bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectrophotometric Determination of Phosphine Residues in Rice
Authors: Rangaswamy Jois R , Muthu Mysore 
Published: February 2020

Abstract
Phosphine residues were determined in 2 types of rice samples, raw polished and parboiled. The yellow chromophore due to phosphine from raw polished rice had 2 absorption maxima, a strong one at 370- 380 nm and a weaker one at 400-410 nm. The chromophore from parboiled rice also had 2, one at 390-400 nm and the other at 410-420 nm. A closed system containing rice and a phosphine tablet or powder yielded 93-99% recovery of fortified phosphine. At any given dose of phosphine, parboiled rice retained a higher amount of residue after aeration than did raw polished rice.
Liquid Chromatographic Determination of 2-(2-Quinolinyl)-l/7-indene-l,3-[2#]-dione and Other Organic-Soluble Matter in D&C Yellow No. 10
Authors: Goldberg Allen L 
Published: February 2020

Abstract
A sensitive, reproducible method that uses an Extrelut QE column and liquid chromatography (LC) in the reverse phase mode is described forthe determination of 2-(2-quinoIinyl)-l//-indene-l,3-[2JJ]-dione and other organic-soluble matter found in D&C Yellow No. 10. With this method the organic-soluble matter is extracted from D&C Yellow No. 10 on an Extrelut QE column, and the extract is concentrated and analyzed by LC. Recoveries averaged 104% for 2-(2-quinolinyl)-l#- indene-l,3-[2tf]-dione added to purified D&C Yellow No. 10 at levels ranging from 0.50 to 5.96 ppm.
Elemental Analysis of Plant Tissue by Plasma Emission Spectroscopy: Collaborative Study
Authors: Isaac Robert A , Johnson William C 
Published: February 2020

Abstract
Fourteen laboratories participated in a collaborative study of 6 homogeneous plant tissue samples to determine the elements P, K, Ca, Mg, Mn, Fe, Al, B, Cu, Zn, and Na by plasma emission spectroscopy. Samples were dry ashed using AOAC method 3.007(a) (13th Ed.). An NBS citrus leaf standard was prepared and a portion of the resulting solution was sent to each collaborator to evaluate sample preparation errors independent of instrument error. Coefficients of variation were better than those obtained in an earlier collaborative study on multielement analysis by spark emission spectroscopy. The plasma emission method has been adopted official first action for determination of P, K, Ca, Mg, Mn, B, Cu, and Zn in plant tissues.
Liquid Chromatographic Determination of Morphine Sulfate and Some Contaminants in Injections and Bulk Drug Material
Authors: Jhangiani Rita k , Bello Ada C 
Published: February 2020

Abstract
A liquid chromatographic (LC) procedure is described for the assay of morphine sulfate in bulk drug material and injection solutions. The bulk drug and injection samples are prepared by direct dilution with LC mobile solvent. The average bulk drug purity (5 manufacturers) determined by the LC method was 99.9% with a difference of 0.1% from the average purity (anhydrous) found by the official USP XX procedure. The average LC recovery (19 studies) of morphine sulfate added to injection samples was 99.4% with a coefficient of variation (CV) of 1.14%. Morphine sulfate content was determined in triplicate for 53 injection samples (1-15 mg morphine sulfate/mL) formulated by 6 manufacturers, using the proposed LC procedure. Individual sample CV (n = 3) averaged 1.14%. The LC method is simple and specific for morphine sulfate. Major degradation products, preservatives, and some contaminants and related compounds are separated during LC.
Liquid Chromatographic Determination of Triadimefon in Technical and Formulated Products: Collaborative Study
Authors: Slahck Stephen C 
Published: February 2020

Abstract
A liquid chromatographic method for the determination of triadimefon (Bayleton™) in triadimefon technical and formulated products has been developed and subjected to a collaborative study with 7 participating collaborators. Formulations were extracted with mobile solvent and analyzed by normal phase chromatography, with 4-chlorophenyl sulfoxide as an internal standard. Collaborators were furnished with standards and samples of technical products, 50% wettable powders, and 25% wettable powders for analysis. Coefficients of variation of the values obtained on these samples were 1.42, 0.82, and 1.05%, respectively. The method has been adopted official first action.
Liquid Chromatographic Determination of Protein Acid Hydrolysate Content in Blended Soy Sauce
Authors: Yeh-Chen Shih-Ling , Hsu Chin-Tan 
Published: February 2020

Abstract
Five methods were investigated for the determination of levulinic acid in soy sauce to determine the addition of protein hydrolysate, mainly acid hydrolysate of defatted soybeans. Best results were obtained by using liquid chromatography (LC) with 0.004M HC104 as the mobile phase and bromcresol purple as a post-column reagent. An innovative LC method with 0.1% H3PO4 as eluant was developed for determination of levulinic acid at 280 nm in soy sauce. This was the most timesaving method.
Volatile Oil Analysis Of Cassia Bark (Cinnamon): Investigation Of Systematic Errors
Authors: Way Raymond M 
Published: February 2020

Abstract
Results of these studies demonstrate that steam-distillable volatile oil within a lot of cassia bark is heterogeneously distributed; that sample preparation can contribute a significant part of the overall analytical error; and that the latter error can be reduced by specifying that the sample be ground to pass a U.S. 20 mesh screen rather than a U.S. 40 mesh screen. An F-distribution value of 6.7 was calculated for the data, from 6 laboratories, used for statistical analysis. The critical F-distribution is 5.05, suggesting a significant difference in the means of the U.S. 20 mesh data and the U.S. 40 mesh data. The problem of sampling segregated materials where the functional form of the quality distribution is not known is briefly discussed.
Liquid Chromatographic Determination of Tenuazonic Acid and Alternariol Methyl Ether in Tomatoes and Tomato Products
Authors: Stack Michael E , Mislivec Philip B , Roach John A G , Pohland Albert E 
Published: February 2020

Abstract
A liquid chromatographic (LC) method for determining tenuazonic acid (TA) and alternariol methyl ether (AME) in tomatoes and tomato products is described. The Alternaria metabolites are extracted from a water slurry of the sample with CHCL3, the mixture is centrifuged, and the extract is fractionated on a silica gel column. Reverse phase LC with an ultraviolet detector (for TA) and a fluorescence detector (for AME) connected in series is used for final separation and determination. The limit of determination for TA and AME is 25 and 3 ng/g, respectively, with average recoveries from catsup of 83 and 68%, respectively. The LC method also detects alternariol, but interfering peaks in some samples prevent accurate quantitation. Chemical ionization mass spectrometry (CI MS) is used to confirm TA. Samples (142) of tomatoes collected from commercial processing lines were analyzed; TA was found in 73 samples (0.4-70 μg/g).
Determination of Total Dietary Fiber in Foods and Food Products: Collaborative Study
Authors: Prosky Leon , Asp Nils-Georg , Furda Ivan , Devries Jonathan W , Schweizer Thomas F , Harland Barbara F 
Published: February 2020

Abstract
A collaborative study was conducted to determine the total dietary fiber (TDF) content of food and food products, using a combination of enzymatic and gravimetric procedures. The method was basically the same as published earlier (/. Assoc. Off. Anal. Chem. (1984) 67,1044- 1052), with changes in the concentration of alcohol and buffers, time of incubation, sample preparation, and some explanatory notes, all with the intent of decreasing the coefficient of variation (CV) of the method. Duplicate blind samples of soy isolate, white wheat flour, rye i bread, potatoes, rice, wheat bran, oats, corn bran, and whole wheat Sour were analyzed by 9 collaborators. TDF was calculated as the weight of the residue minus the weight of protein and ash. CV values of the data from all laboratories for 7 of the samples ranged from 1.56 to 9.80%. The rice and soy isolate samples had CV values of 53.71% and66.25%, respectively; however, each sample contained only about 1% TDF. The enzymatic-gravimetric method for determining TDF has been adopted official first action.
Sampling Barrel Cheese For Moisture Analysis: Comparison Of Methods
Authors: Blattner Thomas M , Olson Norman F , Wichern Dean W 
Published: February 2020

Abstract
Fifty-four steel and 18 fiber barrels of cheese were sampled by the conventional plug method and the samples were analyzed for moisture. These same barrels were sliced vertically through the center, and 72 samples were taken from one exposed surface and analyzed. Finally, all of the remaining cheese from the barrel was ground, blended, and sampled for moisture analysis. Results on the 72 samples obtained from the exposed surface of the sliced cheese were used to create a moisture profile of the barrel cheese. The blended samples were used to establish the "true" moisture content of the cheese. Statistical analysis of the data revealed a bias in the conventional plug sample values compared with the true moisture values. Computer simulation experiments conducted on the profile data suggested an alternative sampling site that could provide measurements with less bias. A verification study was conducted with 40 steel and 12 fiber barrels. These barrels were sampled by the conventional plug method, a new method, and the blending method used previously. Statistical evaluation of the data revealed a potential reduction in bias of 1.7 and 0.5% for steel and fiber barrels, respectively.
Determination of Ethylenethiourea in Grapes and Wine
Authors: Chovancova Jana , Matisova Eva , Batora Vojtech 
Published: February 2020

Abstract
Residues of ethylenethiourea (ETU) in grapes and wine were deter- [ mined by capillary gas chromatography and paper chromatography, without a cleanup step, and after derivatization to 5-benzyl-ETU. The ! detection limit was 0.0002 mg/kg for flame ionization detection, 0.008 mg/kg for paper chromatography with photodensitometric evaluation of the detected spot. Results were compared with a generally used GC method specifying electron capture detection of trifluoroacetylated S- benzyl-ETU. The recoveries of ETU in grapes and wine at different j concentration levels were determined. ETU residues were determined J in treated grapes but no residues were detected in wine
Improved Codistillation Method for Determination of Carbon Tetrachloride, Ethylene Dichloride, and Ethylene Dibromide in Grain and Grain-Based Products
Authors: Devries Jonathan W , Larson Paul A , Bowers Raymond H , Keating Joyce A , Broge James M , Wehling Paul S , Patel Hasmukh H , Zurawski James W 
Published: February 2020

Abstract
A method is described for the determination of the common fumigants carbon tetrachloride (CC14), ethylene dichloride (EDC), and ethylene dibromide (EDB) in grain and grain-based products. A properly prepared sample is mixed with water and hexane, an internal standard mixture of 1,2-dichloropropane (DCP) and 1,2-dibromopropane (DBP) is added, and the fumigants are codistilled with the hexane into an appropriate receiver. After the hexane solution is dried over sodium sulfate, the quantities of fumigants present are quantitated on a gas chromatograph (GC) equipped with an electron capture detector (ECD). For the matrices investigated, the relative standard deviation of the method was 6.0,9.7, and 23.1% for CC14, EDC, and EDB, respectively. Recoveries of added fumigants were 107, 95, and 101%, respectively. Comparison with an acetone-water soak extraction method gave a correlation of 0.967 between methods for EDB with odds of a difference between methods of 35%.
New FDA Migration Cell Used to Study Migration of Styrene from Polystyrene into Various
Solvents
Authors: Snyder Roger C , Breder Charles V 
Published: February 2020

Abstract
A new cell was evaluated for studying the migration of components of plastic food packaging materials into various food simulating solvents. Data obtained using this cell to study the migration of styrene from polystyrene at 40 and 70°C are presented. Food simulating solvents tested were: water; 3% acetic acid; 8, 20, 50, and 100% ethanol; corn oil; HB-307; heptane; hexadecane; and decanol. An iterative Basic computer program is described that fits the migration vs time data obtained to mathematical models, based on Ficks' law, yielding migrant/ polymer diffusion coefficients (£&gt;p). Dp values determined for styrene migration from polystyrene at 40 and 70°C were 3 X 1013 and 4 x 1012 sq. cm/s, respectively.
Liquid Chromatographic Determination of Quinine, Hydroquinine, Saccharin, and Sodium Benzoate in Quinine Beverages
Authors: Valenti Leonard P 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for the determination of quinine, hydroquinine, sodium saccharin, and sodium benzoate in soft drinks. The method involves simple sample preparation, direct injection onto an octadecylsilane column, and elution with a methanol-acetonitrile-water-acetic acid (20 + 10 + 70 + 1) mobile phase. Eluted constituents are measured spectrophotometrically at 254 nm. The relationship between peak height and concentration was linear between 20 and 120 μg/mL for quinine. A relative standard deviation of 0.82% was obtained for commercial samples spiked with quinine, and the average recovery was 100.3%. The proposed procedure is accurate and rapid and can also detect hydroquinine (a natural contaminant of quinine), sodium saccharin, and sodium benzoate. Linear responses ranged from 0.45 to 20 (xg/mL for hydroquinine, from 54.8 to 219 μg/mL for sodium saccharin, and from 10.1 to 145.1 (ig/mL for sodium benzoate. The reproducibility of the LC method was evaluated with standard solutions of hydroquinine, sodium saccharin, and sodium benzoate, which produced relative standard deviations of 0.42, 0.46, and 1.13%, respectively. The average recoveries for sodium saccharin and sodium benzoate from spiked samples were 99.4 and 100.2%, respectively.
Advances in Automated Analysis of Soil Phosphorus, Potassium, Calcium, and Magnesium Through Use of a Microprocessor
Authors: Markus Denes K , Shaw Richard K , Buccafuri Anthony F 
Published: February 2020

Abstract
The use of an automated system equipped with a microprocessor-based controller and data handler is presented for the analysis of soil extracts for P, K, Ca, and Mg. With the aid of drift, gain, and carryover correction features, the system has the potential to improve accuracy and precision of analytical results. Moreover, the system allows the use of faster sampling rates in its operation. Accuracy and precision are evaluated for P, K, Ca, and Mg analyses, determined in standard solutions with the automated system at 50, 85, 120 and 155 hourly sampling rates. Results of P, K, Ca, and Mg analyses in 3 extracts of 50 soil samples, determined with the new system at the 120 hourly sampling rate, are also presented. Analyses performed by the microprocessor- based automated system are compared with those obtained using different nonautomated techniques.
Spectrophotometric Analysis of Mixtures of Acetaminophen, Salicylamide, and Codeine
Phosphate in Tablets
Authors: El Kheir Afaf Abou , Belal Saied F , El Shanwani Abdulla 
Published: February 2020

Abstract
A simple and accurate spectrophotometric procedure for the analysis of a mixture of acetaminophen, salicylamide, and codeine phosphate is described. Determination of the first 2 components depends on pHinduced differential spectral changes of their nitroso derivatives. The third component is assayed by the acid dye method. The proposed procedure was successfully applied to the analysis of laboratory-made and commercial tablets containing the ternary drug mixture
Use of 7,7,8,8-Tetracyanoquinodimethane in the Colorimetric Determination of Some
Antihistamines
Authors: Abdel-Khalek Magdi M , Abdel-Hamid Mohamed E , Mahrous Mohamed S 
Published: February 2020

Abstract
A precise colorimetric method is described for the estimation of phenyltoloxamine dihydrogen citrate, diphenhydramine hydrochloride, and chlorpheniramine maleate. The method is based on the interaction of these drugs as n-electron donors with 7,7,8,8-tetracyanoquinodimethane as π-acceptor to give a highly colored radical anion. This is corroborated by electron spin resonance spectroscopy. The colored product is quantitated spectrophotometrically at 843 nm. Beer's law is obeyed in the concentration range 2-6 µg/mL for each drug. Optimization of the experimental conditions is described. The proposed method was applied to the analysis of these drugs in tablet form, and results were in good agreement with those obtained by the official method
Occurrence of Mycotoxins in Cereals and Animal Feedstuffs in Natal, South Africa
Authors: Dutton Michael F , Westlake Kenneth 
Published: February 2020

Abstract
During the period 1982-1983, just under 800 samples of agricultural commodities, comprising cereals, compound feeds, hay, and silage, were examined for molds and mycotoxins. Aflatoxin Bi showed the highest incidence rate; it occurred in over 27% of all samples analyzed, the highest levels being found in peanut meal at 1500 ppb. Other mycotoxins detected were patulin and a number of trichothecene toxins at incidence rates in all commodities of 5.6 and 3.1%, respectively. The commodities at highest risk were oil seeds, excluding soya bean; the latter was found to be fairly free from contamination with mycotoxins. The most prevalent fungi were Aspergillus flavus and parasiticus, which were found in over 22% of all samples, whereas Penicillium spp. showed the lowest incidence of genera, specifically identified in 8.3% of all samples examined. This latter finding explains in part the low incidence of Penicillium mycotoxins
Problems and Results of Trace Analysis of 2,3,7,8-Tetrachlorodibenzo-P-dioxin in 2,4,5-THchIorophenoxyacetic Acid and Its Esters
Authors: Weeren Rolf D , Asshauer Jurgen 
Published: February 2020

Abstract
Quantitative analysis of tetrachlorodibenzo-p-dioxins (TCDDs) has gained increasing importance in the public domain. The analytical problem is complex because of the large number of interfering isomers and the extremely low limit of determination enforced by legislation. DAPA elaborated a procedure based on the latest published methods and on the existing experience of the collaborators. This procedure involves preseparation of the original sample on a silica column and cleanup by liquid chromatography (LC) on alumina. Alkaline saponification of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) esters seems to create artificial dioxins in the organic extract. Final determination is performed by capillary gas chromatography (GC)-low resolution mass spectrometry (MS). Final international collaborative work was carried out on 4 samples. Results were reported by 13 of 20 laboratories. Mean values ranged from 3.5 to 8.7 μg/kg. The interlaboratory reproducibilities ranged from 3.4 to 8.2 μg/kg (about 100% of the mean value).
Liquid Chromatographic Determination of Benzo[a]pyrene in Total Particulate Matter of Cigarette Smoke
Authors: Tomkins Bruce A , Jenkins Roger A , Griest Wayne H , Reagan Roberta R , Holladay Susan K 
Published: February 2020

Abstract
The benzo[a]pyrene (BaP) delivery of reference and commercially 1 available tobacco cigarettes, as well as reference and placebo marijuana cigarettes, is determined using a sequential liquid chromatographic liquid chromatographic procedure. The total particulate matter of sample cigarette smoke is collected using a Cambridge filter pad, which isultrasonically extracted with acetone. The resulting extract is filtered, then fractionated using semipreparative-scale normal phase liquid chromatography (LC). Quantitative determination is achieved using analytical-scale reverse phase LC equipped with a fluorescence detector. The method is precise (± 10-15% relative standard deviation) and yields 85% or better BaP recovery at the μg/cig. level. A single , pad may be analyzed in 8 person-hours, while a more typical lot of 12 pads (6 pads each for 2 cigarette brands) may be analyzed in 10 person days.
Liquid Chromatographic Determination of Polycyclic Aromatic Hydrocarbons in Fish and Shellfish
Authors: Takatsuki Keigo , Suzuki Shigeru , Sato Nobutoshi , Ushizawa Isamu 
Published: February 2020

Abstract
A simple and accurate analytical method for determination of polycyclic aromatic hydrocarbons (PAHs) in fish and shellfish is presented, which is considered to be useful for routine analyses and for screening purposes. The procedure involves alkaline digestion, extraction with n-hexane, silica gel column chromatography, and liquid chromatographic (LC) determination with fluorometric detection. During development of the analytical method for determination of PAHs, it was found that benzo[a]pyrene, a representative PAH, was decomposed easily by the analytical procedure, and this tendency was investigated for the experimental conditions used. Benzo[a]pyrene was decomposed by the coexistence of alkaline conditions, light, and oxygen; by peroxides in aged ethyl ether; and by oxygen when adsorbed on silica gel. Thus, to obtain good recoveries and precise analytical results, these decomposition conditions must be avoided. The following precautions are recommended: protection from light through all analytical steps; addition of Na2S to alkaline digestion mixture as an antioxidant; complete removal of peroxides from ethyl ether just before use; quick column chromatography on silica gel; and prevention of air from contact with adsorbent. When this simple method was applied to fish and shellfish samples, very good recoveries of PAHs from fortified fish samples were obtained, and no serious interferences were observed in fish and shellfish extracts
Normal Phase Liquid Chromatographic Determination of Pyrethrins in Formulations
Authors: Bushway Rodney J 
Published: February 2020

Abstract
A liquid chromatographic method has been developed to quantitate pyrethrins in pesticide formulations. Samples were dissolved in tetrahydrofuran (THF) and injected onto an amino column with a solvent system of hexane-nonstabilized THF (90 + 10) at a flow rate of 1.5 mL/min. Detection was monitored at 240 nm and 0.4 AUFS. Total elution time was 7 min. Twelve products varying in concentration from 0.05 to 3.75% and formulated with numerous other ingredients were analyzed. Percent coefficients of variation ranged from 1.39 to 9.68 with the majority less than 5.00. Although piperonyl butoxide and Noctyl bicycloheptene dicarboximide (MGK 264) were not quantitated, neither interfered with the pyrethrin analysis
Comparison of Ether and Chloroform for Soxhlet Extraction of Freeze-Dried Animal Tissues
Authors: Firth Nigel L , Ross Deborah A , Thonney Michael L 
Published: February 2020

Abstract
Chloroform was a satisfactory replacement for ether in solvent extraction for lipid determination in freeze-dried animal tissues, although values obtained were not identical. Fat content of tissues used in this study ranged from less than 10 to more than 95%. Chloroform has the great advantage of being fireproof, but proper fume hoods should be used. An antifoaming agent should be added to chloroform, both in the Soxhlet apparatus and when it is redistilled.