bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Small Quantities of Atropine in Commercial Preparations by Liquid
Chromatography with Fluorescence Detection
Authors: Cieri Ugo R 
Published: February 2020

Abstract
A method is presented for the determination of small quantities of atropine in commercial preparations by liquid chromatography (LC) with fluorescence detection. The sample is extracted with CHC13 from basic suspension, the CHC13 is evaporated on the steam bath, and the dry residue is dissolved in a small volume of CH3OH. A reverse phase column is used for the LC analysis; the eluting solvent is prepared by mixing 950 mL CH3OH with 50 mL water containing 1 g of the sodium salt of l-pentanesulfonic acid. The fluorescence detector is set at an excitation wavelength of 255 nm and an emission wavelength of 285 nm. Several commercial tablets and injections containing atropine in combination with other ingredients and a commercial sample of belladonna extract were analyzed by the proposed method. Recoveries of atropine sulfate from aqueous solutions averaged 100.7% with a relative standard deviation (RSD) of 3.35% for atropine sulfate levels of 0.12 mg. Recoveries of atropine sulfate from synthetic injection formulations were 99.8 and 100.0% withRSDsof 2.03and2.35%, respectively; the atropine sulfate concentrations of commercial injections with the same formulations were found to be 97.0 and 100.0% of the labeled amounts with RSDs of 0.53 and 1.46%, respectively
Pesticides, Selected Elements, and Other Chemicals in Infant and Toddler Total Diet Samples, October 1978-September 1979
Authors: Gartrell Marcia J , Craun John C , Podrebarac David S , Gunderson Ellis L 
Published: February 2020

Abstract
The U.S. Food and Drug Administration (FDA) conducts Total Diet Studies to determine the dietary intake of selected pesticides, industrial chemicals, and elements (including radionuclides). These studies involve the retail purchase and analysis of foods representative of the diets of infants, toddlers, and adults. The individual food items are separated into a number of food groups, each of which is analyzed as a composite. This report summarizes the results for infant and toddler Total Diet samples collected in 10 cities between October 1978 and September 1979. The average concentration, range of concentrations, and calculated average daily intake of the chemicals found are presented by food group. The average daily intakes of the chemicals are similar to those found in the several preceding years and generally are within acceptable limits. The results for samples collected during the same period that represent the adult diet are reported separately.
Pesticides, Selected Elements, and Other Chemicals in Adult Total Diet Samples, October 1978-September 1979
Authors: Gartrell Marcia J , Craun John C , Podrebarac David S , Gunderson Ellis L 
Published: February 2020

Abstract
The U.S. Food and Drug Administration (FDA) conducts Total Diet Studies to determine the dietary intake of selected pesticides, industrial chemicals, and elements (including radionuclides). These studies involve the retail purchase and analysis of foods representative of the diets of infants, toddlers, and adults. The individual food items are separated into a number of food groups, each of which is analyzed as a composite. This report summarizes the results for adult Total Diet samples collected in 20 cities between October 1978 and September 1979. The average concentration, range of concentrations, and calculated average daily intake of each chemical found are presented by food group. The average daily intakes of the chemicals are similar to those found in the several preceding years and are within acceptable limits. The results for samples collected during the same period that represent the diets of infants and toddlers are reported separately.
Digestion of Food Samples for Total Mercury Determination
Authors: Louie Hon Way , Go Danny , Fedczina Mara , Judd Kevin , Dalins John 
Published: February 2020

Abstract
A method of digestion by using a mixture of hydrochloric, nitric, and sulfuric acids has been developed for the determination of total mercury in a wide range of food samples. Good recoveries of mercury were obtained from NBS (National Bureau of Standards) Albacore Tuna and from food samples spiked with inorganic mercury. A detection limit of 0.01g mercury/g can be obtained.
Brine Saturation Technique for Extraction of Light Filth from Rubbed, Ground, and Whole Sage: Collaborative Study
Authors: Freeman Clarence C 
Published: February 2020

Abstract
A new approach to the isolation of light filth from the 3 commercial forms of sage was studied collaboratively. It incorporates a simple isopropanol defatting, followed by saturation of the product with brine by alternately heating and cooling, and subsequent trapping of filth from tap water with olive oil. This method circumvents the use of hazardous, expensive solvents and more time-consuming pretreatment procedures. Overall recoveries were 92.1% for rodent hair and 78.7% for insect fragments on clean, easy-to-read papers. An additional blending step was necessary to obtain satisfactory recovery of rodent hair fragments from whole sage. The method has been adopted official first action for light filth in rubbed and ground sage only.
Harmonization of the Standardization of Reference Substances for the Analysis of Pesticide Products
Authors: Pavel Konrad 
Published: February 2020

Abstract
Quantitative analysis of pesticide products is often based on analytical procedures that require substances of precisely known purity as reference materials. In addition, samples of "pure" active ingredient (AI) are needed for registration purposes, in part for the determination of some physical-chemical properties, and also for submission to the authorities. Pure AIs from several pesticides are available commercially or from particular institutes. Some pure pesticides, especially those of newly developed products, must be provided by the manufacturer. Substances like these have a variety of names, such as pure AI, pure pesticide, reference material, pure standard, or analytical grade sample. It is suggested that internationally uniform names be given to highly purified substances and to other samples that are used as reference materials for determination and certification of purity and other quality criteria. DAPA recommends that 2 kinds of reference materials be distinguished: primary reference substance and working standard, and offers draft guidelines for standardization and draft certification forms for reference materials. Finally, it is proposed that CIPAC (Collaborative International Pesticides Analytical Council) or FAO (Food and Agriculture Organization) publish corresponding papers.
Analysis of Diazinon for Impurities and Degradation Materials
Authors: Karr James J 
Published: February 2020

Abstract
Several samples of commercial diazinon were analyzed for impurities and degradation products. A serious impurity identified as sulfotepp (S-TEPP) was found to be present in all of the samples examined; however, the levels of S-TEPP ranged from a low of about 250 ppm to 5500 ppm. The unusually high levels of S-TEPP were correlated with specific suppliers of diazinon. AH of the analytical work, including the quantitative measurements, was carried out using gas chromatographic (GC) techniques and specific detectors. The focus of this study was directed to the presence of S-TEPP in the commercially produced samples of diazinon, and whether the S-TEPP is concentrated in the diazinon or produced as a result of other manufacturing or formulating processes. Specifically, diazinon is the toxicant used in the commercial controlled-release formulation, a microencapsulated insecticide used for residual pest control in and around residential and commercial buildings. The result of the study firmly establishes the role of S-TEPP as being a carryover contaminant and not the result of a degradation process. Other impurities were identified with the aid of a mass spectrophotometer in the electron-impact mode.
Rapid Thin Layer Chromatographic Determination of Aflatoxin M1 in Powdered Milk
Authors: Serralheiro Maria Luisa , Quinta Maria Lurdes 
Published: February 2020

Abstract
A method has been developed for the detection of aflatoxin Mi in milk. The toxin is extracted with chloroform, the extract is evaporated, and the residue is partitioned between carbon tetrachloride and an aqueous saline-methanol solution. The toxin is once again extracted with chloroform from the methanol solution and analyzed by thin layer chromatography. The limit of detection of Mi in powdered milk is 0.5 μg/ kg; recoveries of added Mj are about 83%. The limit of detection can be improved to 0.3 μg/kg if the plate is sprayed with an aqueous solution of H2S04 after development.
Deoxynivalenol in Hard Red Winter Wheat: Relationship Between Toxin Levels and Factors That Could Be Used in Grading
Authors: Shotwell Odette L , Bennett Glenn A , Stubblefield Robert D , Shannon Gail M , Kwolek William F , Plattner Ronald D 
Published: February 2020

Abstract
A study was made of deoxynivalenol (DON) incidences and levels in 1982 hard red winter (HRW) wheat grown in areas of Nebraska and Kansas known to have scabby wheat. Samples of wheat harvested in the areas were collected from elevators and analyzed for DON by gas chromatography with an electron capture detector. Of the 161 samples analyzed, 42% contained s i ppm; 68% contained &lt;2 ppm; 90% contained ^4 ppm. There were differences in the occurrence of DON in the 5 areas identified in eastern Nebraska and Kansas. The mean level of DON decreased from north to south in these areas in the following order: 2.81,2.73,2.05,1.52, and 0.83 ppm. An area in north central Kansas had a mean level of DON of 0.50 ppm. Correlations were made between DON incidences and levels in HRW wheat and factors used in grading wheat. The occurrence of DON was highly correlated with percent total kernels damaged by mold, percent total defects, and percent total scab damage.
Second Derivative Ultraviolet Spectroscopy and Sulfamic Acid Method for Determination of Nitrates in Water
Authors: Simal Jesus , Lage Maria Asuncion , Iglesias Isabel 
Published: February 2020

Abstract
Second derivative ultraviolet (UV) spectroscopy is used for the identification and quantitation of nitrates in water, with satisfactory precision and accuracy. Nitrite interference is eliminated with sulfamic acid; interference from organic matter can be cancelled with the use of second derivative UV spectroscopy. The nitrites can be calculated indirectly.
Antibiotic Residues in Animal-Derived Food
Authors: Livingston Robert C 
Published: February 2020

Abstract
Antibiotics are used extensively in food-producing animals to maintain optimal health and promote growth. The use of these drugs has the potential to leave drug-related residues such as parent drug and metabolites in meat, milk, and eggs. For those drugs that require a withholding period to ensure that residues in the food products are below established tolerances, methods of analysis are required. The majority of approved antibiotics are assayed by microbiological methods. Although these methods are suitable for screening for drug residues, they often lack the specificity and precision required of regulatory methods. Present requirements for regulatory methods have resulted in the submission of physical-chemical methods in support of New Animal Drug Applications for antibiotics.
Methods for Determination of Ionophore-Type Antibiotic Residues in Animal Tissues
Authors: Weiss George , Macdonald Alexander 
Published: February 2020

Abstract
Methods for the analysis of polyether antibiotics in animal tissues and fluids are described. For monensin and nigericin, only methods based on bioautography are available. For lasalocid, in addition to TLC bioautography for quantitation in chicken skin and fat, LC methods based on fluorescence detection have been developed for quantitation in animal blood, milk, liver, skin, and fat. In addition, a confirmatory method for lasalocid is described; this is based on purification by LC followed by silylation and pyrolysis gas chromatography-positive chemical ionization mass spectrometry.
Chromatographic Methods for Determination of Macrolide Antibiotic Residues in Tissues and Milk of Food-Producing Animals
Authors: Moats William A 
Published: February 2020

Abstract
Tylosin, an antibiotic developed specifically for agricultural use, and erythromycin are the main macrolide antibiotics used in animal production. Two-dimensional thin layer chromatography has been used for detection of tylosin in poultry meat, eggs, and milk and for erythromycin in poultry meat. Detection limits reported are, for tylosin, 0.1 ppm in poultry meat, 0.05 ppm in egg, and 0.01 ppm in milk,'and for erythromycin, 0.25 ppm in poultry meat. Liquid chromatography (LC) has also been used for determination of tylosin in milk, blood, and tissues of animals. Samples (milk, blood serum, or tissue homogenates in water or pH 2.2 buffer) were deproteinized with acetonitrile, tylosin was partitioned into methylene chloride, and the extracts were concentrated and dissolved in acetonitrile. Chromatography was done on a reverse phase end-capped C18 column using 0.002-0.005M ammonium dihydrogen phosphate-acetonitrile-methanol (10 + 60 + 30-5 + 80 + 15). Solvent composition was varied with the type of sample analyzed. The method will detect 0.1 ppm tylosin in tissues and less in milk and blood serum. The LC method was more sensitive than microbiological assays for detection of tylosin in tissues of treated swine; recoveries of tylosin by the LC method were frequently several-fold higher.
Liquid Chromatographic Determination of Thiamine in Infant Formula Products by Using Ultraviolet Detection
Authors: Ayi Benjamin K , Yuhas David A , Moffett Kathryn S , Joyce Deidre M , Deangelis Nicholas J 
Published: February 2020

Abstract
A liquid chromatographic (LC) method has been developed for determination of thiamine in infant formula products. The method involves the following steps: (a) dissolution of the formula with water, (b) pH adjustment to induce protein precipitation, (c) filtration, (d) concentration of thiamine by using a cation exchange column and extraction system, (e) cleanup of adsorbed thiamine and other contaminants on the ion exchange column by washing with water and then methanol, (f) elution of thiamine with a mixture of methanol-2M potassium chloride buffer, (g) analysis for thiamine by liquid chromatography. Thiamine is separated from its phosphate esters, the mono-, di-, and triphosphates, as well as its antagonists oxythiamine and pyrithiamine on a 6 p-m particle size column and a mobile phase of 40mM triethylammonium phosphate buffer-methanol (pH 7.7) (90 + 10). The method is reproducible, with relative standard deviations ranging from ± 0.76 to ± 1.2%, depending on the infant formula product tested. Recovery of thiamine from various infant formula products is greater than 99%. Analysis for thiamine of several commercially available infant formulas at different levels of fortification gave results that ranged from 122 to 216% of the declared levels. These results agree well with those obtained using the AOAC fluorometric method.
Gas Chromatographic-Mass Spectrometric Detection of Adulteration of Natural Lime Oils
Authors: Alessandro Rocco T , Adams James M , Miskiewicz Michael A 
Published: February 2020

Abstract
Distilled and expressed lime oils were characterized by glass capillary gas chromatography. Components present at concentrations greater than 0.1% were identified by mass spectrometry. Expressed oils contained less than 1% monoterpene alcohols, whereas distilled oils contained more than 10%. Expressed oils contained sabinene and 4 times as much beta-pinene as distilled oils. Adulteration was detected by finding component area percents and/or their ratios to be outside the 95% confidence intervals established for pure oils.
Analysis of Pharmaceutical Dosage Forms for Oxfendazole: II. Simultaneous Liquid Chromatographic Determination of Oxfendazole and Trichlorfon in Equine Paste
Authors: Fleitman Jeffrey , Neu Daniel , Benjamin Eric 
Published: February 2020

Abstract
A reverse phase liquid chromatographic procedure is described for the simultaneous determination of oxfendazole [2-(methoxycarbonylamino)- 5-phenylsulfinylbenzimidazole] and trichlorfon [(2,2,2-trichloro-1-hydroxyethyl)phosphonic acid dimethyl ester] in equine paste. The sample is extracted by sonication in methanol. Insoluble excipients are removed by centrifugation and an aliquot plus internal standard are diluted with dilution solvent (water-acetonitrile-phosphoric acid, 80 + 20 + 1). The samples are filtered and injected onto a Partisil-5 ODS-3 column with acetonitrile-0.01M phosphate buffer pH 6.0 (20 + 80) as mobile phase. Method specificity is confirmed using an absorbance ratioing technique. The method yields mean recoveries of 100.9 and 100.0% for trichlorfon and oxfendazole, respectively. Dependence of chromatographic performance characteristics on mobile phase organic content, pH, and buffer concentration is also reported.
Thin Layer Chromatographic Determination of Deoxynivalenol in Processed Grain Products
Authors: Trucksess Mary W , Flood Michael T , Page Samuel W 
Published: February 2020

Abstract
The thin layer chromatographic (TLC) method of Trucksess et al. (J. Assoc. Off. Anal. Chem. (1984) 67, 40-43) was modified for the determination of deoxynivalenol (DON) in high-sugar breakfast cereals, corn syrup, and beer. Celite was added to the substrate before extraction with acetonitrile-water (84 + 16). After filtration through an aluminacharcoal-Celite (0.5 + 0.7 + 0.3) column, the filtrate was evaporated to dryness and redissolved in water, which was passed through an octylsilyl reverse phase column. DON was eluted with anhydrous ethyl ether. The residue remaining after the eluate was evaporated to dryness was dissolved in CHCl3-acetonitrile (4 + 1) and chromatographed on AlCVimpregnated silica gel TLC plates. The blue fluorescent DON spot was quantitated fluorodensitometrically after the TLC plate was heated at 120°C for 7 min. Recoveries of DON added to breakfast cereals at 100, 200, and 400 ng/g levels and to syrup and beer at 50, 100, and 200 ng/g levels averaged 86%. The limit of determination in these products was about 50 ng/g.
Thin Layer Chromatographic Method for Determination of Deoxynivalenol in Wheat: Collaborative Study
Authors: Eppley Robert M , Trucksess Mary W , Nesheim Stanley , Thorpe Charles W , Pohland Albert E ,   Collaborators:, Applegate S L , Bean G A , Chang H , Chatel R , Deteghem C van , Gibson G E , Gilbert J , Gross A F , Howell M V , Nowicki T W , Scott P M , Seitz L M , Subryan L , Terhune S , Ware G 
Published: February 2020

Abstract
A collaborative study of a rapid method for the determination of deoxynivalenol (DON) in winter wheat was successfully completed. The method involves sample extraction with acetonitrile-water (84 + 16), cleanup using a disposable column of charcoal, Celite, and alumina, and detection by thin layer chromatography after spraying with an aluminum chloride solution. Each of the 15 collaborators analyzed 12 samples, 2 of which were naturally contaminated, and 10 to which DON was added, in duplicate, at levels of 0,50,100,300, and 1000 ng/ g. Average recoveries of DON ranged from 78 to 96% with repeatabilities of 30-64% and reproducibilities of 33-87%. The results of the study show that false positives were not a problem and that all of the analysts could detect DON at the 300 ng/g level or higher. The method has been adopted official first action.
Absence of Isomerization of Retinyl Palmitate, Retinol, and Retinal in Chlorinated and Nonchlorinated Solvents Under Gold Light
Authors: Landers Gary M , Olson James A 
Published: February 2020

Abstract
Purified solutions of all-trans retinyl palmitate, retinol, and retinaldehyde in chloroform, methylene chloride, or hexane were exposed to white light or gold fluorescent light or were kept in the dark, and the resulting isomer distributions were determined by LC (liquid chromatography). No significant isomerization of any of the retinoids occurred either in the dark or on exposure to gold light in any of the solvents tested. However, a large amount of the 9-cis isomer and only much smaller amounts of other cis isomers were produced when retinol or retinyl palmitate in chloroform or methylene chloride solution was exposed to white light. The isomerization pattern of retinyl palmitate in chloroform was not altered by the addition of free-radical scavengers, addition of an organic base, or substitution of deuterochloroform for chloroform as solvent. Use of other polar solvents such as tetrahydrofuran, acetone, or methanol produced isomer distributions similar to those obtained in chloroform solution. Retinol and retinyl palmitate in hexane solution, on exposure to white light, were isomerized much less extensively than in chloroform or methylene chloride and produced a significant amount of the 13-cis, as well as the 9-cis, isomer. Isomerization of retinaldehyde in chloroform or in methylene chloride solution under white light yielded 13-cis, 11-cis, 9-cis, and 7-cis isomers, in order of decreasing amount, whereas in hexane solution, only the 13-cis and 9-cis isomers were produced in significant quantity
Measurement of Aldrin in Air by Gas Chromatography with Sorbent-FiUed Trapping Tube
Authors: Wallace Brian G , Sherren Andrew J 
Published: February 2020

Abstract
An alternative procedure to the National Institute for Occupational Safety and Health (NIOSH) method has been developed for the determination of aldrin in air. In this alternative procedure, the isooctane gas bubbler is replaced by a stainless steel trapping tube packed with Tenax GC. Radiochemical techniques have been used to validate the use of Tenax GC as an efficient adsorbent for aldrin. The main advantages are a higher trapping efficiency, elimination of the need to replenish frequently the volatile solvent, and the ease of transporting trapping tubes from sampling sites to the laboratory. A sample of 120 L of air is recommended to achieve a limit of determination of 0.04 μg/cu. m.
Determination of Nitrate in Forages by Using Selective Ion Electrode: Collaborative Study
Authors: Carlson Michael P , Schneider Norman R ,   Collaborators:, Everson R , Johnson J , Kosse K , Krause J , McMahon T , Ray A , Ross F , Rottinghaus G , Thiex N , Torma L 
Published: February 2020

Abstract
Each of 10 collaborating laboratories analyzed 4 blind duplicate pairs of forage samples for nitrate, by using a potentiometric method. Two forage controls and a 100 000 mg KNO3/L standard were also provided. Nitrate was extracted into an aqueous Al2(SO4)3 solution containing 70 mg KNO3/L and quantitated with a nitrate-selective electrode. Standards were prepared using extracting solution as diluent. Nitrate concentrations in forage samples ranged from &lt;0.50 to 4.35% KNO3. Repeatability coefficients of variation (CV0) ranged from 1.74 to 3.61%, and reproducibility coefficients of variation (CV1) ranged from 6.92 to 7.66%. Mean recovery of a 0.55% KNO3 spike was 94.5%. The method has been adopted official first action.
Detection of Adulteration in Commercial Cranberry Juice Drinks and Concentrates
Authors: Hong Victor , Wrolstad Ronald E 
Published: February 2020

Abstract
Thirty-one samples of commercial cranberry juice drink and one sample of commercial cranberry juice concentrate were analyzed for nonvolatile acids and anthocyanidin profiles by liquid chromatography (LC). Ultraviolet-visible spectral measurements were used to measure pigment concentration, polymeric color, and percent polymeric color. Nineteen of the 31 samples analyzed were found to be adulterated. The adulterated samples exhibited nonvolatile organic acid profiles indicative of added malic and/or citric acid. Anthocyanidin profiles of the adulterated samples showed the presence of substantial quantities of delphinidin and malvidin, neither of which are present in cranberries in significant amounts. Grape skin extract is believed to be the added colorant.