bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Decoquinate in Feeds
Authors: Stone Loyal R 
Published: February 2020

Abstract
The coccidiostat decoquinate is used in poultry feeds at 0.003%. Its fluorescence in alcoholic solution is greatly enhanced by the presence of calcium, magnesium, or strontium. A method was tested collaboratively in which decoquinate is extracted from feed by shaking with 1% calcium chloride-methanol solution, water and acid are added, and the decoquinate is trans-ferred into chloroform and chromatographed on Florisil to separate interferences. It is eluted with the calcium chloride-methanol and determined by fluorescence measurement. Background interference is negligible. Results by nine collaborators were in good agreement with the formulated drug content of feeds. The method is recommended for adoption as official, first action.
Collaborative Study of Sulfamethazine in Mixed Feeds
Authors: Hill V B 
Published: February 2020

Abstract
A method for measuring sulfamethazine in feeds containing procaine penicillin was studied collaboratively. The drug is extracted with 50% methanol and the azo dyes of sulfamethazine and procaine are formed by the Bratton-Marshall color reaction. The mixed dye solution is shaken with chloroform and made alkaline to remove the procaine dye into the chloroform. An aliquot of the aqueous phase with the drug is reacidified and measured against a standard. Thirteen collaborators obtained good recovery and precision on four samples of feed. Coefficients of variation obtained on the four samples ranged from 1.96 to 5.33%. The method is recommended for adoption as official, first action.
An Unforeseen Problem in the Use of Kel-Paks
Authors: Woodis T C , Brabson J A , Burch W G 
Published: February 2020

Abstract
In Kjeldahl methods for the determination of nitrogen in fertilizers, the digestion temperature must be above 370°C to mineralize the nitrogen in refractory organic compounds such as nicotinic acid. In total nitrogen determinations by the Raney catalyst powder method, temperatures during the digestion step were investigated as a possible cause of occasional low results. Decomposition of the polyethylene envelopes of Kel-Paks in the presence of salts of metallic reductants caused rapid fluctuations and excessive rise in temperature with consequent loss of ammoniacal nitrogen. Complete Kel-Paks can be used without difficulty in methods such as 2.044 (for nitrate-free samples) or 2.045 (salicylic acid) that do not use metallic reductants, but only the contents of the Kel-Paks without the envelopes should be used when Raney catalyst or chromium powders have been used to reduce nitrates.
Gas Chromatographic Analysis of Barbiturates in Pharmaceuticals
Authors: Sibert James L , Fricke Fred L 
Published: February 2020

Abstract
A rapid gas-liquid chromatographic method is described by which barbiturates can be separated, identified, and quantitated. Two columns are used. A 6′ cyclohexanedimethanol succinate column is used for all barbiturates except phenobarbital, which has an excessively long retention time. Phenobarbital is determined on an 18″ cyclohexanedimethanol succinate column with santonin as an internal standard. A comparison is made between the GLC, USP, and AOAC methods for the analysis of barbiturates.
Immunofluorescent Screening for Salmonella in Foods: Comparison with Culture Methods
Authors: Schulte S J , Witzeman J S , Hall W M 
Published: February 2020

Abstract
The sensitivity of an immunofluorescent screening technique was compared to conventional culture methods for Salmonella detection in an examination of 3,991 food samples. The sensitivity of the fluorescent antibody (FA) method was denned as the percentage effectiveness of the FA method for detecting true salmonellae-positive samples when compared with the culture method. Data obtained with an improved polyvalent fluorescein-conjugated somatic antiserum showed an average sensitivity greater than 99% in the analysis of 1,259 food samples.
Collaborative Study of a Quantitative Method for Clostridium perfringens in Foods
Authors: Hall Herbert E 
Published: February 2020

Abstract
The quantitative method published in 1962 for Clostridium perfringens in foods was studied collaboratively on five specimens of beef gravy by six laboratories. Results showed small within-laboratory variations between paired specimens and interlaboratory variations that were judged to be no greater than those expected in an anaerobic plate count procedure. The method is recommended for adoption as official, first action.
Gas Chromatographic Method for Determination of Diethylstilbestrol in Feeds
Authors: Smiley I E , Schall E D 
Published: February 2020

Abstract
A GLC method was developed for the determination of diethylstilbestrol in feeds within the 0.0011–0.0022% range, using dienestrol diacetate as an internal standard. A 10 g sample was extracted with 7% ethanol in chloroform and subjected to a modified alkaline cleanup. The bis-(trimethylsilyl) acetamide derivative was then prepared and determined by GLC. No interference was encountered with commercial feed samples.
Chromatographic Procedure for Determination of Reserpine in Tablets. II. Collaborative Study
Authors: Barkan Susan 
Published: February 2020

Abstract
A method is described for the quantitative determination of reserpine in tablet formulations. A suitable amount of tablet material is triturated with dimethylsulfoxide (DMSO), incorporated onto Celite, and transferred to a chromatographic column containing acid, base, and water layers. The reserpine is eluted with chloroform and quantitated spectrophotometrically. Duplicate results from 16 collaborators averaged 100.7% recovery as determined by UV, 98.8% recovery determined by colorimetric analysis. The method is recommended for adoption as official first action.
Collaborative Study of the Babcock and Foss Milko-Tester Methods for Measuring Fat in Raw Milk
Authors: Shipe W F 
Published: February 2020

Abstract
A rapid test for fat content in fluid milk, based on the measurement of light scattered by fat globules, was studied collaboratively. The Milko-tester instrument, developed by Danish scientists, was used. The milk is homogenized to produce uniformsized fat globules and then diluted with a Versene solution which eliminates the turbidity caused by the casein micelle. The amount of dilutant is adjusted so that the values obtained agree with the reference method being used for calibration. In two collaborative trials involving 6 laboratories and 9 samples, and 5 laboratories and 12 samples, respectively, the standard deviations were ±0.069 and ±0.074 for the Milko-tester and Babcock methods, respectively. The corresponding averages for the 21 samples were 4.70 and 4.69%. The standard deviation of difference between Milkotester and Babcock average values for the 21 samples was ±0.045%.
Comparison of the Dye Binding and Kjeldahl Methods for Protein Analysis of Nonfat Dry Milk and Ice Cream
Authors: Sherbon J W , Luke H A 
Published: February 2020

Abstract
Ten samples of nonfat dry milk and five samples of vanilla ice cream mix were analyzed in quadruplicate in seven laboratories for protein content by the dye binding method. Laboratory and laboratory times sample effects were significant at the 0.5% level but the coefficients of variation were 1% or less. Comparison of average results obtained by dye binding to those obtained by Kjeldahl show the former to have sufficient accuracy. Direct analysis of NFDM was found to give essentially the same results as analysis of the reconstituted product. It is recommended that the dye binding methods for protein in nonfat dry milk and ice cream mix be adopted as official first action.
Acetonitrile Extraction and Determination of Carbaryl in Fruits and Vegetables
Authors: Porter Mildred L , Gajan Raymond J , Burke Jerry A 
Published: February 2020

Abstract
A method of analysis for carbaryl residues in an acetonitrile extract of fruits and vegetables is described. Considerable time is saved by using an aliquot of the extract prepared for the widely used multiresidue analysis. Polarography is used for quantitative analysis; however, cleaned up solutions are also suitable for spectrophotometric or TLC determinations. The proposed method effectively extracts residues of field-incurred carbaryl whereas extraction procedures used in previous methods removed only 60–70% of such residues. Recoveries of 90–112% have been obtained from six fruits and vegetables fortified with 0.2 to 10.0 ppm carbaryl.
Rapid Method for the Extraction of Light Filth from Oregano
Authors: Tekbush L E 
Published: February 2020

Abstract
A method has been developed for the extraction of light filth from oregano which eliminates the petroleum ether defatting and chloroform-carbon tetrachloride heavy filth separation used in method 36.089. Results are comparable to the official method, and analytical time is reduced by one-half. The method is recommended for adoption as official first action.
Atomic Absorption Analysis of Copper and Lead in Meat and Meat Products
Authors: Dalton Edward F , Malanoski Anthony J 
Published: February 2020

Abstract
Atomic absorption spectrophotometric determination of lead and copper in meat products is described. Organic material is destroyed by dry ashing a t 500°C. Copper and lead levels ranged from 1–5 a n d 1–10 ppm, respectively.
Collaborative Study of a Gas Chromatographic Method for Ronnel in Feeds
Authors: Gehrt Albert J 
Published: February 2020

Abstract
A GLC method (flame ionization detector) for ronnel in cattle feeds at levels of 0.038, 0.041, and 0.055% was studied by 11 collaborators. The method involves extraction of ronnel by shaking with acetone followed by direct chromatographic measurement. The method is simple and rapid (no cleanup required), measures true ronnel, and is free from interferences present in the UV methods previously studied. Agreement between laboratories was satisfactory; coefficients of variation were 11.0, 12.0, and 7.2%. Ronnel recoveries were 81.1, 93.5, and 98.0%. Low recovery from the first sample may be due to ronnel hydrolysis or binding during storage (sample was 8 months old). The Associate Keferee recommends that the method be adopted as official first action.
Gas Chromatographic Determination of Methyl Salicylate, Safrole, and Related Compounds in Nonalcoholic Beverages
Authors: Larry Damon 
Published: February 2020

Abstract
As steam distillation GLC method for determining methyl salicylate, safrole, and related compounds in nonalcoholic beverages has been developed and studied collaboratively. Spiked samples of three commercially prepared sirup bases were sent to nine collaborators. Seven components were added at levels from 5 to 80 ppm . Only t he methyl salicylate analysis gave acceptable precision and accuracy at all spiking levels; at the 80 p pm level, the average recovery was 95 ± 5%. It is recommended that the method be adopted as official first action for methyl salicylate and that work be continued on safrole and related compounds.
Colorimetric and Ion-Pair Column Partition Determination of Phenylephrine in Drug Formula
Authors: Margosis Michel 
Published: February 2020

Abstract
The Emerson 4-aminoantipyrine colorimetric reaction as modified by Hiskey and Levin was applied to a number of commercial products containing antibiotics. Acetaminophen and tetracycline were found to interfere.
Four different solutions containing varying known amounts of phenylephrine were submitted to a collaborative evaluation of the Koshy and Mitchner modification of the Emerson reaction, and to the ion-pair column partition method of Levine and Doyle. The results were evaluated statistically. The colorimetric method showed average recoveries of 99.7% for solution 1, 96.1% for solution 2, and 100.7% for solution 3, with a 95% confidence limit of ±1.4, 2.0, and 3.0%, respectively. Average recoveries by the ion-pair column partition method were 84–101% with 95% confidence limits ranging between 10 and 22%. The colorimetric reaction of Emerson as modified by Koshy and Mitchner is recommended for adoption as official first action, but collaborative study of the ion-pair column partition method of Levine and Doyle should be repeated.
Collaborative Study of Enzymatic Glucose Determination in Corn Starch Hydrolysates
Authors: Brady J T , Zagorski J A 
Published: February 2020

Abstract
Glucose in starch hydrolysates was determined by catalytic oxidation of glucose with glucose oxidase to form hydrogen peroxide which, in the presence of peroxidase and a chromogen, yields a colored product. This product, when acidified, is very stable and the color intensity is proportional to the glucose concentration in the sample. Fermco Test S.F.G., a package containing all the ingredients necessary for the reaction, was used. Eleven collaborators who analyzed five different sirup samples found the method to be adequate for determining glucose. Results compared well with those by paper and gas chromatography. The method is recommended for adoption as official first action.
Application of an Automated Coulometric Titrator to the Determination of Water in Phosphoric Acids
Authors: Jordan Donald E , Hoyt Jack L 
Published: February 2020

Abstract
In the described method, water in phosphoric acid is determined by in situ coulometric generation of Karl Fischer reagent with automated end point detection. The variables associated with visual end point detection among different operators are eliminated. Sample size is limited by the generation rate of available coulometers and is 50 mg for samples containing more than 20% water and 100 t o 150 m g for samples containing less than 20% water for a 20 min analysis time . The precision at 99% confidence ranges from 0.43 ± 0.05% for superphosphoric acid to 36.8 ± 0.81% for untreated 10–34–0 base solution; for polished wet process phosphoric acid the precision is 16.49 ± 0.19% compared to 16.70 ± 0.64% by azeotropie distillation. The method is applicable in all systems which do not normally interfere with Karl Fischer reagent; the generating efficiency at the 100% water level is &gt;99%. Coulometer power tube fatigue is the most serious limitation unless a careful check and replacement program is initiated.
Emulsifiers. III. Periodic Acid Analysis for 1-Monoglycerides
Authors: Distler E , Baurs F J 
Published: February 2020

Abstract
Two collaborative studies were conducted to compare the official AOCS method, Cd 11–57, and a revised Miner procedure. The second study used known materials to obtain accuracy information. Studies showed that the revised Miner procedure is more accurate and more precise at low monoglyceride levels such as those encountered in commercial shortenings. It is recommended that the Miner procedure be adopted as official first action. It is further recommended that the joint AOAC-AOCS methods study of these two procedures be continued so that a single common method can be made official by both societies.
Estimation of Nonepoxide Xanthophyll in Sun-Cured and Freeze-Dried Alfalfa, Clovers, and Grasses
Authors: Livingston A L , Nelson J W , Kohler G O 
Published: February 2020

Abstract
Nonepoxide xanthophyll in forage plants was analyzed hy acidifying the xanthophyll fraction obtained by chromatographic purification. The 5,6-epoxy xanthophylls were altered to give their 5,8-epoxy derivatives with shifts in visible spectra of 20–40μ. The nonepoxy xanthophyll was then measured at 475 mμ as lutein equivalents. The procedure was readily applied to sun-cured or freeze-dried alfalfa, clovers, or grasses. Dehydrated alfalfa samples gave the same xanthophyll values by either the nonepoxide method or a previously reported total xanthophyll procedure, due to lower epoxide content and high levels of lutein isomers.
Chromatographic Determination of Caffeine in Instant Tea
Authors: Newton John M 
Published: February 2020

Abstract
An ultraviolet spectropholometric and GLC method for determining caffeine in instant tea utilizes the extraction and cleanup procedures of the official AOAC chromatographic methods for caffeine in APC and in coffee and a KCl thermionic detector. The detector is sensitive to as little as 1 ng caffeine. The method was studied collaboratively in eight laboratories on three instant tea samples. Results were in reasonable agreement, and the method is recommended for adoption as official first action.
Drained Weight Determination of Frozen Alaska King Crabmeat
Authors: Miller George A 
Published: February 2020

Abstract
The drained weight method of the Alaska King Crab Marketing and Control Board and the Werren-Weik drained weight method for frozen shrimp were studied collaboratively for frozen Alaska king crabmeat. An authentic pack of frozen, unglazed king crabmeat, representing three packing practices, was analyzed by 10 collaborators. Recoveries were 96.2 ± 3.3% by the King Crab Board method and 94.6 ± 2.4% by the Werren-Weik method. The Associate Referee recommends that a limited drained weight study be conducted on frozen Alaska king crabmeat with added flood water and glaze to compare the results with the study reported herein.
Key to the Identification of Canned Salmon Species by Scale Characteristics
Authors: Newton Richard T , Burnett James L 
Published: February 2020

Abstract
A key based on characteristic scale patterns has been developed to distinguish the five species of canned salmon. The scales are simply removed from the fish skin, examined under magnification, and keyed as to species. Nine of ten cans of unknown salmon were correctly identified by laboratory personnel unfamiliar with salmon species. The one error was due to inadequate explanation of terms used in the key. It is recommended that the amended key be subjected to collaborative study.
Extraction and Atomic Absorption Analysis of Lead in Plant and Animal Products
Authors: Hoover William L , Reagor John C , Garner Julianne C 
Published: February 2020

Abstract
Samples of plant or animal tissue are digested in a mixture of HNO3, H2SO4, and HClO4. Lead released in the digestion is entrained with strontium sulfate. The sulfate precipitate is separated from the digest and then converted to the carbonate by agitation with ammonium carbonate solution. The carbonate precipitate is dissolved in 1N HNO3, and lead is determined by atomic absorption spectrophotometry. Good recovery of lead (100 ± 3%) was observed except in samples with high calcium content (&gt; 1%). For the latter samples, good recoveries were obtained after separation of the calcium from the digested samples. Moderate quantities of the following elements do not interfere: Al, Fe, P, Sn, Ca, Bi, and Tl. Most elements are soluble as sulfates and, hence, do not interfere. The procedure is rugged. Dry samples containing from 0.5 ppm to 1% lead can be routinely analyzed.
Gas Chromatographic Determination of Chlormadinone Acetate in Cattle Tissues
Authors: Donoho A L , Johnson W S , Koons J R , Scroggs R E 
Published: February 2020

Abstract
The method described will detect concentrations of the progestational steroid, chlormadinone acetate (CA), as low as 0.02 ppm. Muscle, liver, and kidney samples are extracted with methanol, and the CA is partitioned into carbon tetrachloride. Fat samples are dissolved in hexane, and the CA is partitioned into acetonitrile. Muscle, liver, and fat extracts are further purified by silica gel column chromatography. Kidney extracts are purified on alumina columns. CA is measured in benzene by GLC using a 1.5% XE-60 column and electron affinity detection. Recovery of CA in control tissues fortified with 0.05 µg/g was 80–110% in muscle, liver, and kidney and 70–80% in fat.
Thin Layer and Gas-Liquid Chromatography of Cholesterol in Fats and Oils. I. Development of Method
Authors: Thorpe C W , Pohland Linda , Firestone D 
Published: February 2020

Abstract
A inethod is described for analysis of sterols by thin layer chromatography-gas liquid chromatography (TLC-GLC). Sterols are isolated from other components of unsaponifiable matter by preparative TLC. The sterols are quantitatively removed from the TLC plate, extracted from the silica gel, and analyzed by GLC. This method has been used to detect low levels (2–3%) of animal fat in vegetable oil by measuring the cholesterol content of the animal fatvegetable oil admixtures.
Extraction, Separation, and GLC Detection of Silvex and Its Propylene Glycol Butyl Ether Ester in Fish Tissue
Authors: Williams Philip W , Teasley John I 
Published: February 2020

Abstract
A method is described for the quantitative analysis of silvex and its propylene glycol butyl ether ester in fish tissue. A methanolic extraction and gas chromatographic detection yielded recoveries from fortified fish tissue of 80 to 96% at levels of 0.005 to 1 ppm for the ester and 84 to 98% at 0.002 to 1 ppm for the acid. In an additional recovery study, the extraction procedure was monitored with the PGBE ester labeled at the carboxylic carbon (14C). Live fish were exposed to an aqueous environment containing the labeled PGBE ester and were extracted by the procedure. It was found that 95% of the PGBE ester and its degradation products can be extracted from the tissue with methanol.
Analysis of Grains for Multiple Residues of Organic Fumigants
Authors: Malone Bernadette 
Published: February 2020

Abstract
A sweep co-distillation procedure, a published steam distillation procedure, and an adaptation of an established acid reflux procedure for isolating fumigant residues were compared. Residues were detectable by electron capture gas chromatography at levels approaching or surpassing 0.1 ppm. Fumigants used were carbon tetrachloride, carbon disulfide, ethylene dichloride, ethylene dibromide, methyl bromide, and chloroform. Comparison of the three methods, using the same detection for all, showed that acid reflux was the most promising procedure for recovering added fumigants from grain and extracting fumigation residues. This procedure should be further refined.
Gas Chromatographic Determination of Residues of Dalapon in Several Substrates
Authors: Getzendaner M E 
Published: February 2020

Abstract
Methods are described for determining residues of Dalapon in four types of substrates: fresh plant tissues, dry plant tissues not containing oil, dry plant tissues containing oil, and body fluids. After aqueous extraction and partition into diethyl ether, Dalapon is determined by gas chromatography using electron capture detection. Recovery from 22 different substrates averaged 90%. An average of 88% of Dalapon added to 11 crops and stored from 1.5 to 7 years was recovered.
Correlation of Uric Acid Content with Fragment Counts in Insect-Infested Flours and Wheat Grains
Authors: Sen N P , Vazquez Alberto W 
Published: February 2020

Abstract
Seven samples of naturally insect-infested wheat were examined for (a) uric acid content, (b) per cent agricultural damage, (c) whole or equivalent insects, and (d) insect damage as determined by X-ray technique. Thirteen different forms of flours obtained by milling these wheat grains in a Buhler pilot mill were analyzed for uric acid and insect fragment counts. For wheat grains, the correlation between uric acid contents and X-ray data was found to be the best among the six possible intercomparisons. The results for the first break flour samples also indicated good correlation between the uric acid levels and insect fragment counts.
Determination of Moisture in Dried Prunes
Authors: Bolin H R , Nury F S 
Published: February 2020

Abstract
The official AOAC (20.009) and the dried fruit moisture tester (DFMT) methods for determining moisture in dried prunes have been collaboratively studied. Results indicate that there is no significant difference (P &gt; 0.01) between the two method means. A significant difference (P &lt; 0.001) did occur between laboratory means, which reflected individual differences in performing the operations. Results also indicated that the DFMT charts are accurate throughout their temperature range.