bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Chromatographic Determination of L-Ascorbic Acid in Candies and Soft Drinks
Authors: Maeda Yumie , Ochi Sumiko , Masui Toshio , Matubara Sourokurou 
Published: February 2020

Abstract
The L-ascorbic acid (AsA) contents of candies and soft drinks available in the market were determined by liquid chromatography (LC). Samples are cleaned up on a disposable Sep-Pak C,„ cartridge followed by reverse phase separation on an ODS column using a mobile phase of 0.1% phosphoric acid (pH 2.2). The AsA peak is detected on the basis of the UV absorption at 254 nm. The detection limit was 1 µg/mL final concentration. Recoveries of AsA added at levels of 1-10 mg/g candy and 1-10 mg/10 mL soft drink were 99.2-101.7% with a coefficient of variation of 0.52-1.20% (n = 5). The present method allows rapid and accurate assays because it is a simple procedure compared with the official dye-titration method, and it is suitable for the routine analysis of AsA in selected candies and soft drinks
Proton Magnetic Resonance Spectroscopic Method for Determination of Phenylbutazone and
Oxyphenbutazone in Tablets
Authors: Husain Sajid , Kifayatullah M , NAGESWARA RAO R 
Published: February 2020

Abstract
A simple, specific, and rapid 'H nuclear magnetic resonance spectroscopic method for the assay of phenylbutazone and oxyphenbutazone is described. Spectra are recorded in CDC13 containing 1,3- dichloro-5-nitrobenzene as an internal standard. The aromatic proton resonances for the standard, at 57.7 and 8.2, are well separated from those of phenylbutazone and oxyphenbutazone, which are in the region of 56.5-7.3 ppm. Average percent recoveries of phenylbutazone and oxyphenbutazone were 98.9 and 98.6 with standard deviations of 0.6 and 0.7, respectively. Commercial formulations were analyzed and the results obtained by the proposed method closely agreed with those found by the British Pharmacopoeia method
Resolution and Analysis of Enantiomers of Amphetamines by Liquid Chromatography on a
Chiral Stationary Phase: Collaborative Study
Authors: Alembik Marc C , Wainer Irving W 
Published: February 2020

Abstract
A rapid, accurate method for separating and determining the enantiomeric composition of amphetamine bulk drug and commercial preparations was developed and subjected to collaborative study. Amide derivatives of the amphetamine enantiomers are formed by using achiral 2-naphthoyl chloride. The resulting enantiomeric amides are then chromatographed on a commercially available chiral stationary phase with hexane-isopropyl alcohol-acetonitrile (97 + 3 + 0.5) mobile phase, with detection at 254 nm. Seven collaborators received bulk drug and commercial samples of amphetamine. The collaborators and authors determined the mean percent /- and rf-amphetamine from 2 injections of each sample. The method can detect the presence of as little as 0.5% of the /-enantiomer in ^-amphetamine, with reproducibility between laboratories of ±71.3%. The method has been adopted official first action for determination of the enantiomeric composition of amphetamine bulk drug and preparations
Spectrophotometric Method for Determination of Phosphine Residues in Cashew Kernels
Authors: Rangaswamy Jois R 
Published: February 2020

Abstract
A spectrophotometric method reported for determination of phosphine (PH3) residues in wheat has been extended for determination of these residues in cashew kernels. Unlike the spectrum for wheat, the spectrum of PH3 residue-AgN03 chromophore from cashew kernels does not show an absorption maximum at 400 nm; nevertheless, reading the absorbance at 400 nm afforded good recoveries of 90- 98%. No interference occurred from crop materials, and crop controls showed low absorbance; the method can be applied for determinations as low as 0.01 ppm PH3 residue in cashew kernels
Comparison of APHA and Elevated Temperature Enrichment Methods for Recovery of
Vibrio cholerae from Oysters: Collaborative Study
Authors: Depaola Angelo , Motes Miles L , Mcphearson Roland M 
Published: February 2020

Abstract
Two methods (the American Public Health Association (APHA) method and the elevated temperature method) for recovery of Vibrio cholerae from oysters were compared in a collaborative study. Oysters were inoculated with high (about 150 cells/g) and low (about 20 cells/ g) levels of V. cholerae. The elevated temperature method gave a significantly higher (P &lt; 0.05) recovery rate and showed greater specificity (P &lt; 0.01), as determined by the confirmation rate of suspect colonies. The elevated temperature method required only 25% of the labor and materials necessary for the APHA method. The elevated temperature method has been adopted official first action.
Liquid Chromatographic Determination of Triamino-5-Triazine in Fertilizer Mixes:
Collaborative Study
Authors: Arcement Billy P , Nathan Levy Iii H 
Published: February 2020

Abstract
A method for measuring the triamino-s-triazine content in various fertilizer mixes has been developed and collaboratively studied. Samples are dissolved in deionized water and analyzed using liquid chromatographic separation on a RP-18 LiChrosorb column. Collaborators analyzed 5 sets of blind duplicates, comparing peak heights to an external standard to quantitate the triamino-s-triazine content. Coefficients of variation ranged from 0.8 to 2.2%. The method has been adopted official first action.
Performance Characteristics of Methods of Analysis Used for Regulatory Purposes. I. Drug
Dosage Forms. F. Gravimetric and Titrimetric Methods
Authors: Margosis Michel , Horwitz William , Albert Richard 
Published: February 2020

Abstract
The original gravimetric and titrimetric methods approved by AOAC for the analysis of pharmaceutical preparations, particularly during the period 1915-1950, show precision, recovery, and outlier parameters approximately the same as those exhibited by the previously reviewed instrumental methods that are currently used. Fifty-nine published collaborative studies utilized gravimetric methods and 85 used titrimetric. The studies of the gravimetric methods encompassed 47 analytes, 95 dosage forms, and 136 assays; the corresponding figures for the titrimetric studies are 72, 112, and 152. An average of approximately 7 laboratories participated per study. The line of best fit of the relative standard deviation between-laboratories (RSDR) plotted against the negative logarithm of the fractional concentration, C, extends from 1.2 and 1.0% for the gravimetric and titrimetric methods, respectively, at 100% concentration to 2.2 and 2.8% at 1.0% concentration. Below this concentration the precision of the titrimetric methods degenerates faster than that of the gravimetric methods. Above about 0.1% concentration the gravimetric and titrimetric methods are somewhat more precise than the instrumental methods in current use for drug analysis. The difference, however, is not statistically significant and the general equation, RSDR = 2 exp(l - 0.5 log C), is also applicable to gravimetric and titrimetric methods above a concentration level of about C = 0.001 (0.1%)
Enzyme Immunoassay for Detection of Drosophila melanogaster Antigens in the Juice of
Various Foods
Authors: Kauffman Peter E , Shah Dhirendra B 
Published: February 2020

Abstract
An enzyme immunoassay (EIA) was developed to identify and quantitate soluble antigens originating from Drosophila melanogaster eggs. Polystyrene microtiter plates were coated with anti-egg antibody. Egg antigen standards or samples were reacted with the sensitized wells. The immobilized antigen was reacted with biotinylated antibody, and the complex was quantitated by an avidin-horseradish peroxidase conjugate. The assay can detect egg antigens equivalent to 0.03 eggs/ mL. The antibody was directed against a number of antigens and cross-reacted with extracts of adult Drosophila melanogaster flies. Homogenized eggs diluted in various juice samples were detectable by EIA. Heating the antigen diluted in buffer or juice at a temperature used in processing of juice reduced the immunological response approximately 40-45%. Brine separated from fresh-packed sauerkraut showed EIA responses equivalent to 0.3-3 eggs/mL. Electrophoretic, chromatographic, and immunological analyses suggested that the EIA responses for sauerkraut brine were related to the Drosophila melanogaster egg antigens
Isolation and Identification of Listeria monocytogenes in Dairy Products
Authors: Lovett Joseph 
Published: February 2020

Abstract
After an outbreak of listeriosis in Massachusetts in 1983, the ability of Listeria monocytogenes to survive in raw and pasteurized milk was investigated. An enrichment broth (EB) containing acriflavine, nalidixic acid, and cycloheximide was used to eliminate overgrowth of the culture by competing organisms, and a modification of McBride's agar (MMA) was used as the isolation medium. The culture was incubated 24 h at 30°C. To isolate Listeria from soft cheese, the incubation period was lengthened to 1 week, and the EB culture was streaked to MMA at 1 and 7 days. Physical and biochemical patterns, the CAMP test, serological tests, and mouse pathogenicity studies were helpful in determining the identity of L. monocytogenes
Development of USDA-FSIS Method for Isolation of Listeria monocytogenes
from Raw Meat and Poultry
Authors: Mcclain Dennis , Lee Wei H 
Published: February 2020

Abstract
A method was developed specifically to detect naturally occurring Listeria monocytogenes in meat because the traditional cold enrichment procedure was extremely slow and other procedures were ineffective. This method could identify beta-hemolytic Listeria colonies in 3-4 days. The use of a 2-stage enrichment, highly selective LPM agar, and a thin-layer horse blood agar plate for the detection of beta-hemolytic Listeria isolates are the important steps of this method. L. monocytogenes was recovered from 20 of 41 samples of frozen ground beef, 12 of 23 samples of pork sausage, and 7 of 22 samples of poultry. These results indicate that L. monocytogenes is common in raw meat and that this method is effective for its recovery
Methodology for Isolation of Listeria from Foods—A Canadian Perspective
Authors: Farber Jeffrey M , Sanders Gregory W , Speirs Joan I 
Published: February 2020

Abstract
A previously described monoclonal antibody-enzyme immunoassay system for dairy products was examined to determine its potential for detecting Listeria in naturally contaminated ground meats. In addition, a microtiter plate system was developed which has potential in the rapid detection of Listeria species in foods. Experience in Canada with the U.S. Food and Drug Administration procedure for dairy products, the cold enrichment procedure, and the U.S. Department of Agriculture procedure for meats is discussed. Also, the status on attempts to devise improved selective media for the isolation of Listeria species from foods is described
Rapid Monoclonal Antibody-Based Enzyme-Linked Immunosorbent Assay for Detection of Listeria in Food Products
Authors: Mattingly Jerome A , Butman Bryan T , Plank Mary C , Durham Rebecca J , Robison Barbara J 
Published: February 2020

Abstract
A rapid diagnostic test for the detection of Listeria in food products has been created. This test, known as Listeria-Tek, uses 2 monoclonal antibodies specific for Listeria in an enzyme-linked immunosorbent assay (ELISA) format. The test requires only 40 h of broth enrichment with no culturing on solid media. It is extremely simple to perform and easy to interpret, and is at least as sensitive and accurate as the best of the culture methods. The test can be used with dairy products, meat products, and environmental samples. The ELISA test is safely performed on the open bench of the laboratory because no live cultures, no radioactivity, no phage, etc., are necessary. There is no need for special licenses or reserved laboratory space, and no waste disposal problems are encountered. If necessary, one technician could easily perform hundreds of assays per day. A printed data sheet is available for permanent records.
First Derivative Spectrophotometric Determination of Anhydrotetracyclines in Tetracyclines
Authors: Wahbi Abdel-Aziz M , Al-Khamees Hamad A , Yousef Ahmad M A 
Published: February 2020

Abstract
A rapid method is presented for detection and determination of anhydrotetracycline- HCl (ATC-HC1) and 4-epianhydrotetracycline-HCl (4-EATC-HCl) in tetracycline-HCl (TC-HCl). The method determines the 2 compounds as a sum, not individually. The first derivative absorption curve has a trough (D1) at 460 nm which is linearly related to concentration (1-10 mg/mL). ATC-HC1 + 4-EATC-HCl content was determined in TC-HCl powder and capsules by the D1 and the compensation D1 spectrophotometric methods. The results were compared with those obtained using U.S. Pharmacopeia and British Pharmacopoeia methods
Liquid Chromatographic Determination of Naringin and Neohesperidin as a Detector of Grapefruit Juice in Orange Juice
Authors: Rouseff Russell L 
Published: February 2020

Abstract
Naringin/neohesperidin ratios can be used to differentiate orange juice which may contain added grapefruit juice from orange juice which may include juices from other naringin-containing cultivars. The naringin/neohesperidin ratios in juice vary from 14 to 83 in grapefruit (C. grandis) and from 1.3 to 2.5 in sour orange (C aurantium) cultivars; the ratio is always 1 for the K-Early tangelo. Concentrations of both naringin and neohesperidin can be determined in orange juice by using a single liquid chromatographic isocratic reverse-phase system with a C-18 column. The detection limit for both compounds is 1 ppm with a linear working range to 500 ppm. Concentration relative standard deviations range from 0.47 to 1.06% for naringin and from 0.4 to 1.27% for neohesperidin. Naringin and neohesperidin recoveries ranged from 93 to 102% at concentrations of 5 and SO ppm. Naringin values from blind duplicate samples of orange/grapefruit juice blends could be duplicated to ± 3%.
Determination of Twenty-one Chloroanisoles in Water and Sediment Samples
Authors: Lee Hing-Biu 
Published: February 2020

Abstract
A simple and sensitive method for the determination of 19 chloroanisoles and 2 chloromethylanisoles was developed for water; another method was developed for sediment samples. Water samples were extracted with dichloromethane; sediments were extracted with a mixture of hexane and acetone in a Soxhlet apparatus. The extracts were concentrated on a Snyder column and then were cleaned up on an activated Florisil column. The anisoles were separated by either an OV-1 or SPB-5 capillary column and were detected by an electroncapture or a mass selective detector. Recoveries of chloroanisoles in fortified water and sediment samples generally ranged between 70 and 85%. The method detection limits were 0.02 /tg/L and 0.002 Mg/g for mono- and di-chloroanisoles in water and sediments and 0.002 jug/L and better than 0.001 jig/g for tri-, tetra-, and pentachloroanisoles in those matrixes. The electron-impact mass spectra of all chloroanisoles exhibited intense peaks for the molecular ions (M+ ), as well as (M - 43)+ and either (M - 15)+ or (M - 30)+ fragments. These masses were used as characteristic ions for quantitative and confirmation purposes.
Liquid Chromatographic-Fluorometric Determination of Cinnamyl Alcohol in Perfumes, Colognes, and Toilet Waters
Authors: Wisneski Harris H , Yates Ronald L , Wenninger John A 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for the determination of cinnamyl alcohol (3-phenyl-2-propen-l-ol) in fragrance compositions. The fragrance product is partially cleaned up by diluting the fragrance with a 95% ethanol-water mixture and passing it through a short column containing RP-8 packing. An aliquot of the effluent is then analyzed by LC using an RP-18 column interfaced to a spectrophotofluorometer equipped with double monochromators. The fluorescence emission intensity of the eluted cinnamyl alcohol is measured and compared with that of a standard to calculate the amount of cinnamyl alcohol present. Recoveries from fragrance products fortified with cinnamyl alcohol at levels ranging from 0.0020 to 0.060 mg/mL ranged from 85 to 105% with a mean of 94%. The lowest level of determination was 0.0005 mg/mL.
Determination of ρ-Hydroxybenzoic Acid Esters in Cosmetics by Liquid Chromatography with Ultraviolet and Fluorescence Detection
Authors: Akimoto Noriko , Yamamoto Masatoshi , Sato Shiro , Masui Toshio , Narita Hiroko 
Published: February 2020

Abstract
A simple, precise, and accurate liquid chromatographic method with both ultraviolet (UV) and fluorescence detection is described for the determination of methyl, ethyl, propyl, and butyl /&gt;-hydroxybenzoates (PHBA-esters) in cosmetics. sec-Butyl /?-hydroxybenzoate is added to the sample as an internal standard. Then the PHBA-esters are extracted with ether, the ether is evaporated to dryness, and the residue is dissolved in 60% (v/v) acetonitrile. The acetonitrile solution is passed through a Sep-Pak C,8 cartridge to remove co-extracted lipids. PHBA-esters are determined by reverse-phase liquid chromatography with UV detection at 254 nm and fluorescence detection at ex 280 nm, em 305 nm. The mobile phase is acetonitrile-water (35 + 65). The method was linear over the concentration range of 0.005-0.15 mg/mL. Mean recoveries of each PHBA-ester were 98.9- 102.7% (coefficients of variation &lt;2.0°/o).
Determination of Volatile iV-Nitrosamines in Frankfurters Containing Minced Fish and Surimi
Authors: Pensabene John W , Fiddler Walter 
Published: February 2020

Abstract
A method was developed to quantitatively measure volatile /V-nitrosamines, particularly ./V-nitrosodimethylamine (NDMA), in cured minced fish or surimi-meat frankfurters. This method is free from artifact formation. First, 2 dry solid-phase extraction columns are prepared. Solvent is passed through the top column containing the fish-meat into a second column containing acid Celite. The eluate from the Celite column is then passed through a third column containing silica gel. Nitrosamines are eluted from the acid Celite column and then from the silica gel column into the same receiver. Recovery of the internal standard, /V-nitrosoazetidine, added at the 10 ppb level, was 86.5%. In addition, a few samples of nitrite-treated salmon (lox) were also tested for ./V-nitrosamines. The results show that the method is applicable to samples containing nitrite-treated fish and fish-derived products.
Rapid and Selective Method for Quantitation of Metronidazole in Pharmaceuticals
Authors: Sanyal Asis K 
Published: February 2020

Abstract
A selective and highly sensitive assay for /V-1-substituted nitroimidazoles has been modified and adapted for rapid estimation of metronidazole in pharmaceuticals. The color reaction is based on diazotization of sulfanilamide with the nitrite ions liberated by alkaline hydrolysis of metronidazole and subsequent coupling of the diazonium salt with JV-l-(naphthyl)-ethylenediamine dihydrochloride. This method is applicable for the assay of benzoyl metronidazole in oral suspension. Officially recommended excipients and preservatives do not interfere.
Determination of Moisture by Mid Infrared Transmission Spectroscopy
Authors: Van De Voort Frederick R , Laureano Marilou , Smith James P 
Published: February 2020

Abstract
An investigation was undertaken to determine whether commercially available mid infrared filter instrumentation (i.e., Multispec MK1) could be used to determine moisture in a manner similar to the AOAC near infrared method. Using a specially designed IR scanning spectrophotometer capable of working with aqueous systems, functional sample (6.02 jtm) and reference (5.56 iim) wavelengths were determined for quantitating water-methanol mixtures, and a standard curve was derived. Skim milk powder, bread crumbs, and flour were mixed with dry methanol to extract moisture into the solvent; moisture was quantitated relative to 3 AOAC methods. The results indicated that the wavelength pair selected worked well and had the potential to determine moisture content of low moisture food products, given that appropriate moisture extraction protocols were derived. This work indicates that the capabilities of commercial filter-based mid infrared instruments could be expanded to include moisture analyses if such instruments were equipped with the appropriate interference filters to carry out this determination.
Residue Level Determination of the Aquatic Herbicide Fluridone and a Potential
Photoproduct (N-Methylformamide) in Water
Authors: West Sheldon D , Turner Larry G 
Published: February 2020

Abstract
Methods are presented for the determination of the aquatic herbicide fluridone and /V-methylformamide (NMF), a potential photoproduct of fluridone which has thus far been observed only in a laboratory aqueous photolysis study. Water samples are passed through a Sep- Pak C,8 cartridge to extract fluridone while NMF passes unretained through the cartridge with the water. Fluridone is eluted from the cartridge with methanol, which is then concentrated for analysis by liquid chromatography with UV detection at 313 nm. The water eluate containing NMF is concentrated for analysis by rotary vacuum evaporation at 40-46°C. Methanol is added to help evaporate the water, and glycerol is added as a keeper solvent to retain NMF during the evaporation. The residual NMF is dissolved in methanol for analysis by gas chromatography with a Hall electrolytic conductivity detector operated in the nitrogen mode. The assay limits of detection are 1 and 2 ppb for fluridone and NMF, respectively. Recoveries averaged 98% for fluridone at 1-400 ppb and 87% for NMF at 2- 50 ppb.
Reverse-Phase Liquid Chromatographic Determination of Benzoic and Sorbic Acids in
Fresh Cheese
Authors: Kuppers Frans J. E. M , Jans Jan A 
Published: February 2020

Abstract
The sorbate and benzoate contents of commercial fresh cheese (quarg) samples are determined by reverse-phase liquid chromatography following extraction with a methanol-acetate buffer pH 4.5 mixture (37 + 63). The mobile phase is acetonitrile-acetate buffer pH 4.5 (20 + 80), the effluent flow rate is maintained at 1.0 mL/min, and the detector is set at 232 nm. Recoveries from quarg spiked at the 5-50 mg/kg level ranged from 95 to 99%, which compares favorably with methods previously published. Precision averaged 2-5% RSD, whereas the limit of detection was 0.3 mg/kg (sorbic acid) and 1.0 mg/kg (benzoic acid).
Aflatoxin, A Human Carcinogen: Determination in Foods and Biological Samples by Monoclonal Antibody Affinity Chromatography
Authors: Groopman John D , Donahue Kevin F 
Published: February 2020

Abstract
We have used monoclonal antibody technology to produce antibodies that recognize aflatoxins in order to develop noninvasive methods in conjunction with other chemical analytical techniques to monitor human exposure to environmental carcinogens. These methods require the ability to quantitate aflatoxins and their metabolites, including DNA and protein adducts, in readily accessible compartments such as serum and urine. The techniques permit efficient analysis of many samples in a relatively short time. Also, these monoclonal antibody affinity columns have been extremely useful for rapid isolation of aflatoxins from food and grain samples, as well as aflatoxin M, from milk. Monoclonal antibody affinity methods are nondestructive to the aflatoxin molecule, so the sample aliquot can be used for confirmation. The use of monoclonal antibody preparative affinity columns represents a major, substantive breakthrough for analytical chemists and will be a generally applicable technology for isolation of many different substances.