bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Direct Saponification Method for Determination of Cholesterol in Meats
Authors: Adams Mark L , Sullivan Darryl M , Smith Randall L , Richter Earl F 
Published: February 2020

Abstract
A gas chromatographic (GC) method has been developed for determination of cholesterol in meats. The method involves (a) ethanolic KOH saponification of the sample material, (b) homogeneous-phase toluene extraction of the unsaponifiables, (c) derivatization of cholesterol to its trimethylsilylether, and (d) quantitation by GC-flame ionization detection using 5-α-cholestane as internal standard. This direct saponification method is compared with the current AOAC official method for determination of cholesterol in 20 different meat products. The direct saponification method eliminates the need for initial lipid extraction, thus offering a 30% savings in labor, and requires fewer solvents than the AOAC method. It produced comparable or slightly higher cholesterol results than the AOAC method in all meat samples examined. Precision, determined by assaying a turkey meat sample 16 times over 4 days, was excellent (CV = 1.74%). Average recovery of cholesterol added to meat samples was 99.8%.
Determination of Trace Elements in Foods by HCl-HNO3 Leaching and Flame Atomic Absorption Spectroscopy
Authors: Puchyr Richard F , Shapiro Rubin 
Published: February 2020

Abstract
Aluminum, iron, tin, zinc, calcium, magnesium, nickel, copper, chromium, cadmium, and potassium in foods can be extracted by HC1- HN03 leaching and determined quantitatively using flame atomic absorption spectroscopy (AAS), with recoveries ranging from 90 to 110%. Thirty to 40 samples of almost any type of food sample can be analyzed routinely for 2 elements in 4-5 h. In contrast, one or 2 days are required when a wet-ash or dry-ash technique is used. Extraction consists of weighing 2-10 g samples into 125 mL Erlenmeyer flasks, adding 20 mL concentrated HCI-HNO3 (9 + 1), then heating in a 82- 93°C water bath for 30 min. After cooling, samples are diluted to volume in 50 mL Nessler tubes and then filtered through No. 541 or 540 Whatman paper. The filtrate is analyzed directly by AAS.
Determination of Nivalenol and Deoxynivalenol in Cereals by Electron-Capture Gas Chromatography
Authors: Scott Peter M , Kanhere Shriniwas R , Tarter Edward J 
Published: February 2020

Abstract
Nivalenol (NIV) is an important Fusarium mycotoxin shown to occur naturally in grains from several countries. Extraction and cleanup procedures previously described for trichothecene analysis have been modified to give good recoveries of NIV from cereal products. The extraction solvent is methanol-water (7 + 3). The extract is treated with 10% aqueous ammonium sulfate solution and then a 10 mL aliquot is partitioned into ethyl acetate (160 mL) on a hydrophilic matrix. After evaporation, the sample extract is dissolved in methylene chloridemethanol (3 +1) for column chromatography on silica gel 60. The toxins are eluted with methylene chloride-methanol (9 + 1) following column washes with toluene and n-hexane. NIV and deoxynivalenol (DON) trimethylsilyl ethers are formed with Tri-Sil TBT and determined by gas chromatography on a 3% OV-3 packed column or DB-5 capillary column with electron-capture detection. The method has been evaluated for wheat, wheat flour, corn flour, rye flour, and barley. Recoveries averaged 89% for NTV and 106% for DON from ground cerealsand flours at a spiking level of 1 μ/g; 72% and 82%, respectively, from wheat spiked at 0.5 μ/g; and 90% and 100%, respectively, from cereals spiked at 0.2 μ/g. Heptafluorobutj rates are used for confirmation of identity; the problem of 2 derivative peaks forming with NTV on the OV-3 packed column has been overcome by using an SPB-5 or DB-5 capillary column which gave single peaks.
Instability of Some TWchothecenes in Methanol
Authors: Wei Ru-Dong , Chu Fun S 
Published: February 2020

Abstract
Stability of 8 trichothecenes stored in methanol at room temperature was studied by thin layer chromatography. Results indicate that the trichothecenes which bear an acetoxy group at both C3 and C4 are very susceptible to methanolysis. In the early stage, the acetoxy group at C3 is most favorable for the transesterification. All trichothecenes tested were transformed to several products after prolonged (22 days) exposure to methanol.
Rapid Analysis of Xanthophyll and Carotene in Dried Plant Materials
Authors: Livingston A Lyle 
Published: February 2020

Abstract
An alternative method using minimal equipment has been developed for the rapid analysis of xanthophyll and carotene in dried plant materials and mixed feeds. The method includes an ambient temperature stirring technique that may be substituted for hot extraction and saponification, thereby avoiding possible losses due to oxidation and heat isomerization. The method permits rapid analysis of xanthophyll and carotene in pigment sources including alfalfa protein concentrates, corn gluten meal, marigold concentrates, whole corn and mixed feeds containing these ingredients. The results are compared with those obtained by the official AOAC method (43.018-43.023) for xanthophyll and carotene in these ingredients. The alternative method gave the same analyses (P ≤ 0.01) for xanthophyll in alfalfa protein concentrates, marigold, whole corn, corn gluten, and mixed feeds
Titrimetric Assay of Pancreatic Lipase in Pharmaceutical Preparations
Authors: Lecat Daniel , Letavernier Jean-Francois , Bourquin Thierry , Soroste Michele , Vaucher Daniel 
Published: February 2020

Abstract
Lyophilized pancreas and pancreatic extracts are widely used in therapy of pancreatic exocrine function deficiencies. Among the measures for quality of the extracts, assay for lipolytic activity appears to be one of the best. However, assay precision is poor, because the specificity and mode of action of lipase requires careful optimization of the assay parameters, especially substrate and measurement conditions. In the method proposed here, substrate quality is improved by the use of sodium desoxycholate and a high-speed stirrer for more reproducible emulsions. Fatty acids are assayed by a titrimetric method, using an electronically monitored pH meter. A comparative statistical study of the U.S. Pharmacopeia method, the International Pharmaceutical Federation (FIP) method, and a modified FIP method showed the latter to have improved accuracy and reproducibility.
Liquid Chromatographic Determination of Amprolium in Chicken Tissues, Using Post-Column Reaction and Fluorometric Detection
Authors: Nagata Tomoko , Saeki Masanobu 
Published: February 2020

Abstract
A method is presented for determination of amprolium residues in chicken muscles by a liquid chromatographic post-column reaction system. The drug is extracted from muscles with methanol, and the extract is concentrated to 3-4 mL. This aqueous solution is rinsed with n-hexane and cleaned up by alumina column chromatography. The drug is separated from the interferences on a LiChrosorb RP-8 column, reacted with ferricyanide in alkaline solution, and quantitated by fluorometric detection at 367 nm (excitation) and 470 nm (emission). Recoveries of amprolium added to chicken muscles at levels of 0.1 and 0.2 ppm were 74.9 and 80.9%, respectively. The detection limit was 1 ng for amprolium standard and 0.01 ppm in chicken muscles.
Improved Procedure for Determining Water Activity in a High Range
Authors: Flom Walter D , Tanaka Nobumasa , Kovats Susan K , Finn Lynda M 
Published: February 2020

Abstract
A procedure for accurate determination of water activity (aw) in a high range (aw between 0.920 and 0.970) using a Beckman Hygroline apparatus was devised because the prescribed calibration procedure was inadequate. This new procedure uses NaCl solutions as standards and the aw values for NaCl solutions reported by Robinson as the reference scale. A quadratic calibration curve:
Recorder reading = b0 + b1aw + b2aw2
was established for each sensor. A 3-point calibration scheme, taking measurements of 0.9m (molal), 1.6m, and 2.4m NaCl solutions, was used before and after a series of aw measurements of samples to estimate b0 and verify the constancy of shape of the calibration curve. The equation was solved for aw to convert each recorder reading to an aw value on Robinson’s scale. This procedure yielded precision and accuracy levels for a single determination of 0.0009 and 0.0013 aw unit, respectively. Accuracy of 0.0009 aw unit was obtained by averaging 2 determinations on different sensors.
Liquid Chromatographic Determination of Ochratoxin A in Coffee Beans and Coffee Products
Authors: Terada Hisaya , Tsubouchi Haruo , Yamamoto Katsuhiko , Hisada Kazuo , Sakabe Yoshio 
Published: February 2020

Abstract
A liquid chromatographic method for the determination of ochratoxin A in coffee beans (green and roast), instant coffee, and coffee drink is described. The sample is subjected to extraction with methanol-1% aqueous sodium bicarbonate (1 + 1) and C18 cartridge cleanup. The extract is chromatographed on a Nucleosil 5C18 column with a mobile solvent of acetonitrile-water-0.2M phosphate buffer pH 7.5 (50 + 47 + 3) containing 3mM cetyltrimethylammonium bromide as an ionpair reagent. Ochratoxin A is detected with a fluoromcter (excitation 365 nm, emission 450 nm). The sensitivity was increased 20-fold by using ion-pair resolution. The detection limits corresponded to 2 μg/kg for coffee beans, 5 μg/kg for instant coffee, and 0.2 μg/kg for coffee drink. The recoveries from coffee products were generally better than 80.7% and the relative standard deviations were 3.43-5.93%. The peak coinciding with ochratoxin A can be confirmed by treatment using alcohol (methanol, ethanol, or n-propanol) and H2S04.
Simultaneous Gas Chromatographic Determination of Dibutyltin and IHbutyltin Compounds in Biological and Sediment Samples
Authors: Tsuda Taizo , Nakanishi Hiroshi , Morita Takashi , Takebayashi Junko 
Published: February 2020

Abstract
A method is described for the simultaneous determination of nanogram amounts of dibutyltin and tributyltin compounds in biological and sediment samples. These compounds are converted to the corresponding chlorides with HC1, extracted with ethyl acetate-hexane (3 + 2) for biological samples and with hexane for sediment samples, and hydrogenated with sodium borohydride. The corresponding hydrides, Bu2SnH2 and Bu3SnH, are detected by electron-capture gas chromatography after cleanup by silica gel column chromatography. Detection limits are 1.0-2.0 and 0.5-1.0 ng/g, respectively, for biological and sediment samples.
Purge and Trap Method for Determination of Fumigants in Whole Grains, Milled Grain Products, and Intermediate Grain-Based Foods
Authors: Heikes David L , Hopper Marvin L 
Published: February 2020

Abstract
A method developed for the determination of 1,2-dibromoethane in whole grains and grain-based products has been modified and expanded to include 8 other fumigants. Samples are stirred with water and purged with nitrogen for 0.5 h in a water bath at 100°C. The fumigants are collected on a trap composed of Tenax TA and XAD-4 resin, eluted with hexane, and determined by gas chromatography (GC) using electron capture detection or Hall electrolytic conductivity detection. Flame photometric detection in the sulfur mode is used to determine carbon disulfide. Thick-film, wide-bore capillary columns were used exclusively in both the determination and confirmation of the halogenated fumigants. The higher levels of fumigants are also confirmed by full scan GC/mass spectrometry. Samples are analyzed for carbon disulfide, methylene chloride, chloroform, 1,2-dichIoroethane, methyl chloroform, carbon tetrachloride, trichloroethylene, 1,2-dibromoethane, and tetrachloroethylene. A total of 25 whole grains, milled grain products, and intermediate grain-based foods analyzed by this method contained fumigant levels up to 51 ppm (carbon tetrachloride in wheat). Recoveries from fortified samples ranged from 82 to 104%. Chromatograms from this purge and trap method are clean, so that low parts per billion and sub-parts per billion levels can be quantitated for the halogenated analytes. The quantitation level for carbon disulfide is 12 ppb.
Measurement of Trace Levels of Total Aluminum in Foods by Atomic Absorption Spectrophotometry
Authors: Sullivan Darryl M , Kehoe Daniel F , Smith Randall L 
Published: February 2020

Abstract
A graphite furnace atomic absorption spectrophotometry method was used to determine the total aluminum content of various foods found in an average American diet. The food products were ashed in platinum dishes, and the inorganic residue was fused using a sodium carbonate-sodium borate mixture. The fusion step allowed detection of all the various forms of aluminum found in food products. A L'vov platform was used in the graphite furnace to increase the sensitivity of the assay. Care was taken throughout the analysis to avoid various sources of aluminum contamination such as glass and porcelain dishes. All reagents were ultra-pure grade and were continuously monitored for aluminum content. Sodium borate used in the fusion flux mixture had previously been extracted with 8-hydroxyquinoline in chloroform to remove any aluminum present. Both raw and cooked foods were analyzed for aluminum with this method. Average recoveries of aluminum from food products ranged from 84 to 112%. The overall coefficient of variation of this method on the food products tested was 10%.
Gas Chromatographic Analysis of Amino Acids as the jV-Heptafluorobutyryl Isobutyl Esters
Authors: MacKenzie Samuel L 
Published: February 2020

Abstract
The N-heptafluoroburyryl isobutyl derivatives of proteic amino acids are well resolved by gas chromatography and form the basis of a convenient, rapid assay. The derivatives are prepared by acid-catalyzed esterification at 120°C for 20 min in 3N HCl-isobutanol followed by acylation with heptafluorobutyric anhydride at 150°C for 10 min. The reaction sequence is performed without any transfers or extractions and thus is compatible with microscale analysis. A complete proteic amino acid profile can be completed in less than 20 min by using a packed column or less than 10 min by using a capillary column in combination with an elevated oven temperature program rate. Physiological sample matrixes, which frequently contain a complex mixture of components, and thus require maximum resolution, can be assayed in less than 1 h using a program rate of 4°C/min. A capillary column is recommended for this application. Capillary column chromatography, in combination with a nitrogenspecific detector, is useful for identifying and assaying nonproteic amino acids in physiological sample matrixes. Frequently, a prior cleanup of the sample can be avoided.
Analysis of Amino Acids by Gas Chromatography as the N-Trifluoroacetyl η-Butyl Esters
Authors: Gehrke Charles W , Kuo Kenneth C , Kaiser Floyd E , Zumwalt Robert W 
Published: February 2020

Abstract
This presentation describes amino acid analysis with the gas chromatographic method and experimental conditions using the N-trifluoroacetyl n-butyl ester derivatives; the study we describe here was undertaken to compare gas chromatographic (GC) and ion-exchange chromatographic (IEC) analyses of amino acids in hydrolysates of 9 diverse sample types to gain insight into effects of these 2 chromatographic methods of analysis on variation in amino acid results. Our study showed that values for samples prepared by 2 separate laboratories using the same procedure were generally in good agreement when all of the hydrolysates were analyzed by a single laboratory using a single method of analysis. To compare results from gas chromatography with those from ion-exchange chromatography analyses were performed by 2 different laboratories on the same hydrolysates and on different hydrolysates prepared by the same method by both laboratories. The data demonstrate that GC and IEC can be expected to yield essentially identical results when applied to the same hydrolysate. Agreement is so close that interlaboratory differences in hydrolysate preparation of the same sample contribute as much to variation in amino acid results as does the method of analysis, a fact which should be noted in planning collaborative studies.
Most Probable Number Method for Isolation and Enumeration of Staphylococcus aureus in Foods: Collaborative Study
Authors: Lancette Gayle A , Lanier John 
Published: February 2020

Abstract
Enumeration of Staphylococcus aureus in foods was collaboratively studied by comparing the present AOAC final action method, 46.062, which uses trypticase soy broth with 10% NaCl to a proposed replacment method which uses the same broth with 1% sodium pyruvate added. Fifteen collaborators analyzed uninoculated samples of milk, tuna salad, and ground turkey, as well as samples inoculated with low (102 cells/g), middle (104 cells/g), and high (106 cells/g) levels of S. aureus. The samples were frozen immediately to maintain the inoculated level of S. aureus in the food. A different strain of S. aureus was used for each food; heat-stressed S. aureus cells were used to inoculate the milk samples. The pyruvate-amended broth significantly (α = 0.05) increased enumeration of low, middle, and high levels of S. aureus from milk and ground turkey, and from tuna salad at middle and high levels. The pyruvate-amended media method has been adopted official first action to replace method 46.062
Liquid Chromatographic Determination of Penicillin V Potassium in Tablets and Powders for Oral Solution
Authors: Mopper Barry 
Published: February 2020

Abstract
A reverse-phase liquid chromatographic method is described for the assay of penicillin V potassium in tablets and powders for oral solution. Under isocratic conditions, the combined use of an octadecjrlsilane column, with a mobile phase composed of acetonitrile-methanol- O.OlM monobasic potassium phosphate (21 + 4 + 75, v/v), and photometric detection at 225 nm, separated penicillin V potassium from excipients, related compounds, and degradation products. Sulfadimethoxine was used as an internal standard. Detector responses were linearly related to concentrations of penicillin V over the range 25-225 μg/mL (r = 0.99997). Standard addition recoveries ranged from 98.8 to 99.9% (mean 99.5%, n = 8) for tablets and from 97.9 to 101.6% (mean 99.8%, n = 8) for powders for oral solution. The liquid chromatographic assay results were compared with those obtained by the official iodometric titration method. The proposed method is simple, selective, stability-indicating, and free from interference by excipients and degradation products
Gas Chromatographic Determination of Isofenphos in Technical and Formulated Products: Collaborative Study
Authors: Terry Daniel E 
Published: February 2020

Abstract
A gas chromatographic method for the determination of isofenphos (OFTANOL®) in isofenphos technical and liquid formulations has been developed and collaboratively studied by 11 laboratories. Two technical samples and 2 liquid flowable samples were analyzed after shaking/extracting in methanol which contained diisobutyl phthalate as an internal standard. The extracts were analyzed by gas chromatography using an SP-2100 column and either flame ionization or thermal conductivity detection. Coefficients of variation were 0.57 and 1.27% for the technical and formulated products, respectively. The GC method has been adopted official first action as a AOACCTPAC method.
Determination of Nitrogen and Protein Content of Meat and Meat Products
Authors: Benedict Robert C 
Published: February 2020

Abstract
Chemical and instrumental methods for determination of nitrogen and protein are reviewed for their mode of action and utility in analysis of meat proteins and products. Although the Kjeldahl digestion method is satisfactory for determining total nitrogen, it is imprecise for determining total protein content. Presence of variable amounts of nonprotein nitrogenous components and of connective tissue proteins such as collagen and elastin produces error if the formula (N x 6.25) is used to calculate crude protein. Such fibrous proteins have higher nitrogen levels (over 18%) than other muscle proteins (about 16%), and a higher than actual protein value will be determined unless a lower conversion factor is used to correct for their content. To determine meat protein content more accurately, a combination of Kjeldahl determination with one or more additional tests to correct for nonprotein and fibrous protein content is recommended. The choice of the additional method(s) is based on the user's requirement for protein characterization, available time, type of meat product, and sample size.
Wiley Led the Way: A Century of Federal Honey Research
Authors: White Jonathan W 
Published: February 2020

Abstract
Jonathan W. White, Jr, received the AOAC Harvey W. Wiley Award at the 100th AOAC Annual International Meeting and Exposition in Scottsdale, AZ, September 15, 1986. In 1942, after earning his Ph.D. at Purdue University, White became assistant chemist at the Eastern Regional Research Center (ERRC) of the U.S. Department of Agriculture at Wyndmoor, PA, where he spent almost his entire professional career. In 1948, he began the extensive research on honey for which he was selected as the 1986 Wiley Award recipient. He was named chief of the ERRC Plant Products Laboratory in 1965; 10 years later he requested reassignment to conduct research on the detection of adulteration of honey by high-fructose corn syrup. He retired from USDA in 1978 and until recently headed a honey testing service called Honeytech, Inc. White was elected a Fellow of AOAC in 1969 and was named Associate Referee of the Year in 1977
Gas Chromatographic Determination of Calcium Propionate Added as Preservative to Bread
Authors: Lamkin William M , Unruh Natalie C , Pomeranz Yeshajahu 
Published: February 2020

Abstract
A simple and rapid gas chromatographic procedure was developed for determining low concentrations of propionate added as a preservative to bread. A bread sample to be analyzed was ground in a meat grinder with a 3 mm hole plate and finely divided by rubbing through a No. 8 sieve. The propionate was then extracted into 0.050M formic acid in a blender at low speed for 5 min, and an aliquot of a filtrate was analyzed directly by gas chromatography. Chromatographic separation was accomplished on a Carbopack C column coated with 0.3% (w/w) Carbowax 20M and 0.1% (w/w) phosphoric acid. Less than 0.2 ppm propionic acid could be detected in the aqueous extract. Over the range of 0.03-0.23% calcium propionate, average relative error was —1.20% with an average coefficient of variation of 2.02%.
Total Nitrogen Determination of Various Sample Types: A Comparison of the Hach, Kjeltec, and Kjeldahl Methods
Authors: Watkins Kevin L , Veum Trygve L , Krause Gary F 
Published: February 2020

Abstract
Conventional Kjeldahl analysis with modifications, Kjeltec analysis with block digestion and semiautomated distillation, and the Hach method for determining nitrogen (N) were compared using a wide range of samples. Twenty different sample types were ground and mixed. Each sample type was divided into 5 subsamples which were analyzed for N by each of the 3 methods. In each sample type, differences (P &lt; 0.05) were detected among the 3 N determination methods in 5 of the 20 N sources analyzed. The mean N content over all 20 samples was higher with Kjeldahl analysis (P &lt; 0.05) than with Kjeltec, while Hach analysis produced intermediate results. Results also indicated that the Hach procedure had the greatest ability to detect differences in N content among sample types, being more sensitive than either other method (P &lt; 0.05).