bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraction of Light Filth from Whole Peppermint Leaves: Collaborative Study
Authors: Boese Jack , Nakashima Marvin , Glaze Larry E 
Published: February 2020

Abstract
Results are reported for a collaborative study of a method for the extraction of light filth from whole peppermint leaves. A 5 g sample is defatted with isopropanol in a simple reflux appartus. Rat hairs, insect fragments, and whole insects are isolated by wet sieving on a No. 230 sieve, a deaerating boil in 40% isopropanol solution, flotation with Tween 80-Na4edta (1 + 1) and mineral oil-heptane (85 + 15), and trappings in a Wildman trap flask. Average recoveries obtained by 6 collaborators for 3 spike levels of rat hairs (5,10,15) were 83.3, 87.5, and 82.2%, respectively. For whole insects (5,10,15) recoveries averaged 85.0, 80.0 and 77.2% respectively; for insect fragments (20, 30, 50) recoveries averaged 79.6, 88.3, and 84.8%, respectively. The average recoveries for the 3 levels of each analyte were not significantly different. The method has been adopted official first action.
Mass Spectrometry and Identification of Sterols in Vegetable Oils as Butyryl Esters and Relative Quantitation by Gas Chromatography with Flame Ionization Detection
Authors: Brumley William C , Sheppard Alan J , Rudolf Theodore S , Shen Chih-Shang J , Yasaei Parvin , Sphon James A 
Published: February 2020

Abstract
Electron ionization mass spectrometry (MS) of sterol butyrates is ' described. Fragmentation of common sterol butyrates is related to structure and is discussed in relation to the fragmentation of free sterols I and of commonly used sterol derivatives. Derivatized samples of vegetable oils are introduced using a 10 m capillary gas chromatographic ) (GC) column for complete separation of the sterol butyrates. Quantitation of sterol butyrates in vegetable oils by packed column GC/flame ionization detection is based on percent relative area of peaks identified } by MS. Results of analyses of sunflower, castor, rapeseed, and virgin f olive oils, and other oils are presented. These techniques have been applied to the rapid screening of marketed olive oils for possible adulteration.
Capillary Gas Chromatographic Determination of Some Chlorobiphenyls in Eel Fat: Interlaboratory Study
Authors: Tuinstra Louis G M Th , Roos Arie H , Werdmuller Geziena A 
Published: February 2020

Abstract
A method for determination of 6 individual chlorobiphenyls in eel fat, based on saponification of the sample and determination with capillary gas chromatography, was studied collaboratively. Eleven laboratories submitted analytical results in duplicate for 6 individual chlorobiphenyls on 2 naturally contaminated eel fat samples. The reproducibility coefficient of variation was about 14% at the 1 mg/kg level for each chlorobiphenyl compound and about 23% at the 0.1 mg/kg level. For each compound, the mean recovery was about 90% with a standard deviation varying from 7 to 9%.
Determination of Acrylonitrile in Foods by Headspace-Gas Chromatography with Nitrogen-Sensitive Detection: Collaborative Study
Authors: Page Denis B 
Published: February 2020

Abstract
A headspace-gas chromatographic procedure, with nitrogen-phosphorous (N-P) specific detection for the determination of acrylonitrile (AN) in cold pack cheese, peanut butter, honey butter, and margarine, was collaboratively studied. Seven laboratories analyzed 7 samples of each food for AN at levels ranging from 5 to 60 ppb. For cold pack cheese, mean recoveries for AN added at about 5, 15, and 50 ppb were 65.9, 92.4, and 96.6%, respectively; for peanut butter, mean recoveries for AN added at about 10, 30, and 60 ppb were 59.6, 61.7, and 66.5%, respectively; for honey butter, mean recoveries for AN added at 5,15, and 50 ppb were 88.6, 96.4, and 94.6%, respectively; and for margarine, mean recoveries for AN added at 5, 15, and 50 ppb were 130.6, 91.9, and 88.7%, respectively. The overall coefficients of variation for cold pack cheese, peanut butter, honey butter, and margarine spiked at the above levels were 67.7,22.0, and 38.5%; 71.8,23.8, and 23.8%; 45.3, 30.4, and 13.0%; and 79.7, 38.9, and 16.2%, respectively.
Comparison of Rapid Perfringens Medium and Lactose Sulfite Medium for Detection of Clostridium perfringens
Authors: Smith Marilyn 
Published: February 2020

Abstract
Two tubed media, lactose sulfite (LS) and rapid perfringens medium (RPM), were evaluated and compared for their ability to detect and enumerate Clostridium perfringens in inoculated and naturally contaminated samples. In a 3-tube most probable number system, the number of organisms recovered from spiked samples was several-fold higher with RPM than with LS and was close to the numbers inoculated.Levels detected in 15 naturally contaminated samples were also higher with RPM. Only 13 of the samples were positive for C. perfringens ' with LS medium. These results indicate that RPM is a more effective medium than LS; therefore, its use is recommended
Overview of Physical-Chemical Methods for Determining Aminoglycoside Antibiotics in Tissues and Fluids of Food-Producing Animals
Authors: Shaikh Badar , Allen Edward H 
Published: February 2020

Abstract
A survey of literature is presented dealing with physical-chemical methods for the detection and quantitation of aminoglycoside antibiotics (gentamicin, streptomycin, dihydrostreptomycin, and neomycin) that are used in food-producing animals. Recent developments in cleanup and determinative procedures, particularly liquid chromatography, for these compounds in fluids and tissues are emphasized. Little research has been done on residues in tissues compared with other biological matrices. This review also covers the chemistry, general characteristics, tolerances, and withdrawal times for the approved uses of these antibiotics in animals that are used for food.
Liquid Chromatographic Method for Determination of Furazolidone in Premixes and Complete
Feeds: Collaborative Study
Authors: Smallidge Robert L 
Published: February 2020

Abstract
A liquid chromatographic (LC) method for determining furazolidone in finished feeds and premixes was collaboratively studied. Finished feed sample is extracted with acetone-water (93 + 7) on a Goldfisch apparatus, extracting solvent is removed, and the residual material is dissolved in warm DMF. A solution of tetraethylammonium bromide is added, the fat layer is removed, and the sample is clarified by filtration and injected onto a reverse phase LC system with detection at 365 nm. Premixes, extracted by shaking with DMF and diluted so that the final furazolidone concentration is about 55 (xg/niL, are chromatographed and detected the same as finished feed samples, using a mobile phase of acetonitrile-2% acetic acid (20 + 80). Ten commercial feed samples were preweighed and supplied to 14 collaborators. The 5 matched pairs were chosen to represent the following allowed levels: 0.0055, 0.022, 0.033, 2.2, and 22%. Two familiarization samples at the 0.0055 and 11% levels were also supplied. Instructions called for a single analysis of each sample. Two results were eliminated by the Dixon test. The coefficients of variation, following treatment by the ranking test, ranged from 2.0 at the 22% level to 6.5 at the 0.0055% level. Calculated F-values are not significant (P &gt;0.01) except for the 0.0055% level samples extracted overnight. This method has been adopted official first action
Evaluation of Liquid Chromatographic Methods for Analysis of Chlorphoxim Formulations
Authors: Mount Dwight L , Miles James W 
Published: February 2020

Abstract
Liquid chromatographic (LC) methods for determination of active ingredient in chlorphoxim formulations have been developed independently by Bayer AG and the Centers for Disease Control (CDC). Both methods specify separation on a silica gel column. The Bayer method uses a 5% solution of tetrahydrofuran in hexane as the eluting solvent and quantitates results on the basis of an external standard. The CDC method uses a 5% solution of ethyl acetate in hexane as the eluting solvent and uses 4-fluorophenyl sulfone as an internal standard. The 2 methods were compared by replicate analyses of samples of chlorphoxim technical and water-dispersible powder and emulsifiable concentrate formulations. The precision of both methods was acceptable
TYace Analysis of Chloramphenicol Residues in Eggs, Milk, and Meat: Comparison of Gas Chromatography and Radioimmunoassay
Authors: Arnold Dieter , Somogyi A 
Published: February 2020

Abstract
A radioimmunological assay (RIA) to detect chloramphenicol (CAP) residues in eggs, milk, and meat is described. For tissues and other edible products of chloramphenicol-treated animals (chickens, cows, and pigs), the limit of detection is about 200 βg/kg. Residue levels above 1 ng/kg can easily be quantitated. When highly specific antisera produced in sheep were used, cross-reactivity was insignificant except for metabolites deviating from the parent compound in the acyl side chain only. Thiamphenicol fails to bind to the antisera; hence, it does not interfere with the assay. In the procedure described, the role of cleanup is merely to remove lipids. Thus, skim milk can be analyzed following appropriate dilution without cleanup. The results obtained by RIA were confirmed by gas chromatography with electron capture detection. The new RIA allows rapid, sensitive, and specific screening of large numbers of samples.
Control of Chemical Contaminants in Foods: Past, Present, and Future
Authors: Jelinek Charles F 
Published: February 2020

Abstract
In the late 1930s and early 1940s, almost the only analyses carried out for chemical contaminants in foods were for lead arsenate and other arsenical pesticides in fruits. Since then, a tremendous expansion has occurred in the types of chemical contaminants found in foods and in the activities of the U.S. Food and Drug Administration and other organizations responsible for monitoring and controlling the presence of these contaminants in the food supply. This paper describes the findings and control of additional chemical contaminants in foods, including synthetic pesticides, PCBs (polychlorinated biphenyls), other industrial chemicals, fungal metabolites such as aflatoxins, toxic metals, and radionuclides. The common characteristics of problems connected with these defferent types of contaminants include uncontrolled entry into the food supply, incidents causing extreme public worry, and near impossibility in removing these contaminants from the food supply. Problems may also arise from new technologies and environmental developments. New approaches beyond ordinary regulatory activities are being used to meet these problems. Broader analytical methods requiring less time and faster and more sophisticated toxicological methods are needed to assess the hazard of these environmental food contaminants
Effect of iV-Nitrosothiazolidine-4-Carboxylic Acid on Formation of N-Nitrosothiazolidine in Uncooked Bacon
Authors: Pensabene John W , Fiddler Walter 
Published: February 2020

Abstract
iV-Nitrosothiazolidine-4-carboxylic acid (NTHZC) was recently identified in a variety of smoked fish and cured meat products. While the toxicological properties of NTHZC are currently unknown, it has been speculated that A'-nitrosothiazoIidine (NTHZ) in fried bacon may be caused in part by decarboxylation of NTHZC. A limited survey of uncooked cured meat products failed to demonstrate any correlation between levels of NTHZC and NTHZ. However, NTHZC levels were significantly higher, ranging from 8 to 1400 ppb, than the corresponding NTHZ levels, which ranged from &lt;2 to 18 ppb. Decarboxylation of NTHZC to NTHZ in a model system occurs at 110°C, which is significantly higher than the average bacon processing temperature of 54°C, but lower than the normal frying temperature of 177°C recommended for bacon. Results from both model system and frying experiments with NTHZC and its precursors suggest that NTHZC decarboxylation to NTHZ is not the principal pathway to NTHZ formation in uncooked bacon.
Brine Saturation Technique for Extracting Light Filth from Ground Cinnamon: Intralaboratory Study
Authors: Freeman Clarence C 
Published: February 2020

Abstract
An intralaboratory study was performed using the new brine saturation technique for isolating light filth from ground cinnamon. Recoveries of light filth averaged ^96.5%. The excellent recovery plus improvements in safety and simplicity give this new technique considerable advantage over the present official method.
Headspace Gas Chromatographic Method for Determination of Methyl Bromide in Food Ingredients
Authors: DeVries Jonathan W , Broge James M , Schroeder John P , Bowers Raymond H , Larson Paul A , Burns Nancy M 
Published: February 2020

Abstract
A headspace gas chromatographic (GC) method, which can be automated, has been developed for determination of methyl bromide. This method has been applied to wheat, flour, cocoa, and peanuts. Samples to be analyzed are placed in headspace sample vials, water is added, and the vials are sealed with Teflon-lined septa. After an appropriate equilibration time at 32°C, the samples are analyzed within 10 h. A sample of the headspace is withdrawn and analyzed on a gas chromatograph equipped with an electron capture detector (ECD). Methyl bromide levels were quantitated by comparison of peak area with a standard. The standard was generated by adding a known amount of methyl bromide to a portion of the matrix being analyzed and which was known to be methyl bromide free. The detection limit of the method was 0.4 ppb. The coefficient of variation (CV) was 6.5% for wheat, 8.3% for flour, 3.3% for cocoa, and 11.6% for peanuts.
Rapid Screening Method for Detection of Deoxynivalenol
Authors: Shannon Gail M , Peterson Robert E , Shotwell Odette L 
Published: February 2020

Abstract
A rapid method for detecting deoxynivalenol (DON), also known as vomitoxin, was developed. DON was extracted from grains and other samples with acetonitrile-4% potassium chloride solution (9 + 1). Impurities that would interfere with detection were removed on a Ci8 silica gel reverse phase column. Water was removed from eluates on a hydrophilic matrix column. DON was detected by thin layer chromatography using an aluminum chloride solution to develop the blue response characteristic of the mycotoxin. Total time involved is approximately 30 min. The method was applicable to corn, wheat, and barley at detection levels of 1 ppm, and oats at 1.5 ppm. It is applicable to environmental samples (soil, green plants, and water) at detection levels of 0.75 ppm.
Capillary Gas Chromatographic Determination of Pyrethrins in Low Level Formulations
Authors: Stringham Rodger W , Schulz Ray P 
Published: February 2020

Abstract
Low level pyrethrin formulations are extracted with tetrahydrofuran and determined via capillary gas chromatography with electron capture detection. Quantitation is based on the sum of peak heights of the 6 pyrethrin esters. The method was tested for precision, linearity, and recovery. Quadruplicate analysis of 5 formulations gave an average relative standard deviation of 3.3 %. Linearity and recovery were excellent (correlation coefficient = 0.997, recovery = 101.2%). The data presented support the use of the method for formulations that cannot be analyzed by the AOAC official method.
Liquid Chromatographic Determination of Vanillin and Related Flavor Compounds in Vanilla Extract: Cooperative Study
Authors: Guarino Philip A , Brown Susan M 
Published: February 2020

Abstract
Vanillin and related flavor compounds present in vanilla extract were determined by reverse phase liquid chromatography. Results compared favorably with the official AOAC spectrophotometric method. Compounds such as p-hydroxybenzaldehyde and ethyl vanillin known to interfere in the official method were resolved from vanillin. The method was evaluated by 6 industrial laboratories under the aegis of the Technical Committee of the Flavor and Extract Manufacturers Association. The method is suggested for AOAC collaborative study.
Spectral Characteristics of Florida Orange Juice and Orange Pulp wash. Collaborative Study
Authors: Petrus Donald R , Attaway John A 
Published: February 2020

Abstract
Visible and ultraviolet absorption and room temperature fluorescence excitation and emission spectra, obtained from alcoholic solutions of Florida orange juice (OJ) and orange pulpwash (PW), were used to characterize the collaborative study samples. The absorbance sum at 443, 325, and 280 nm and absorbance 443/325 nm ratio were used to estimate the percent total citrus material (TCM), OJ, PW, and dilution of the samples. Six laboratories participated in the study. Known samples of OJ and PW were given to each laboratory for familiarization and instrumental verification. Ten unknown samples (various combinations of OJ and PW) were analyzed by each laboratory. Three duplicate and 2 "closely matched pair" sample set combinations were reported. The results revealed that the method successfully detected the differences in sample formulations. The UV/vis and fluorescence spectrophotometric method has been adopted official first action for detecting adulteration of Florida orange juice with orange pulpwash.
Titrimetric and Spectrophotometric Determination of Acetylenic Hypnotics, Using Brominating Agents
Authors: Walash Mohamed I , Rizk Mohamed S , El-Brashy Amina 
Published: February 2020

Abstract
Titrimetric and spectrophotometric titration methods are described for the quantitative determination of acetylenic hypnotics ethchlorvynol, ethinamate, and meparfynol carbamate as pure substances and in dosage forms. The methods involve the use of different brominating agents. A known excess of the reagent is added and, after the specified time, the residual reagent is determined iodometrically. These procedures permit semimicro determination (1-20 mg) of the drug. Recoveries ranged from 98.48 ± 0.76 to 102.74 ± 2.60%. The procedures have been successfully applied to pharmaceutical dosage forms; the results agree well with those for compendial methods.
Fluorometric and Spectrophotometric Determination of Pirbuterol Hydrochloride in Authentic and Dosage Forms
Authors: Mohamed Mohamed E , Aboul-Enein Hassan Y 
Published: February 2020

Abstract
Pirbuterol hydrochloride has been assayed in alkaline medium by using a fluorometric method to measure fluorescence intensity at 372 nm with excitation at 310 nm and by the ▵A method at 242 nm.The linearity ranges are 0.5-4 μg/mL and 10-50 μg/mL, respectively. An authentic pirbuterol HC1 sample was analyzed by nonaqueous potentiometric titration using 0.1N perchloric acid, and the results were compared with those for fluorometric and AA methods. The mean percent recoveries for the authentic sample were 98.72 ± 1.13 and 99.24 ± 0.85, respectively. When applied to commercial capsules containing 10 mg and 15 mg each, the fluorometric method gave mean percent recoveries of 101.11 ± 1.05 and 98.12 ± 0.93; the ▵A method gave mean percent recoveries of 100.57 ± 0.83 and 97.80 ± 0.75, respectively.
Extraction and Determination of Selected Polycyclic Aromatic Hydrocarbons in Plant Tissues
Authors: Coates John T , Elzerman Alan W , Garrison A Wayne 
Published: February 2020

Abstract
A procedure has been developed for analysis of plant material for polycyclic aromatic hydrocarbons (PAHs). Sonication is used to extract the PAHs from homogenized plant material into acetonitrile and then the PAHs are partitioned into pentane. The pentane extract is fractionated on a micro silicic acid column and is analyzed by capillary gas chromatography with flame ionization detection. Overall method recoveries for 16 PAHs spiked into hybrid grain sorghum ranged from 45 to 90%, with relative standard deviations ranging from 3 to 38% and averaging 17%. This method can be used to measure PAHs in hybrid grain sorghum, fescue grass, and similar plants at the 25 μ/kg level. The procedure was applied to a preliminary study of PAH uptake by sorghum and fescue irrigated with secondary treated municipal wastewater spiked with 5 PAHs. Accumulation of fluoranthene and pyrene by fescue and hybrid grain sorghum from the PAH-contaminated irrigation water was apparent.
Dual Enzyme Method for Determination of Total Nonstructural Carbohydrates
Authors: Khaleeluddin Khaja , Bradford Linda 
Published: February 2020

Abstract
Total nonstructural carbohydrates (TNC) in plant tissue are underestimated by single enzyme (a-amylase or glucoamylase) extraction and overestimated by mild acid hydrolysis. A combination of glucoamylase and mycolase degraded starch completely to glucose at 60°C and pH 4.9. This dual enzyme extraction procedure was effective in determining TNC in plant tissues that do not accumulate fructosans. The reducing sugar (mainly glucose and/or fructose) extracts produced by enzymatic digestion of plant tissue were clarified with barium hydroxide and zinc sulfate solutions and analyzed by the Shaffer-Somogyi copperiodometric titration method. The dual enzyme method hydrolyzed pure starch derived from corn, wheat, and potato, and potato-soluble starch to about 100% glucose, whereas mycolase only yielded about 88% hydrolysis. Although corn starch was completely hydrolyzed in 2 h by the dual enzyme method, plant tissues required at least 24 h hydrolysis for maximum TNC values. Lead acetate precipitation of the protein in the dual enzyme extracts interfered with the copper-iodometric titration. Gelatinization of starch in plant tissue by autoclaving gave higher TNC values than heating on a hot plate for 5 min. The Schaffer-Somogyi copper iodometric titration method could be used to measure/or define the activity of certain enzymes.
Stability-Indicating Method for Determination of Some Acid-Stable Penicillins
Authors: El-Bardicy Mohammed G , Ellaithy Moustafa M , Ibrahim Mohammed W , Ahmad Abdel Kader S 
Published: February 2020

Abstract
A proposed titrimetric procedure for determining some acid-stable penicillins is investigated. The procedure has been used for both pure substances and dosage forms and was fairly accurate. A study of the mechanism of the reaction of the suggested stability-indicating method is presented.
Volatile N-Nitrosamines in Infant Pacifiers Sold in the United States as Determined by Gas Chromatography/Thermal Energy Analysis
Authors: Billedeau Stanley M , Thompson Harold C , Miller Barbara J , Wind Marilyn L 
Published: February 2020

Abstract
Volatile N-nitrosamines in infant latex rubber pacifiers were determined using a modification of a previously described dichloromethane extraction procedure, followed by gas chromatography/thermal energy analysis. Under an interagency agreement between the National Center for Toxicological Research and the Consumer Product Safety Commission (CPSC), data were obtained on the baseline and compliance concentrations of volatile N-nitrosamines in infant pacifiers sold in the United States. Pacifiers made by 18 different manufacturers before and after the January 1, 1984 action level of 60 ppb was set by the CPSC were analyzed for volatile N-nitrosamines. N-Nitrosodibutylamine was the principal N-nitrosamine found, along with trace amounts of N-nitrosodimethylamine, N-nitrosodiethylamine, and N-nitrosopiperidine. Mean total volatile N-nitrosamine levels for baseline and compliance samples were 63.9 and 21.2 ppb, respectively. The pacifier lots sampled after January 1, 1984 showed a significant decrease in contamination levels, indicating that at least 98% of the market share is in compliance with the CPSC enforcement policy for N-nitrosamines in infant pacifiers sold in the United States.