bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bacillus cereus
Authors: Jackson Susan G 
Published: February 2020

Abstract
Bacillus cereus is an environmentally ubiquitous, Grampositive, spore-forming bacillus responsible for 2 distinct foodborne disease syndromes as well as other manifestations of pathogenicity. The rapid-onset, "emetic," foodborne-disease syndrome is associated with an emetic toxin; the delayed-onset, "diarrheal" syndrome is associated with elaboration of enterotoxin. The majority of methods for detection of these toxins have relied on In vivo testing. More recent work on purification of enterotoxin facilitated the development of a rapid, specific, fluorescent Immunodot assay and a tissue culture screening assay for enterotoxin. Work on characterization and detection of emetic toxin is ongoing
Modifications to the Official Method for Testing Chlortetracycline HC1 in Animal Feeds
Authors: Hasselberger Mary Lee 
Published: February 2020

Abstract
Results are compared for the microbiological analysis of chlortetracycline using the AOAC method and a modified method applicable to potencies above 50 g/ton. Two modifications are presented: substitution of a pH range of 4.0-4.5 instead of the specified pH of 4.5 for the plating solution, and substitution of extraction by shaking instead of the blending procedure. There were no significant differences in results between the AOAC method and the modified method
Single-Laboratory Evaluation of Method 8060 for the Determination of Phthalates in Environmental Samples
Authors: Avila Viorica Lopez , Milanes June , Beckert Werner F 
Published: February 2020

Abstract
Method 8060 of the SW-846 methods manual for the determination of phthalates In aqueous and solid matrixes was modified and evaluated in a single laboratory. The range of compounds of interest was expanded to 16 phthalates. The results of a study to determine the extent and the sources of phthalate contamination in the laboratory and ways to minimize background contamination, conducted as part of this work, were reported elsewhere. The packed columns specified in Method 8060 for the gas chromatographic analysis were replaced with 2 fused-silica open-tubular columns of dissimilar stationary phases. These columns were connected to an inlet splitter and 2 electron capture detectors; this dual-column/ dual-detector setup allowed the primary and confirmatory analyses to be conducted simultaneously. Extracts were cleaned up by column chromatography on 10 g Florisil or alumina. Of the 16 target compounds, only 13 were recovered from the Florisil column (Method 3620), but all 16 were recovered from the alumina column (Method 3610). The use of commercially available Florisil and alumina solid-phase extraction cartridges for sample extract cleanup was evaluated, and a method that uses such cartridges (Florisil or alumina) was developed. This latter method gave quantitative recoveries for all 16 compounds. The effects of interferences represented by corn oil, dlesel hydrocarbons, and elemental sulfur were evaluated, and an internal standard and 3 surrogate compounds were identified and proposed for use with this method. The revised method was tested with samples of an estuarine water, a leachate, a groundwater, an estuarine sediment, a municipal sludge, and a sandy loam soil, each spiked with the 16 phthalates. For the aqueous samples spiked at 20 and 60 μg/L, the method accuracy ranged from 60 to 117% and method precision was better than 28%. The method accuracy and precision for solid samples extracted by Method 3550 were highly dependent on matrix type and on analyte concentration.
Microwave Acid Digestion of Various Food Matrixes for Nutrient Determination by Atomic Absorption Spectrophotometry
Authors: Oles Philip J , Graham Wanda M 
Published: February 2020

Abstract
Food matrixes were digested by treatment with nitric acidsulfuric acid-hydrogen peroxide mixtures and heating with a commercially available microwave apparatus. The digests were analyzed for sodium, potassium, magnesium, iron, calcium, zinc, copper, and manganese content by flame atomic absorption spectrophotometry. A total of 3 digestion programs were adopted for a variety of food matrixes. Microwave digestion times of 30-45 mln were normally sufficient for obtaining clear digests compared to hot plate digestion times of 8-12 h. Precision for microwave digestion of most nutrients was equal to or better than that of hot plate digestion. Microwave digestion gave comparable results for the nutrient elements. National Institute of Standards and Technology reference materials were analyzed for nutrient content after microwave digestion and the results compared favorably with the certified values. A laboratory breakfast cereal control sample with a history of over 20 separate hot plate digestions was prepared using the microwave technique. Results for the 8 elements were within ±7% of the hot plate digestion values. Predlgestlon spikes were recovered from several food matrixes with no effects resulting from Incomplete digestion of samples.
Gas Chromatographic Determination of Captan, Folpet, and Captafol Residues in Tomatoes, Cucumbers, and Apples Using a Wide-Bore Capillary Column:
Interlaboratory Study
Authors: Gilvydis Dalia M , Walters Stephen M 
Published: February 2020

Abstract
An interlaboratory study of the determination of captan, folpet, and captafol in tomatoes, cucumbers, and apples was conducted by 4 laboratories using wide-bore capillary column gas chromatography with electron capture detection. The 3 fungicides were determined using the Luke et al. multlresidue method modified to Include additional solvent elutlon in the optional Florisll column cleanup step used with this method. The crops were fortified with each fungicide at 3 levels per crop. Mean recoveries ranged from 86.2% for a 25.1 ppm level of captan in apples to 115.4% for a 0.288 ppm level of captafol In apples. Interlaboratory coefficients of variation ranged from 3.4% (24.7 ppm folpet) to 9.7% (0.243 ppm captafol) for tomatoes; from 2.8% (2.0 ppm captafol) to 8.2% (24.8 ppm captan) for cucumbers; and from 1.5% (0.234 ppm folpet) to 22.1% (0.266 ppm captafol) for apples.
Residue Analysis of Glyphosate and Its Principal Metabolite in Certain Cereals, Oilseeds,and Pulses by Liquid Chromatography and Postcolumn Fluorescence Detection
Authors: Wigfield Yuk Y , Lanouette Monique 
Published: February 2020

Abstract
A postcolumn liquid chromatographic method to determine the extractable residues of glyphosate (GLYPH) and its principal metabolite, (amlnomethyQphosphonic acid (AMPA), In various cereals and beans Is described. The finely ground sample Is extracted with a mixture of chloroform and water, and the resulting aqueous layer is passed through a cation exchange column. The eluate is adjusted to pH 7-10 and passed through an anion exchange column. The second column is eluted with 0.3M HCI solution and the resulting acidic eluate Is analyzed with liquid chromatography coupled with postcolumn fluorescence detection. The mean recoveries for GLYPH In barley, canola, dry pea, flax, soybean, wheat, and white bean ranged from 90.9 to 98.1%, with coefficients of variation (CV) from 2.9 to 10.0% and limits of detection (LOD) from 0.07 to 0.14 ppm. Similarly, mean recoveries for AMPA in the same crops ranged from 87.4 to 98.9%, with CV from 4.6 to 7.7% and LOD from 0.05 to 0.12 ppm. Using this method, an analyst can routinely analyze 6 samples per 1.5 days. The advantages of this procedure are discussed
Time Required to Achieve Homogeneity of Test Substances Added to Dog Feed
Authors: Sapienza Philip P , Ikeda George J , Warr Patricia I , Albert Richard H 
Published: February 2020

Abstract
The homogeneity of test substances in a carrier (animal feed) is a critical factor In conducting long-term feeding studies in laboratory animals. A method for determining the adequate amount of mixing to achieve homogeneity by a mixer of the type described has been determined when 2 distinctly different compounds are added to ground dog feed. Nicotinic acid and butylated hydroxyanlsole at a concentration of 1% were separately mixed with the dog feed for 15,30,45,60, and 120 min to determine optimum mixing time. Test portions were taken from 4 different sampling sites at each time period and analyzed in duplicate for the added substance. Four batches were prepared and the results were aggregated. Very little interbatch variability was observed. The variance of the average values from the 4 sampling sites at each time period was calculated and used as a simple, crude, but effective numerical quantity to monitor the approach to homogeneity of the mixture.
Validation of Methods Used in the Florida Department of Agriculture and Consumer Services' Chemical Residue Laboratory
Authors: Parker Gail Abbott 
Published: February 2020

Abstract
Very few methods for detecting residues of pesticides in food or agricultural samples have undergone rigorous collaborative study and possess official AOAC status. The Chemical Residue Laboratory has formalized a method validation scheme to use when incorporating or developing new, unofficial methods. These methods are validated by assessing certain performance parameters: scope, specificity, linear range, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ). For accuracy and precision assessment, 12 replicate fortifications must yield recoveries within the range of 70-120% with a coefficient of variation (CV) that compares favorably to the Horwitz CV. LOD and LOQ are equivalent to 3 and 10 times, respectively, the background signal contributed by a sample matrix blank. This criterion that we use for LOD/LOQ is not universal. In fact, because of differing definitions, we have encountered difficulties in enforcing a tolerance by using a registrant's method. This paper also presents an example of our method validation scheme, using a recent method development project for detecting sulfamethazine in raw milk. The sulfamethazine project also revealed unanticipated personnel problems, underscoring the importance of the human factor in quality assurance.
Optimization of Sample Introduction Parameters for Determinations of Pesticides by
Capillary Gas Chromatography Using a Two Column, Two Detector System
Authors: Penton Zeldae E 
Published: February 2020

Abstract
A study was undertaken to determine if another injection mode could be substituted for splitless Injection in the trace analysis of pesticide samples. This technique often leads to problems such as carryover, poor repeatability, and breakdown of labile pesticides. Two capillary injectors were compared: a hot splitless injector and a temperature- programmable Injector, in which the sample is introduced into a glass insert under nonvaporizing conditions. With each injector, 2 columns of different polarity were Installed and a test sample containing a variety of pesticides was split between the 2 columns immediately after introduction. The effects of changing parameters such as Injector temperature, injection speed, method of installation of the 2 columns, and method of filling the syringe were examined for splitless injection. K was concluded that optimization is more difficult with splitless injection. Additionally, a comparison of precision and discrimination data demonstrated superior performance with the nonvaporizlng temperature-programmable Injector.
General Method for Determination of Pesticides in Soil Samples from Pesticide Mixer/Loader Sites
Authors: Taylor Sue G 
Published: February 2020

Abstract
A method was developed using gas and liquid chromatography (GC and LC) for the general pesticide screening of soil samples from mixer/loader sites. Samples were extracted in methanol-acetone in a sonicator and concentrated before analysis. Capillary GC with flame ionization detection and LC-dlode array were used for the screening of the soil extracts. Chromatograms were compared to standard tables for possible matches, and spectral confirmation was achieved In every case before a finding was reported as a contaminant. Also, the confirmed contaminations were quantltated on at least 2 weighings of the sample with at least 2 separate standards. Spike recoveries were performed for all soils found to contain a pesticide contaminant to determine the effect of the soil matrix on the extraction of the pesticide. Spike recovery and reproducibility data suggest that the method can be used effectively to determine pesticide contaminants in soil samples. The proposed method is a general method for screening many types of soils for many kinds of pesticides
Degradation of Organophosphorus Pesticides in Coastal Water
Authors: Wang Tsen C , Hoffman Marisae.E 
Published: February 2020

Abstract
Organophosphorus pesticides, such as malathlon and parathlon, ars considered to be a relatively safe group of pesticide chemicals. Once pesticides ars deposited to the coastal water, they could undergo chemical, photochemical, and biological processes. This study was mads to determine the persistence and dsgradation of both malathlon and parathlon In the Indian River estuary, which is located along the east coast of Florida. Hydrogsn ion concentration, temperature, salinity, and microorganisms affected the persistence of both malathlon and parathlon in the Indian River estuary. Alkaline hydrolysis was ths most competitive pathway for malathlon degradation. Only slight biological and photolytical degradation of malathlon was observed. By contrast, biological interaction was the most significant pathway for parathlon degradation. Alkaline hydrolysis and sunlight photolysis were only secondary pathways In the degradation of parathlon. The half-lives for parathlon and malathlon In the Indian River water (24 ppt salinity; pH 8.16) were 7.84 and 1.65 days, respectively.
Analytical Evaluation of the Globulin Proteins of Cottonseed Meals
Authors: Marshall Henry F , Conkerton Edith J 
Published: February 2020

Abstract
A method for the analytical evaluation of the globulin (saltsoluble) fraction of cottonseed meals has been developed. Cottonseed of 14% moisture content is stored for 6 and 9 weeks at 50°C. Meals obtained after seeds are defatted with pet ether are analyzed for nitrogen content, and then extracted with water. Residues are then extracted with 10% NaCI to isolate the globulin fraction. This fraction is characterized by liquid chromatography (LC) and gel electrophoresis (LDS-PAGE). Kjeldahl analyses showed no loss of nitrogen in meals from stored seed compared with those from unstored seeds. However, a large decrease in NaCI extractable nitrogen was noted in meals from stored cottonseed. LC and LDS-PAGE showed that an alteration of the globulin proteins occurred during storage, and the method demonstrated a progressive change in the 11S and 7S components of the globulin fraction.
Analysis of Trypsin Inhibitors and Lectins in White Kidney Beans (Phaseolus vulgaris, var. Processor) in a Combined Method
Authors: Roozen Jacques P , de Groot Jolan 
Published: February 2020

Abstract
Buffered saline extraction, affinity chromatography, and Folin-BSA protein assay were used consecutively to provide a combined method for analysis of trypsin inhibitors and lectins in white kidney beans (Phaseolus vulgaris, var. Processor). The method was tested by following the decrease of both antinutritional factors by germination of the beans for 7 days at 20°. Repeatability coefficients of variation were 2-7.4% for the trypsin inhibitors and 2.2-10% for the lectins. After 7 days of germination, trypsin inhibitors and lectins were reduced by 72 and 92%, respectively.
Evaluation of Methods for Detection of Listeria monocytogenes in Foods: NMKL Collaborative Study
Authors: Westöö Anna , Peterz Mats 
Published: February 2020

Abstract
Eleven Nordic laboratories participated in a collaborative study on qualitative methods for the detection of Listeria monocytogenes in foods. Two enrichment methods (U.S. Department of Agriculture, Food Safety and Inspection Service method for meat, and modified U.S. Food and Drug Administration/International Dairy Federation method for dairy products) and 2 agar media (lithium chloride-phenylethanol-moxalactam (LPM) and Oxford agar) were compared. The effect of treatment of the enriched culture with KOH before plating was also studied. Food samples, blue and white mold cheese and canned corned beef, were Inoculated with 3 levels of L. monocytogenes. Beef was also Inoculated with a microbial flora derived from raw meat. The recoveries of L. monocytogenes using the 2 enrichment methods did not differ significantly. The Oxford agar was superior to the LPM agar. KOH treatment of the enriched culture did not significantly increase the detection rate of the organism. For cheese, the detection level of the methods was below 0.2 cfu L. monocytogenes/g and for meat, the detection level was below 5 cfu L monocytogenes/g.
Simultaneous Liquid Chromatographic Determination of Fenamiphos and Its Metabolites in Soil
Authors: Khazanchi R , Walia S , Handa S K 
Published: February 2020

Abstract
A reversed-phase liquid chromatographic method has been developed for the determination of fenamiphos and the metabolites fenamiphos sulfoxide, fenamiphos sulfone, 3-methyl-4-(methylthlo)- phenol, and 3-methyl-4-(methylsulflnyl)phenol. Trace quantities of the nematlclde and Its metabolites In soil can be determined simultaneously. The limit of detection of the method was 5 ppm. Recoveries of fenamiphos and Its degradation products at fortification levels of 25,50, and 100 ppm ranged from 99.2 to 100.8%. Standard deviations ranged from 0.29 to 0.70 ppm.
Batching Oils on Sisal Bags Used for Packaging Foods:
Analysis by Coupled LC/GC
Authors: Grob Konrad , Artho Anna , Biedermann Maurus , Caramaschi Adrian , Mikle Heinz 
Published: February 2020

Abstract
Sisal fibers are treated with a batching oil before spinning. Such oils usually consist of mineral oil products and cause considerable contamination of the packed foods (typically 10-100 mg/kg). Batching oils recovered from sisal bags previously used for transporting cocoa and coffee beans were analyzed for total concentrations on the bag as well as the composition of the paraffins and aromatics. Concentrations of total hydrocarbons ranged between 0.3 and 39 g/kg sisal bag; concentrations of aromatics ranged between &lt;0.1 and 2.7 g/kg. The applied batching oils varied between raw mineral oil fractions, somewhat purified fractions, and a crystallized product.
Evaluation of Method for Enumeration of Brochothrix thermosphacta in Foods
Authors: Peterz Mats 
Published: February 2020

Abstract
A method for enumeration of Brochothrix thermosphacta In foods was evaluated in a collaborative study. Freeze-dried mixtures of bacteria were used as simulated food samples. Fifteen laboratories analyzed 2 negative control samples and 4 blind duplicate samples containing different levels of B. thermosphacta. The freeze-dried samples were reconstituted and spread on the surface of streptomycin sulphate-thallous acetate-actidlone agar and Incubated 2-3 days at 20-25°C. The method shows good repeatability (0.13) and reproducibility (0.21). Reproducibility might be Improved by specifying a more exact Incubation temperature. The number of false-positive results was rather high, but could be diminished if a catalase test was Included and the oxidase test performed by using commercial strips instead of by allowing a solution of an oxidase reagent (tetramethyl-p-phenylenedlamlne dlhydrochloride) to flow over the agar surface.
Liquid Chromatographic Determination of Cyclopiazonic Acid in Corn and Peanuts
Authors: Urano, Takashi , Trucksess, Mary W , Matusik Jean , Dorner Joe W 
Published: February 2020

Abstract
A liquid chromatographic (LC) method Is described for the determination of cyclopiazonic acid (CPA) in corn and peanuts. CPA was extracted from the test portion with methanol-2% NaHC03 solution (7 + 3); the extract was defatted with hexane and then acidified. CPA was partitioned into chloroform and applied to a Sep-Pak silica cartridge. CPA was eluted with chloroform-methanol (3 + 1), the solvent was evaporated, and the residue was dissolved In methanol- water (60 + 40). CPA was quantitated by reversed- phase LC with a linear gradient of 0-4mM ZnS04 In methanol-water (85 + 15) and UV measurement at 279 nm. Recoveries of CPA from corn spiked over the range of 50-500 ng/g and peanuts spiked over the range of 100-500 ng/g were 72-84% and 74-80%, respectively. The limits of quantitation for CPA in corn and peanuts were about 50 and 100 ng/g, respectively. CPA (820 ng/g) was found In corn naturally contaminated with anatoxin Bi, and CPA Identity was confirmed by tandem mass spectrometry.
Determination of Mono- and Disaccharides in Foods by Interlaboratory Study: Quantitation of Bias Components for Liquid Chromatography
Authors: Bugner Emmanuel , Feinberg Max 
Published: February 2020

Abstract
In 1988, a group of French food manufacturers decided to validate the methods used to determine mono- and disaccharides in foods (fructose, glucose, sucrose, maltose, and lactose) based on liquid chromatography with refractive Index detection. Twenty laboratories analyzed 12 products. The reproducibilities obtained exceeded Horwltz's criteria but were still acceptable because laboratories used different equipment and the sample matrixes were complex. Six different sources of variation were characterized because of a more complex experimental design. The method for calculating concentration, In particular, had considerable impact on the final precision; the choice between peak area and peak height must be strictly considered.
Gas Chromatographic Determination of Dimethoate Residues in Chrysanthemums and Soil
Authors: Wu Jia-Lun , Fan De-Fang 
Published: February 2020

Abstract
A gas chromatographic (GC) method was developed for determination of dimethoate residues In chrysanthemums and soil. Dry flowers, fresh flowers, and leaves of chrysanthemum and soil samples are extracted with acetone, cleaned up by coagulation, and partitioned with dlchloromethane. Dimethoate is determined by GC with nitrogenphosphorus detection. Recovery ranges of dimethoate from samples of dry flowers, fresh flowers, and leaves of chrysanthemums are 86.7-91.0% (fortified at 0.5-2.0 ppm), 88.1-93.6% (fortified at 0.036- 0.721 ppm), and 83.3-96.9% (fortified at 0.5-1.31 ppm), respectively. Recovery ranges of dimethoate from soil samples are 93.0-104% (fortified at 0.125- 0.327 ppm). Average recoveries of the 4 kinds of samples (n = 9) are 88.4 ± 8.94%, 91.5 ± 4.18%, 91.1 ± 4.69%, and 97.3 ± 5.1 %, respectively
Matrix Solid-Phase Dispersion Extraction and Liquid Chromatographic Determination of Ivermectin in Bovine Liver Tissue
Authors: Schenck Frank J , Barker Steven A , Long Austin R 
Published: February 2020

Abstract
A method for the isolation and liquid chromatographic (LC) determination of the antiparasitic drug ivermectin in bovine liver is presented. Liver samples (0.5 g) are blended with 2 g C18 (octadecylsilylderivatized silica packing material). A column made from the C18liver matrix is washed with 3 mL hexane, then the ivermectin is eluted with methylene chloride-ethyl acetate (3 + 1). After purification by alumina solid-phase extraction, the ivermectin is derivatized and analyzed by LC with fluorescence detection. The overall recovery of ivermectin added to liver was 74.6%. The lowest level validated in tissue by the method was 10 ppb, and the limit of detection was 1 ppb. This method and a classical extraction method gave comparable results for a liver sample that contained incurred ivermectin residues. The method uses small volumes of solvents, has a limited number of sample manipulations, and does not require solvent partitioning or backwashing of extracts. These characteristics make this method attractive when compared to classical isolation procedures for ivermectin.