bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two Lipoxidase Methods for Measuring cis,cis-Methylene Interrupted Polyunsaturated Fatty Acids in Fats and Oils : Collaborative Study
Authors: Sheppard Alan J , Waltking Arthur E , Zmachinski Helen , Jones Shirley T 
Published: February 2020

Abstract
Two methods for measuring the cis, cis methylene interrupted polyunsaturated fatty acids (cis, cis-PUFA) content of fats and oils were compared collaboratively. The methods evaluated were one proposed by the Food and Drug Administration (Method I) and one used by industry (Method II). Analyses of variance between methods and samples and between laboratories and methods showed similar select differences significant at the 95% level (P &lt; 0.05) for both methods. The reproducibility standard deviations were lower with Method II for 3 of the 5 samples, but equally higher than with Method I for 2 other samples. The repeatability standard deviation for one of the oils was significantly higher for Method II but were significantly higher for Method I for 2 other oils. Over all of the samples, the 2 methods gave similar results and there was no overall statistical difference in the performance.
High Pressure Liquid Chromatographic Determination of Atropine Sulfate and Scopolamine Hydrobromide in Tablets
Authors: Walters Milda J 
Published: February 2020

Abstract
A reverse phase high pressure liquid chromatographic (HPLC) system utilizing ion-pairing, similar to that previously reported for methscopolamine bromide, was developed for the quantitation of atropine sulfate and scopolamine hydrobromide in tablets. This HPLC system is capable of differentiating the major tropane alkaloids, with the exception of the atropine- hyoscyamine optical isomer pair, by their k' values and separating a significant degradation product, tropic acid. Optimum sensitivity is obtained by using a variable wavelength ultraviolet detector at 230 nm resulting in a detection limit of &lt; 0.5 μg alkaloid/injection. The response is linear in the range of 3–19 ---g atropine sulfate and scopolamine hydrobromide. The coefficient of variation for injection reproducibility is &lt; 1 %. The method has been applied to composite and individual tablet assays of scopolamine hydrobromide and atropine sulfate. The HPLC results are comparable (within 1%) to those obtained using the USP procedure; the HPLC method requires less sample preparation.
High Pressure Liquid Chromatographic Determination of Rotenone and Degradation Products in Animal Chow and Tissues
Authors: Bowman Malcolm C , Holder Claude L , Bone Larry I 
Published: February 2020

Abstract
An analytical procedure is described for determining residues of rotenone, rotenolone, dehydrorotenone, and rotenonone in admixture in animal chow and tissues. The methanol or ethyl ether extracts from samples of chow and tissues, respectively, are subjected to a liquidliquid partitioning cleanup with hexane-acetonitrile, further cleanup on a column of silica gel, and subsequent analysis by high pressure liquid chromatography using an ultraviolet absorption detector set at 295 nm. Animal chow, mouse fetuses, and gastrointestinal tracts spiked with 0.5 ppm of each compound in admixture yielded average recoveries of 92, 51, and 79%, respectively; minimum quantities of the 4 compounds detectable in the 3 substrates averaged 0.12, 0.04, and 0.14 ppm, respectively. Stability studies indicate that rotenone reacts with animal chow with a half-life of 7–8 days and is photodegraded in incandescent light with a half-life of 0.65 day. No transplacental transfer of rotenone or its products was observed in fetuses from mice receiving 7 consecutive daily doses of rotenone at levels up to 25 mg/kg.
Gas-Liquid Chromatographic Determination of Sodium 5- [2-Chloro-4- (trifluoromethyl) phenoxy] -2-nitrobenzoate Residues on Soybeans and Foliage, Soil, Milk, and Liver
Authors: Adler Irving L , Augenstein Larry L , Rogerson Thomas D 
Published: February 2020

Abstract
Residues of sodium 5- [2-chloro-4-(trifluoromethyl) phenoxy] -2-nitrobenzoate and its free acid are determined by treating a sample extract with diazomethane to convert the residues to methyl 5- [2-chloro-4-(trifluoromethyl)phenoxy] -2-nitrobenzoate. This compound is purified by chromatography on Florisil and measured by electron capture gas-liquid chromatography. The method has been used on soybeans, soybean foliage, soil, milk, and liver. It can detect 0.01 ppm with recoveries of 70–75%.
Confirmation of Pesticide Residues Identity. X. Mirex
Authors: Chau Alfred S Y , Carron John M , Tse Hung 
Published: February 2020

Abstract
Three procedures using 3 different ratios of chromous chloride and acetone at room temperature or 55–60°C are described for confirming the presence of Mirex (dodecachlorooctahydro- l,3,4-metheno-2H-cyclobuta [cd] pentalene). Each procedure gives a different major product with a different gas-liquid chromatographic retention time. The factors that could affect this reductive dechlorination were also studied. The procedures can detect, respectively, 1.1, 0.7, and 0.5 times the amount of the Mirex standard (taken as 1.0) used in the investigation.
Investigation of the Integrity of Seven Herbicidal Acids in Water Samples
Authors: Chau Alfred S Y , Thomson Karen 
Published: February 2020

Abstract
The stability of the following 7 herbicidal acids in distilled water and natural water preserved with sulfuric acid was investigated: 2,4-D, 2,4-DB (4-(2,4-dichlorophenoxy)butyric acid), 2,4-DP (2-(2,4-dichlorophenoxy)propionic acid), dicamba, MCPB (2-methyl-4-chlorophenoxyacetic acid), silvex, and 2,4,5-T. None of the acids showed detectable degradation in distilled water up to the 40 day period of investigation or in Hamilton Harbour water up to the 50 day period of investigation.
Analysis of Chloroxuron Technical and Its Formulations: Collaborative Study
Authors: Heizler Werner , Meier Juerg , Nowak Klaus , Suter Rolf , Bosshardt Hans P 
Published: February 2020

Abstract
Chloroxuron technical and its 50% wettable powder were analyzed by 17 participants in a CIPAC collaborative study. The analytical method used involves acid extraction to remove interfering free amines, followed by alkaline hydrolysis of the extraction residue, distillation, and titration of the liberated dimethylamine. Related byproducts which may interfere are determined by semiquantitative thin layer chromatography. Results obtained from 17 government and industrial collaborators showed good repeatability within laboratories. Good agreement was also achieved between laboratories. A reproducibility of about 1.5% was obtained. The method has been adopted as an interim official CIPAC-AOAC method.
Colorimetric Determination of Carbofuran in Formulations
Authors: Handa Swadesh K , Dikshit Anand K 
Published: February 2020

Abstract
Carbofuran formulations are cleaned up by thin layer chromatography to separate possible interferences from carbofuran. Carbofuran phenol is reacted with vanillin to form a colored compound with an absorption maximum at 550 nm. The relationship between absorbance and concentration of carbofuran is linear from 5 to 50 μ5 ml solution. Recoveries of carbofuran from laboratory-prepared formulations ranged from 98.0 to 98.93%.
Determination of Amitraz in Cattle Dipping Baths and Sprays
Authors: Machin Michael V , Mcdougall Kerryn W 
Published: February 2020

Abstract
Infrared (IR) and gas chromatographic methods have been developed for determining the acaricide amitraz (N-(2,4-dimethylphenyl)-N - [[(2,4- dimethylphenyl)imino]methyl] - N - methanimidamide) in cattle dip solutions. Extraction with petroleum ether, followed by IR and gas-liquid chromatography (GLC) gave coefficients of variation of 3.4 and 3.6%, respectively, for 0.010-0.035% amitraz. Dilution of the dip sample with acetone and determination by GLC gave a coefficient of variation of 3.6% in the same range. Recovery of amitraz from fortified dip samples was 97–100%.
Determination of o-Toluenesulfonamide in Artificial Sweeteners Containing Saccharin
Authors: Kacprzak Jurgen L 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) procedure with p-toluenesulfonamide (p-TS) as an internal standard is used to determine o-toluenesulfonamide (o-TS), a major impurity in artificial sweetening substances containing saccharin. Although p-TS can itself occur as an impurity in samples, it is usually absent or present in very small amounts; the highest quantity found in the 13 samples analyzed was about 1 ppm. The presence of appreciable amounts, however, would not pose a problem with the GLC procedure. Recoveries of standard o-TS added at various levels were approximately 90%.
Comparison of Methods for Determining Biuret in Urea
Authors: Corominas Luis F , Boy Victor M , Guijosa Manuel 
Published: February 2020

Abstract
The official first action AOAC method for the spectrophotometric determination of biuret in urea, 2.072—2.074, was compared with official first action AOAC method 2.C01-2.C03 (atomic absorption spectrophotometry), 2 simplified versions of 2.072-2.074, and modified versions of 2 alternative procedures of the International Organization for Standardization. Three synthetic urea samples (0.3, 1.4, and 3.0% biuret) and 1 commercial urea sample (1.0% biuret) were analyzed. The methods proved to be equivalent and none showed a definite advantage over 2.072-2.074. The purification of biuret and the interference by ammonia are also discussed.
Nuclear Magnetic Resonance Studies of Cyanogenetic Glycosides: Spectra of Amygdalin and Neoamygdalin in DMSO-d6 and D2O; Epimerization Studies; Predicted Laetrile Spectrum
Authors: Turczan John W , Medwick Thomas 
Published: February 2020

Abstract
The nuclear magnetic resonance (NMR) spectra of amygdalin and neoamygdalin have been studied in D2O and dimethylsulfoxide-d6 and have been compared. The epimerization of amygdalin has been studied under various conditions, using the NMR spectra to monitor changes in the aglycone chiral center. Observations indicate that a base is necessary to abstract a proton from the aglycone and permit epimerization. There is evidence that the surface of the glass container may provide the base (as silicate) because no epimerization is observed when a platinum vessel is used. Epimerization is observed when amygdalin is melted. On the basis of the spectra of prunasin, β3-D-glucose, and β-glucuronic acid, a spectrum has been predicted for Laetrile because the latter compound is not currently available.
Modified Chromogenic α-Amylase Assay for Sprouted Wheat
Authors: Mathewson Paul R , Pomeranz Yeshajahu 
Published: February 2020

Abstract
Sensitivity of a test in which a commercially available substrate was used for the assay of α-amylase in sprouted wheat has been increased by the use of optimally buffered (pH 6.20) Cibacron-Blue dyed amylose at 60°C. With the modified test, measurable α-amylase levels were in the range of 3—30 millidextrinizing units (mDU) as compared to the 10—90 mDU range in a test previously reported for bread wheats. The modification extends the use of the test to evaluation of sprout damage in wheats used in the manufacture of Japanese noodles and sponge cakes.
Reaction-Rate Method for Determining Protein Nitrogen in Grains and Feeds
Authors: Mccracken Michael S , Malmstadt Howard V 
Published: February 2020

Abstract
In a new automated reaction-rate method for the quantitative determination of protein nitrogen in grains and feeds, the ammonia-sodium phenate-hypochlorite reaction is used for the reaction-rate determination. After samples are digested by the official AOAC block digestion procedure, automated instrumentation is used to precisely and rapidly combine the reactants and transfer the mixed solution to an automated spectrophotometer. The rate of formation of the indophenol during 15 sec at 635 nm is automatically determined and compared with rates obtained for nitrogen standards to determine the protein nitrogen content in the sample. Relative standard deviations of about 0.6% are obtained. Results for grain and feed samples are comparable to those obtained by the official AOAC method.
Gas-Liquid Chromatographic and Mass Spectrometric Identification of Chlorinated Trifluorotoluene Residues in Niagara River Fish
Authors: Yurawecz Martin P 
Published: February 2020

Abstract
Several unknown halogenated compounds were detected in Niagara River fish using a method similar to the AOAC multiresidue method for chlorinated pesticides in high-moisture foods. From gas-liquid chromatographic-mass spectrometric (GLC/MS) data and GLC retention times on 3 columns, 7 of the compounds were identified as 4-chloro-α,α,α-trifluorotoluene (0.17—2.0 ppm), 2-chloro-α,α,α-trifluorotoluene (0.002—0.1 ppm), 3,4-dichloro-α,α,α-trifluorotoluene (0.02—0.28 ppm), 2,4-dichloro-α,α,α-trifluorotoluene (0.02—0.17 ppm), 2,3-dichloroa, α,α,α-trifluorotoluene (trace-0.005 ppm), 2,6-dichlorotoluene (not quantitated), and 2,4,5-trichlorotoluene (0.31 ppm was found in the only sample quantitated). Other isomers of triand tetrachloro-α,α,α-trifluorotoluene and di-, tri-, and tetrachlorotoluene were also present in these samples. Recoveries of the specific chlorinated trifluorotoluenes identified in these samples ranged from 86 to 108%.
Automated Sampling/Readout Devices for Analysis of Dissolution Media: Continuous-Cycling System and Application to Dissolution Profiling of Phenytoin Products
Authors: Myrick James W , Wells Clyde E 
Published: February 2020

Abstract
An automated system has been developed for sampling and analyzing dissolution media for in vitro determinations. This system simultaneously takes filtered aliquots at precisely spaced intervals from 6 test vessels, dilutes each aliquot, and presents them sequentially either for direct absorbance monitoring or for additional chemical treatment before absorbance monitoring. Because the apparatus dilutes the aliquots by a factor of 1:6, the system is most effective in monitoring unit dosage levels of 50—500 mg. Lower dosages may be examined if an extremely sensitive detection method is available. Long-term operation of the sampler on a 10 min cycle basis showed a coefficient of variation of 0.46%. The sampling system was used with a newly developed, sensitive automated method for determining phenytoin and sodium phenytoin. The sample is treated at pH 8.1 with a mercuric chloride solution to form a phenytoin/mercury complex which is extracted into chloroform. Adding dithizone to the chloroform extract produces the typical orange mercuric dithizonate with peak absorbance at 480 nm. Detection sensitivity is 0.28 μg phenytoin/ml, corresponding to 5% dissolution of a 30 mg tablet in 900 ml medium. The sampler and detection system showed a coefficient of variation of 0.95% on a 15 min cycle basis. Phenobarbital interferes with the method.
Spectrophotometric Analysis of Binary Mixtures of Sulfonamides
Authors: Wahbi Abdel-Aziz , Abdine Hassan , Korany Mohamed , El-Yazbi Fawzi 
Published: February 2020

Abstract
Different methods for analyzing binary mixtures by using 2 wavelengths are reviewed. The absorbance ratio calculated at 2 wavelengths, not including the isoabsorptive point, was a quadratic function of relative concentration. The curve-fitting process using orthogonal polynomials was applied to obtain the quadratic equation. An absorbance ratio can be used as a rapid purity index for sulfacetamide sodium in the presence of sulfanilamide. Sulfacetamide sodium has been determined in eye drop preparations.
Preparation of Pure 1- and 2-Naphthalenesulfonic Acids and Analysis of Their Mixtures
Authors: Marmion Daniel M 
Published: February 2020

Abstract
Procedures are presented for the preparation of the pure sodium salts of 1- and 2-naphthalenesulfonic acids, and for the high pressure liquid chromatographic (HPLC) analysis of mixtures of both in the presence of highersulfonated homologs. The purified samples are prepared by the recrystallization from water of commercially available materials. The HPLC procedure specifies a 4.6 mm id × 25 cm Whatman Partisil PXS10/25 ODS-2 column, an eluant prepared by diluting 90 ml isopropanol to 2 L with 0.15M aqueous (NH4)2S04, and isocratic elution at 40°C.
Gas-Liquid Chromatographic Determination of Individual Sugars in Confectionery Products
Authors: Prager Manfred J , Miskiewicz Michael A 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) procedure is presented for the separation and quantitative determination of sucrose, lactose, maltose, and glucose in commercial confectionery products. By converting reducing sugars to oximes and then forming trimethylsilyl ethers of these compounds and separating them on a 6 ft × 4 mm id glass column packed with 2% OV-17 on 100—120 mesh Supelcoport, single peaks were obtained for each of the sugars. Results for sugars present in samples at levels of 5% or more are within 2.8%, on the average, of results obtained by polarization measurements. The data also compare favorably with others in the literature on similar products analyzed by other GLC procedures that do not involve oxime formation.
Screening Test for Amygdalin in Tablets, Solutions, Powders, and Seeds
Authors: Egli Keith L 
Published: February 2020

Abstract
A rapid screening test for detecting amygdalin in tablets, solutions, powders, and seeds, based on the liberation of both hydrogen cyanide and benzaldehyde as a result of enzymatic decomposition, is described. The procedure can be easily performed outside the laboratory with small amounts of sample; the samples require no special preparation or pretreatment. The test can be performed in ≤60 min and is sensitive to at least 0.2 nig amygdalin. Vicianin, lucumin, prunasin, and sambunigrin would also give positive tests, but instrumental analysis can be used to distinguish amygdalin from these compounds.
Determination of Microquantities of Lead in Ferrous Sulfate, Zinc Oxide, Manganese Sulfate, and Iron Powder by Using Solvent Extraction and Flameless Atomic Absorption Spectroscopy
Authors: Ng Samuel S M , Bhattacharyya Pranab K 
Published: February 2020

Abstract
A method is described for quantitative measurement of lead at &lt; 1 ppm levels in ferrous sulfate, zinc oxide, manganese sulfate, and iron powder by using solvent extraction and flameless atomic absorption spectroscopy. Lead is separated from the heavy matrix before the analysis. It is complexed with sodium diethyldithiocarbamate in the presence of excess sodium cyanide and ammonium citrate and extracted into methyl isobutyl ketone. The extract is placed in a graphite furnace for quantitation. The sensitivity and absolute sensitivity of this method are 0.01 μg/mL and 5.0 X 10-11 g lead, respectively. The recovery of lead from the spiked samples was good. The reproducibility of the signal response for sample solutions containing ≥ 0.2 ppm lead is within 6.0%.
Gas-Liquid Chromatographic Determination of Limonene in Orange Juice
Authors: Lund Eric D , Shaw Philip E 
Published: February 2020

Abstract
The limonene content of orange juice was quantitatively determined by a porous polymer trapping gas-liquid chromatographic (GLC) procedure. A 10 mL juice sample was stripped of volatiles by a nitrogen stream, and the limonene and other volatiles were trapped on Chromosorb 105. The volatiles were desorbed and collected in the upstream end of a GLC column. The column was rapidly heated, and the area of the resultant sharp limonene peak was measured. Recoveries ranged from 96 to 103% over the usual concentration range of limonene in orange juice (0.006–0.120 volume % ) . Coefficients of variation for repeated measurements (precision) were ±1 % , and for overall accuracy, ±3 % . Experimental error increased considerably in the 0.001-0.003% range. These errors are comparable to those reported for the presently used Scott-Veldhuis bromate titration procedure. Analysis of a canned orange juice sample showed that the titration method gave a slightly higher limonene value, probably due to consumption of bromine by a small amount of non-limonene volatiles.
Sampling of Insecticides from Pressurized Cans: Collaborative Study
Authors: Kawano Yoshihiko 
Published: February 2020

Abstract
Seven laboratories collaboratively studied 3 methods for sampling water-based insecticides in pressurized cans. Method 1 was a direct sampling method where the sample was collected continuously from an aerosol outlet into the solvent, using a U-shaped sampling assembly. Method 2 was an indirect method, in which the sample was collected in the solvent from an open can after the propellent was discharged under frozen conditions. Method 3 was an extension of Method 1, where ≥3 samples were collected continuously from an aerosol outlet into the solvent through a U-shaped sampling assembly. The solvent, which contained the active ingredient, was concentrated and transferred to a suitable volumetric flask for gasliquid chromatographic (GLC) analysis. The means of the analytical results for Methods 1 and 3 did not show a significant difference at the 95% confidence level. However, a significant difference was found at the 95% confidence level for the mean value for Method 2 compared with the means for Methods 1 and 3. Methods 1 and 3 have been adopted as official first action for sampling pressurized cans containing aerosols.
Methods for Determining Carbohydrates, Hydroxymethylfurfural, and Proline in Honey: Collaborative Study
Authors: White Jonathan W 
Published: February 2020

Abstract
A modification of the official selective absorption method for honey carbohydrates, 31.124–31.133, was studied collaboratively; the determinations of sucrose, total monosaccharides, disaccharides, and higher sugars by this procedure were satisfactory and were adopted by the AOAC. High pressure liquid chromatography of glucose, fructose, and sucrose in honey showed better precision than the modified official method and gave concordant results; it was also adopted. Two methods for hydroxymethylfurfural do not qualify. A method for proline was also adopted.
Spectrophotometric Determination of Tolbutamide in Tablets
Authors: Elsayed M Abdel-Hady , Belal Saied F , Elwalily Abdel-Fattah M , Abdine Hassan 
Published: February 2020

Abstract
Two spectrophotometric methods, Glenn's method of orthogonal function and the basic dye method, are described for determining tolbutamide in tablets without interference from the tablet excipients. In Glenn's method, the absorbance of tolbutamide in 95% ethanol is measured in the vicinity of 250–270 nm at 4 nm intervals and the p2 coefficient is calculated. The coefficient is linearly related to concentration within a range of 0.1–0.4 mg/mL. Tolbutamide gives a complex of a ratio 1:1 with basic dye Brilliant Cresyl Blue (BCB) or Safranin T (ST). The complex is easily extracted with chloroform. The absorbance of the chloroform extract is measured against either a blank or reference experiment. The latter is obtained by using a specific concentration of tolbutamide: 0.4 mg/mL in tolbutamide–BCB or 0.024 mg/mL in tolbutamide-ST. The ST complex method is more sensitive compared with the other methods. When the t-test is applied, the results of the proposed methods are more accurate than those of the traditional ultraviolet spectrophotometric method.
Spectrophotometric Determination of Acetaminophen in Tablets, Sirups, and Suppositories
Authors: Elsayed M Abdel-Hady , Belal Saied F , Abdel-Fattah M Elwalily , Abdine Hassan 
Published: February 2020

Abstract
A differential spectrophotometric method and Glenn’s method of orthogonal function are described for the assay of acetaminophen in tablets, sirups, and suppositories. Interference from excipients in the formulations is thereby avoided. Accuracy of the analyses is greater with the proposed methods than with the British Pharmacopoeia method.