bluuebunny/crossref_metadata_2025_split huggingface dataset:
Confirmation of Leucogentian Violet in Chicken Fat by Gas Chromatography/Mass Spectrometry
Authors: Wilson Roger T , Wong John , Johnston John , Epstein Robert , Heller David N 
Published: February 2020

Abstract
A gas chromatographic/mass spectrometry (GC/MS) procedure for confirming the identity of leucogentian violet (LGV) in chicken fat was developed for regulatory application. The unused portion of the extract remaining from a determinative procedure was back-extracted into an organic phase, concentrated, and analyzed by GC/MS. Confirmation of the identity of LGV was based on matching the retention times and relative abundances of 6 ions in the extract to corresponding values obtained for the LGV standard. The procedure was validated by replicate analyses of negative control, fortified control, and residue-incurred chicken fat. The presence of LGV was confirmed by the GC/MS procedure in all samples found to contain LGV by prior liquid chromatographic analyses. There were no interferences in the control samples.
Chemical Test for Mammalian Feces in Ground Black Pepper: Collaborative Study
Authors: Gerber Harriet R 
Published: February 2020

Abstract
A collaborative study for determining mammalian feces in ground black pepper was conducted, using a modified version of the AOAC Of ficial Method 986.28 for mammalian feces in grain products. With the proposed method, the presence of alkaline phosphatase, an enzyme found in mammalian feces, was determined by using phenolphthalein diphosphate as the enzyme substrate in a test agar medium containing 1% agar in a borate buffer, pH 9.5. Ground black pepper was stirred in water to extract interfering color. The mixture was filtered and the residue was scattered on plates of liquid test agar. The alkaline phosphatase cleaved phosphate radicals from phenolphthalein diphosphate, generating free phenolphthalein, which appeared as pink to red-purple around the fecal particles in the previously colorless medium. For the 10- and 20-particle spike level, collaborators recovered averages of 12.3 and 24.1 particles, respectively. The experimental background was zero. Collaborators reported that the method was clear and easy to perform.
Effects of Incubation Atmosphere, Novobiocin, and Modified Plating Media on the Efficiency of a DNA Probe for Recovering Shigella flexneri
Authors: Satchell Felicia B , Bruce Verneal R , Andrews Wallace H , June Geralddse , Sherrod Patricia S , Hammack Thomas S , Feng Peter 
Published: February 2020

Abstract
An oligonucleotide probe specific for the invasion plasmid of Shigella spp. was used to study the effect of several culture method variables described in the Bacteriological Analytical Manual for retention of the plasmid in Shigella flexneri. Results of colony hybridization analyses showed that, in many instances, a slightly greater number of Shigella were detected by the DNA probe on MacConkey agar than on trypticase soy agar. Elevating the incubation temperature from 35° to 42°C slightly reduced the number of Shigella detectable by the probe. However, neither aerobic nor anaerobic incubation atmosphere or the inclusion of novobiocin in the media showed any consistent effect on the recovery of S. flexneri by the probe. Moreover, the detection efficiency of the probe was not generally affected by the different MacConkey agar formulations tested.
Reversed-Phase Liquid Chromatographic Determination of Hypoglycin A (HG-A) in Canned Ackee Fruit Samples
Authors: Sarwar Ghulam , Botting Herbert G 
Published: February 2020

Abstract
A reversed-phase liquid chromatographic (LC) method involving precolumn derivatization with phenylisothiocyanate (PITC) was developed for determining levels of hypoglycin A (HG-A) in canned ackee fruit samples. HG-A was extracted by homogenizing the drained fruit in 80% ethanol. By using a Waters Pico-Tag amino acid analysis 15-cm-long column (which is also used for analyzing protein hydrolysates and biological samples) and an LC system, the baseline separation of HG-A from other amino acids was completed in about 6 min. The total time for analysis and equilibration was 16 min. HG-A levels in the edible portion of fruit in 18 cans varied from 18.27 to 87.50 mg HG-A/can. Recoveries of added standard HG-A averaged 101%. To our knowledge, this is the first report of the use of this method to determine HG-A in ackee fruit.
Comparison and Assessment of the Difference in Total Dietary Fiber in Cooked Dried Legumes as Determined by Five Methods
Authors: Mongeau Roger , Brassard René 
Published: February 2020

Abstract
Dried beans (kidney and great northern) and dried peas (chick, green, and yellow) were cooked according to package instructions. Total dietary fiber (TDF) was measured by the Mongeau (AOAC 992.16), Prosky (AOAC 985.29), and Lee (AOAC 991.43) methods (A, B, and C, respectively). Non-starch polysaccharides (NSP) were measured by the Englyst gas-chromatographic method that included dimethyl sulfoxide treatment, and the lignin measured separately was added to NSP (method D). TDF was also measured by the Li method (E). TDF values ranged from 7 to 48 g/100 g dry weight. Methods B and C gave similar TDF values, which were higher than those from other methods. For kidney beans I, TDF values by methods B and C were up to 2.5 times higher because of the inclusion of starch. The fiber residues from methods A and C contained the same amounts of arabinose, xylose, mannose, galactose, and uronic acid, but glucose was 4 times higher in residue C than in residue A. When α-amylase from porcine pancreas was incorporated in methods B or C for 5 samples, the discrepancies among methods A, B, and C were reduced by 60-98%.
Determination of Sulfite in Rainwater by Solid-Phase Spectrophotometry
Authors: Bosque-Sendra Juan M , Molina Francisca , Nechar Mounir 
Published: February 2020

Abstract
A simple and specific method was developed for the determination of sulfite in rainwater based on solid-phase spectrophotometry (SPS). Rainwater was collected on morpholine, sulfite was stabilized by forming an adduct that reacted with pararosanil-ine and formaldehyde, and the reaction product was fixed on Dowex 1-X8 resin. The absorbance of the solid phase was measured directly at 565 and 700 nm. The calibration curve was linear in the concentration range of 1-50 μg/L in solution (relative standard deviation = 1.7%); the International Union of Pure and Applied Chemistry detection limit was 0.8 μg/L. In simulated rainwater, the values of the calibration curve slopes were similar to that of the standard calibration curve slope, and recoveries for 40-497 μg/L sulfite ranged from 97 to 105%. Linearity, analytical sensitivity, and precision were better for the SPS method than the solution method, and the detection and quantitation limit values were lower for the SPS method than the solution method based on the similar reaction. The SPS method was subsequently used to determine sulfite in real rainwater.
Determination of Levels of Lead Contamination in Food and Feed Crops
Authors: Cabrera Carmen , Gallego Carmen , Lopez Maria C , Lorenzo Maria L , Lillo Enrique 
Published: February 2020

Abstract
A rapid, precise procedure is described for the determination of lead in food and feed products with electrothermal atomic absorption spectrophotometry. Samples were mineralized in a microwave acid digestion bomb in the presence of nitric acid and vanadium pentoxide. Lead concentrations were determined directly from digested samples. The detection limit was 0.04 ng/mL. Accuracy and precision were checked against National Institute of Standards and Technology standard reference material. The analytical method was tested with 51 food and feed crops from Mediterranean zones in Spain and found to be suitable for these products. Lead concentrations in samples ranged from not detectable to 2.695 μg/g (fresh weight).
Analysis of Calcium and Lead in Calcium Supplements by Inductively Coupled Plasma-Atomic Emission Spectrometry and Graphite Furnace Atomic Absorption Spectrophotometry
Authors: Shtonen Paul H , Thompson Harold C 
Published: February 2020

Abstract
A method was developed to analyze various calcium supplements for Ca and Pb content. The analysis involves a dry ash of the supplements followed by wet digestion. The Pb is determined by graphite furnace atomic absorption spectro–photometry (GFAAS). Analysis of Ca is by inductively coupled plasma–atomic emission spectrometry (ICP–AES). Ca supplements fortified with Pb at levels ranging from 0.25 to 10.0 μg/g yielded recoveries ranging from 82.7 ± 4.2 to 105.0 ± 1.7%. To test accuracy, the method was applied to National Institute of Standards and Technology standard reference materials (NIST SRMs) 1572 citrus leaves and 1486 bone meal. GFAAS analysis of SRM 1572 averaged 13.1 ± 0.6 μg Pb per g (certificate value, 13.3 ± 2.4 (μg Pb per g), and analysis of SRM 1486 averaged 1.34 ± 0.11 μg Pb per g (certificate value, 1.335 ± 0.014 μg Pb per g). ICP–AES analysis of SRM 1572 averaged 3.12 ± 0.01% Ca (certificate value, 3.15 ± 0.10% Ca by weight), and analysis of SRM 1486 averaged 27.63 ± 0.27% Ca (certificate value, 26.58 ± 0.24% Ca). The method's limit of quantitation (LOQ), on supplement Ca basis and a 1 g sample, averaged 0.75 μg Pb per 1 g Ca for supplements containing 9 to 35% Ca by weight. At a Pb level of 0.663 μg/g Ca, the reproducibility relative standard deviation (RSDr) averaged 7.3% and the repeatability relative standard deviation (RSDr) averaged 8.0%. It is recommended that the method be studied collaboratively.
Identification of Synthetic Colors in Beverage Alcohol Products by Solid-Phase Extraction and Thin-Layer Chromatography
Authors: Dugar Sumer M , Leibowitz Jeffrey N , Dyer Randolph H 
Published: February 2020

Abstract
A solid-phase extraction (SPE) sample cleanup and enrichment procedure coupled with thin-layer chromatography (TLC) is described for the enrichment of synthetic colors in all types of beverage alcohol products. SPE followed by TLC provides the identification of synthetic colors at sub-part-per-million levels. TWo complementary solvent systems afford detection of all the permitted (and some prohibited) synthetic colors in beverage alcohol products. This method is simple, offers consistency, and has no artifacts in TLC.
Determination of Ardacin in Premix, Supplement, and Animal Feed by a Rapid and Sensitive Two-Peak Liquid Chromatographic Method with Correlation to a Gradient Multipeak Liquid Chromatographic Method
Authors: Abdel-Kader Hafez , Fagan Sylvia V , Menon Govtnd K , Wigman Larry S , Chapin Frederic 
Published: February 2020

Abstract
A rapid and sensitive 2-peak liquid chromatographic (LC) method is described for extracting and quantitating ardacin in premix, supplement, and animal feed formulations. Ardacin is extracted from the formulations and analyzed after dilution or cleanup by reversed-phase LC with UV detection at 220 nm. The method correlates well with a more information-rich gradient multipeak LC method. Recoveries for premix formulations ranged from 96.8% (relative standard deviation [RSD], 0.8%) to 103.7% (RSD, 1.3%) for laboratory samples spiked at levels ranging from 1.6 to 39.6% ardacin. Recoveries for protein supplement mash formulations ranged from 98.7% of claim (RSD, 4.1%) to 106.0% of claim (RSD, 7.7%) at ardacin levels ranging from 37.5 to 600 mg/lb. Recoveries for cattle feed ranged from 90.0% of claim (RSD, 11.9%) to 105.6% of claim (RSD, 2.7%) at ardacin levels ranging from 4 to 30 g/ton.
Validation Study of Assay for Neomycin in Feed
Authors: Stahl Gerald L , Gilbertson Terry J , Kratzer D Dal , Blondia James J , Stoline Michael R 
Published: February 2020

Abstract
The neomycin microbiological cylinder plate assay using an ionic extraction method was validated for 2 swine feeds with neomycin base concentrations of 140.0 and 280.0 g/ton, 2 cattle feeds with neomycin base concentrations of 140.0 and 280.0 g/ton, and 2 premixes with neomycin base concentrations of 1.4 and 7.0 g/lb. The accuracy, precision, and reproducibility were evaluated by assaying the 6 feed samples in duplicate on 6 different days by an Upjohn laboratory (Laboratory 1) and 2 outside laboratories (Laboratories 2 and 3) for a total of 72 data points per laboratory. Three plates were used for each sample assayed. The recovery over all complete (type C) feed samples and (type B) premixes tested, ranged from 82 to 109% for Laboratory 1,85 to 114% for Laboratory 2, and 78 to 134% for Laboratory 3. Mean percent recoveries for all samples tested were 98.0,98.9, and 103.7% for Laboratories 1,2, and 3, respectively. Day-to-day performance yielded 95% confidence limits of ±11.9, ±16.9, and ±25% for Laboratories 1,2, and 3, respectively. Of 215 assay values, 206 (96%) fell within 20% of the actual targeted recovery (100%). Plate-to-plate variation of each of the 3 laboratories also was assessed. Statistical estimates for the use of 1,5, and an infinite number of plates showed that when 2 plates were used by Laboratories 1,2, and 3, than 99,99, and 95%, respectively, of the assay results fell within the acceptable assay compliance limits (70–125% recovery) for complete feeds and premixes. Slight improvement was found only for Laboratory 3, when more than 2 plates were used.
Identification and Quantitation of Corticosteroids and Their Esters in Pharmaceutical Preparations of Creams and Ointments by Thin-Layer Chromatography and Densitometry
Authors: Datta Kajal , Das Saroj K 
Published: February 2020

Abstract
A rapid, simple, and specific thin-layer chromatographic (TLC) method is described for estimation of various corticosteroids and their esters when present in combination with other drugs in pharmaceutical preparation of creams and ointments. The cream or ointment is dissolved in chloroform; water and insoluble material, if any, are removed by centrifugation, and the steroid is separated from other ingredients by TLC on silica gel G with n-hexane as the first developing solvent (to wash out cream or ointment base) and chloroform–ethyl acetate (1 + 1 , v/v, for free steroids or 2 + 1 , v/v, for steroid esters) as the second developing solvent. The separated steroid or ester is visualized under shortwave UV (254 nm) and estimated by spectrodensitometry at 240 nm. Recoveries of the steroids are between 98.0 and 101.7%. Results were compared with those obtained by official methods, where applicable, and excellent agreement was found.
Simultaneous Determination of Ibuprofen and Acetaminophen in Pharmaceutical Preparations by Proton Magnetic Resonance Spectroscopy
Authors: Husain Sajid , Kifayatullah M , Sekhar R 
Published: February 2020

Abstract
A simple, rapid, and specific method for simultaneous determination of ibuprofen and acetaminophen in pharmaceutical preparations by 1H Fourier transform nuclear magnetic resonance spectroscopy was developed using methyl and aromatic proton signal areas against ferf-butyl alcohol as internal standard. Average recoveries of ibuprofen and acetaminophen were 99.2 and 98.6%, with standard deviations of ± 0.76 and ± 0.81, respectively. The results were compared with those obtained using the procedure recommended by the British Pharmacopoeia and were in close agreement.
Determination of Leucogentian Violet in Chicken Fat by Liquid Chromatography with Electrochemical and Ultraviolet Detection: Interlaboratory Study
Authors: Schermerhorn Patricia G , Munns Robert K 
Published: February 2020

Abstract
A laboratory trial was completed for a liquid chromatographic method that can quantitate leucogentian violet (LGV) in chicken fat at 10 ppb. With this method, LGV is isolated from the fat matrix by a series of liquid–liquid extractions. This trial evaluated 2 detection systems: electrochemical (EC) and ultraviolet (UV). The participating laboratories determined incurred residues at 2 levels as well as fat samples fortified at 5,10, and 20 ppb. Using UV detection, the 3 laboratories reported the following range of recoveries: 71.0–89.6% at 5 ppb, 74.7–83.9% at 10 ppb, and 77.2–79.0% at 20 ppb. When these same samples were chromatographed with EC detection, the 2 reporting laboratories obtained the following average recoveries: 79.0 and 92.5% at 5 ppb, 75.9 and 85.4% at 10 ppb, and 77.3 and 79.8% at 20 ppb. The average concentrations found for the first level of incurred sample were 6.3,6.3, and 5.4 ppb with coefficients of variation (CVs) of 2.4,7.6, and 33.7%, respectively, when UV detection was used. Samples chromatographed with EC detection averaged 6.3 and 6.4 ppb with CVs of 4.0 and 8.2%, respectively. The second level of incurred sample gave average concentrations of 27.6,29.0, and 10.9 ppb with CVs of 11.0,5.0, and 42.8%, respectively, when the UV detection system was used. With the EC detector, the concentrations averaged 27.2 and 30.7 ppb with CVs of 15.7 and 3.5%, respectively.
Extraction and Liquid Chromatographic Analysis of Sulfadimethoxine and 4-N-Acetylsulfadimethoxine Residues in Channel Catfish (Ictalurus punctatus) Muscle and Plasma
Authors: Walker Calvin C , Barker Steven A 
Published: February 2020

Abstract
A simple and rapid method was developed for the simultaneous extraction and liquid chromatographic (LC) determination of sulfadimethoxine (SDM) and 4-N-acetylsulfadimethoxine (N-acetyl SDM) in channel catfish muscle and plasma. Tissues fortified at 0, 50,100,200,400, and 1000 ppb were examined. Matrix solid phase dispersion (MSPD) was used for muscle extraction. Plasma was extracted with a modified MSPD procedure in which 100 μL plasma and 400 mg C18 were blended by Vortex mixing in a disposable chromatographic column. Recovery of SDM based on radioactivity was 79% for muscle and 67% for plasma. Standard curves based on extracted fortified samples were used for quantitation of /V-acetyl SDM. LC run times of 12 min were obtained using a microbore analytical column and an isocratic mobile phase of aqueous 0.017M phosphoric acid–acetonitrile at ratios of 71:29 for muscle and 73:27 for plasma extracts. Method detection limits were 26 ng SDM and 26 ng N-acetyl SDM/g muscle, and 33 ng SDM and 11 ng N-acetyl SDM/mL plasma. Intra-assay variation was &lt;10% for both compounds at all concentrations examined. Inter-assay variation for SDM was 13% for muscle and 14% for plasma, and for N-acetyl SDM was 11% for muscle and 10% for plasma.
Determination of Total Phosphorus in Foods by Colorimetric Measurement of Phosphorus as Molybdenum Blue after Dry-Ashing: NMKL1 Interlaboratory Study
Authors: Pulliainen T Katrdna , Wallin Harriet C 
Published: February 2020

Abstract
A spectrophotometric method in which the sample is dry-ashed in the presence of zinc oxide, and total phosphorus content is measured colorimetrically as molybdenum blue was evaluated by 12 participating laboratories from the Nordic countries. The study included potato flour, sausage, cold ham, infant formula powder, cheese, and skimmed milk powder. The materials were presented to the participants as 12 randomly coded samples of 2 blind duplicates of each material. The phosphorus content of the materials varied between 0.076 and 0.96 g/100 g. The relative standard deviation for repeatability of the method varied from 1.1% for 0.96 g phosphorus/100 g to 5.4% for 0.29 g phosphorus/100 g. The relative standard deviation for reproducibility varied from 3.6% for 0.96 g phosphorus/100 g to 7.7% for 0.23 g phosphorus/100 g.
Full Scan Confirmation of Tetrahydrophthalimide in Whole Milk Using Gas Chromatography/Ion Trap Mass Spectrometry
Authors: Chichila Tina M P , Erney D Ronald 
Published: February 2020

Abstract
The determination of tetrahydrophthalimide (THPI) in whole milk extracts by gas chromatography/ion trap mass spectrometry (GC/ITMS) in the full-scan, electron impact (El) mode is presented. THPI is first isolated from whole milk by a procedure including protein precipitation, liquid–liquid partitioning, and 2 solid-phase extraction (SPE) cleanup steps. GC/ITMS in the El mode is used for the determinative step. The average recovery of THPI at fortification levels ranging from 5 to 54 ppb was 85.6% (n = 16, coefficient of variation = 9.13%). Full-scan mass spectral confirmation of THPI in milk extracts was obtained at the 5 ppb fortification level. The limit of detection was estimated to be 0.5 ppb. Chemical ionization also was used for THPI determination in whole milk extracts. The simultaneous isolation and determination of captan and captofol in whole milk are also discussed.
Simple Cleanup Procedure for Analysis of Buprofezin Residues and Its Metabolite in Crops by Gas Chromatography
Authors: Nishizawa Hideo , Shigemura Masao , Suzuki Takashi , Uchida Matazaemon 
Published: February 2020

Abstract
An analytical method for determining residues of buprofezin (2-tert-butylimino-3-isopropyl-5-phenylperhydro- 1,3,5-thiadiazin-4-one) and its p-hydroxy metabolite (p-hydroxybuprofezin, one of its major metabolites in plants) in crops such as rice, citrus, and tomato was investigated. On the basis of the basicity of these compounds, a liquid–liquid partition, rather than column chromatography, was used for cleanup. Samples were extracted with acetone or methanol, and the concentrated extracts were partitioned between n-hexane and 1N HCI. After the aqueous layer was neutralized with 10N NaOH, the compounds were extracted with n-hexane, and the extract was analyzed with a gas-liquid chromatograph (GLC) equipped with an alkali flame ionization detector (AFID). p-Hydroxy- buprofezin was detected after acetylation with acetic anhydride–pyridine because its peak was broad and showed tailing on GLC. The limits of detection for buprofezin and p-hydroxybuprofezin were 0.005 ppm in hulled rice, citrus flesh, and tomato and 0.01 ppm in rice straw and citrus peel. Recoveries of both compounds fortified at 0.1 or 0.2 ppm were 75–97%.
Reversed-Phase Liquid Chromatographic Determination of Cromolyn Sodium in Drug Substance and Select Dosage Forms
Authors: Ng Linda L 
Published: February 2020

Abstract
This study, presented as a technical communication, describes a reversed-phase liquid chromatographic method for select commercial formulations, namely, inhalation solution, nasal solution, capsule and inhalation aerosol. Miscellaneous validation parameters are also discussed.
Improved Precision in the Automated Analysis of P2O5 in Fertilizer
Authors: Kane Peter F , Newlon Natalie F 
Published: February 2020

Abstract
Traacs autoanalyzers were first configured to analyze fertilizer P2O5 in 1988. In order to maximize precision, changes in the original instrument hardware and manifold design were developed. Platens were machined to higher tolerances and now allow better pump performance. Run protocols were modified to minimize sampler variation. Sampler wash reagent was changed to match sample matrix. The manifold was modified to eliminate wetting agent pump tubes. Heating and cooling effects were minimized with the use of insulated manifold tubing. Standard deviations of replicate analysis of the same solution were reduced to ⅓ of those obtained before modifications were made.