bluuebunny/crossref_metadata_2025 huggingface dataset:
Kaposi Sarcoma-Associated Herpesvirus Infection and Endemic Burkitt Lymphoma
Authors: Oluoch Peter O , Oduor Cliff I , Forconi Catherine S , Ong’echa John M , Münz Christian , Dittmer Dirk P , Bailey Jeffrey A , Moormann Ann M
Published: February 2020

Background

Endemic Burkitt lymphoma (eBL) is associated with Epstein-Barr virus (EBV) and Plasmodium falciparum malaria coinfections. However, the role of Kaposi sarcoma-associated herpesvirus (KSHV), also endemic in Africa, has not been evaluated as a cofactor in eBL pathogenesis.

Methods

Multiplexed seroprofiles for EBV, malaria, and KSHV were generated for 266 eBL patients, 78 non-eBL cancers, and 202 healthy children. KSHV and EBV loads were quantified by PCR.

Results

KSHV seroprevalence did not differ by study group but was associated with age. Seropositivity, defined by K8.1/LANA or in combination with 5 other KSHV antigens (ORF59, ORF65, ORF61, ORF38, and K5) was associated with antimalarial antibody levels to AMA1 (odds ratio [OR], 2.41, P < .001; OR, 2.07, P < .001) and MSP1 (OR, 2.41, P = .0006; OR, 5.78, P < .001), respectively. KSHV loads did not correlate with antibody levels nor differ across groups but were significantly lower in children with detectable EBV viremia (P = .014).

Conclusions

Although KSHV-EBV dual infection does not increase eBL risk, EBV appears to suppress reactivation of KSHV while malaria exposure is associated with KSHV infection and/or reactivation. Both EBV and malaria should, therefore, be considered as potential effect modifiers for KSHV-associated cancers in sub-Saharan Africa.
Lung penetration, bronchopulmonary pharmacokinetic/pharmacodynamic profile and safety of 3 g of ceftolozane/tazobactam administered to ventilated, critically ill patients with pneumonia
Authors: Caro Luzelena , Nicolau David P , De Waele Jan J , Kuti Joseph L , Larson Kajal B , Gadzicki Elaine , Yu Brian , Zeng Zhen , Adedoyin Adedayo , Rhee Elizabeth G
Published: February 2020

Objectives

Ceftolozane/tazobactam is approved for hospital-acquired/ventilator-associated bacterial pneumonia at double the dose (i.e. 2 g/1 g) recommended for other indications. We evaluated the bronchopulmonary pharmacokinetic/pharmacodynamic profile of this 3 g ceftolozane/tazobactam regimen in ventilated pneumonia patients.

Methods

This was an open-label, multicentre, Phase 1 trial (clinicaltrials.gov: NCT02387372). Mechanically ventilated patients with proven/suspected pneumonia received four to six doses of 3 g of ceftolozane/tazobactam (adjusted for renal function) q8h. Serial plasma samples were collected after the first and last doses. One bronchoalveolar lavage sample per patient was collected at 1, 2, 4, 6 or 8 h after the last dose and epithelial lining fluid (ELF) drug concentrations were determined. Pharmacokinetic parameters were estimated by non-compartmental analysis and pharmacodynamic analyses were conducted to graphically evaluate achievement of target exposures (plasma and ELF ceftolozane concentrations >4 mg/L and tazobactam concentrations >1 mg/L; target in plasma: ≥30% and ≥20% of the dosing interval, respectively).

Results

Twenty-six patients received four to six doses of study drug; 22 were included in the ELF analyses. Ceftolozane and tazobactam Tmax (6 and 2 h, respectively) were delayed in ELF compared with plasma (1 h). Lung penetration, expressed as the ratio of mean drug exposure (AUC) in ELF to plasma, was 50% (ceftolozane) and 62% (tazobactam). Mean ceftolozane and tazobactam ELF concentrations remained >4 mg/L and >1 mg/L, respectively, for 100% of the dosing interval. There were no deaths or adverse event-related study discontinuations.

Conclusions

In ventilated pneumonia patients, 3 g of ceftolozane/tazobactam q8h yielded ELF exposures considered adequate to cover ceftolozane/tazobactam-susceptible respiratory pathogens.
Polyamine and Histamine Content of Rockfish, Salmon, Lobster, and Shrimp as an Indicator of Decomposition
Authors: Mietz John L , Karmas Endel
Published: February 2020

A chemical method to determine decomposition in rockfish, salmon, lobster, and shrimp was developed. Dansyl derivatives were formed from extracts of these products and separated using gradient elution high pressure liquid chromatography. The dansylated polyamines, putrescine, cadaverine, spermidine, and spermine, and the amine histamine were quantitated, and the results were entered into an index formula. The resulting index was used to classify each product into passable (class 1), initial decomposition (class 2), and advanced decomposition (class 3). A comparison of results obtained by the chemical classification of 21 samples (rockfish, salmon, and lobster) showed good correlation with organoleptic evaluations of the same products by 23 examiners. The chemical index classified the samples correctly 90.5% of the time vs. an 83.9% correct classification by organoleptic means. Analysis of shrimp composites of the 3 organoleptic classes showed a similar relationship between the chemical index and the degree of decomposition.
Gas-Liquid Chromatographic Determination of Kepone in Field-Collected Avian Tissues and Eggs
Authors: Stafford Charles J , Reichel William L , Swineford Douglas M , Prouty Richard M , Gay Martha L
Published: February 2020

A procedure is described for determining Kepone (decachlorooctahydro-l,3,4-metheno-2H-cyclobuta [cd]pentalene-2-one) residues in avian egg, liver, and tissue. Samples were extracted with benzene-isopropanol, and the extract was cleaned up with fuming H2SO4-concentrated H2SO4. Kepone was separated from organochlorine pesticides and polychlorinated biphenyls on a Florisil column and analyzed by electron capture gas-liquid chromatography GLC). The average recovery from spiked tissues was 86%. The analyses performed on 14 bald eagle carcasses and livers, 3 bald eagle eggs, and 14 osprey eggs show measurable levels which indicate that Kepone accumulates in the tissues of fish-eating birds. Residues were confirmed by GLC-mass spectrometry.
Improved Rapid Colorimetric Method for Carbadox in Feeds
Authors: Thorpe Virginia A
Published: February 2020

The extraction step in the rapid colorimetric method for determining carbadox in feeds was modified to include a water pretreatment for pelleted feeds. The extraction solvent was changed from dimethylformamide (DMF) to CHCl3-methanol (3+1). The water in the extract is removed with anhydrous Na2SO4, and an aliquot is evaporated to dryness, solubilized in DMF, and transferred to an alumina column. The method is then essentially the same as originally reported. Recoveries of carbadox added to unmedicated feeds were increased from 98 to 100% by inserting in the method the column recovery step to determine the standard absorbance values.
Combined Gas-Liquid Chromatographic Mass Spectrometric Analysis of Some Commercial Aryl Phosphate Oils
Authors: Deo Padmakar G , Howard Philip H
Published: February 2020

Five commercial samples of synthetic aryl phosphate oils, which are widely used as fire retardant hydraulic fluids and as flame retardant plasticizers, have been analyzed by combined gas-liquid chromatography/mass spectrometry (GLC/MS). Each sample contained at least 4 isomers of aryl phosphate esters. The peaks were identified by a close examination of the mass spectral data and, wherever possible, by comparing retention times of the peaks with those of either the purchased or synthesized compounds. One aryl phosphate hydraulic fluid contained a small amount of a hydrocarbon. The results indicate that most of the aryl phosphate esters in the commercial samples were formed from phenol, cresols, xylenols, and other alkyl phenols. No free phenols could be detected in the samples analyzed.
Quantitation of Polychlorinated Biphenyl Residues by Electron Capture Gas-Liquid Chromatography: Reference Material Characterization and Preliminary Study
Authors: Sawyer Leon D
Published: February 2020

Weight per cent compositions of individual peaks of Aroclors 1016, 1242, 1248, 1254, and 1260 were determined under standard gas-liquid chromatographic (GLC) conditions. The GLC peak compositions were determined by using a Hall electrolytic conductivity detector for chlorine measurement and chemical ionization mass spectrometry with single ion monitoring for molecular weight characterization. The Aroclors used are available as reference materials for individual peak quantitation of polychlorinated biphenyl (PCB) residues by electron capture GLC. On the basis of a limited interlaboratory study and a collaborative study, the individual peak method shows improved interlaboratory precision and/or accuracy in PCB quantitation over existing methods.
Aflatoxin Formation on Sixteen Soybean Varieties
Authors: Shotwell Odette L , Vandegraft Elsie E , Hesseltine Clifford W
Published: February 2020

Sixteen commercial varieties of soybeans were each inoculated with 5 isolates of fungi from the Aspergillus flavus series to determine varietal differences in supporting aflatoxin production. The isolates were 2 strains of A. parasiticus (NRRL 2999 and NRRL 3145), 2 strains of A. flavus (NRRL 3357 and NRRL 3353), and 1 strain from a new variant of A. flavus (NRRL 3251). Levels of aflatoxin formed were dependent both on the isolate and on the variety of soybeans. Amsoy-71, Calland, Harosoy, and Pamona varieties were the poorest substrates for aflatoxin production in the laboratory fermentation, so they may be resistant to mold invasion and /or toxin formation.
Flash Point and Specific Gravity of Ethanol-Water-Sugar Solutions
Authors: Strunk Duane H , Hamman Jack W , Steimel Jacob , Andreasen Arthur A
Published: February 2020

Flash points and specific gravities were determined for ethanol-water-sugar solutions in the concentration range normally found in liqueurs. Flash point determinations were made using a Tag closed cup tester. Increasing the proof of ethanol-water solutions from 60 to 120° lowers the flash point from 32.8 to 24.4°C. The flash point is also lowered by the addition of sugar, e.g., from 32.8 to 25.0°C at 60° proof when the sugar concentration is increased from 0 to 40%. This is due largely to the sugar replacing a portion of the water, and to hydrogen bonding between the sugar and water, thereby effectively increasing the proof and vapor pressure of the ethanol at the air interface. A graph is presented showing the relationship between the concentration of sugar and the specific gravity for different proof samples, which can be used to estimate the per cent sugar in a liqueur when the proof and specific gravity are known. When the sugar concentration and proof are known, the flash point can be estimated.
Quantitative Determination of Carbaryl in Apples, Lettuce, and Water by Densitometry of Thin Layer Chromatograms
Authors: Sherma Joseph , Kovalchick Andrew J , Mack Richard
Published: February 2020

A method for the quantitative determination of carbaryl insecticide by in situ densitometry was developed. After separation on silica gel thin layer plates, carbaryl residues were detected by using p-nitrobenzenediazonium fluoborate reagent and quantitated by scanning the resultant blue spots with a fiber optics densitometer and comparing them with standards. The method was applied to water fortified with carbaryl at 8 ppb and apples and lettuce fortified at 0.10 ppm; all recoveries were greater than 89%. The 2 crop extracts were cleaned up by using the AOAC thin layer chromatographic method for visual estimation of carbaryl. Related carbamate insecticides were detected by using the same reagent, and the potential for quantitation was demonstrated.
Gas-Liquid Chromatographic Determination of Residues from the Herbicide 2-Chloro-l-(3-Ethoxy-4-Nitrophenoxy)-4-(Trifluoromethyl) Benzene
Authors: Adler Irving L , Haines Linwood D , Marco Jones Brent
Published: February 2020

Residues of 2 - chloro - 1 - (3 - ethoxy- 4 - nitrophenoxy)-4-(trifluoromethyl) benzene and reduced metabolites are determined by digesting a sample methanol extract with aluminum in aqueous 10% sodium hydroxide to convert residues to 4-[2-chloro-4-(trifluoromethyl)-phenoxy]-2-ethoxybenzenamine. This compound is partitioned into hexane, using a simultaneous distillation-extraction process. The heptafluorobutyryl derivative is then prepared, partially purified by chromatography on Florisil, and measured by electron capture gas-liquid chromatography. The method is sensitive to 0.01 ppm.
Analytical Behavior Data for Chemicals Determined Using AOAC Multiresidue Methodology for Pesticide Residues in Foods
Authors: McMahon Bernadette , Burke Jerry A
Published: February 2020

Analytical methods capable of detecting more than one pesticide residue simultaneously (multiresidue methods) become more effective with an increase in the number of chemicals whose behavior through the various steps of the method has been documented. Since 1970, the method behavior data related to the AOAC official method for residues of 25 chlorinated and phosphated pesticides and polychlorinated biphenyls have been extended to include information on twice as many chemicals as was previously available. The value of having a large bank of method behavior data is outlined and the experimental protocol by which the data were collected is described. A complete listing is included of the available data on the analytical behavior of over 300 pesticidal and/or industrial chemicals.
Separation of Polychlorinated Biphenyls, Chlordane, and p,p'-DDT from Toxaphene by Silicic Acid Column Chromatography
Authors: Bidleman Terry F , Matthews Janis R , Olney Charles E , Rice Clifford P
Published: February 2020

Small columns of precisely deactivated silicic acid (3 g, 3.3% water) were investigated for separating hexachlorobenzene, polychlorinated biphenyls (PCBs), DDE, DDT, and cis- and trans-chlordane from toxaphene. The chlorinated hydrocarbons were eluted from the column in 3 fractions: Fraction 1 (50 ml petroleum ether) contained HCB, PCBs, DDE, and 10-30% o,p'-DDT. If desired, HCB could be separated from PCBs by further dividing fraction 1 into 2 portions, the first 13 ml containing HCB and the next 37 ml containing PCBs and DDE. Fraction 2 (80 ml petroleum ether) contained the chlordanes, p,p'-DDT, and 70–90% o,p'-DDT. Dieldrin and p,p'-DDD were eluted in a third (15 ml dichloromethane) fraction. The percentages of toxaphene eluted in the 3 fractions were approximately 10, 30, and 60%, respectively. Most of the toxaphene components interfering with the analysis of p,p'- DDT were eluted in the third fraction. This procedure has been very helpful in separating and identifying many of the high molecular weight chlorinated hydrocarbons in ambient air.
Oil Flotation Extraction of Light Filth from Ground Capsicums Excluding Paprika: Collaborative Study
Authors: Thrasher Joel J , Colliflower Emma Jean
Published: February 2020

A collaborative study has been completed on an improved method for the isolation of light filth from ground capsicums other than paprika. The proposed method involves isopropanol pretreatment, wet-sieving, and extraction from cooled 6 0% ethanol with a mineral oil-heptane mixture. The collaborative tests by the proposed method showed an approximate 2-fold increase in recoveries of insect fragments and rodent hairs with acceptable coefficients of variation and clean filter papers. The proposed method has been adopted as official first action to replace 44.123.
Thin Layer Chromatographic Method for the Detection of Uric Acid: Collaborative Study
Authors: Thrasher Joel J , Abadie Annette
Published: February 2020

A collaborative study has been completed on an improved method for the detection and confirmation of uric acid from bird and insect excreta. The proposed method involves the lithium carbonate solubilization of the suspect excreta material, followed by butanol-methanol-water-acetic acid thin layer chromatography, and trisodium phosphate-phosphotungstic acid color development. The collaborative tests resulted in 100% detection of uric acid standard at the 50 ng level and 75% detection at the 20–25 ng level. No false positives were reported during tests of compounds similar to uric acid. The proposed method has been adopted official first action; the present official final action method, 44.161, will be retained for screening purposes.
Mineral Oil Extraction of Light Filth from Rubbed Sage: Collaborative Study
Authors: Holtgreve Naoma Doris
Published: February 2020

An improved method has been developed for extracting light filth in rubbed sage. The method is similar to 44.A04 and 44.A05, except the light filth is isolated by using 20% isopropanol with mineral oil. Collaborative results show that the proposed method yielded better recoveries than the present official first action method. The method has been adopted as official first action.
Improved Microbiological Assay for Penicillin Residues in Milk and Dairy Products
Authors: Katz Stanley E , Fassbender Carol A
Published: February 2020

The microbiological assay for penicillin residues in milk was improved. Acidification of milk with phosphoric acid to pH 4.5, centrifugation to remove precipitated proteinaceous matter, adjustment of pH to 6.0, a second centrifugation, and the use of a 2% agar base layer resulted in the consistent measurement of 0.01 unit penicillin activity/ml milk. Sarcina lutea was used as the assay organism. Recoveries in milk averaged 94%, in nonfat dry milk 84%, in cottage cheese 97%, and in cream cheese 94%.
Lead in Evaporated Milk by Anodic Stripping Voltammetry and Atomic Absorption Spectrophotometry: Cooperative Interlaboratory Study
Authors: Sulek Arlene M , Elkins Edgar R , Zink Eric W
Published: February 2020

The results of a cooperative study on the determination of lead in evaporated milk, using a double blind referee technique, are reported. This study was designed to determine the normal variability of methods currently used for lead analysis by canned food industry laboratories. Twenty-three laboratories participated in this study. Each laboratory was instructed to use atomic absorption spectrophotometry (AOAC 25.065), anodic stripping voltammetry, or carbon rod atomic absorption spectrophotometry. Overall, the results appear to be in close agreement with the spiking levels. The coefficient of variation for all laboratories was 36.0% at the 0.15 ppm lead level and 16.8% at the 0.40 ppm lead level.
Statistical Study to Reduce the Number of Slides Microscopically Examined in the Geotrichum Mold Count Methods
Authors: Cichowicz Stanley M , Atkinson John C
Published: February 2020

Variation in the data obtained from the 4 slides counted in the Geotrichum mold count methods was statistically examined to determine if the number of slides could be reduced. The mean and standard deviation for 4 replicate slides for each can of carrots, green beans, and pineapple demonstrated that mold count variation is a function of the mean, that significant variations exist among lots and among cans within a lot, and that quadruplicate slide counts are unnecessary. Duplicate counts would save 50% of the analyst’s counting time.
Sensitive and Specific Gas-Liquid Chromatographic-Spectrophotometric Screening Procedure for Trace Levels of Five Sulfonamides in Liver, Kidney, and Muscle Tissue
Authors: Goodspeed Donald P , Simpson Randy M , Ashworth Raymond B , Shafer Jerry W , Cook Henry R
Published: February 2020

Free and conjugated sulfonamides are extracted from edible animal tissue with acetone. Carbohydrate "is precipitated and removed, and the acetone is evaporated. The residue is transferred to a separatory funnel with ethyl ether and 17V HC1. The acid layer is drawn off and a portion of the 17V HC1 is screened, using the Bratton-Marshall reaction. If this portion is positive, the remaining portion is buffered to pH 6.5 and extracted with methylene chloride. The residue is methylated with diazomethane and then acylated with pentafluoropropionic anhydride. The resulting derivatives are detected by gas-liquid chromatography, using electron capture (63Ni) detection and a column packed with 3% OV-17 on Gas-Chrom Q. This method has been validated by recovering sulfathiazole, sulfachloropyrazine, sulfamethazine, sulfadimethoxine, and sulfabromomethazine from liver, kidney, and muscle at levels of 0.1, 0.5, and 1.0 ppm. The 5 sulfonamides were recovered in excess of 60%, with an average mean recovery of 81.5% at the 0.1 ppm level, 79.1% at the 0.5 ppm level, and 76.0% at the 1.0 ppm level.
Regulatory Agency Interaction in the Control of Drug Residues in Animal Tissue
Authors: Malanoski Anthony J
Published: February 2020

The U.S. Department of Agriculture has the responsibility of determining if a method for residues of drugs and pesticides in animal tissues is acceptable for regulatory control, reviewing data on interfering compounds, validating methods, monitoring drug residues in animal and poultry tissues, assigning priority for monitoring drugs and pesticide residues. These responsibilities are carried out in cooperation with the U.S. Food and Drug Administration in the areas of method development, determination of priorities, and punitive action.
Effect of Storage and Processing on Tetracycline Residues in Meat and Bones
Authors: Honikel Karl O , Schmidt Udo , Woltersdorf Wolfgang , Leistner Lothar
Published: February 2020

A semiquantitative microbiological screening test for antibiotics, a sensitive and quantitative microbiological assay, and a fluorometric method specific for tetracyclines are described. Using these procedures, tetracycline residues in animals derived from feed can be detected in tissues like organs, muscles, and bones. Meat contaminated with chlortetracycline (CTC) and oxytetracycline (OTC) and stored at +8°C and —22°C showed very little decrease in antibiotic concentration; however, heating above 65°C reduced the tetracycline content in meat. Temperatures above 130°C were necessary to destroy CTC in bones, CTC in bones was insoluble above pH 4. Manufacturing products with contaminated meat reduced the tetracycline content only if heating was involved.
Vapor Infrared Spectrophotometry Identification of Chloroform, Halothane, Methoxyflurane, Tetrachloroethylene, and Trichloroethylene
Authors: Schwartzman George
Published: February 2020

The British Pharmacopoeia, USP, and NF contain nonspecific chemical and/or physical tests for the identification of chloroform, halothane, methoxyflurane, tetrachloroethylene, and trichloroethylene. Vapor phase infrared spectrophotometry yields characteristic and distinct curves for each of these substances, thus eliminating the need for other tests.
Sampling and Analysis for Polychlorinated Naphthalenes in the Environment
Authors: Erickson Mitchell D , Michael Larry C , Zweidinger Ruth A , Pellizzari Edo D
Published: February 2020

Soil, sediment, biota, 24-hr integrated water, and 2 consecutive 24-hr integrated air samples were collected at several geographic sites, extracted, cleaned up, and analyzed for polychlorinated naphthalenes (PCNs). Analysis by quadrupole gas-liquid chromatography /mass spectrometry / computer (GLC / MS / COMP), using multiple ion detection (MID), provided a sensitivity of <50 pg or about 0.5 μg/kg for soil, 0.2 μg/L for water, and 0.3 ng/cu. m for air. Individual PCN isomers were accurately and positively determined in the presence of other compounds (e.g., polychlorinated biphenyls). Polychlorinated naphthalene levels in soil near a PCN manufacturing site averaged 940 μg/kg (range 130—2300 μg/kg). Air samples contained from 25 to 450 ng/cu. m (average 150 ng/cu. m) on the first day and 120—2900 ng/cu. m (average 1400 ng/cu. m) the second day. A small dead fish contained 39 μg/kg, and locally obtained apples contained 90 μg/kg. Only trace amounts of PCNs were found in the water samples. Analysis of samples collected on consecutive days near a capacitor manufacturer showed an average of 3.1 ng/cu. m (range undetectable to 7.3 ng/cu. m) and 1.2 ng/cu. m (range undetectable to 3.9 ng/cu. m) in air, 2.0 μg/ kg (range undetectable to 7.3 μg/kg) in soil. No PCNs were detected in integrated water samples. Crab water samples contained 0.6 and 5.5 μg/L. Samples collected on consecutive days near a second capacitor manufacturer contained an average of 19 ng/cu. m (range 9.8— 31 ng/cu. m) and 17 ng/cu. m (range 9.8—33 ng/cu. m), respectively, in air, 240 μg/kg (range undetectable to 470 μg/kg) in soil, and 0.6 μg/L in water downstream of the plant (undetectable in upstream sample). An amber resinous solid collected near the plant contained 920 μg PCNs/kg, mostly as the di-, tri-, and tetrachloronaphthalenes. The results of this study demonstrate a wide range of PCN concentrations in the environment near manufacturing and use sites.
Trends in Levels of N-Nitrosopyrrolidine in Fried Bacon
Authors: Havery Donald C , Fazio Thomas , Howard John W
Published: February 2020

Commercially purchased bacon has been periodically analyzed since 1971 for N-nitrosopyrrolidine in the fried product. The downward trend in the concentration of N-nitrosopyrrolidine that has been observed is partially explained by the use of reduced levels of nitrite and increased levels of ascorbate in bacon curing mixtures.
High Pressure Liquid Chromatographic Determination of Theobromine and Caffeine in Cocoa and Chocolate Products
Authors: Kreiser Wesley R , Martin Robert A
Published: February 2020

A method was developed for determining theobromine and caffeine in cocoa and chocolate products by high pressure liquid chromatography. After a simple hot water extraction, both theobromine and caffeine were separated by using a reverse phase Cl s column and a mobile phase of methanol-water-acetic acid (20+ 79+1). Theobromine and caffeine were quantitated at 280 nm; average recoveries were 98.7 and 95.0%; and coefficients of variation were 2.31 and 3.91%, respectively.
Fluorometric Determination of Methylergonovine Maleate and Ergonovine Maleate in Tablets and Injections
Authors: Kirchhoefer Ross D
Published: February 2020

A column cleanup, followed by a shakeout and fluorometric determination, has been developed to determine methylergonovine maleate and ergonovine maleate in tablets and injections. The ether eluate is extracted with tartaric acid solution. An aliquot is diluted with sodium tartrate solution, and this solution is excited at 325 nm. The resulting fluorescence is measured at 432 nm. Results obtained using this method compare favorably with those from the official NF XIV procedure and a semiautomated procedure. Recoveries of 100 and 99% were obtained from one sample each of spiked excipient tablets of methylergonovine maleate and ergonovine maleate, respectively.
Ion Selective Electrode for Determination of Chloride Ion in Biological Materials, Food Products, Soils, and Waste Water
Authors: Sekerka Ivan , Lechner Josef F
Published: February 2020

The chloride ion selective electrode is used for a rapid, simple, and reliable determination of chloride ion in biological materials (blood serum, urine, fish, and plant tissues), food products (milk, beef extract, nutrient broth and orange, tomato, and grapefruit juices), soils, and waste water (industrial and municipal). The method consists of treating the samples with perchloric acid (pH 1) and potassium peroxydisulfate and determining the chloride content either by a calibration curve or by known addition or analyte addition, using the chloride ion selective electrode. Such sample treatment eliminates most of the interferences occurring in the samples, including iodide, complexing and reducing compounds, and macromolecular and surface-active species. The method is suitable for a wide range of chloride concentration, e.g., 5010 ppm CI in nutrient broth and 4890 ppm in beef extract and as low as 12 and 80 ppm in soil extracts.
Electrolytic Determination of Surface Lead in Empty Metal Containers
Authors: Estiandan Fe S , Schafer Glen H , Gedang Delia B
Published: February 2020

The lead content of an empty metal container (tin can) can be determined by an electrolytic process using a constant voltage power supply and dilute acid electrolyte. The ionic lead in the solution after electrolysis is determined by anodic stripping voltammetry.
Semiautomated Analyses of Some Ergot Alkaloid Formulations
Authors: Kirchhoefer Ross D
Published: February 2020

The following pharmaceutical preparations were assayed using a modification of a semiautomated procedure for methylergonovine and ergonovine maleate: ergotamine tartrate tablets and injections, ergotamine tartrate tablets and suppositories with caffeine, methysergide maleate tablets, and dihydroergocornine-dihydroergocristine - dihydroergokryptine mesylate sublingual tablets. These formulations could be assayed by either the fluorometric or by the colorimetric procedure. Good results were obtained using the fluorometric and colorimetric methods for these compounds. The standard deviation for an ergotamine tartrate injection solution was 1.76, using the colorimetric system, with a mean of 98.7% of declared potency. The method compares favorably with the NF XIV procedure for ergotamine tartrate and caffeine tablets. In addition, low level dissolution rates can easily be determined on ergotamine tartrate and caffeine tablets using the fluorometric system.
High Pressure Liquid Chromatographic Determination of Polynuclear Aromatic Hydrocarbons in Oysters
Authors: Hanus James P , Guerrero Humberto , Biehl Edward R , Kenner Charles T
Published: February 2020

A high pressure liquid chromatographic (HPLC) procedure is described for determining 13 polynuclear aromatic hydrocarbon (PNA) compounds in oysters at the 2 ppb level. These compounds are extracted from shellfish with acetonitrile and partitioned into petroleum ether; the petroleum ether is removed and the residue is saponified. The aromatic compounds are isolated by passing the saponified residue through silica gel and further purified and fractionated by μStyragel gel permeation chromatography. The individual PNAs are then quantitatively determined by using a reverse phase HPLC column coupled to fluorescence, spectrophotometric, and 254 nm absorbance detectors in series. Recoveries from spiked samples generally were >80%.
Application of Vertical Plate Gel Electrophoresis to the Separation of Pigmented and Non-Pigmented Trout and Salmon Species
Authors: Coduri Richard J , Bonatti Karen , Simpson Kenneth L
Published: February 2020

Pigmented and non-pigmented trout and salmon species were obtained from the ocean and from aquaculture facilities. Sarcoplasmic extracts of each sample were made and protein separations were obtained using vertical plate gel electrophoresis (VPE); rainbow, brook, and brown trout were easily distinguished from coho, chinook, and sockeye salmon. No correlation or relationship appears to exist between pigment concentration and VPE protein pattern. These fish can thus be distinguished regardless of the level of pigmentation.
Spectrofluorometric Determination and Thin Layer Chromatographic Identification of Tyramine in Wine
Authors: Gonzalo Julian C Rivas , Moreno Concepcion Garcia , Cerro Auxiliadora Gomez , Font Abel Mariné
Published: February 2020

A method is described for determining tyramine in wine by sand column extraction in an alkaline medium with anhydrous sodium sulfate. Tyramine is identified and quantitated by spectrofluorometry after the final extract is reacted with α-nitroso-β-naphthol; identity is confirmed by thin layer chromatography. The average recovery was 98.93%. The method is applied to samples of 3 different wines obtained throughout the vinification process. Tyramine, which was not present in the must, appears in considerable quantities 15 days after the vinification process has begun.
Relative Productivity of Five Selective Plating Agars for the Recovery of Salmonella from Selected Food Types
Authors: Andrews Wallace H , Wilson Clyde R , Poelma Paul L , Romero Aida
Published: February 2020

During a 3-year period, the relative productivity of brilliant green (BG), bismuth sulfite (BS), Salmonella-Shigella (SS), Hektoen enteric (HE), and xylose lysine desoxycholate (XLD) agars for recovering Salmonella from 9 food types was determined. Following preenrichment, selective enrichment of food samples in tetrathionate broth followed by streaking to BS agar was the single most productive selective enrichment broth-agar combination for recovery of Salmonella in 5 of these food types. A study of the performance of these 5 agars used individually and in various combinations, showed that none of the 5 agars used individually nor any of the possible paired combinations of these agars could be used to satisfactorily detect Salmonella in the 9 food types. The use of all 5 agars was not necessary because one combination of 4 agars (BG, BS, HE, and XLD) recovered 100% of the Salmonella isolates, as compared with the number of Salmonella isolates recovered by the 5-agar combination, in each food category. This particular 4-agar combination, along with two 3-agar combinations (BG, BS, and XLD agars, and BS, HE, and XLD agars), were each able to recover more Salmonella isolates than the combination of BG, BS, and SS agars, the combination currently recommended by the AOAC. Finally, the relative costs of using these agars, singly and in various combinations, were determined.
Volumetric Method for Determining Traces of Organic Chlorine in Lipids
Authors: Cunningham Hugh M , Lawrence Guillaume L
Published: February 2020

The official AOAC method for determining chlorine in cake flour lipids has been modified to determine chlorine in lipids of animal carcasses cooled with chlorinated water. The sensitivity of the method has been improved 1000- fold to attain a detection limit of 2 ppm CI in lipids. Recovery of the fine silver chloride precipitate was improved through centrifugation rather than filtration. The official method also did not take into consideration that when the silver chloride precipitate is exposed to light, it is converted to free chlorine and silver. Recovery of organic chlorine ranged from 84.6% at 4.1 ppm to 100.1% at 100 ppm. A number of samples of commercially chlorinated beef, pork, and chicken and laboratory-chlorinated chicken were analyzed by this method. In all cases where the level of chlorination was sufficient to result in a chlorine level in lipids in excess of 2 ppm, the chlorine content of the carcass lipids was measurable.
Automated Urease-Chromous Method for Determining Nitrogen in Fertilizers
Authors: Wall Larry L , Gehrke Charles W
Published: February 2020

An automated urease-chromous colorimetric method (AUCM) has been developed for determining nitrogen in fertilizers. The method is applicable to fertilizer samples that contain only ammoniacal, nitrate, and urea nitrogen. The concept of this method, combining nitrate reduction and enzymatic urea hydrolysis to produce a single method for total nitrogen, is new. The AUCM is an almost totally automated method with only an acidic dissolution step as the manual sample preparation. The urea is hydrolyzed to ammonia and carbon dioxide with urease, and the nitrate is reduced to ammonia with chromous ion within the continuous flow analytical system. The final step, also within the analytical system, is the spectrophotometric measurement of the ammonia, employing the ammonia-salicylate-hypochlorite chemistry. The sampling rate is 30 samples/hr. The method is not applicable to fertilizer samples containing refractory organic nitrogen forms, water-insoluble nitrogen, or significant levels of biuret. The average per cent nitrogen recovery by the AUCM for ammonium nitrate-diammonium phosphate bulk-blended fertilizer samples was 99.7, suspensions and liquids 99.7, urea fertilizers 97.8, and urea-diammonium phosphate bulk blends 98. The relative standard deviation for the analytical system was 0.40%, and for the method, 0.70%. The sample preparation is short and simple. This method offers many advantages as a screening method for fertilizer industry and control laboratories.
Spectrophotometric Method for Hydroxymethylfurfural in Honey
Authors: White Jonathan W
Published: February 2020

A new method is described for hydroxymethylfurfural (HMF) in honey; accuracy and precision are improved over the most used optical and chemical methods. With a clarified honey solution containing 0.1% sodium bisulfite as reference and a similar solution without bisulfite as sample, a difference spectrum is obtained which represents only the HMF in the sample, without the interfering absorption of the honey. The average recovery was 97.5% for 24 additions to honey of 0.8-40 mg HMF/100 g. Forty honey samples ranging from 0 to 40 mg/100 g were analyzed by 3 methods with the following average results: Winkler optical method, 7.25; Winkler chemical method, 4.83; and new bisulfite method, 5.05 mg HMF/100 g honey. Values by the latter 2 methods did not differ at the P = 0.05 significance level.
Application of Orthogonal Functions to the Spectrophotometric Determination of Calciferol in Oily Injections
Authors: Hassan Sayed M
Published: February 2020

The method of orthogonal functions has been applied to the rapid spectrophotometric determination of vitamin D in oily injections. The method involves saponification of the sample and extraction of the unsaponifiable matter with ether. After cautious evaporation of ether, the residue is dissolved in isopropanol and the absorbance of the solution is measured in the range 246–296 nm at 10 nm intervals. For BPC injections, the saponification step may be omitted. A suitable dilution of the sample in isopropanol is measured in the range 250.5– 300.5 nm at 10 nm intervals. Accurate and precise results are obtained in both cases.
DC Polarography of Cephradine and Its Application to Capsules
Authors: Nuñez-Vergara Luis J , Squella Juan A , Gonzalez Ernesto M
Published: February 2020

A polarographic method has been developed for the quantitative analysis of cephradine and its dosage forms. Direct determinations on capsules are carried out; excipients and coloring matter do not interfere in the determination. The electroactive product is formed by acidic hydrolysis with 5.0N HCl and heating at 80°C for 60 min. Two polarographic waves are obtained: I = - 0.46 v and II = - 0.78 v vs. SCE. Both reduction waves are diffusion controlled. Wave I is preferred for analytical purposes. The precise chemical identity of the electroactive product has not been determined, but UV spectral data and the TLC Rf value are reported. A linear relation is established for levels of cephradine between 10-2 and 10-5M in 5.0N HCl.
Simultaneous Extraction and Fractionation and Thin Layer Chromatographic Determination of 14 Mycotoxins in Grains
Authors: Takeda Yuiko , Isohata Etsuko , Amano Ryuji , Uchiyama Mitsuru
Published: February 2020

A simple, systematic analytical method for multiple mycotoxins was developed for detecting 14 mycotoxins: aflatoxins Bl, B2, G1, and G2, sterigmatocystin, T-2 toxin, diacetoxyscirpenol, neosolaniol, fusarenon X, zearalenone, ochratoxin A, citrinin, luteoskyrin, and rugulosin. These mycotoxins were extracted with 20% H2SO4-4% KCl-acetonitrile (2+20+178), defatted with isooctane, and transferred to chloroform. The chloroform extract was cleaned up by silica gel column chromatography; the first 10 toxins were eluted with chloroform-methanol (97+3) and the remaining 4 toxins with benzene-acetone-acetic acid (75+20+5). Each fraction was analyzed by thin layer chromatography for the final determination. The method has been applied to polished rice, rough rice, corn, wheat, and peanuts as an analytical screening procedure. The detection limits in these commodities ranged from 10.0 to 800.0 μg/kg, depending on the mycotoxin, but all limits were superior to those obtained for the individual mycotoxins by using other methods.
High Pressure Liquid Chromatographic Determination of Aflatoxins in Corn
Authors: Pons Walter A
Published: February 2020

A high pressure liquid chromatographic (HPLC) method is proposed for determining aflatoxins in corn. The sample is extracted with methanol-10% NaCl (4+1) , pigments are precipitated with zinc acetate, and the extract is cleaned up on a small (2 g) silica gel column. Aflatoxins in the purified extract are resolved by normal phase HPLC on a microparticulate (10 μm) silica gel column with water-saturated chloroform-cyclohexane-acetonitrile solvent, and detected by fluorescence on a silica gel-packed flowcell. The method was compared with chloroform-water extraction of the official CB method on 15 samples of contaminated corn. In 5 of the 6 samples containing aflatoxins B1, B2, G1, and G2, methanol-10% NaCl extracted more aflatoxin than did cloroform-water, as measured both by HPLC and by thin layer chromatography. In samples containing only B1 and B2, the 2 extraction solvents were virtually equivalent. Agreement was good between HPLC and TLC for each extraction solvent. Average recovery of aflatoxins Bl, B2, Gl, and G2 added to yellow cornmeal at 3 levels was >90%.
Comparison of Mineral Wool Insulations in the Forensic Laboratory: Second Collaborative Study
Authors: Miller Elmer T
Published: February 2020

A method for comparing mineral wool insulationswas collaboratively studied a second time.Specimens are examined microscopically forcolor, disposition of resin, fiber diameters,quantity of slugs, and other gross microscopiccharacteristics. The resin is burned off and thefibers are annealed at 500°C. The heat-cleanedfibers are examined for shortwave ultravioletfluorescence, microscopic appearance, solubilityin HCI, and indices of refraction according to45.002-45.007. Ten collaborators examined 9specimens of mineral wool, 4 of which werefrom one large lot of Owens-Corning Fiberglasand 2 of which were from a single Johns-Manville ceiling tile. The other 3 were fromdifferent sources. Eight collaborators correctlyconcluded that the Owens-Corning samplescould have had a common origin, that theJohns-Manville samples could have had a commonorigin, and that the others were of independentlydifferent origins. Two collaboratorsin the same laboratory, using other than therecommended equipment, concluded that theOwens-Corning samples were one class, that theJohns-Manville samples were one class, andthat the others were of different origin, but theyfound slight differences in the refractive indicesof the Johns-Manville samples and did not concludecommon origin for them. The method hasbeen adopted as interim official first action.
Teratology
Authors: Staples Robert E
Published: February 2020

Two categories of collaborative studies are defined. Examples of each type are presented through teratologic studies conducted at the National Institute for Environmental Health Sciences (NIEHS) in collaboration with an Environmental Protection Agency laboratory and a laboratory in the USSR. These studies and the few pertinent studies found in the literature point out the problem of obtaining repeatability and uniformity of results among tests conducted to determine teratogenic potential. Collaborating laboratories should take more time to select the procedures to be used, to standardize the intended protocol in greater detail, to train participating personnel uniformly, and to test for repeatability by use of a known teratogen, before tackling major interests. Establishment of an archives would improve duplication of published results by making available additional pertinent unpublished information. Finally, possible advantages of collaborative studies for the testing of teratogenic potential are offered.
Comparison of Carcinogenicity Studies with Aldrin and Dieldrin
Authors: Ritper David L
Published: February 2020

Laboratory testing of animals is the principal method used to identify chemical carcinogens. However conflicting results are often obtained. This is emphasized in a cross-comparison of 6 aldrin-dieldrin studies; 3 were positive for tumor induction and 3 were negative. Four components of the assays are examined: husbandry, compound administration, observation, and interpretation of results.
Induction of Enzyme Activity in Cell Culture: A Rapid Screen for Detection of Planar Poly chlorinated Organic Compounds
Authors: Bradlaw June A , Casterline James L
Published: February 2020

Induction of aryl hydrocarbon hydroxylase (AHH) activity in rat hepatoma cell line serves as a simple and rapid method to detect minute (pg) amounts of certain classes of compounds, e.g., dibenzo-p-dioxins, dibenzofurans, and biphenyls. This method may provide a quick screen for such substances in extracts from foods prior to chemical identification. AHH activity is measured by conversion of benzo[a]pyrene (BP) to 3-hydroxy BP in homogenized cell extracts from control and treated cultures and is reported as pmol product formed/mg protein/min. Substances screened by this method include polyhalogenated analogs of dibenzo-p-dioxin (24 compounds), dibenzofuran (11 compounds), biphenyl (7 compounds), and extracts from several food sources. Response of the most reactive compound, 2,3,7,8-tetrachlorodibenzop- dioxin (TCDD) was used to prepare a standard curve, and the AHH activity induced by mole doses of test substance is reported as an ED50 response (the estimated dose needed to produce 50% maximum enzyme induction). The AHH activity induced by food extracts is equated to the standard curve and reported as TCDD equivalents. A potent ED50 response in cell culture appears to correlate well with known toxic responses in other mammalian and avian systems for certain test substances. This correlalation suggests that the cell culture enzyme induction method is a useful model for screening food extracts that are suspected to be contaminated with polychlorinated planar substances. A collaborative study would demonstrate the reproducibility of the method.
Gas Chromatographic Determination of 1,4-Dioxane in Polysorbate 60 and Polysorbate 80
Authors: Birkel Thomas J , Warner Charles R , Fazio Thomas
Published: February 2020

A gas chromatographic method is presented for the quantitative determination of 1,4- dioxane in polysorbate 60 and polysorbate 80. Dioxane is isolated from the matrix by closedsystem vacuum distillation with water as the carrier solvent. The distillate is chromatographed on Chromosorb 104 and detected by flame ionization. Recoveries of dioxane from polysorbate 60 samples fortified at 0.5, 1, 2, and 20 ppm averaged 90, 91, 85, and 75%, respectively. Recoveries from polysorbate 80 fortified at the same levels averaged 100, 88, 95, and 95%, respectively. Samples of polysorbate 60 and polysorbate 80 were found to contain from 5.5 to 378 ppm dioxane.
Gas-Liquid Chromatographic Determination of Sorbic Acid and Sodium Benzoate in Table Sirup
Authors: Zygmunt Lucian C
Published: February 2020

A gas-liquid chromatographic method is described for the simultaneous determination of sorbic acid and sodium benzoate in table sirup. The preservatives are extracted from acidified sirup with ethyl acetate and are analyzed on a gas chromatograph equipped with a flame ionization detector and a glass column (4 ft × 4 mm id) containing 9% SP-1200 and 2% H3PO4 on Chromosorb W (AW). Coefficients of variation for sorbic acid and sodium benzoate are 0.62 and 0.41%, respectively. Analysis time is less than 20 min, with recoveries exceeding 90%.
Effects of pH and Sodium Chloride Concentration on the Reaction Between Nitrite and Sulfanilic Acid/N-(Naphthyl)ethylenediamine
Authors: Hildrum Kjell Ivar
Published: February 2020

The reaction between nitrite and sulfanilic acid/N-(naphthyl) ethylenediamine has been investigated. In buffer systems, the rate of the reaction was pH-dependent with an optimum at pH 3.0 (±0.2). Adding sodium chloride to the system significantly increased the rate of the reaction.
High Pressure Liquid Chromatographic Determination of Pentachlorophenol by Using Paired Ion Chromatography Reagents
Authors: Hayes Elmer H
Published: February 2020

A high pressure liquid chromatographic (HPLC) method for determining pentachlorophenol in formulations is described. Samples containing pentachlorophenol are accurately weighed in suitable volumetric flasks and diluted with dioxane. The sample is then injected onto a stainless steel column containing μBondapak C18. The mobile phase is 60% methanol/PIC A and 40% water/PIC A. This method is simple and eliminates many of the extractions required in other methods of analysis.