bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Determination of 4,4′-(Diazoamino)-dibenzenesulfonic Acid in FD&C Yellow No. 6 by Elution Chromatography
Authors: Fratz D Douglas , Bailey John E 
Published: February 2020

Abstract
An elution chromatographie procedure is presented which separates 4,4′-(diazoamino)-dibenzenesulfonic acid (DAADBSA) from FD&C Yellow No. 6 The DAADBSA is determined spectrophotometrically. Recoveries of DAADBSA added to FD&C Yellow No. 6 at levels of 0.03 to 0.2% ranged from 94 to 104%. DAADBSA was found in commercial samples of FD&C Yellow No. 6 in amounts ranging from 0.036 to 0.23%.
Determination of Saccharin, Sodium Benzoate, and Caffeine in Beverages by Reverse Phase High-Pressure Liquid Chromatography
Authors: Smyly Dan S , Woodward Betsy B , Conrad Edward C 
Published: February 2020

Abstract
A reverse phase high-pressure liquid chromatographic method is presented for the simultaneous separation and determination of saccharin, sodium benzoate, and caffeine in soft drinks, fruit juices, fruit cocktails, fruit punches, coffee, and artificial sweetener concentrates. Decarbonated soft drinks, fruit punches, and artificial sweetener concentrates are injected directly into the chromatograph. Fruit juices and coffee solutions require filtration through a 0.45 μm pore membrane filter prior to injection. Samples arc eluted from a μBondapak/C18 column with 5% glacial acetic acid and are quantitated with an ultraviolet detector. The results of saccharin, sodium benzoate, and caffeine determinations in 34 soft drinks (representing 11 manufacturers and 20 flavors); 8 fruit juices, cocktails, and punches; 7 coffees; and 6 artificial sweetener concentrates are presented. Average recoveries of saccharin, sodium benzoate, and caffeine from soft drinks are 99.0, 99.3, and 100.2%, respectively.
High-Speed Liquid Chromatographic Determination of o-Phenylphenol Residues in Citrus Products
Authors: Reeder Samuel K 
Published: February 2020

Abstract
A method is presented for the quantitative analysis of o-phenylphenol residues in citrus oils, encapsulated flavors, and dried meal. The method utilizes high-speed liquid chromatography for the determination after specific sample preparations for each material. These preparations include hexane extraction of acidified basic extracts or steam distillation and extraction. The limit of the analysis is &lt;1 ppm with an analysis time of &lt;45 min.
Reference Raman Spectra of DDT and Five Structurally Related Pesticides and of Five Pesticides Containing the Norbornene Group
Authors: Nicholas Mark L , Powell David L , Williams Theodore R , Bromund Richard H 
Published: February 2020

Abstract
The Raman spectra of DDT and 5 structurally related pesticides, TDE (DDD), Perthane, methoxychlor, dicofol, and tetradifon, and of 5 pesticides containing the norbornene group, heptachlor, chlordane, dieldrin, endrin, and endosulfan, have been recorded. These spectra are presented, along with tables giving values for the frequencies.
Second Collaborative Study of a Gas-Liquid Chromatographie Method for the Assay of Thiocarbamate Formulations
Authors: Barney James E 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method previously evaluated for the assay of 6 thiocarbamate herbicides in formulations has been tested on 2 new formulations containing Eptam and Sutan plus a safener. The method was tested collaboratively by 17 laboratories. The coefficient of variation for 4 formulations was 4.10%. Most of the error is systematic. It is recommended that the present method, 6.367–6.371, be continued as official first action, and that other GLC stationary phases be evaluated.
Volumetric Determination of Malathion, Using Dichlorofluorescein as Indicator
Authors: Siquiroff Miguel , Pollero Ricardo , Goyena Rodolfo 
Published: February 2020

Abstract
A method has been developed which is based on alkali cleavage of malathion and volumetric determination of the resulting dimethylphosphorodithioate with silver nitrate, using dichlorofluorescein as the indicator. Pure malathion standards were analyzed by the proposed method, yielding a standard deviation of 0.27. Four typical malathion formulations containing talc, wheat flour, and anionic and nonionic emulsifiers were analyzed by both the proposed method and the former official first action colorimetric method with comparable results. Potential interferences from surfactants currently employed in liquid formulations are avoided by the use of Florisil column chromatography. Malathion is eluted from the column with petroleum ether-ethyl ether with an average recovery of 92.5%.
Gas-Liquid Chromatographic Headspace Method for Vinyl Chloride in Vinegars and Alcoholic Beverages
Authors: Williams David T 
Published: February 2020

Abstract
Vinyl chloride (VC) is determined in vinegars and alcoholic beverages by gas-liquid chromatographic headspace analysis. The lower limit of detection is 10 ppb and confirmation by gas chromatography-mass spectrometry, single ion monitoring at m/e 62, is possible at this level. Comparison of the headspace and the direct injection methods for the determination of VC in vinegars and alcoholic beverages showed that the results obtained by the 2 methods were not significantly different (P&gt;0.05).
Pyrolysis-Gas Chromatographic Techniques for the Analysis of Automobile Finishes: Collaborative Study
Authors: Stewart William D 
Published: February 2020

Abstract
Samples of 7 automobile topcoats currently used by the major American automobile manufacturers were analyzed by various pyrolysis-gas chromatographic techniques. The samples were similar shades of white paint with small differences in the organic vehicle composition. The study involved analysis of the 7 samples and identification of an unknown sample chosen from the 7. A ninth chip was also included for determination of the reproducibility of the analytical technique. The samples were analyzed by other methods of analysis, including diamond cell infrared spectroscopy and mass spectrometry. Sample sizes from 4 to 200 μg were needed for the various methods of analysis and, in all cases, the unknown sample was correctly identified.
Detection of Sulfonamides in Animal Feeds
Authors: Cieri Ugo R 
Published: February 2020

Abstract
The animal feed sample is extracted with ethanol or acetone and the extract is evaporated to dryness. Another portion of the same sample, spiked at the 3 ppm level with 8 sulfonamides, is similarly extracted and the extract is evaporated to dryness. The residue from each solution is dispersed with 5 ml 0.1N NaOH and, following the addition of 1 ml 1N HCl and mixing, the solution is filtered. The filtrate is mixed with Celite, transferred to a column, and eluted with ammoniacal ether. Aliquots of the concentrated sample and control eluates are spotted on a neutral Adsorbosil-1 thin layer chromatographic (TLC) plate. Following development in chloroform-methanol (95+5) and drying, the plate is sprayed with an alcoholic solution of p-dimethylaminobenzaldehyde until the control chromatogram shows 6 yellow spots which are, from top to bottom; sulfadimethoxine (SO), the combined sulfamerazine (SM)-sulfamethazine (SH)-sulfaquinoxoline (SQ) spot, sulfadiazine (SD), sulfapyridine (SP), sulfathiazole (SZ), and sulfaguanidine (SG). A spot on the sample chromatogram can be identified if the Rf is identical to one of the 5 sulfonamides not overlapping with another compound. If the Rf of the sample spot is approximately the same as that of the combined SM-SH-SQ spot, more definite identification can be obtained by using basic Adsorbosil-1 TLC plates, with chloroform-methanol (92+8) as the developing solvent.
Detection of Arsanilic Acid in Animal Feeds
Authors: Cieri Ugo R 
Published: February 2020

Abstract
The animal feed sample is extracted with alcohol, the extract is evaporated to a small volume, and an aliquot is spotted on a silica gel H plate. After development of the plate in chloroform-methanol (80+20), the spotting area is scraped and extracted with ethanol, which is evaporated to dryness. The residue is dissolved in 3 ml alcohol, and an aliquot is reacted with p-dimethylaminobenzaldehyde solution; another aliquot of the extract is used as a sample blank. A control is prepared by spiking another portion of the same feed with about 5 ppm arsanilic acid. The method is applicable in the presence of procaine and sulfonamides.
Collaborative Study of a Semiautomated Fluorometric Method for the Determination of Reserpine in Tablets
Authors: Kreienbaum Mary A 
Published: February 2020

Abstract
A semiautomated fluorometric method for the determination of resperpine in tablets was collaboratively studied by 7 laboratories. The method is a modification of the semiautomated method of Urbányi and Stober, which involves formation of a fluorogen with vanadium pentoxide. Collaborators were supplied with 3 composites, each from a different dosage level of commercial tablets. The results obtained agreed well with the AOAC manual fluorometric method; coefficients of variation ranged from 0.45 to 2.70%. The method has been adopted as official first action.
Qualitative Tests for Added Coloring Matter in Meat Products
Authors: McNeal Jon E 
Published: February 2020

Abstract
The rapid qualitative detection of coal tar dyes, chemicals added to color meat products, and some natural coloring materials was investigated through extraction and subsequent identification by spectrophotometric, paper chromatographic, and specific reaction techniques. These techniques will detect the presence of coal tar dyes, imidazole, histamine, histidine, cochineal, beet powder, annatto, alkanet, carotene, paprika, saffron, turmeric, and materials causing discoloration in meats.
Relationship Between the Biological Availability and Solubility Rate of Reduced Iron
Authors: Pla Gwendolyn W , Fritz James C , Rollinson Carl L 
Published: February 2020

Abstract
Solubility rate determinations were conducted on electrolytic iron and hydrogen reduced iron and carbonyl iron samples to study the correlation of biological availability and solubility. There was excellent correlation for the hydrogen reduced iron and electrolytic iron samples. The carbonyl iron samples showed a direct relationship between solubility and bioavailability, but these data were not numerically equivalent to data from other types.
Semiautomated Ring Carrier to Facilitate and Expedite Disinfectant Testing by the AOAC Use-Dilution Method
Authors: Walter George R , Mahl Mearl C , Sadler Colin 
Published: February 2020

Abstract
The AOAC use-dilution test requires the replicate examination of a number of contaminated metal rings. Ten metal rings may be tested within the 20 min structure of the test. From a statistical and economical viewpoint, it would be highly desirable to increase the number of rings examined in a single test. A semiautomated ring carrier permits testing 200 rings within a 20 min test.
Digestion of Fish Samples for Mercury Determination by Flameless Atomic Absorption Spectrophotometry
Authors: Pearce Isobel D , Brooks Robert R , Reeves Roger D 
Published: February 2020

Abstract
Methods of digestion of fish samples for mercury determination by flameless atomic absorption spectrophotometry have been investigated. Digestion in Teflon bombs, Kjeldahl flasks, or borosilicate test tubes gives comparable precisions and mercury recoveries. Because of their cost and effect in limiting productivity, Teflon bombs were considered unnecessary for analysis of fish samples. Experiments with cooked and uncooked fish samples have confirmed that no appreciable loss of mercury occurs during baking 30 min at 170°C.
Spectropliotometric Analysis of Alkaloids with Picrolonic Acid
Authors: Taha Aly M , Gomaa Camelia S 
Published: February 2020

Abstract
The spectroscopic characteristics of the interaction of alkaloids with picrolonic acid were studied. In solvents of low and intermediate polarity, the presence of alkaloids caused a red shift of the 322 nm band of nonionized picrolonic acid to 355 nm, corresponding to the anionic resonance band. There was also a considerable increase in absorptivity, which was dependent on both the basicity (pKa) and molar concentration of the alkaloid present. Arylamines, aromatic N-heterocycles, and alkaloids lacking an aliphatic amine moiety did not show observable shifts. The interaction was developed into a spectrophotometric assay for the following alkaloids in pharmaceutical preparations: atropine, ephedrine, codeine, emetine, quinine, and strychnine. The method is sensitive to 2 μg alkaloid/ml, with an accuracy of ±1.5% and a standard deviation of ±1.05—1.31%.
High-Speed Liquid Chromatographie Determination of Phenothiazine in Commercial Pesticide Formulations
Authors: Byrne Martin J 
Published: February 2020

Abstract
Phenothiazine (thiodiphenylamine) in commercial pesticide formulations is analyzed by high-speed liquid chromatography and ultraviolet absorption detection. Phenothiazine is extracted from the formulation with methanol and injected into the liquid chromatograph. Methanol-water (1+1) is the mobile phase. The amount of phenothiazine is calculated from peak height ratios. The liquid chromatographic procedure is much faster than the infrared or colorimetric method and yields values in close agreement with both of these methods.
Chemical Composition of Technical Chlordane
Authors: Cochrane William P , Greenhalgh Roy 
Published: February 2020

Abstract
Technical chlordane, a multicomponent organochlorine insecticide, was separated into 26 peaks by temperature-programmed gas chromatography, using a 3% OV-17 column. Peaks were identified by using combined gas chromatography-mass spectrometry (GLC-MS) and, where individual standards were available, by comparing retention times on various columns. Technical chlordane constituents were also investigated by GLC-MS, using a Dexsil 300 column; 19–20 peaks were observed. Quantitation studies indicated differences in the per cent contributions of the constituents, particularly for heptachlor and trans-chlordane, in 2 different technical chlordane reference standards. For the same reference standard higher results were obtained by using 63Ni electron capture detection than by using flame ionization detection. By using a combination of 4 GLC columns to overcome peak overlap, we determined that the 11 known constitutents of technical chlordane constituted approximately 40%.
Ultraviolet and Infrared Analysis of Rotenone: Effect of Other Rotenoids
Authors: Delfel Norman E 
Published: February 2020

Abstract
Biases evidenced by past collaborative trials of ultraviolet (UV) and infrared (IR) methods for rotenone can be caused by interference from other rotenoids that occur in extracts of cubé and derris. In the UV analysis, sumatrol, rotenolone, and deguelin cause positive errors of decreasing magnitude; elliptone, toxicarol, tephrosin, dehydrodeguelin, and dehydrorotenone produce negative biases of increasing magnitude. In the IR analysis, error depends on rotenoid concentration relative to rotenone concentration. At equal proportions, bias is positive with toxicarol and deguelin and negative with other rotenoids. The baseline version of the IR method has an inherent positive bias of approximately 8% but is superior to the base point version because of greater insensitivity to deguelin. The official first action UV method for the determination of rotenone in derris and cubé powder, 6.162–6.163, has been deleted, and the IR method, 6.164–6.165, has been revised to exclude derris products.
Gas-Liquid Chromatographic Determination of Pentachloronitrobenzene in Pesticide Formulations
Authors: Hanks Alan R , Cramer Christine W 
Published: February 2020

Abstract
A gas-liquid chromatographic method has been developed to determine pentachloronitrobenzene (PCNB) in pesticide formulations including dusts, powders, granules, liquids, and fertilizers. Captan, disulfoton, and Terrazole do not interfere. Samples are extracted with chloroform, and an aliquot is mixed with an equal volume of internal standard solution containing o-terphenyl. PCNB is chromatographed on a 5% SE-30 column and quantitated by peak height ratios. The method has been subjected to a ruggedness test which indicates little sensitivity to changes in extraction and chromatographic conditions.
Derivatization Procedure for Identification of Aflatoxin M1 on a Thin Layer Chromatogram
Authors: Trucksess Mary W 
Published: February 2020

Abstract
A commodity extract containing presumptive aflatoxin is placed on an origin spot of a thin layer chromatographic plate and overspotted with trifluoroacetic acid. The mixture is held in the dark 30 min at ambient temperature and then 30 min at 55°C. The plate is developed with CHCl3-acetone-2-propanol (85+10+7). The Rf values of reacted and unreacted aflatoxin M1 are compared with authentic similarly treated for identification. The lowest concentration that has been identified is 0.1 μg/kg.
Culture Method for Detection of Salmonella in Dried Active Yeast: Collaborative Study
Authors: Poelma Paul L , Romero Aida , Wilson Clyde R , Andrews Wallace H 
Published: February 2020

Abstract
A method for detecting Salmonella in dried active yeast was subjected to collaborative study. This method employs trypticase soy broth as the pre-enrichment medium, a sample-to-broth ratio of 1:10, and subsequent transfers to lauryl sulfate tryptose broth and tetrathionate before streaking onto selective agars. Each collaborating analyst received ten 25 g samples of dried active yeast. Duplicate 25 g samples were each inoculated with Salmonella Oranienburg at a low level (28 cells) and a high level (107 cells). Similarly, duplicate 25 g samples were each inoculated with S. senftenberg at a low level (30 cells) and a high level (114 cells). The remaining 2 of 10 samples were not inoculated. Results from 12 of 13 collaborators were evaluated. Only 2 (8.2%) of the 24 low level S. oranienburg samples were reported incorrectly as negative. Twelve of the analysts detected S. senftenberg at both levels and S. Oranienburg at the high level in the inoculated samples. Results from 12 collaborators used in the final evaluation show that 117 of 119 (98.3%) collaborative determinations are in agreement. The official final action method for the detection and identification of Salmonella, 46.013–46.026, has been revised official first action to include applicability to dried active yeast.
Gas-Liquid Chromatography and Infrared Spectroscopy of Resmethrin in Nonaqueous Aerosols
Authors: Law Mark W , Bontoyan Warren R , Looker Jack B 
Published: February 2020

Abstract
Two rapid and precise methods have been developed for the determination of resmethrin in nonaqueous aerosol formulations. The propellents are evaporated, the residue is dissolved in carbon disulfide, and the resulting solution is analyzed by gas-liquid chromatography or infrared spectroscopy. The accuracies of the methods were confirmed by a collaborative study.
Nitrite in Meat Products Determined by Fluorescence Quenching of p-Aminobenzoate Ion
Authors: Coppola Elia D , Wickroski Alphonse F , Hanna J Gordon 
Published: February 2020

Abstract
A direct fluorometric method is presented for determining nitrites in meat products by means of quenching. The extracted sodium nitrite is consumed in a diazotization reaction with a measured excess of the fluorescent reagent p-aminobenzoic acid (PABA) in boiling water and at pH ≤1.4. The amount of decrease in fluorescence (quenching) of PABA, in alkaline medium (pH 11.0) with excitation at 265 nm and fluorescence at 339 nm, is directly related to the amount of nitrite present. The slope for the standard curve is 1 % decrease in relative fluorescence intensity per 2.76 ppm NaNO2. Results obtained for a series of 20 meat samples analyzed by this fluorometric method are in good agreement with results obtained by a colorimetric method with an average difference of ±6.1 ppm NaNO2.
Colorimetric Determination of Aconitine in Galenicals and in Biological Samples
Authors: Karawya Mohamed S , Sharaf Abdel-Aziz A , Diab Aly M 
Published: February 2020

Abstract
A sensitive method is presented for determining aconitine. Aconitine is complexed with Co2+, the aconitine-cobalt complex is extracted with chloroform, and the absorbance is measured at 320 nm. The sensitivity of the method ranged between 0.06 and 3 mg/25 ml, and the color was stable for 6 hr. The method was successfully applied for the quantitative determination of aconitine in animal tissues.
High-Pressure Liquid Chromatography of 4,4′-Diazoaminobis-(5-methoxy-2-methylbenzenesulfonic Acid) in FD&C Red No. 40
Authors: Marmion Daniel M 
Published: February 2020

Abstract
Ten analysts representing 7 laboratories participated in the evaluation of a high-pressure liquid chromatographic procedure for the determination of 4,4′-diazoaminobis(5-methoxy-2-methylbenzenesulfonic acid) (DMMA) in FD&C Red No. 40; each collaborator analyzed 7 samples. Between-laboratory standard deviations ranged from 0.0015 to 0.0033% for samples nominally containing 0–0.05% DMMA. The stability of DMMA vs. pH was also studied. It is recommended that the high-pressure liquid chromatographic method be further studied.
Gas-Liquid Chromatographic Analysis of N-(4-Chlorophenyl-N′-2,6-difluorobenzoyl)urea Insecticide After Chemical Derivatization
Authors: Lawrence James F , Sundaram Kanth M S 
Published: February 2020

Abstract
The gas-liquid chromatographic analysis of TH 6040 (N-(4-chlorophenyl)-N′-(2,6-difluorobenzoyl)urea) was carried out after the insecticide was converted to its N,N′-dimethyl analog (N-methyl-N-(4-chlorophenyl)-N′-methyl-N′-(2, 6-difluorobenzoyl)urea). The methylation was accomplished in DMSO with sodium hydride and methyl iodide. The derivative was thermally stable and chromatographed as a single peak on 3% OV-1 at 235°C. Support for the structure of the product was given by mass spectrometry. The sensitivity of the product to electrolytic conductivity detection was approximately 50 ng for 50% full-scale deflection in the nitrogen mode and 70 ng for the same response in the chloride (reductive) mode. About 0.25 ng was required for 50% full-scale deflection by electron capture (at 1 × 10−9 amp standing current). Foliage samples were analyzed for TH 6040, using the proposed method.
Collaborative Study of Accelerated Development of Latent Fingerprint Images on Paper by Application of Steam
Authors: Connor Charles M 
Published: February 2020

Abstract
Nine latent fingerprint examiners participated in a collaborative study in the use of a steam iron to accelerate chemical development of latent images on bond and newsprint papers treated with a 0.5% solution of ninhydrin in acetone. Four latent images were placed on each paper by the Associate Referee during an 8 hr period. The papers were paired and numbered 1, 2, and 3. Three pairs were mailed to each collaborator who treated Pair 1 by dipping, Pair 2 by brushing or swabbing, and Pair 3 by spraying. After air-drying, the papers were subjected to heat and steam from a household steam iron until the images developed. The average time for developing all images was 5.8 min/paper. Of the total images available, 92.1% were developed to some degree; 47.9% of these images or 43.5% of all images were identified by the collaborators. The method has been adopted as official first action.
Applications of Mass Spectrometry to the Analysis of Mycotoxins
Authors: Kingston David G I 
Published: February 2020

Abstract
Methods of identifying mycotoxins by mass spectrometry are reviewed, with special reference to the value of a complete listing of known fungal metabolites, arranged by molecular weight. Such a list is applied to the identification of various mycotoxins, and mass spectrometry is applied to the structural elucidation of dimethylnidurufin and ostreogrycin A.