bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interim Method for Determination of Volatile Organic Compounds in Hazardous Wastes
Authors: Gurka Donald F , Warner J Scott , Silvon Larry E , Bishop Thomas A , Mckown Mary M 
Published: February 2020

Abstract
An analytical protocol is presented for the determination of volatile organic compounds in hazardous wastes that are amenable to the purge-and-trap method. The protocol features a tetraethylene glycol dimethyl ether (tetraglyme) extraction of the liquid or solid waste, addition of an aliquot of the tetraglyme waste to water, and purging of the tetraglyme-water mixture with subsequent gas chromatographic/ mass spectrometric (GC/MS) analysis. The size of the tetraglyme aliquot is determined by gas chromatographic screening of a hexadecane waste extract. Quality assurance/quality control procedures are included within the analytical protocol. Spike extraction recoveries of industrial wastes obtained by following this protocol are given.
Automated Sample Cleanup for Pesticide Multiresidue Analysis. Part II—Design and Evaluation of Column Chromatography Module
Authors: Gretch Fred M , Rosen Joseph D 
Published: February 2020

Abstract
An automated, continuous flow system is described for Florisil column chromatography of pesticide residues from food extracts. Evaluation of the system using 5 common organochlorine and organophosphorus pesticides in 2 crop matrices demonstrates essentially no difference in recovery or precision between automated and currently used manual analyses. The automated procedure uses only 20% of the solvents and adsorbents used in the manual procedure and is 3 times faster.
Decomposition of 4,4'-(Diazoamino)-bis(5-methoxy-2-methylbenezenesulfonic Acid) in Solutions ofFD&C Red No. 40
Authors: Richfield-Fratz Naomi 
Published: February 2020

Abstract
4,4'-(Diazoamino)-bis(5-methoxy-2-methylbenzenesuIfonic acid), when present as a reaction by-product in FD&C Red No. 40, is shown to decompose rapidly in aqueous solutions of the color additive. The decomposition is halted by the addition of sodium borate buffer. Quantitationly liquid chromatography shows that decomposition is nonlinear with time and follows approximate first order kinetics.
Quantitative Amino Acid Analysis of Feedstuff Hydrolysates by Reverse Phase Liquid Chromatography and Conventional Ion-Exchange Chromatography
Authors: Elkin Robert G 
Published: February 2020

Abstract
Corn, soybean meal, and isolated soybean protein samples were acidhydrolyzed and analyzed for amino acid content by reverse phase liquid chromatography (LC) and by conventional ion-exchange chromatography (IEC) using an amino acid analyzer. The former method employed pre-column derivatization with orthophthalaldehyde (OPTA)/ethanethiol and fluorescence detection. In the LC procedure, glycine and threonine were not resolved, and proline and cyst(e)ine were not detected. In general, amino acid values obtained by LC and IEC compared closely within and across feedstuffs, and both agreed well with published amino acid composition data. The notable exceptions were aspartic acid, glutamic acid, and alanine. Results of this study suggest that reverse phase LC with pre-column OPTA derivatization can be applied to accurately measure primary amino acids in individual feedstuffs.
Extraction of Organic Acids by Ion-Pair Formation with Tri-n-Octylamine. Part V. Simultaneous Determination of Synthetic Dyes, Benzoic Acid, Sorbic Acid, and Saccharin in Soft Drinks and Lemonade Syrups
Authors: Puttemans Marc L , Dryon Louis , Massart Désiré L 
Published: February 2020

Abstract
Synthetic dyes, benzoic acid, sorbic acid, and saccharin are extracted simultaneously from soft drinks with 0.01M tri-n-octylamine at pH = 5.5 and are back-extracted to an aqueous phase with 0.1M sodium perchlorate. The perchlorate solution is injected directly into the reverse phase liquid chromatographic system which permits the separation of all the substances investigated. Forty-six commercial samples of soft drinks and 11 lemonade syrups were analyzed. All samples conformed to the legal prescriptions.
Separation and Analysis of Pilocarpine, Isopilocarpine, and Pilocarpic Acid by Reverse Phase Liquid Chromatography: Collaborative Study
Authors: Van Ackeren John L , Venable Richard M , Wainer Irving W 
Published: February 2020

Abstract
A method for separating and determining pilocarpine and 2 degradation products was developed and subjected to collaborative study. Pilocarpine, isopilocarpine, and pilocarpic acid were isolated on a reverse phase liquid chromatographic phenyl bonded column and detected by UV spectrophotometry at 220 nm. Nine collaborators received commercial samples labeled to contain 2,1, and 0.5% pilocarpine and a 2% practice sample. The collaborative results for pilocarpine were excellent; coefficients of variation ranged from 3.20 to 4.10%. The method was adopted official first action for determination of the active component, pilocarpine, in the presence of isopilocarpine and pilocarpic acid. Although quantitative results for the degradation products were not as good, the method is suitable as a limits test for these substances.
X-Ray Powder Diffraction Data for Selected Drugs: Furosemide, Hydrochlorothiazide, Naproxen, Naproxen Sodium, Propranolol Hydrochloride, and the Halopheniramine Maleates
Authors: De Camp Wilson H 
Published: February 2020

Abstract
X-ray powder diffraction data for 9 commonly used drug substances are reported. The data for furosemide, hydrochlorothiazide, propranolol hydrochloride, dexchlorpheniramine maleate, and brompheniramine maleate have been indexed by reference to published crystal structure data. The racemic modifications of propranolol hydrochloride and brompheniramine maleate are shown to exist as racemic compounds rather than racemic mixtures.
Determination of Chlorinated Methylthiobenzenes and Their Sulfoxides and Sulfones in Fish
Authors: Gardner Albert M , Abramovitch Akiva 
Published: February 2020

Abstract
A procedure was developed to determine chlorinated methylthiobenzenes and their respective sulfur oxidation products in fish. Perch samples fortified at the 0.1 ppm level with 2,4,5-trichloromethylthiobenzene, pentachloromethylthiobenzene, and their sulfoxides and sulfones were extracted and cleaned up using an adaptation of the official AOAC method for multiple residues of organochlorine pesticides. The Florisil column cleanup was modified; 200 raL 6% petroleum etherethyl ether eluted the methylthiobenzenes, 200 mL 50% PE-EE eluted the sulfones, and 200 mL EE eluted the sulfoxides. Recoveries determined by electron capture (ECD) gas chromatography (GC) were 75- 101% for the methylthiobenzenes and their sulfones and 63-93% for the sulfoxides. Co-extracted materials in the Florisil eluates that interfered with the ECD/GC quantitation were removed by partitioning the sulfoxides and sulfones into sulfuric acid and by thin layer chromatography on silica gel, using methylene chloride-hexane (50 + 50) as the developing solvent. Seven fish samples containing residues of chlorinated benzenes or polychlorinated biphenyls (PCBs) were examined for chlorinated methylthiobenzenes, methylthio-PCBs, and their oxidation products by matching GC retention times obtained with the EC detector and a flame photometric detector operated in the sulfur mode. These analytes were not found in the fish samples above a detection level equivalent to 0.02 ppm 2,4,5-trichloromethylthiobenzene.
Chemical Derivatization Analysis of Pesticide Residues. IX. Analysis of Phenol and 21 Chlorinated Phenols in Natural Waters by Formation of Pentafluorobenzyl Ether Derivatives
Authors: Lee Hing-Biu , Weng Li-Da , Chau Alfred S Y 
Published: February 2020

Abstract
A sensitive, isomer-specific method is described for the simultaneous and quantitative analysis of 22 phenols (phenol, 18 chlorophenols, and 3 chloroalkylphenols) in natural waters. The sample was acidified to pH ≤2, extracted with dichloromethane, evaporated, and dissolved in acetone. The phenol extract was then reacted with pentafluorobenzyl bromide (PFBBr) to give the PFB ether derivatives. After silica gel column cleanup, the ethers were chromatographed on a 12 m OV-1 fused silica capillary column attached to an electron capture detector (ECD). The detection limit was 0.1 ppb for 1 L samples. Recoveries of phenols from pH 2 water samples fortified at 10, 1, and 0.1 ppb were a80% in most cases except for phenol which was only 30 to 35% recovered. Coefficients of variation were between 2 and 10% for all phenols. However, phenol recovery was quantitative when the sample volume was reduced to 100 mL. Because ECD sensitivities to the 22 phenol PFB ethers were similar, this method is most suitable for simultaneous screening of nonchlorinated and monochlorinated phenols as well as other higher chlorophenols at trace levels.
Determination of Xanthomegnin in Grains and Animal Feeds by Liquid Chromatography with Electrochemical Detection
Authors: Carman Allen S , Kuan Shia S , Francis Octave J , Ware George M , Luedtke Alan E 
Published: February 2020

Abstract
A sensitive, highly selective liquid chromatographic (LC) method is described which uses electrochemical (EC) reduction of the analyte in the determinative step. The method is capable of determining xanthomegnin in mixed animal feeds and grains at levels ranging from 15 to 1200 ng/g. The method can detect as little as 0.5 ng xanthomegnin injected on the LC column. Xanthomegnin is extracted with chloroform and 0.1M phosphoric acid. An aliquot of the crude extract is purified by silica gel column chromatography using a Sep-Pak silica gel cartridge. A novel feature of the method is that xanthomegnin is "backed off' the column by reversing the flow of the eluant through the column. LC is then used to separate xanthomegnin from other interfering substances. Xanthomegnin is detectd by EC reduction at −0.16 V. Recoveries of xanthomegnin added to samples at levels ranging from 15 to 1200 ng/g averaged 79% with a coefficient of variation of 7.9%. Results also demonstrate that this LC system can separate the related metabolites viomellein and rubrosulphin from each other and from xanthomegnin and that the same EC detection system can be used to detect these metabolites.
Capillary Gas Chromatographic Determination of T-2 Toxin, HT-2 Toxin, and Diacetoxyscirpenol in Cereal Grains
Authors: Cohen Huguette , Lapointe Michel 
Published: February 2020

Abstract
A capillary gas chromatographic (GC) method using an electron capture detector is described for determining T-2 and HT-2 toxins and diacetoxyscirpenol (DAS) in cereal grains at levels as low as 100 ppb for T-2 and DAS and 50 ppb for HT-2. Samples are extracted with methanol-water according to the Scott method, and further purified on a silica gel cartridge and a cyano column. Heptafluorobutyrylimidazole (HFBI) is added to form the esters of the analytes. Ester(s) of T-2, HT-2 and DAS are separated on a 30 m × 0.32 mm DB-5 fused silica column and measured with a "Ni electron capture detector. Samples were confimed by gas chromatography/mass spectrometry using electron impact ionization and single ion monitoring at the molecular mass of 501.11 m/z for T-2, 665.08 m/z for HT-2, and 502.12 m/z for DAS at 10 000 resolving power. The method was applied to wheat, oats, and barley. Average recoveries ranged from a low of 65% for T- 2 in barley to a high of 99% for DAS in oats.
Liquid Chromatographic Determination of Ammoniacal and Urea Nitrogen in Fertilizer
Authors: Mizobuchi Munehiko , Kitada Yoshimi , Tamase Kikuo , Sasaki Michiko , Ueda Yasuyuki 
Published: February 2020

Abstract
Ammoniacal nitrogen in fertilizer is converted to an ammonium-fluorophor derivative and determined by liquid chromatography (LC) on a LiChrosorb RP-18 column and subsequent measurement of fluorophotometric intensity. Urea is converted to ammonia with the aid of urease and then determined similarly. Detection limit of the method is 0.2 μg nitrogen in 2.2 mL. When 5.0 g fertilizer is diluted to 500 mL and then diluted 50-fold with deionized, distilled water, the detection limit equals 1 % ammoniacal or urea nitrogen in commercial fertilizer.
Evaluation of Laboratory Performance of the AOAC Method for PSP Toxin in Shellfish
Authors: Adams Willard N , Furfari Santo A 
Published: February 2020

Abstract
Laboratory performance of the official AOAC method for paralytic shellfish poison (PSP) toxin in shellfish was evaluated. Two series of naturally toxic shellfish split samples were distributed (15 in 1979 and 19 in 1982) to state shellfish-monitoring laboratories which participate in the National Shellfish Sanitation Program. The laboratories performed bioassays on duplicate 100 g portions of each 220 g split sample. Bioassays were consistent among the laboratories and compared favorably with those of previous studies.
Paper Chromatographic Method for Identification and Semiquantitative Determination of
Pyridine and α-Picoline in Denatured Spirit, French Polish, and their Derived Preparations
Authors: Mali Bhagwat D , Ambade Kartik A 
Published: February 2020

Abstract
A paper chromatographic method is described for determination of pyridine and a-picoline in ordinary denatured spirit, french polish, and their derived illicit liquors. The method is based on conversion of the pyridine bases to their salts (sulfate or hydrochloride). The salt residue is subjected to 2-dimensional paper chromatography on filter paper, using methanol-butanol-acetic acid-ethyl acetate (20 + 10 + 1 + 10) as developing solvents, and is sprayed uniformly with sodium rhodizonate followed by barium chloride (for sulfate salts), or ammmoniacal silver nitrate followed by fluorescein (for hydrochloride salts). Pyridine bases in alcoholic samples containing resinous/volatile matter are estimated in the filtrate obtained after their treatment with alum at pH 5-6. The amount of pyridine and a-picoline is calculated from calibration graphs obtained by plotting the square of the spot diameter against pyridine and a-picoline concentrations. The method allowed detection and estimation of pyridine bases in denatured alcoholic samples at a concentration as low as 60 mg/L. Average recovery of added pyridine bases was 99.4% by this method.
Gas Chromatographic Determination of Oxalic Acid in Foods
Authors: Ohkawa Hironori 
Published: February 2020

Abstract
A new quantitative gas chromatographic (GC) method has been developed for the determination of oxalic acid in foods. Solid sample is extracted with water (soluble oxalic acid) or 2N hydrochloric acid (total oxalic acid) at room temperature. An aliquot of sample extract is evaporated to dryness, and the oxalic acid in the residue is methylated with 7% hydrochloric acid-methanol. The reaction mixture is extracted with chloroform, and dimethyl oxalate is quantitated by GC. Recovery of oxalic acid added to liquid samples averaged 100.6%; recoveries from extracts of solid samples were 96.2-99.5 and 97.2-100.1% for water and hydrochloric acid extractions, respectively. Results are shown for determination of oxalic acid in spinach and beverages. The technique is simple, rapid, and accurate, and small samples may be used. The limit of determination is 20 μg.
Performance Characteristics of Methods of Analysis Used for Regulatory Purposes.
I. Drug Dosage Forms. C. Automated Methods
Authors: Horwitz William , Albert Richard 
Published: February 2020

Abstract
For analysis of drug dosage forms, precision measures of AOAC approved automated methods, usually containing a spectrophotometric or fluorometric measurement step, were recalculated on a consistent statistical basis, using a computer program "FDACHEMIST." Ten collaborative studies of 14 compounds in 38 materials, consisting of various dosage forms, usually in 10 replications by an average of 7 laboratories, with a total of 2461 determinations, were reviewed. The average relative standard deviations within-laboratory (RSD0) and among-laboratories (RSDX) were 1.1 and 1.9%, respectively, and the ratio of RSD„/RSDX was 0.57, with an average outlier rate of 0.57% of the reported values. The line of best fit for RSDX plotted against — log concentration increases slightly with decreasing concentration, extending from an RSDX of about 1.6% at 100% concentration to an RSDX of 2.2% at 0.1% concentration, a change in RSDX of about 0.2% for a 10-fold decrease in concentration, independent of analyte and matrix.
The FDA Surveillance Index for Pesticides: Establishing Food Monitoring Priorities Based on Potential Health Risk
Authors: Reed Donald V 
Published: February 2020

Abstract
Through an approach called the Surveillance Index (SI), the U.S. Food and Drug Administration (FDA) is systematically evaluating the potential health risk of pesticides that may be present as residues in foods. The SI is being used as a primary tool in the establishment of monitoring priorities. Each pesticide is classified and assigned to one of 5 levels of potential risk. The SI documents that are prepared for individual pesticides (a) summarize the information used to assess potential dietary exposure and health risk, (b) provide the rationale for the assigned classification, and (c) identify needs and actions necessary to accomplish appropriate monitoring of the food supply. Reasons are described for the development of the SI, the content of the SI Documents, and the use of the SI in planning and redirecting FDA pesticide monitoring activities.
Disappearance of Organochlorine Residues from Abdominal and Egg Fats of Chickens, Ontario, Canada, 1969-1982
Authors: Frank Richard , Rasper Jarka , Braun Heinz E , Ashton Gordon 
Published: February 2020

Abstract
Abdominal fats were collected from 8-week old broilers slaughtered at provincially inspected abattoirs across Ontario between 1969 and 1982. Domestically produced hen eggs were collected from either egg grading stations or producers over the same period. Composite samples were analyzed for organochlorine insecticides and industrial chemicals. Between 1979 and 1982, organophosphorus insecticides were routinely included in these analyses. ΣDDT and PCB residues declined rapidly between 1969 and 1982 in extractable lipids of both abdominal and egg fats, while dieldrin declined less markedly over the same period. Declines in residues followed first order logarithmic regression equations. Chlordane and heptachlor epoxide were rarely observed above the detection limit of 1 μg/kg in egg fat; however, the incidence of these residues in abdominal fat increased after 1973 following the removal of aldrin, dieldrin, and heptachlor in 1969 and the subsequent increased use of chlordane for soil insect control until 1977. Lindane residues were rarely observed above the detection limit. In 1979, when the detection limit was reduced, both a-BHC and lindane were identified, but at levels below 1 μg/kg. Endosulfan, methoxychlor, and fenthion were identified on one or 2 occasions over the 13-year period.
Long-Term Preservation of Egg and Tissue Homogenates for Determination of Organochlorine Compounds: Freezing Versus Freeze-Drying
Authors: Norstrom Ross J , Won Henry T 
Published: February 2020

Abstract
Storage of wet egg homogenates at temperatures from —18° to — 28°C was more suitable for long-term preservation than freeze-drying. Changes in residue levels of heptachlor epoxide, oxychlordane, dieldrin, hexachlorobenzene, p,p'-DDE, mirex, and PCBs were not significant over a 3-year period in fresh herring gull egg homogenates stored at —18° to -28°C. Compounds with gas chromatographic retention times shorter than hexachlorobenzene vaporized during freeze-drying at a rate proportional to their volatility. Evaporative losses of components with vapor pressures less than hexachlorobenzene did not occur in naturally contaminated herring gull eggs after storage at room temperature for up to 1 year. Higher losses of all compounds, up to 25% for p,p'-DDE, occurred in freeze-dried whole-body herring gull homogenates. Easily dehydrochlorinated compounds were rapidly degraded in freeze-dried chicken egg homogenate at room temperature: The half-life of p,p'- DDT and p,p'-DDD was about 20 days, and that of α and γ-hexachlorocyclohexane was &lt;16 days. About one-third of oxychlordane in herring gull eggs was lost in 1 year under these conditions, but none was lost after freeze-drying when the homogenate was stored at -18° to -28°C.
Improved Method for Extraction of Light Filth from 90% Rye Bran Crisp Bread
Authors: Haynos Richard R 
Published: February 2020

Abstract
A new technique has been developed for the analysis of light filth in a high bran rye product. Compared with the official AOAC method, 44.063, the plates were much easier and less time-consuming to read microscopically (about 8 min compared with about 34 min for the AOAC method). Average recoveries for insect fragments and mouse hairs were 93.4 and 90.8%, respectively, with coefficients of variation (32 samples) of 7.7 and 7.9%, respectively. Average recoveries by the AOAC method were 87.5% for insect fragments and 62.5% for mouse hairs, with coefficients of variation (6 samples) of 7.9 and 14.1%, respectively. A ruggedness test for 7 variables in the extraction indicated that 2 variables caused significant changes in the results.
Screening Tests for Sulfa Drugs and/or Dinitrobenzamide Coccidiostats and Their Monoamino
Metabolites in Chicken Livers
Authors: Parks Owen W 
Published: February 2020

Abstract
Two procedures were developed for the simultaneous determination of 0.1 ppm sulfaquinoxaline and sulfadimethoxine, 1.0 ppm Zoalene and nitromide, and/or 0.1 ppm of their reduced coccidiostat metabolities from the same sample of chicken liver. Both methods include blender extraction of 5 g liver with chloroform-ethyl acetate (1 + 1), adsorption of the drugs and metabolites on neutral alumina, and subsequent elution with 0.2M carbonate buffer (pH 11.0). In Method A, all parent drugs and coccidiostat metabolites were partitioned into dichloromethane, following the addition of a small amount of tetrabutylammonium hydroxide (TBAH). The presence of the dinitrobenzamides was confirmed by the formation of a color with TBAH, which occurs when the solvent is concentrated (Zoalene = green; nitromide = red). Sulfa drugs and coccidiostat metabolites were detected by the Bratton- Marshall reaction after thin layer chromatographic (TLC) separation. Method B separates the individual classes by selective extraction techniques. The coccidiostats and their metabolites were extracted from the buffer eluate by ethyl acetate-dichloromethane (3 + 1) before ion pairing: sulfa drugs were extracted with dichloromethane after ion pairing with TBAH. The detection techniques were similar to those described for Method A.
Sensitive Determination of Ethopabate Residues in Chicken Tissues by Liquid Chromatography
with Fluorometric Detection
Authors: Nagata Tomoko , Saeki Masanobu , Nakazawa Hiroyuki , Fujita Masahiko , Takabatake Eigo 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for determination of ethopabate residues in chicken tissues. The drug is extracted from tissues with acetonitrile, and the extract is concentrated to 2-3 mL. This aqueous solution is rinsed with ethyl acetate and cleaned up by Florisil column chromatography. LC analysis is carried out on a Zorbax ODS column, and ethopabate is quantitated by using a fluorometric detector set at 306 nm (excitation) and 350 nm (emission). Recoveries of ethopabate added to chicken tissues at levels of 0.01 and 0.05 ppm were 87.8 and 92.7%, respectively. The detection limit was 100 pg for ethopabate standard, and 0.5 ppb in chicken tissues.