bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nuclear Magnetic Resonance Spectroscopic Method for Determination of Penicillamine in Capsules
Authors: Nelson James 
Published: February 2020

Abstract
A rapid and specific nuclear magnetic resonance (NMR) spectroscopic method for the determination of penicillamine in capsules is presented. The sample is directly dissolved in D2O and its spectrum recorded on a 90 MHz instrument. The 2 singlets appearing at 1.58–1.64 ppm, due to the nonequivalent gem-dimethyl groups, were integrated and compared with the integral obtained for the phenyl proton signals of sodium saccharin, which is the internal standard. The results obtained by the proposed method closely agreed with those found by the method of USP XX.
Improved Multiresidue Gas Chromatographic Determination of Organophosphorus, Organonitrogen, and Organohalogen Pesticides in Produce, Using Flame Photometric and Electrolytic Conductivity Detectors
Authors: Luke Milton A , Froberg Jerry E , Doose Gregory M , Masumoto Herbert T 
Published: February 2020

Abstract
The multiresidue procedure of Luke et al., which uses extraction with acetone and partition with petroleum ether and methylene chloride, was simplified and shortened by eliminating the Florisil cleanup. Double concentration with petroleum ether in the Kuderna-Danish evaporator following the initial concentration removed the last traces of methylene chloride. The extract was then injected into a gas chromatograph, using a Hall electrolytic conductivity detector for organohalogen, organonitrogen, and organosulfur pesticides or a flame photometric detector for organophosphorus pesticides. Recoveries of 79 pesticides are presented.
Gas-Liquid Chromatographic-Mass Spectrometric Confirmation of Endosulfan and Endosulfan Sulfate in Apples and Carrots
Authors: Wilkes Perry S 
Published: February 2020

Abstract
A gas-liquid chromatography-mass spectrometric (GLC-MS) procedure is described for the confirmation of endosulfan I, endosulfan II, and endosulfan sulfate in apples and carrots. After extraction, cleanup, and determination by electron capture gasliquid chromatography using current AOAC methodology, residues are confirmed by GLC-MS. The chemical ionization (CI) mode is used with methane as a reagent gas. Each residue is confirmed by a scan of only 4 regions of its mass spectrum rather than the full mass range. The 4 mass regions for the 2 endosulfan isomers are 274-280, 340-346, 368-374, and 404-412 atomic mass units (amu). For endosulfan sulfate, the mass regions are 286-294, 322-330, 384-392, and 420-428 amu. Four ions and their chlorine isotopic distributions are detected for each compound by this scanning technique. This method was developed by using carrots and apples to which had been added 0.1 ppm (50% of the current legal tolerance on carrots) of each of the 3 pesticides. The gas chromatographic retention times and the mass spectra of the 4 mass regions specified for the 3 pesticides were compared to those of reference standards injected under identical GLC-MS conditions and were used as the basis for confirming identity of the 3 compounds.
Novel Thin Layer Chromatographic Techniques for Aflatoxin Analysis
Authors: Kozloski Richard P 
Published: February 2020

Abstract
Some procedures for improving thin layer chromatographic (TLC) spot size and fluorescence intensity are described. By using strong eluting solvents, diffuse TLC spots can be reduced in size and poorly resolved chromatograms returned to their original state for redevelopment. The blanketing of weak aflatoxin bands with an inert layer of gas results in an increase in UV fluorescence
Examination of the Use of Glass Filter Paper in Asbestos-Free Fiber Determination
Authors: Craddick Richard C , Hatfield Linda 
Published: February 2020

Abstract
A modification is presented of asbestos-free method 7.066 for the determination of crude fiber in feeds. In the final filtering step, the fritted glass crucible is replaced with a 7.5 cm disc of glass filter paper in a California Buchner funnel. The data supporting the use of filter paper indicate that good precision and accuracy can be achieved.
Gas-Liquid Chromatographic Determination of Pirimicarb in Formulations: Collaborative Study
Authors: Bland Peter D ,   Collaborators:, Bagness J , Black W , Brown L , Gentry M , Ginther B , Hayes E , Holland P , Jackling S , Padmore J , Torma L , Winstead G 
Published: February 2020

Abstract
A method is described for the determination of pirimicarb (2-(dimethylamino)-5,6-dimethyl-4-pyrimidinyl dimethylcarbamate) in formulated products by gas-liquid chromatography (GLC). Samples are dissolved in a chloroform solution of an internal standard and injected into a gas chromatograph equipped with a flame ionization detector. Quantitative data are obtained by comparing peak areas of the compound and internal standard with those obtained by injecting a standard solution. Eleven collaborators made replicate determinations on 6 samples including a technical product, a granular product, and 4 powder products. The average coefficient of variation was 1.14% for the technical product, 1.82% for the granular product, and 0.73% for the powder products.
Evaluation of Ion Exchange Resins and Various Enzymes in Thiamine Analysis
Authors: Ellefson Wayne C , Richter Earl , Adams Mark , Baillies N Thomas 
Published: February 2020

Abstract
Four ion exchange resins and 9 enzyme preparations are evaluated for use in the official AOAC thiamine method because Decalso and Clarase or Mylase P either are no longer available or are available in a form that is not suitable for use in the assay. The enzymes are prepared in the same manner described for Clarase or Mylase P in the AOAC method and are compared with Clarase T300 for their effectiveness in releasing thiamine from thiamine phosphate, and their ability to produce similar results on samples. Rhozyme S is 90–100– as effective as Clarase T300 in both of these respects. The other enzymes tested were not satisfactory. Further study is necessary because Rhozyme S also is no longer manufactured. The ion exchange resins are prepared for use in the manner described for Decalso in the AOAC method. Recoveries of thiamine range from 95 to 100%, using Bio-Rex 70 (hydrogen form) ion exchange resin. The other resins tested were not satisfactory.
Gas Chromatography with Electron Capture and Mass Spectrometric Detection of Deoxynivalenol in Wheat and Other Grains
Authors: Scott Peter M , Lau Pui-Yan , Kanhere Shriniwas R 
Published: February 2020

Abstract
A method for determining deoxynivalenol (DON) in wheat has been developed in conjunction with an assessment of contamination in Canada. The sample is extracted with methanol-water; the extract is treated with 30% aqueous ammonium sulfate solution and extracted with 4 portions of ethyl acetate. After further cleanup by column chromatography, the sample extract is derivatized with AT-heptafluorobutyrylimidazole, and the DON tris-heptafluorobutyrate is determined by gas-liquid chromatography with electron capture detection. Mass spectrometric single ion monitoring at m/z 884 is used for confirmation. Detection limits are ≤0.01 μg DON/g and recoveries from wheat, using the proposed method, averaged 72 and 80% in 2 different laboratories, with coefficients of variation of 10.2 and 10.0%, respectively. The method is also applicable to determining DON in barley and corn and T-2 toxin in wheat. Virtually 100% contamination by DON of the 1980 Ontario white winter wheat and Quebec red spring wheat crops was found, based on 72 analyses made in this laboratory, but western Canadian wheat contained little or no DON.
Estimation of Lactose Hydrolysis by Freezing Point Measurement in Milk and Whey Substrates Treated with Lactases from Various Microorganisms
Authors: Chen Shih-Ling Yeh , Frank Joseph F , Loewenstein Morrison 
Published: February 2020

Abstract
β-Galactosidase concentrates obtained from several microorganisms were used to hydrolyze skim milk, low fat (2%) milk, sweet whey, acid whey, acid whey permeate, and acid whey concentrate. Among acid substrates, the freezing point depression for each 1% lactose hydrolyzed was the greatest with the lactase from Aspergillus niger (0.0501°H); among neutral substrates, the depression was greater in sweet whey (0.0495°H) and lesser in low fat milk (0.0445°H). All data were statistically significant. The average freezing point depression for each 1% lactose hydrolyzed was 0.0468°H (range 0.0436-0.0501°H). Oligosaccharides formed in the lactose hydrolysis, inconsistent freezing point readings of the cryoscope at the low freezing points measured, and protease contamination in some lactases may affect the precision of freezing point determination. Hydration and volume of non-protein components in commercial enzymes, unstable color complex formed by lactose in methylamine solution, and difficulty in the use of methylamine solution might cause variations in determination of lactose by the analytical procedure. These factors can be eliminated or minimized. This method is the simplest and quickest estimation of lactose hydrolysis, and it offers great accuracy and consistency
Protein Nitrogen Unit Precipitation Procedure for Allergenic Extracts: Collaborative Study
Authors: May Joan C , Sih Jenny T C ,   Collaborators:, Laboratories Allergy , Best J , Douglas G , Rancour J M , Renker H R , Spingola F , Daele L Van , Zudeck S 
Published: February 2020

Abstract
Protein nitrogen unit (PNU) determination is one of the methods used to test and label the concentration of allergenic extracts. This recently standardized method is applicable to all allergenic extracts. One PNU/mL is equivalent to 1 × 10−5 mg nitrogen determined to be in the material precipitated from 1 m l allergenic extract by phosphotungstic acid (PTA), a protein precipitant. The nitrogen is quantitated by the Kjeldahl method or another analytical method of equivalent accuracy and precision. A collaborative study of the optimized PNU precipitation method in which 6 samples were analyzed in duplicate by 6 laboratories using the Kjeldahl method for the determination of nitrogen yielded a mean of 0.1358 mg N/ml, a repeatability standard deviation and coefficient of variation of 0.0071 mg N/mL and 5.23%, respectively, and a reproducibility standard deviation and coefficient of variation of 0.0188 mg N/mL and 13.84%, respectively. The method has been adopted official first action.
Gas-Liquid Chromatographic-Thermal Energy Analyzer Method for N-Nitrosodiethanolamine in Cosmetics
Authors: Black Donald B , Lawrence Robert C , Lovering Edward G , Watson James R 
Published: February 2020

Abstract
A gas-liquid chromatography-thermal energy analyzer (GLC-TEA) method has been developed for the quantitation of N-nitrosodiethanolamine (NDELA) in a variety of cosmetic products. Samples are cleaned up by a preliminary shakeout of an aqueous mixture of the cosmetic with ethylene dichloride, followed by removal of other polar and nonpolar constituents from the aqueous layer with commercial extraction columns, separation cartridges, and selected solvents. Common transnitrosating 1,3-diol preservatives sometimes found in cosmetics were eliminated after conversion to less polar cyclic boronates. The isolated NDELA fraction was trimethylsilylated at room temperature and the product was subjected to GLC-TEA, with N, N’-dinitrosopiperazine (DNPiz) used as the internal standard. Recoveries of NDELA from spiked samples usually ranged from 60 to 90%. The limit of detectability was about 5-10 ppb. The identity of NDELA was confirmed by GLC-mass spectrometry.
Fish Species Identification by Thin Layer Agarose Isoelectric Focusing and Densitometric Scanning
Authors: Hamilton Warren D 
Published: February 2020

Abstract
Examination of sarcoplasmic proteins of fish by thin layer polyacrylamide gel isoelectric focusing as a means of fish species identification is a powerful and reliable technique, but it displays a number of disadvantages. These problems include the care required when handling acrylamide monomer (a neurotoxin), the mechanical skill needed in molding the gel, the difficulties in ensuring correct gel polymerization, and the extensive destaining periods. Specially treated agarose has been used to obtain protein patterns for an interval of pH 5-8. The patterns so produced were scanned by a densitometer in the visible range after completing staining and destaining. Most of the problems associated with polyacrylamide gels have been overcome by using agarose is a support medium.
Determination of Polysorbate 60 in Salad Dressings by Colorimetric and Thin Layer Chromatographic Techniques
Authors: Daniels Daniel H , Warner Charles R , Selim Sami 
Published: February 2020

Abstract
Methods are described for the quantitation and verification of polysorbate 60 (PS 60) in salad dressing. The sample is partitioned between methylene chloride and water. The methylene chloride extract is further treated by silica gel column chromatography. The isolated PS 60 is complexed with ammonium cobaltothiocyanate and determined spectrophotometrically at 620 nm. Additional evidence indicating the presence of PS 60 is obtained from thin layer chromatographic analysis using the modified Dragendorff reagent for visualization of spots.
Gas Chromatographic-Mass Spectrometric Analysis, Identification, and Detection of Adulteration of Natural and Concentrated Lemon Oils
Authors: Prager Manfred J , Miskiewicz Michael A 
Published: February 2020

Abstract
Lemon oils were characterized by quantitative glass capillary gas chromatography. Components present to the extent of more than 0.05% were measured and identified by mass spectrometry. In expressed lemon oils, monoterpenes and geranial were the only components present at concentrations of 1.0% or more. In concentrated lemon oils, β-caryophyllene, linalool, neral, β-terpineol, neryl acetate, and geranyl acetate were present in some samples in amounts of 1% or more. Adulteration was detected by component concentrations outside characteristic ranges for oils judged to be authentic.
Manual Headspace Gas-Solid Chromatographic Determination of Sub-Parts per Trillion Levels of Acrylonitrile in 3% Acetic Acid
Authors: McNeal Timothy , Breder Charles V 
Published: February 2020

Abstract
A procedure was developed for determining acrylonitrile (AN) in 3% acetic acid, the solvent used to simulate carbonated beverages. Manual headspace sampling, a detector output amplifier/filter, and vapor phase enhancement using an ionic material were combined to give a detection limit in the low parts per trillion range. AN standards were analyzed using the method, and the results are presented.
Simple Colorimetric Method for Determination of Organothiophosphate Insecticides in Technical Materials and Formulations
Authors: Sane Ramesh T , Kamat Sudhir S 
Published: February 2020

Abstract
A simple colorimetric method based on the reaction of benzophenone with thiophosphate is described. The method is specific for compounds containing the P═S moiety, gives recoveries of 99 ± 1%, and obeys Beer's law for the concentration range 35-350 μ/mL. Other sulfur-containing compounds such as sulfa drugs, thiobarbiturate, thiourea, carbon disulf ide, and dithiocarbamates do not interfere in the reaction. The method is useful in studying the shelf-life of formulations.
High Pressure Liquid Chromatographic Determination of Supplemental Methionine in Poultry Premix
Authors: Matešič Dubravka 
Published: February 2020

Abstract
Supplemental methionine was extracted from a feed sample with O.IM HCI and separated by reverse phase or ion-exchange high pressure liquid chromatography and isocratic elution with KH2PO4 buffer solution as the mobile phase. Methionine was detected at 205 nm. The most reliable results were obtained by using reverse phase chromatography, 0.05M KH2PO4 buffer at pH 2.6 as mobile phase, and tyrosine as internal standard.
Radioisotope Dilution Technique for Determination of Vitamin B12 in Foods
Authors: Casey Patrick J , Speckman Keevin R , Ebert Frank J , Hobbs William E 
Published: February 2020

Abstract
A radioisotope dilution (RID) method for the determination of vitamin B12 is presented. The method combines a standard extraction procedure (AOAC 43.108,12th ed.) with a commercially available RID assay kit. The method was evaluated on a wide range of fortified and unfortified food products. Recovery studies on both groups yielded average recoveries of 98.1 and 95.8%, respectively. Reproducibility data generated from replicate analyses on both groups gave a relative standard deviation of 6.9% for the fortified group and 9.2% for the unfortified group. For the samples studied, the mean vitamin B12 content determined by the RID method was 8.01 μg/100 g vs imean of 7.54 μg/100 g by the AOAC microbiological method; the correlation coefficient was r = 0.983.
Comparison of Rapid High Pressure Liquid Chromatographic and CB Methods for Determination of Aflatoxins in Corn and Peanuts
Authors: Devries Jonathan W , Chang Henry L 
Published: February 2020

Abstract
A method is described for the rapid determination of aflatoxins in corn and peanut samples by high pressure liquid chromatography. The method was compared with the current CB method (AOAC 26.026). For 7 samples of corn and 14 samples of peanut meal and peanut butter, the correlation between methods is 0.991, and no significant difference exists between methods, using the Student's t-test at 15.7% a-risk.
Density Meter Determination of Proof of Ethanol-Water Solutions: Collaborative Study
Authors: Strunk Duane H , Aicken John C , Hamman Jack W , Andreasen Arthur A ,   Collaborators:, Cherolis J , Daggs W D , Feeny F J , Hamman J W , Holmes R N , Jones J C , Mark F G , Martin G E , O'Bryan W C , Olson R E , Perrault A W , Rapp F L , Rehn B W , Timmel B M , Worden D 
Published: February 2020

Abstract
Density meter procedures and the official AOAC pycnometer method to measure proof of ethanol-water solutions in the 25-79° proof range were collaboratively studied. Measurement of proof by density meter is simpler, requires less time and smaller samples, and gives more reproducible results than the AOAC pycnometer method. Differences of —0.05 to +0.02° proof between averages of results reported for density meter and pycnometer are acceptable, considering that proof of finished alcohol products is reported to 0.1°. The density meter method has been adopted official first action.
Spectrophotometric Determination of Color Intensity of Whisky: Collaborative Study
Authors: Strunk Duane H , Timmel Bertha M , Hamman Jack W , Andreasen Arthur A 
Published: February 2020

Abstract
A method for measuring color intensity of whisky was developed to replace the present AOAC method, which has become obsolete. The new method was collaboratively studied by 20 persons. Color intensity of whisky was measured as absorbance by a spectrophotometer, using a 1 cm cell, a bandwidth ≤10 nm, and a wavelength of 525 nm. Water was used as reference. Collaborator results appear acceptable for whisky samples that vary in color intensity from 29 to 374 CIU (absorbance X 1000 = Color Intensity Units (CIU)). The maximum standard deviation and coefficient of variation were 5.8 CIU and 6.68%, respectively. The method has been adopted official first action.
Comparison of Azomethine H Microcolorimetric and AOAC Titrimetric Methods for Boron in Fertilizer: Collaborative Study
Authors: Melton James R ,   Collaborators:, Coggin D M , Erickson M , Hunter G B , Jones N , Kummer J A , Minyard J P , Pelletier M F , Price R N , Reynolds B L , Sensmeier R K , Smith J L , Sweeney R , Vickery R M , Wetherbee R T 
Published: February 2020

Abstract
Sixteen fertilizer samples were sent to 11 collaborating laboratories for boron determinations. Each sample was analyzed once by the azomethine H microcolorimetric method and once by the AOAC titrimetric method (2.114-2.116). There were no statistical differences in matched pairs by the 2 methods at the 98% confidence level even though quantities ranged from 0.01 to 15%. The azomethine H microcolorimetric method has been adopted official first action.
Gas-Liquid Chromatographic Determination of Pyrethrins and Piperonyl Butoxide: Collaborative Study
Authors: Meinen Vernon J , Kassera Dean C ,   Collaborators:, Anderson P , Audino J B , Bennett B R , Carlson D J , Chang W L , Conigliaro P J , Earls P , Garbrecht T P , Gentry G M , Guzman B , Hayes E H , Hodgins W E , Jorengby D , Korger P D , Launer J E , Martin R , Nielson P , Tannahill G O , Torma L , Vaught C , Vonnahme T 
Published: February 2020

Abstract
A gas-liquid chromatographic method is described for the quantitative determination of pyrethrins and piperonyl butoxide in various formulations. The samples are diluted in acetone and analyzed by gas chromatography, with a flame ionization detector and a column packed with OV-101 or OV-1 on Chromosorb W (HP). The method was collaboratively studied with technical piperonyl butoxide and 3 pyrethrin-piperonyl butoxide formulations. The coefficients of variation for piperonyl butoxide ranged from 1.36 to 3.41% for the 5 samples. For pyrethrins in 3 formulations, the coefficients of variation were 2.20, 4.73, and 2.22%. An examination of the t-values indicated little or no contribution to systematic error, with the exception of one formulation. The method has been adopted official first action.
Ceramic Fiber for Replacement of Asbestos as Filter Aid in Crude Fiber Determination: Collaborative Study
Authors: Holst David O ,   Collaborators:, Cashman C J , DeCann J , Komenda L , Lewis S , Psotka J J , Rigler J R , Salah D M , Smallidge R L , Tinsley G , Vick R 
Published: February 2020

Abstract
A commercially available ceramic fiber has been tested collaboratively for replacement of asbestos as a filter aid. Eleven laboratories participated, using 10 samples with crude fiber content from 1 to 40%, one sample high in starch, and 2 samples high in protein. The following data were obtained for asbestos and the proposed ceramic fiber, respectively, in AOAC method 7.061-7.065: sd = 0.52 and 0.62; sr = 0.22 and 0.28; sb = 0.47 and 0.55; average range be- tween independent analyses = 0.18 and 0.24% crude fiber; and average maximum spread among laboratories = 1.65 and 2.42% crude fiber. The blank value for ceramic fiber varied considerably among laboratories, necessitating more precise control over size or weight of ceramic filter pad. A ceramic filter pad or-material of 1.5-2.0 g dry weight will give a uniform blank of approximately 2 mg. Ceramic fiber is suit- able for replacing asbestos and is not known to be carcinogenic. Replacement of asbestos in 7.061-7.065 with ceramic fiber has been adopted official first action.
Screening Procedure for Uric Acid as Indicator of Infestation in Spices
Authors: Brown Susan M , Abbott Susan , Guarino Philip A 
Published: February 2020

Abstract
Uric acid levels in selected spice products were determined by using a glucose analyzer, modified and calibrated for uric acid. In the method, uricase is used to decompose the uric acid; the reaction is monitored with an oxygen-sensitive electrode. Uric acid levels correlated with infestation as determined by AOAC methods.
Time Required to Achieve Homogeneity in Swine Feed Mixtures
Authors: Ikeda George J , Miller Eugene , King Mark T , Perfetti Gracia A , Warner Charles R , Adamo Nicholas C , Sporn Eugene M 
Published: February 2020

Abstract
FD&C Red No. 3 was mixed with 20 kg pig feed to give a concentration of 0.1%. A mixing time of 30 min was sufficient to achieve homogeneity for this mixture. For larger amounts or more flocculent types of additives, a longer time may be required. Ammoniated glycyrrhizin was mixed with 8 separate batches of pig feed at a concentration of 1%; 1 h was sufficient mixing time.