bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Zearalenone in Cornflakes and Other Corn-Based Foods by Thin Layer Chromatography, High Pressure Liquid Chromatography, and Gas-Liquid Chromatography/High Resolution Mass Spectrometry
Authors: Scott Peter M , Panalaks Thavil , Kanhere Sri , Miles Walter F 
Published: February 2020

Abstract
A simple cleanup procedure based on pH adjustments was used to obtain extracts of corn foods. The method gave good recoveries of zearalenone determined by thin layer chromatography (TLC) and high pressure liquid chromatography (HPLC). As little as 5 ng zearalenone was detected by TLC, using Fast Violet B Salt as the spray reagent; the lower limit of detection in cornflakes was about 20 ≧kg. With HPLC on Spherisorb silica (5 ≧m) and detection by fluorescence at an excitation maximum of 310 nm as little as 5 ≧g zearalenone/kg cornflakes could be determined. While the TLC method was also applicable to corn chips, cornmeal, popcorn, and frozen corn, an interference was observed in HPLC of the latter 3 products. This interference was separated from zearalenone by adding a second HPLC analytical column (Spherisorb ODS). Gas-liquid chromatography coupled with mass spectrometric single ion monitoring at high resolution, although of limited availability, was shown to be the most sensitive and selective method for determining zearalenone in corn foods. The natural occurrence of zearalenone in a sample of cornflakes (13–20 ≧/kg) was demonstrated by all 3 detection procedures.
Spectroanalytical Parameters of Fungal Metabolites. V. Rubratoxin B
Authors: Neely William C , Siraj Mohamed Y , Smith Libby B , Wallace Hayes A 
Published: February 2020

Abstract
Using ultraviolet absorption spectrometry, rubratoxin B can be quantitatively determined over the concentration range 1.0 × 10−3 to 3.8 × 10×5M in acetonitrile or p-dioxane. Fluorescence, while observable, is a practical method only with apparatus of exceptional sensitivity and low signal-to-noise ratio. The calculated mean lifetime of fluorescence is 0.211 nsec. The calculated fluorescence quantum yield is 0.058. No phosphorescence was observed for rubratoxin B. Reasonable precautions should be taken to avoid exposure of dissolved rubratoxin B to light but the solid form is relatively stable. While water hydrolyzes the anhydride ring on the toxin, the process is reversible so that subsequent analysis is possible. Rubratoxin B is relatively stable to dry oxidation, in the dark, at room temperature even on thin layer chromatographic plates where the large surface area gives maximal exposure to oxygen.
Thymidine Kinase Heterozygous L5178Y Mouse Lymphoma Forward Mutational Assay
Authors: Palmer Kenneth 
Published: February 2020

Abstract
The biological basis and protocol for the thymidine kinase heterozygous L5178Y mouse lymphoma forward mutational assay (TK+/−) are described. The TK+/− assay is used for the detection of mutations produced by chemicals or radiation.
Atomic Absorption Spectrometric Determination of Cyhexatin in Apples
Authors: Love John L , Patterson John E 
Published: February 2020

Abstract
A rapid method using atomic absorption spectrometry has been developed for determining residues of cyhexatin in apples. Each analysis takes less than 30 min and the method is sensitive to less than 0.1 mg cyhexatin/kg. Recoveries varied from approximately 100% at 0.25 and 0.05 mg/kg to 70% at 5 mg/kg. No acid digestion or cleanup is required for the analysis.
Atomic Absorption Spectroscopic Determination of Lead Extracted from Acid-Solubilized Tissues
Authors: Farris Fred F , Poklis Alphonse , Griesmann Guy E 
Published: February 2020

Abstract
A method is presented for determining lead in a variety of tissues. Lyophilized samples are solubilized with nitric acid at room temperature in glass screw-cap culture tubes. Following neutralization with sodium hydroxide and sodium bicarbonate, the lead is extracted into methyl isobutyl ketone as the pyrrolidine dithiocarbamate complex and analyzed by flame atomic absorption spectrophotometry. Brain, heart, liver, lung, and spleen gave recoveries ranging from 92 to 102% with standard deviations of less than 8%. Aorta, kidney, and rib were unsuitable for analysis by this method. A large number of samples can be analyzed without specialized equipment or intricate experimental steps. The detection limit is 35 ng/g tissue (wet weight) and sensitivity is approximately 140 ng/g tissue (wet weight).
Flameless Atomic Absorption Spectroscopic Determination of Heavy Metals in Whole-Fish Samples
Authors: Okuno Iwao , Whitehead James A , White Robert E 
Published: February 2020

Abstract
Flameless atomic absorption spectroscopy with a carbon rod atomizer was used to determine lead, cadmium, and chromium in wholefish samples. Samples were dry-ashed, and the metals were separated by solvent extraction with ammonium pyrrolidine dithiocarbamate in methyl isobutyl ketone, and then back-partitioned into an aqueous acid solution for analysis. The back-partitioning step allows a direct comparison of sample solutions with aqueous solutions of the standard. Recoveries of the metals from fortified samples averaged 91% (±9.6) for lead and 100% (±5.6) for chromium at the 0.1–1 ppm level, and 100% (±13.3) for cadmium at the 0.01–0.1 ppm level.
Gas-Liquid Chromatographic Determination of TYans-Unsaturation in Fats and Oils on Packed Columns: Effect of Positional Isomers
Authors: Conacher Henry B S , Iyengar Jagannath R 
Published: February 2020

Abstract
Studies in our laboratories indicated that the trans contents of a number of commercial margarines, determined by gas-liquid chromatography (GLC) on a 15 ft column packed with 10% Silar IOC, were approximately 80-85% of those determined by infrared spectroscopy. This is mainly due to overlap of some of the trans positional isomers with the cis positional isomers in the octadecenoate fraction, shown by studies involving determination of the transoctadecenoate content of the margarines by silver ion thin layer chromatography/GLC, and by preparation and study of the GLC behavior of the cis and trans positional isomers of Δ6-, Δ9-, Δ12-, and Δl5-octadecenoates. The last 3 isomers were prepared by hydrazine reduction and nitrous acid isomerization of linoleic and linolenic acids. Since it is possible that longer, more efficient columns might result in better separation of the cis- and traru-octadecenoate isomers, it is recommended that studies be continued on longer packed columns (20 ft) and possibly on support-coated open tubular columns.
Atomic Absorption Spectrometric and Colorimetric Determination of Iron in Seafoods
Authors: Gordon Dennis T 
Published: February 2020

Abstract
Iron levels in 14 seafoods were determined by atomic absorption spectrometry (AAS) on freeze-dried composites. Samples were prepared for analysis after dry-ashing at 550°C and wet digestion in HNO3-HCIO4. Paired analysis of wet digests were accomplished by AAS and use of the colorimetric reagent, ferrozine. There was no significant difference in iron levels of seafoods due to sample preparation. While individual species levels were not significantly different between the AAS and colorimetric procedures, evaluation of all determinations indicates that ferrozine gives lower values (P &lt; 0.005) by 8%. Iron levels in seafoods in /tg/g dry weight (nig/100 g wet weight) determined by AAS on wet-digested samples were: 8 species of white /infish, 16.3±4.2 (0.31 ±0.08) ; Pacific shrimp, 12.3±1.4 (0.29±0.03) ; canned tuna, water pack, 16.6±2.9 (0.49±0.09); sockeye salmon, 29.0±5.5 (0.89±0.25) ; American shad, 29.1±1.5 (0.97±0.05) ; Pacific oysters, 391± 45 (6.54±1.39); and Dungeness crab, 17.1± 2.5 (0.35±0.05).
Application of the Official AOAC Cholesterol Method to a Wide Variety of Food Products
Authors: Punwar Jalam K , Derse Philip H 
Published: February 2020

Abstract
This paper presents fa.^iytical data on the cholesterol content of selected consumer food products including some fats and oils. The cholesterol data are grouped by food products. To determine the reproducibility of cholesterol values, recovery data were obtained from samples of pure vegetable shortening spiked at 40 and 20 mg cholesterol (as cholesteryl palmitate)/ 100 g fat. Average recoveries were 97.1% and 95.4% with coefficients of variation of 1.27 and 3.24%, respectively.
Fossomatic Method of Somatic Cell Counting in Milk: Collaborative Study
Authors: Mochrie Richard D , Monroe Robert J 
Published: February 2020

Abstract
Fossomatic, a fully automatic, fluoro-optoelectronic somatic cell counter, was evaluated in 6 laboratories. One set of 6 duplicate milk samples, fresh and preserved, was read with instruments as routinely calibrated to each laboratory’s direct microscopic somatic cell counts (DMSCCs), i.e., local standard. A second set was read after standardizing the instrument to a 3-sample common standard (DMSCC) shipped to each collaborator. Cell levels of the unknowns ranged from 371 to 2301 thousand (th)/ml by DMSCC, with an s per sample of 14.8% and s of a level mean of 1.8%. Fossomatic values averaged 1014 compared to 1031 th cells/ml by DMSCC, had homogeneous variance for duplicates within laboratories (s = 4.0%), and had an error per observation of 6.2%. The linear coefficient of 0.9966±0.0039 (for fresh milk and common standard) for the Fossomatic values regressed on DMSCC gave an excellent and unbiased estimate of the cell concentration in a milk sample. A small bias was evident in only 5 of 24 linear regressions (fresh or preserved within each standard) where slopes differed significantly from 1. All 5 were on values derived from a local standard with maximum biases of +18% and —28% (at a 1 million level). Preserved milk had slightly lower (P &lt; 0.01) cell concentrations than fresh milk but only by 3.6% at 1 million. Although condition X level was significant (P &lt; 0.01), the 6 cell levels differed by a magnitude of only 27— 45 th cells/ml. Between-laboratory variation (the component was 4.6%) and laboratory X level interaction were both significant, but their contributions to error were small. The spread in laboratories at any cell level was about 12% and the error of estimate for a sample sent to 2 laboratories was 6.8%. Although interactions were significant with this precise method, they were not of such a magnitude as to invalidate cell count estimates in practice. The Fossomatic method has been adopted as official first action.
Gas-Liquid Chromatographic Determination of Kepone Residues in Finfish, Shellfish, and Crustaceans
Authors: Carver Richard A , Borsetti Arnold P , Kamps Laverne R 
Published: February 2020

Abstract
Finfish, shellfish, and crustacean samples are extracted with isopropanol and benzene; the extract is filtered and then concentrated. The extract, dissolved in hexane, is treated with oleum and extracted with aqueous alkali. The aqueous phase is acidified and extracted with petroleum ether-ethyl ether (1+1). The Kepone residue is determined by electron capture gas-liquid chromatography (GLC). Recoveries obtained by 8 laboratories from 15 species of finfish fortified at 0.02-0.23 ppm ranged from 37 to 107% with a mean ± relative standard deviation of 79.4±14.5%. For oysters fortified at 0.01- 0.10 ppm, recoveries range from 63 to 129% with a mean of 78.2 ±20.8%. For crustaceans fortified at 0.05—0.26 ppm, recoveries ranged from 52 to 110% with a mean of 78.8±16.4%. The approximate limits of quantitation for finfish and for shellfish and crustaceans are 0.02 and 0.05 ppm, respectively, under the GLC conditions used in this study.
Enzymatic Digestion of Compounded Poultry Diets for Estimation of Methionine
Authors: Datta Salil C 
Published: February 2020

Abstract
Compounded laying diets were digested with pepsin and hydrochloric acid followed by pancreatin and pH 8.0 phosphate buffer at 4°C to estimate methionine. Biological studies on egg production were also conducted. Methionine content of a poultry diet determined analytically in the enzymatic digest agreed with the data derived biologically through egg production.
Non-Parametric Methods for Detection of Adulteration of Concentrated Orange Juice for Manufacturing
Authors: Schatzki Thomas F , Vandercook Carl E 
Published: February 2020

Abstract
The composition of organic constituents (total sugars, reactive phenols, total amino acids, arginine, and γ-aminobutyric acid) has been measured in a large (360 samples) selection of concentrated orange juice for manufacturing and orange pulp wash in the U.S. trade. The detection of adulteration with sugar, reducing sugars, and citric acid addition has been investigated by using non-parametric nearest neighbor classification techniques in the 4-space of log ratios of the compositions. The results show that such detection is possible with a type 1 = type 2 error rate of 1 0% for 2 0% adulteration if at least 7 samples are taken. The assumptions of such samplings are discussed.
Evaluation of Potential for Aflatoxin Occurrence on Celery, Cauliflower, Lettuce, and Taro Root Inoculated with Aspergillus flavus and A. parasiticus
Authors: Raghu Aparna , Eadie Thomas , Llewellyn Gerald C 
Published: February 2020

Abstract
Culture samples of lettuce, cauliflower, celery, and taro root (Colocasia esculenta) were assayed for the presence of aflatoxin after inoculation with Aspergillus flavus and A. parasiticus. Cultures of A. flavus produced both aflatoxins B1 and G1 on taro root, but produced only B1 on lettuce, cauliflower, and celery. For taro root, the percentage of aflatoxin G1 produced was considerably greater than that of B1. While A. parasiticus did produce mycelia and spores on the lettuce and taro root samples, there were no detectable levels of any aflatoxin produced. All the samples studied were successfully extracted and analyzed qualitatively and quantitatively for the presence of aflatoxin by using official AOAC thin layer chromatographic procedures. There is sufficient evidence that Aspergilli can grow on some leafy produce and one strain produced aflatoxins.
Quantitation of Added Water in Milk by Using Vapor Pressure Osmometry
Authors: Richardson Gary H , Mortensen Margaret S , Crockett Reed G 
Published: February 2020

Abstract
A vapor pressure osmometer (VPO) was successfully studied in 1975. An improved osmometer with greater range and temperature stability was evaluated. Repeatability on 290 mOs/kg standard solution was 289.5±1.08. The mean and standard deviation on 36 water-free milk samples was 280.5±4 compared to 280.1±3 in the previous study. Instrument data from 2 osmometers and 2 cryoscopes produced acceptable chi-square values, and the correlation coefficients between methods were better than 0.99 for samples containing 1—21% added water. In a survey involving 760 samples, more than 37% of producer samples in one cheese plant contained &gt; 3 % added water. Additional evidence of added water in market milk samples suggests the immediate application of the VPO to help prevent milk adulteration. The vapor pressure osomometer method for quantitating added water in milk has been adopted as official first action.
Thin Layer and High Pressure Liquid Chromatographic Analysis of Celery Seed Oil
Authors: Lund Eric D 
Published: February 2020

Abstract
The phthalide content of celery seed oil was determined by thin layer (TLC) and high pressure liquid chromatography (HPLC). Concentrations of the major phthalides, 3-n-butyl phthalide and sedanenolide, ranged from 3 to 10%. Both commercial seed oil and seed extract could be analyzed on silica gel TLC plates with a benzene-1% ethanol solvent system. HPLC analysis, with a Durapak-Carbowax 400 column and hexane-1% isopropanol mobile phase, was suitable only for seed oil because of interference from lipids in the extract. Analysis time was about 40 min for the HPLC procedure compared with an estimated 1—1½ hr for the TLC method. The TLC procedure was preferable, however, because of its wider scope and capability for simultaneous analysis of several samples.
Determination of Water in Compound Fertilizers
Authors: Kostyrko Krystyna , Wagner Wanda 
Published: February 2020

Abstract
A method is proposed for determining the water content of nitrogen-potassium-phosphorus compound fertilizers. The method combines drying with methanol extraction, with or without ultrasonic comminution of the fertilizer. The total moisture content of the sample is calculated as a sum of1 that found by drying and that determined by the extraction method (residual moisture). Two methods of methanol extraction were used: extraction of the uncomminuted fertilizer sample directly in the titration vessel, or extraction of the comminuted sample by ultrasonic vibration. Water contents determined by the proposed method ranged from 0.3 to 1.7%. Standard deviations for extraction without and with comminution were 0.015 and 0.018%, respectively. Moreover, ultrasonic comminution of fertilizer increased the amount of residual water extracted by about 20% compared with other methods.
Collaborative Study of the Gas-Liquid Chromatographic Determination of Bromoxynil Octanoate in Formulations
Authors: Helfant Laurence J 
Published: February 2020

Abstract
The determination of bromoxynil octanoate by a gas-liquid chromatographic (GLC) method with di-n-butylphthalate as internal standard was subjected to testing by 10 collaborators. The standard deviation for bromoxynil octanoate and bromoxynil octanoate-MCPA (2-methyI- 4-chlorophenoxyacetic acid) ester formulations averaged 0.6%. While the deviation indicates that the method is statistically sound, the results were dependent upon the efficiency of the GLC column. Therefore, it is recommended that the method be subjected to continued study to further determine the GLC conditions necessary for improved method reliability.
Sample Preparation by Column Elution for Elemental Analysis of Plant Tissue
Authors: Gaines T Powell , Mitchell G Allen 
Published: February 2020

Abstract
A method of sample preparation based on column elution is described for the elemental analysis of plants. Plant tissue was mixed with acid-washed Celite 545, packed in a column, and eluted with 3ZV HC1. The cluate was analyzed for K, Ca, Mg, Zn, Fe, and Mn by atomic absorption spectroscopy. Values derived from column elution compare favorably with certified values for NBS Orchard Leaves reference material and dry ash values, except for Fe which was relatively low. Precision, expressed as % coefficient of variation, ranged from 0.7 to 4.4 for column elution compared to 0.7—8.7 for dry ashing. Column elution is a fast, simple technique for sample preparation that is especially suitable for a small number of samples.
Trace Analysis: A Requirement for Toxicological Research with Carcinogens and Hazardous Substances
Authors: Bowman Malcolm C 
Published: February 2020

Abstract
The protocol of a valid chronic toxicity experiment involving carcinogens and other hazardous chemicals will include several requirements for determining trace quantities of these compounds. Analytical procedures must provide assurance that no extraneous substances are present that could bias the results; that accurate dosages of the chemical are administered; that personnel and work areas remain free of contamination by the substances; and that the chemical and contaminated experimental material are disposed of safely. Analyses generally involve the separation of the chemical from several dissimilar substrates of varying complexity, cleanup, and quantitation by the detection system most suitable to the compound. Since there is no general agreement on the existence of a threshold level at which most carcinogens cause cancer or at which other substances produce damage, the analyst must strive for the ultimate sensitivity allowed by the state-of-the-art. Procedures have been developed for determining low ppb levels of compounds such as 2-acetylaminofluorene, benzidine, 4-aminobiphenyl, diethylstilbestrol, and estradiol in animal diet or drinking water. These procedures specify various detection systems such as spectrophotofluorescence, high pressure liquid chromatography, and electron capture gas chromatography; however, no one system is ideal for all compounds. We report a scheme for analyzing 13 compounds, in admixture, in human urine, wastewater, and environmental surveillance samples (swabs, air niters, etc.) based on electron capture gas chromatography of their pentafluoropropionyl derivatives.
Improved Automated Optical Somatic Cell Counting Method for Raw Milk: Collaborative Study
Authors: Kelley Wesley N 
Published: February 2020

Abstract
A collaborative study was conducted to compare the improved automated optical somatic cell counting procedure (OSCC II) with the direct microscopic somatic cell counting method (DMSCC) in raw milk. Samples were prefixed with formaldehyde and introduced into an Auto- Analyzer system. Dilution, clarification, and cell counting were performed automatically. Five collaborators participated in the study; they analyzed 48 samples in duplicate, using 2 different sampling rates. The results were compared with DMSCC counts reported by 3 different analysts. Statistical results show that the standard deviation for the DMSCC method is 0.0825 and for the OSCC II, at a sampling rate of 80/hr, 0.0434. When results are compared, the OSCC II procedure is as accurate as, and is significantly more precise than, the DMSCC method. The faster sampling rate of the OSCC II at 120/hr has some effect on precision but little effect on accuracy. The method has been adopted as official first action.
Determination of Iodide in Nutritional Beverage Products Using an Ion Selective Electrode
Authors: Miles Preston 
Published: February 2020

Abstract
An ion selective electrode procedure is described for the precise, accurate determination of iodide at the sub-ppm level in a variety of nutritional beverages. The relative standard deviation of the analysis is 1-4%; recoveries range from 90 to 120%. Comparison with results from neutron activation analysis and the traditional Sandell-Kolthoff procedure shows that the ion selective electrode procedure is free of determinant error and that dry ashing of samples can lead to low results.
Gas-Solid Chromatographic Procedures for Determining Acrylonitrile Monomer in Acrylonitrile-Containing Polymers and Food Simulating Solvents
Authors: Brown Margaret E , Breder Charles V , Mcneal Timothy P 
Published: February 2020

Abstract
A gas chromatographic method is described for acrylonitrile monomer (AN), using a nitrogen/phosphorus detector. Procedures for the analysis of AN in 5 food simulants (water, 3% acetic acid, heptane, 50% ethanol, and 8% ethanol) as well as in the polymer matrix are included. The quantitation limit for direct injection of AN/food simulant solution is 0.04 ng AN/μl. AN-based polymers are dissolved in N,N-dimethylacetamide and injected directly. Residual AN in the polymer can be quantitated at the 0.5 ng/μl level. Results of migration studies are also presented.
Separation Testing of Hemodialysis Shunts Using Dynamic and Static Forces in a Controlled Environment
Authors: Mack George D , Smith William M 
Published: February 2020

Abstract
Analytical methods are presented for determining the longitudinal dynamic and static forces needed to overcome the transverse frictional forces and effect the separation of hemodialysis shunt connections under controlled environmental conditions. Results for different types of shunts and their associated connectors are reported along with the factors that affect the separation force and separation times.