bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cooperation, Collaboration, and Contracts Between Industry and University Analytical Facilities
Authors: Spittler Terry D 
Published: February 2020

Abstract
Ranging from service units to basic research facilities, analytical laboratories associated with universities have both unique capabilities and limitations. Method development and validation in cooperation with professional peers in government and industry is encouraged and straightforward to the extent that such efforts are within the laboratories' mandate(s). In certain situations, university laboratories are more flexible in their research objectives and are able to pursue interesting trails not specifically justified in project/profit schemes. University policies may, on the other hand, preclude specific areas of inquiry. Contract arrangements with universities can take several forms depending on the magnitude of intended support, the degree of confidence and confidentiality required, and the urgency of the project. Direct gifts, equipment grants, research contracts, consulting arrangements, competitive grants, memoranda of understanding, invoiced analyses, third party agreements—each of these has advantages and potential disadvantages for the participants. Universities represent tremendous pools of scientific talent and technical resources that may be enlisted for exploratory assaults on a problem before an industry makes inappropriate capital and organizational commitments
Gas Chromatographic/Mass Spectrometric Determination of Daminozide in High Protein Food Products
Authors: Conditt Margaret K , Baumgardner James R , Hellmann Lesle M 
Published: February 2020

Abstract
A gas chromatographic/mass spectrometric (GC/MS) method for determining daminozide in high protein products has been developed. Daminozide is hydrolyzed in the presence of a strong base to form unsymmetrical dimethylhydrazine (UDMH) which is then distilled from the food matrix. A stable derivative is formed by reacting UDMH with salicylaldehyde to form salicylaldehyde dimethylhydrazone. This derivative is separated and quantitated by GC/MS using selected ion monitoring (SIM) of key ions in the fragmentation pattern: m/z 164 (molecular ion of hydrazone) and m/z 120 (C7H6ON). An internal standard, 4-nitroanisole, is monitored at m/z 153 (molecular ion) and m/z 123 (C6H502N). The limit of detection is 0.01 ppm daminozide in a 50 g sample; however, because of variation at low levels, the limit of quantitation is 0.1 ppm. Recoveries are 90% or greater from peanuts and peanut butter spiked at the 0.1-2 ppm level. Reproducibility of the method depends on the food matrix and is 26% RSD in the worst case. Data are compared for the GC/MS method and the official EPA colorimetric procedure. Results showed a high bias in the colorimetric method, especially when roasted peanut products were analyzed.
Simple and Rapid Spectrophotometry Method for Determination of Adrenaline and Isoprenaline
Authors: El-Shabouri Salwa R , Hussein Samiha A , Abdel-Alim Abdel-Alim M 
Published: February 2020

Abstract
A simple, rapid, and specific method for determination of adrenaline bitartrate and isoprenaline sulfate was developed. The method is based on the oxidation reaction in aqueous solution of either adrenaline bitartrate or isoprenaline sulfate in the presence of silver oxide to give a red aminochrome measurable at 490 nm. The color is stable for 2 h. Beer's law is valid within a concentration range of 5-80 ng/ mL for each drug. All variables were studied to optimize the reaction conditions. The method is specific for catecholamine drugs having a secondary amine in the side chain. Other catecholamines such as orciprenaline and noradrenaline do not interfere, and no interference was observed in the presence of common pharmaceutical adjuvants. Interference due to sodium metabisulfite and sodium chloride was circumvented. The validity of the method was tested by analyzing adrenaline injections and isoprenaline tablets. Good recoveries were obtained for these preparations. The results were comparable to those obtained by official procedures. The proposed method is also recommended as a stability indicating assay for oxidative degradation of both drugs.
Ion-Pair Liquid Chromatographic Determination of Some Penicillins in Canine and Equine Sera
Authors: Tyczkowska Krystyna , Aronson Arthur L 
Published: February 2020

Abstract
A sensitive liquid chromatographic method was developed for determining oxacillin, cloxacillin, and dicloxacillin (simultaneously), and penicillin G, amoxicillin, carbenicillin, and ticarcillin in canine and/ or equine serum. The method involves filtering diluted serum through a 30 000 molecular weight cut-off filter and separating penicillins from other serum components by ion-pair liquid chromatography using a reverse-phase column eluted with acetonitrile-water solutions. The ultraviolet absorbance of the column effluent was monitored at 230 nm. Recoveries of oxacillin, cloxacillin, dicloxacillin, and penicillin G (spiked at 2.5 μg/mL), amoxicillin (spiked at 5 μg/ mL), and carbenicillin and ticarcillin (spiked at 10 μg/mL) from canine and equine serums ranged from 78.3 to 104.4% with coefficients of variation ranging from 3.35 to 5.95%. The limit of detection for these penicillins was 0.02-0.05 μg/mL
Liquid Chromatographic Separation and Fluorometric Determination of cw- and frans-Isoeugenol in Perfumes, Colognes, and Toilet Waters
Authors: Wisneski Harris H , Yates Ronald L , Wenninger John A 
Published: February 2020

Abstract
A liquid chromatographic (LC)-fluorometric method is described for the determination of cis- and frans-isoeugenol (2-methoxy-4-propenylphenol) in perfumes, colognes, and toilet waters. A test portion of the product is added to diethyl ether, and the isoeugenol isomers are extracted with sodium hydroxide solution. The basic extract is then acidified, and the isoeugenol isomers are extracted with isooctane. Aliquots of the isooctane extract are analyzed by using a silver ion cation exchange LC column interfaced to a spectrophotofluorometer. Each isomer in the product is determined by comparing its fluorescence emission intensity with that of an external standard consisting of a mixture of both isomers in which the relative concentration of each has been determined. Average recoveries from various commercial fragrances fortified with a mixture of cis- and trans-isoeugenol with total isoeugenol content of 0.1,0.5, and 4.0 mg/mL ranged from 87 to 105% for the taww-isomer (SD = 4.6%) and from 83 to 113% for the cw-isomer (SD = 6.7%). The limit of determination is approximately 0.002 mg/mL.
Evaluation of Amino Acid Analysis as Reference Method to Quantitate Highly Purified Proteins
Authors: Sittampalam G Sitta , Ellis Robert M , Miner David J , Rickard Eugene C , Clodfelter Dean K 
Published: February 2020

Abstract
The applicability of amino acid analysis for accurate quantitation of reference standard preparations of proteins has been evaluated. This approach is very useful since, in addition to absolute quantitative information, it also provides a measure of composition, partial identity, and purity in a single experiment. Comparisons with Kjeldahl nitrogen assay and/or UV measurements shows that amino acid analysis is reliable for the quantitation of small-to-medium size proteins in the molecular weight range of 6-22 kDa. For larger proteins such as immunoglobulins (150 kDa), amino acid analysis may "underestimate" the total protein concentration. These results also show the effect of recovery of individual residues on protein quantitation. As expected, the recovery of more than one stable residue could be used to calculate total protein content of samples, which is in good agreement with the results obtained by Kjeldahl nitrogen assay. However, the protein concentrations calculated from the total mass of the recovered residues appear to give relatively low estimates in almost all cases. Thus, it is concluded that amino acid analysis is an appropriate reference method only when stable residues are employed for quantitation, particularly for highly purified proteins of rDNA origin
Determination of Tartaric Acid and the Sum of Malic and Citric Acids in Grape Juices by
Potentiometric Titration
Authors: Godinho Oswaldo E S , Desouza Nilson E , Aleixo Luiz M , Ivaska Ari U 
Published: February 2020

Abstract
Application of a linear algebraic method to the potentiometric titration of a mixture of tartaric and malic acids makes it possible to determine the individual concentrations of both acids in the same sample. These 2 acids have also been determined in grape juice free of citric acid after their separation from the juice matrix by precipitation as barium salts, followed by selective solubilization. It is also possible to determine tartaric acid and the sum of malic acid and citric acid in grape juice when the latter is present.
Liquid Chromatographic Determination of Morphine Sulfate and Some Contaminants in
Injections and Bulk Drug Material: Collaborative Study
Authors: Bello Ada C , Jhangiani Rita K 
Published: February 2020

Abstract
A liquid chromatographic method for the assay of morphine sulfate and some preservatives and impurities in the bulk drug and in injections has been developed and collaboratively studied in 8 laboratories. Each collaborator analyzed 5 samples: 1 bulk drug, 3 different concentrations of injectable dosages, and 1 prepared mixture containing, in addition to morphine sulfate, phenol, 2-mercaptobenzothiazole, and pseudomorphine. The proposed method quantitates morphine sulfate and resolves the other components for identification using a Clg reverse-phase column with a mobile solvent containing 240 mL methanol, 720 mL 0.005M 1-heptanesulfonic acid Na salt, and 10 mL acetic acid. Samples are prepared by direct dilution with mobile solvent minus 1-heptanesulfonic acid. All collaborators met system suitability requirements and performed the analysis without difficulty. No outliers were found when data were analyzed by the Dixon, Grubbs, double Grubbs, and Cochran tests. Relative standard deviations between laboratories (RSDR) for duplicate determinations of morphine sulfate ranged from 1.4 to 2.1%. Mean morphine sulfate recoveries for the bulk drug and the prepared mixture were 100.8 and 100.4%, respectively. The method has been approved interim official first action.
Gas Chromatographic Determination with Electron Capture Detection of Residual Ethylene
Oxide in Intraocular Lenses
Authors: Kikuchi Hiroshi , Nakamura Akitada , Tsuji Kusuo 
Published: February 2020

Abstract
A sensitive method is described to determine trace quantities of ethylene oxide (EO) in EO-sterilized intraocular lenses (IOLs). An IOL is dipped in ethanol containing 0.25 ppm propylene oxide (PO) in a 4 mL vial, 2 drops of freshly distilled hydrobromic acid is added through a septum, and the mixture is warmed at 50°C for 24 h. It is then neutralized by vigorous shaking with sodium bicarbonate, dehydrated with anhydrous sodium sulfate, and filtered. The filtrate is injected into a gas chromatograph with electron-capture detection, and the peak height ratio of ethylene bromohydrin/propylene bromohydrin is measured. EO residue is calculated from the calibration curve obtained through a similar procedure with the standard EO/ PO solutions. The limit of determination is 0.04 fig/lens (ca 2.0 ppm). When EO residue levels were determined for IOLs sampled at 3 different aeration periods after sterilization, we found that 9 days of aeration was necessary to meet the U.S. Food and Drug Administration proposed limit for EO residue in IOLs.
Effect of Volume of Solution per Cylinder on Estimation of Antibiotic Potency in Diffusion
Assay
Authors: Ragheb Hussein S 
Published: February 2020

Abstract
The volume of antibiotic solutions in cylinders used for diffusion assays is assumed to have no significant effect on estimation of potency. The size of zones of inhibition from cylinders containing 0.10, 0.20, and 0.30 mL of sample solution was compared with zones of inhibition from cylinders containing 0.20 mL of standard solutions. For zinc bacitracin, chlortetracycline-HCl, oxytetracycline, lincomycin- HCl, monensin Na, neomycin sulfate, K penicillin, streptomycin sulfate, and tylosin, the percent recovery (95-102) was optimum when both standard and sample cylinders contained the same volume (0.20 mL/cylinder). At 0.30 mL/cylinder for sample and 0.20 mL for standard solutions, there was a positive bias in potency of about 50%. At 0.10 mL/cylinder, there was a negative bias of approximately 25% except for neomycin, monensin, and bacitracin. For these antibiotics, the bias was about -50%. For hygromycin B, variation in volume of solution per cylinder has little effect on assay results. Experiments on commercial feeds and premixes gave essentially the same results as for the standard solutions experiments.
Validation Study of Gas Chromatographic Determination of Pentachlorophenol in Animal Liver
Authors: Gillard Douglas , Epstein Robert L , Ashworth Raymond B , Curry Kevin , Nathan Quincy 
Published: February 2020

Abstract
A validation study was conducted of a gas chromatographic procedure for the determination of pentachlorophenol (PCP) in chicken, pork, and beef liver. Five analysts representing 5 laboratories analyzed randomly numbered blind duplicates at 3 fortified tissue concentrations and one incurred tissue on 2 consecutive days. The PCP concentrations ranged from approximately 40 to 400 parts per billion (ppb). All data were reported to 3 significant figures in ppb. The coefficients of variation for repeatability were between 2.8 and 8.5%, except for the beef liver, at a mean value of 80 ppb PCP, where the CV was 11.3%. The CVs for reproducibility were in the range of 9.7- 16.5% with little significant difference by species. The CV asymptotically approached 10% as the PCP level increased.
Enzyme-Linked Immunosorbent Assay for Deoxynivalenol in Corn and Wheat
Authors: XU Yi-Chun , Zhang Guang S , Chu Fun S 
Published: February 2020

Abstract
The availability of antibody against deoxynivalenol (DON) triacetate (Tri-Ac-DON) has enabled development of a direct enzyme-linked immunosorbent assay (ELISA) and an indirect ELISA for DON in corn and wheat. In both assays, DON is extracted from the sample with acetonitrile- water, reacted with acetic anhydride to form Tri- Ac-DON, and diluted in phosphate buffer for analysis. Direct ELISA was found to be the more sensitive procedure. Fewer interferences are evidenced, and the assay is less time consuming than is indirect ELISA. For direct ELISA, recovery of 10-1000 ppb DON added to corn and wheat was 100% (SD 15, CV 15%) and 102.1% (SD 12.2, CV 11.9%), respectively. For indirect ELISA, overall recovery of 10- 1000 ppb DON added to wheat was 121.5% (SD 39.5, CV 32.5%); in the higher concentration range (500-1000 ppb), recovery was 105% (SD 18, CV 17%). The minimal detection level for DON was around 10 ppb. Analysis of 7 naturally contaminated samples for DON showed that the ELISA results agreed well with those obtained by radioimmunoassay and thin-layer chromatography.
Determination of Ochratoxin A by Monoclonal Antibody-Based Enzyme Immunoassay
Authors: Candlish Alan A G , Stimson William H , Smith John E 
Published: February 2020

Abstract
A simple and rapid indirect enzyme-linked immunosorbent assay was developed for the quantitative determination of ochratoxin A in barley after the successful production of a high affinity, specific monoclonal antibody. A rapid sample cleanup was achieved by extracting ochratoxin A from barley with chloroform and partitioning the toxin into bicarbonate buffer; the buffer solution was then added directly to the assay plate and ochratoxin A content was assessed. Recoveries were greater than 85% and detection limits were 5 μg ochratoxin A/ kg barley.
Location Dependent Biases in Automatic 96-Well Microplate Readers
Authors: Harrison Robert O , Hammock Bruce D 
Published: February 2020

Abstract
Procedures performed in 96-well microplates and quantitated by automatic readers assume instruments to be precise, accurate, and free of well location dependent bias. Instrument specifications generally focus on precision and accuracy without specifically addressing biases which are dependent on well location. These biases appear to be meniscus dependent and can be demonstrated in varying degrees in automatic readers of many designs by using a reverse plate wet test, which compares repeated readings of a dye loaded plate in normal and reversed positions. This test analyzes differences between readings and is, therefore, independent of pipetting error or other experimental variables such as protein binding or immunoassay variability. Different plates increased or decreased the magnitude of observed errors but did not themselves cause the errors measured by the reverse plate wet test. Error patterns were consistent for each reader and varied widely among the 16 instruments tested. Only 4 of 16 instruments passed an existing manufacturer's specification for precision, and only one of the 16 readers tested passed a similar specification for accuracy. The severest location dependent bias was found in an instrument which exhibited excellent repeatability and consistently passed its built-in diagnostic tests. One reader with significant bias was returned to the manufacturer for routine service and calibration, but it was not demonstrably improved. The reverse plate wet test is an extremely useful diagnostic tool for quality control at all stages of instrument manufacture and use.
Determination of Trace Volatile Organic Compounds in Fish Tissues by Gas Chromatography
Authors: J Murray Derek A , Lockhart W Lyle 
Published: February 2020

Abstract
Several volatile organic compounds associated with petroleum fuels (mainly alkylated benzenes) were extracted from spiked fish tissue samples with a stream of air, trapped on charcoal, eluted with a solvent, and analyzed by gas chromatography. These volatile compounds are among the most water-soluble components of crude oils and petroleum products, and they have been associated with tainting in fish tissues. Recoveries for these compounds were about 90% when spiked directly either onto traps or into fish tissues although naphthalene desorbed poorly from the charcoal; recoveries of this compound were about 50%. Relative standard deviations (RSD) for most recoveries of spiked samples were in the 2-10% range based on 6 samples analyzed in duplicate. However, when live fish were contaminated experimentally by adding the aromatic compounds to the aquarium water, the RSDs were higher (10-30%)
Spectrophotometric Determination of Isocarboxazid Bulk Drug and Tablets by Reaction
with/7-Dimethylaminocinnamaldehyde
Authors: El-Kommos Michael E 
Published: February 2020

Abstract
A Spectrophotometric Method Is Described For The Determination Of Isocarboxazid. The Method Is Based On The Reaction Of The Drug With p-Dimethylaminocinnamaldehyde In The Presence Of Trichloroacetic Acid In A Methanolic Medium To Produce A Very Intense Red Chromophore (ℷmax = 500 Nm, Emax= 1.05 X 105). The Reaction Is Proposed To Proceed Via Electrophilic Attack At The C-4 Position Of The Isoxazole Nucleus. Job's Plot Indicated A 1:1 Drug-To-Reagent Ratio. Regression Analysis Of Beer's Plot Showed Excellent Correlation (R = 0.9996) In The Concentration Range 0.25-2.10 Fig Isocarboxazid/Ml. The Developed Color Is Stable For At Least 12 H. Results Of Analyses Of Bulk Drug And Tablets By The Proposed Method Are Comparable To Those For Usp Xxi Methods.
Gas Chromatographic Assay of Supplemental Vitamin E Acetate Concentrates:
Collaborative Study
Authors: Labadie Michael P , Boufford Charles E 
Published: February 2020

Abstract
A gas chromatographic (GC) method for determination of supplemental a-tocopheryl acetate in high potency vitamin £ powders and oils was collaboratively studied as an alternative to the AOAC colorimetric method (43.147-43.151, Emmerie-Engel), which requires saponification, extraction of the saponifiable fraction, and quantitation by colorimetry. The simpler GC procedure requires only extraction and/or enzymatic digestion and dilution before quantitation. Six blind duplicates were distributed to 10 laboratories; all 10 returned results. Repeatability (sr) and reproducibility (sR), % vitamin E/g, for the feed oil concentrates was 1.1 and 1.3, respectively; for the feed adsorbates 1.0 and 1.5; and for the spray-formulated powders 1.4 and 1.3. These results compare favorably with results obtained in a comparison study of the GC and Emmerie-Engel methods conducted by BASF in 1985. The method has been approved interim official first action for determination of a-tocopheryl acetate in vitamin E acetate concentrates as an alternative for those products only to AOAC colorimetric method 43.147-43.151
Survey of Aflatoxins, Ochratoxin A, Zearalenone, and Sterigmatocystin in Some Brazilian Foods by Using Multi-toxin Thin-Layer Chromatographic Method
Authors: Soares Lucia M Valente , Rodriguez-Amaya Delia B 
Published: February 2020

Abstract
A previously published method for ochratoxin A was evaluated and proved appropriate for simultaneous determination of aflatoxins, ochratoxin A, sterigmatocystin, and zearalenone, with considerable savings in time and reagent costs. The detection limits were 2, 5,15, and 55 μg/kg, respectively. The recoveries and coefficients of variation obtained with artificially contaminated samples were 91-101% and 0-16% for aflatoxin B1, 98-117% and 0-17% for sterigmatocystin, and 96-107% and 0-17% for zearalenone, respectively. The coefficients of variation for naturally contaminated samples (aflatoxins in rice and ochratoxin A in beans) ranged from 0 to 8%. The method was used to survey 296 samples that included 10 cultivars of dried beans, 8 types of corn products, 3 types of cassava flour, and both polished and parboiled rice between May 1985 and June 1986 in Campinas, Brazil. Only aflatoxin B, (9 samples, 20-52 μg/kg), aflatoxin G, (4 samples, 18-31 μg/kg), and ochratoxin A (5 samples, 32-160 μg/kg) were found. The average contamination percentage was 4.7%; beans showed the highest (6.6%) and rice showed the lowest (3.3%) incidence rates. Zearalenone and sterigmatocystin were not detected. Positive samples were confirmed by chemical derivatization, corroborated by development in 3 solvent systems.
Methods of Analysis for Toxic Elements in Food Products. 1. Mineralization Methods to Determine Heavy Metals and Arsenic According to the USSR Standard
Authors: Skurikhin Igor M 
Published: February 2020

Abstract
Results of the work of 22 laboratories in the USSR on optimizing methods for mineralizing foods to determine Pb, Cd, As, Zn, Cu, Sn, and Fe are summarized. Recommendations are given on dry and wet mineralization as related to the analyte and the kind of food product. Optimum amounts of test portions for 22 food groups are also recommended according to the element of interest.
Survey of Lead in Canned Evaporated Milk
Authors: Capar Stephen G , Rigsby Eddie J 
Published: February 2020

Abstract
A Food and Drug Administration survey of lead in canned evaporated milk conducted in fiscal year 1985/86 found a mean level of 0.006 μg Pb/g. This level is much lower than that found in previous surveys and is attributed to the use of nonlead-soldered cans for packaging evaporated milk.
Ion Chromatographic Determination of Lactose, Galactose, and Dextrose in Grated Cheese Using Pulsed Amperometric Detection
Authors: Pollman Roger M 
Published: February 2020

Abstract
A method is presented to determine lactose, galactose, and dextrose in grated cheese using ion chromatography with pulsed amperometric detection (IC/PAD). The method is specific, sensitive, rapid, and precise. Sugar levels as low as 0.01% are detectable, and recoveries ranged from 114% at the 0.1% level to 93.3% at the 2.0% level. The precision expressed as coefficient of variation (CV) was 2.3% for lactose, 2.1% for galactose, and 3.1% for dextrose. Lactose, galactose, and dextrose levels are given for 45 authentic hard cheeses and 26 authentic soft cheeses.