAC Method and Indirect Atomic Absorption Spectroscopic Method for Determining Biuret in Fertilizers: Collaborative Study
Authors: Corominas Luis F 
Published: February 2020

Abstract
A collaborative study was carried out to compare the official first action method, 2.072—2.074, for determining biuret in urea and mixed fertilizers with the indirect atomic absorption spectrophotometric (AAS) method. Six urea samples (0.3–3.0% biuret) and 6 mixed fertilizer samples (0.1–0.6% biuret) were sent to 14 collaborators; results from 10 collaborators were received and evaluated. Results analyzed by the technique of closely matched pairs indicated the AAS indirect method was better for mixed fertilizer samples, but the 2 methods did not differ greatly for the urea samples. The indirect AAS method was adopted as official first action for determining biuret in urea and mixed fertilizers; the present AOAC method, with modifications, was retained as an alternative method for determining biuret in urea.
Automated Analysis of Thiamine, Ascorbic Acid, and Vitamin A
Authors: Kirk James R 
Published: February 2020

Abstract
Methods currently used in most nutrient analysis laboratories are the classical AOAC methods. One of the major challenges facing the analytical chemist is the need for new or modified quantitative and reliable nutrient assay methods, which are rapid and less labor intensive. Recently, numerous vitamin assays have been published which use continuous flow and high pressure liquid chromatographic techniques. This paper deals with some of the recent methods reported for analysis of thiamine and ascorbic acid, using continuous flow wet chemistry, and high pressure liquid chromatography for vitamin A in food products.
Infrared Studies of the Effects of Acid, Base, Heat, and Pressure on Asbestos and Structurally Related Substances
Authors: Chen Jo-Yun T 
Published: February 2020

Abstract
Reference infrared (IR) spectra of 5 asbestos fibers (amosite, anthophyllite, chrysotile, crocidolite, and tremolite), talc, and sea sand are presented. These reference spectra were recorded using microgram amounts of commercial samples, and the observed characteristic frequencies were tabulated. Some chemical properties of asbestos were investigated by IR spectroscopy. In acid, chrysotile is rapidly hydrolyzed to silicic acid at room temperature; amphibolic asbestos and talc are degraded under heat and pressure ; sea sand is most stable in acid. The asbestos fibers, talc, and sea sand are stable in saturated aqueous sodium hydroxide at room temperature for 1 day or potassium hydroxidemethanol (10+90) at 65°C for 3 hr. All of the samples except sea sand degrade to sodium silicate under heat and pressure in alkali.
Effects of Threonine Supplementation on the Slope Assay for Protein Quality
Authors: McLaughlan John M , Keith Murray O 
Published: February 2020

Abstract
Several diets considered to be marginally deficient in threonine were fed to young male rats at protein levels ranging from 3 to 9%. Protein sources included lactalbumin (reference standard), soy protein with added methionine, pea protein with added methionine, rice-casein, and peanut-sesame-fish. Chemical scores and plasma amino acid scores indicated that these diets were limiting in threonine at the 3–4% protein level; increased growth resulted from supplementation with threonine. After threonine supplementation, all protein sources except pea were limiting in lysine. Increased growth at low protein levels with little or no extra growth at high protein levels due to threonine supplementation resulted in decreased slopes in the relative protein value (RPV) assay. Consequently, threonine supplementation apparently decreased RPV values for these samples but the protein efficiency ratio was not affected. It was concluded that the RPV assay underestimates the protein quality of lysine-deficient proteins.
Simultaneous Determination of Captan and Captafol in Apples and Potatoes by Thin Layer Chromatography and in situ Fluorometry
Authors: Francoeur Yves , Mallet Victorin 
Published: February 2020

Abstract
A simple method is described for the simultaneous quantitative determination of captan [N-(trichloromethylthio)-3a,4,7,7a-tetrahydrophthalimide] and captafol [N-(1,1,2,2-tetrachloroethylthio)-3a,4,7,7a-tetrahydrophthalimide] in apples and potatoes. The fungicide residues are extracted with acetonitrile, partitioned into a solution of methylene chloride in petroleum ether, separated from each other and the co-extractives on a thin layer chromatographic plate impregnated with aluminum chloride, sprayed with sodium chlorate, and heated. The fluorescence is then measured directly from the chromatogram. Recoveries were greater than 90% in the test crops at the 0.2 ppm level.
Collaborative Study of a Spectrophotometric Determination of Ferric, Ferrous, and Total Iron in Drugs by Reaction with α,α′-Dipyridyl
Authors: Sullivan Daniel J 
Published: February 2020

Abstract
A spectrophotometric method for determining Fe2+, Fe3+, and total Fe in drugs has been developed, using α, α′-dipyridyl as the colorimetric reagent. The method is applicable to tablets, elixirs, injectables, and bulk powders. Eight collaborators analyzed a synthetic iron preparation and 7 commercial samples. For the synthetic iron preparation, the average recovery was 100.3% and the coefficient of variation was 1.02%. For 7 commercial samples, the average coefficient of variation was 1.44%. The method has been adopted as official first action.
The Variability of AOAC Methods of Analysis as Used in Analytical Pharmaceutical Chemistry
Authors: Horwitz William 
Published: February 2020

Abstract
Pharmaceutical analytical chemistry, which ordinarily deals with the analysis of formulations containing from 0.1 to 100% of active ingredient, uses methods with a reproducibility (between-laboratory variability) of about 2.5% and a repeatability (within-laboratory variability) of about half that amount. The best between-laboratory precision attainable appears to be about 1.0% and within-laboratory precision, about 0.5%. On the basis of the results available, automated methods do not appear to be any more precise than manual methods, although the studies show fewer outlying data points. Replicates (preferably blind ones) should always be conducted in a collaborative interlaboratory study in order to obtain the important information as to whether efforts should be concentrated on improving the method itself or on the performance of laboratories and analysts in applying it.
High Pressure Liquid Chromatographic Determination of N-3-Pyridylmethyl-N′-p-nitrophenylurea in Rodenticides
Authors: Sims Carl W , Gard Richard K 
Published: February 2020

Abstract
A simple and rapid method is described for determining N′-3-pyridylmethyl-N′-p-nitrophenylurea (RH-787) in Vacor Ratkiller rodenticide. The bait is extracted with acetone, the extract is evaporated to dryness, an internal standard is added, and the solution is injected into a high pressure liquid chromatograph. The sample is analyzed by normal phase chromatography on a Partisil 10 column with a mobile phase of methanol-methylene chloride (10+90). An 8 μl injection containing 4 μg pyridine internal standard and 8 μg RH-787 produces half-scale peaks at 254 nm with a full scale absorbance of 0.5 absorbance unit. In an alternative procedure, the active ingredient is extracted from the bait with acetone and titrated to a methyl red end point with 0.1N perchloric acid dissolved in acetic acid. Two samples of Vacor Ratkiller and a spiked blank were analyzed by both procedures.
Leaching of Pewterware by Organic Acids
Authors: Gould John H 
Published: February 2020

Abstract
Three pewter goblets were repeatedly leached by acetic, citric, lactic, malonic, and tartaric acid solutions. The leach solutions were periodically analyzed for Pb, Cd, Cu, Bi, Sb, and Sn by atomic absorption spectrophotometry. Analysis of the leach solutions showed that, without the addition of nitric or perchloric acid to the acetic and malonic acid leach solutions, Pb precipitated from the solutions on standing. Addition of the mineral acids redissolved the precipitate. Pb, Cd, and Bi were found in higher concentrations in the leach solution than in the metal; Cu and Sb were less concentrated in the leach, while the amount of Sn was approximately equal in both. Tartaric acid solution dissolved about 9 times as much metal from the pewter as the other organic acids but removed less Pb than acetic or malonic acids. None of these samples tested exceeded the Food and Drug Administration standards for Pb or Cd release.
Acid Digestion, Hydride Evolution Atomic Absorption Spectrophotometric Method for Determining Arsenic and Selenium in Foods: Collaborative Study. Part I
Authors: Ihnat Milan , Miller Hanford J 
Published: February 2020

Abstract
The hydride evolution atomic absorption spectrophotometric (AAS) method for determining As and Se in foods developed and evaluated by the Food and Drug Administration and Agriculture Canada laboratories was subjected to collaborative study. Twenty-four laboratories provided results for As and 23 provided results for Se levels in 13 different samples consisting of tuna, swordfish, flounder, oyster, liver, flour, skim milk powder, spinach, kale, and apple containing natural levels of As and Se in the ranges 0–15,000 and 0–4000 ng/g, respectively. Reference materials formed a substantial segment of samples, and a number of other laboratories using fluorometry, colorimetry, neutron activation, spark source mass spectrometry, and graphite furnace AAS provided confirmative reference values for the remaining samples. A variety of hydride generation instruments were used, ranging from commercially available devices to semiautomated and fully automated custom-made instruments. Although the accuracy of the method was fairly good, between-laboratory and between-determination (hydride evolution AAS measurement) precisions were not favorable. The main advantage of the hydride AAS method is the rapidity of the determinative step.
Factors regulating axon regeneration via JNK MAP kinase in Caenorhabditis elegans
Authors: Shimizu Tatsuhiro , Hisamoto Naoki 
Published: February 2020

Abstract
Axon regeneration following nerve injury is a highly conserved process in animals. The nematode Caenorhabditis elegans is an excellent model for investigating the molecular mechanisms of axon regeneration. Recent studies using C. elegans have shown that the c-Jun N-terminal kinase (JNK) plays the important role in axon regeneration. Furthermore, many factors have been identified that act upstream of the JNK cascade after axotomy. This review introduces these factors and describes their roles during the regulation of axon regeneration.
Why Political Appointments to Truth Commissions Cause Difficulties for these Institutions: Using the Crisis in the Transitional Justice Process in Nepal to Understand How Matters of Legitimacy and Credibility Undermine Such Commissions
Authors: Sarkin Jeremy , Bhandari Ram Kumar 
Published: February 2020

Abstract
Over five decades and with dozens of examples of truth commissions to look back on, an undeniable aspect of their legacy is that the world has become far more focused on dealing with the past and uncovering the truth about past atrocities. While there is typically a focus in the literature on the more widely publicized and famous truth commissions, scores of other processes have taken place, especially since the 1990s. Post-conflict or divided societies have designed institutions in ways that achieve specific objectives but at the same time conform to international standards, creating a reputation of being both democratic and accountable. Using the prism of Nepal, this article examines why the process to establish transitional justice mechanisms, and specifically truth commissions, needs to be legitimate and credible for them to be effective and be impactful. It specifically examines issues relating to appointments to such institutions and why such appointments need to be done independently and not overtly politically. It scrutinizes why appointment mechanisms and processes are so important to enhancing the legitimacy and independence of such bodies. The case of Nepal is used as an example to extrapolate conclusions about the problems that affected its processes, and the various crises that have emerged in those processes. The article argues that commissioners ought to be chosen on the basis of their impartiality, moral integrity, and known commitment to human rights and disclosure of the truth. This is essential to ensure that the process is seen to be independent and credible.
THE CASE FOR LIMITING PRIVATE EXCESSIVE PRICING LITIGATION
Authors: Gal Michal S 
Published: February 2020

ABSTRACT
In the European Union, private litigation of competition law violations is in its nascence. As this article shows, excessive pricing raises strong concerns for such litigation, for three reasons: (1) the inherent difficulty of defining what constitutes an unfair price; (2) additional challenges inherent to private excessive pricing litigation, such as the need to pinpoint when exactly a price becomes unfair; and (3) the institutional features of general courts in EU member states, which are ill-suited to the required tasks. We elaborate on these concerns, pointing to four specific challenges inherent to private litigation and to three instances where a lack of sufficient economic understanding could entrap general courts (a cost trap, a fairness trap, and a monopolistic competition trap). Together, these factors create a risk of error costs much higher than any experienced so far, which could potentially reduce welfare. The article suggests some measures that can be taken to ensure that welfare is served.
Advocacy Coalitions and Foreign Policy Change: Understanding US Responses to the Syrian Civil War
Authors: Lantis Jeffrey S 
Published: February 2020

AbstractInsights from the public policy advocacy coalition framework (ACF) may offer richer explanations of the scope and timing of US foreign policy changes toward the Syrian civil war (2011–present) than traditional approaches in foreign policy analysis (FPA). This article surveys the existing FPA literature and then probes the plausibility of a new ACF model of change through case studies of the reluctant engagement of the United States in Syria. Cases shed light on how, despite pronouncements of restraint by Presidents Obama and Trump, the government has armed and trained rebel fighters, deployed thousands of troops to the country, conducted airstrikes against the Islamic State, and moved to counterbalance Iranian influence in the region. This study helps draw connections between competition among rival advocacy coalitions and strategic drift in US foreign policy, including patterns of change and “purposive non-change.” The article concludes with a discussion of the added value of the ACF model and details its promise for application in other comparative cross-national contexts.
Psychosocial Risk Profiles Among American and Dutch Families Affected by Pediatric Cancer
Authors: Sharkey Christina M , Schepers Sasja A , Drake Sarah , Pai Ahna L H , Mullins Larry L , Grootenhuis Martha A 
Published: February 2020

AbstractObjectiveLittle is known about relations between domains of psychosocial risk among pediatric cancer populations. The Psychosocial Assessment Tool 2.0 (PAT2.0) is one internationally validated screening measure that can examine these relations. This study aimed to examine risk profiles and predictors of these patterns exhibited by American and Dutch families.MethodsCaregivers of children newly diagnosed with cancer (N = 262; nUSA=145, nNL=117) completed the PAT2.0 as part of larger studies conducted in the United States and the Netherlands. Latent profile analysis and multinomial logistic regression examined differences in demographic and medical variables across risk profiles. Domains assessed included Family Structure/Resources, Child Problems, Sibling Problems, Family Problems, Caregiver Stress Reactions, and Family Beliefs.ResultsFour groups were identified: “Low-Risk” (n = 162) defined by generally low risk across domains; “Moderate-Caregiver” (n = 55) defined by elevated Caregiver Stress Reactions domain; “Moderate-Children” (n = 25) defined by elevated Child Problems and/or Sibling Problems, and “Elevated-Risk” (n = 20) marked by generally high overall risk. Dutch families had higher odds of being in the Elevated-Risk group, compared to the Low-Risk group. Caregiver age, gender, and educational attainment predicted group membership. Families classified as Targeted or Clinical had higher odds of being in the Moderate or Elevated risk groups.ConclusionThe PAT2.0 appears to identify largely similar patterns of risk, suggesting that families experience common psychosocial difficulties in both American and Dutch societies. The two Moderate groups demonstrated specific risk sources, suggesting that evaluation of domain patterns, rather than reliance on PAT2.0 risk level, could be of clinical benefit.