bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Chromatographic Method for Multiresidue Determination of Benzimidazoles in Beef Liver and Muscle: Collaborative Study
Authors: Levan Leon W , Barnes Charlie J 
Published: February 2020

Abstract
A liquid chromatographic method for determination of thiabendazole, 5-hydroxythiabendazole, oxfendazole, mebendazole (MBZ), and fenbendazole (FBZ) In cattle liver and muscle was collaboratively studied in 7 laboratories In 1986. For blind fortified samples containing 800 ppb FBZ, average recovery and relative standard deviations for repeatability and reproducibility (RSDr and RSDR) based on results from 6 of the participating laboratories were 83%, 12.7%, and 14.0%, respectively. Recoveries of FBZ from incurred liver samples were more variable. Recoveries of MBZ from livers fortified at the 100 ppb level were encouraging; however, the drug levels were too low in the incurred samples used for MBZ studies. Except for FBZ and MBZ In liver, the study data were not satisfactory. The method has been adopted official first action by AOAC for determination of 800-1600 ppb fenbendazole In liver. The analysis should be repeated using a smaller sample size when Initial analyses show levels greater than 1600 ppb FBZ.
Rapid Immunochemical Screening Method for Afiatoxin B1 in Human and Animal Urine
Authors: Stubblefield R D , Greer J I , Shotwell O L , Aikens A M 
Published: February 2020

Abstract
A method has been developed to determine the presence of afiatoxin B1 in the urine of animals (including humans) by utilizing commercial immunochemical kits that can be used in the field. Urine is treated with diatomaceous earth and filtered to clarify the sample; 2-3 ppb afiatoxin B1, corresponding to about 300 ppb in the ingested feed/food, can be detected in the filtered urine without futher purification. To improve sensitivity, the urine filtrate is passed through a C18 solid phase column to extract the afiatoxin. The column is washed with acetonitrHe-water (15 + 85) and water, afiatoxin B1 is eiuted with methanol-water (7 + 3), and water is added to the eluate, which is then tested for afiatoxin with the test kit. The limit of detection is 0.2 ppb, reflecting consumption of 40 ppb or more afiatoxin In the feed/food. When the initial sample volume is adequate, purification through the C18 column step Is usually sufficient. For limited sample volumes, the eluate from the C18 column is mixed with water, added to an immunosorbent affinity column, and washed with water to remove excess sample matrix and impurities. Afiatoxin B1 is eiuted with acetonltrile. The extract is evaporated under nitrogen and the residue is redissolved in methanolwater (25 + 75). At this purification stage, the limit of detection is reduced to 0.05 ppb.
Multiresidue Screening Method for Fresh Fruits and Vegetables with Gas Chromatographic/Mass Spectrometric Detection
Authors: Liao Wenta , Joe Ton , Cusick William G 
Published: February 2020

Abstract
A gas chromatographic/mass spectrometric (GC/MS) screening method has been developed for the determination of pesticide residues in a variety of crop samples. Samples are extracted with acetonitrlle and partitioned with sodium chloride saturated aqueous solution. Targeted pesticide analytes are separated on a short, narrow bore capillary column, identified by electron ionization MS scanned from 100 to 400 amu, and quantitated by the monitoring of base ions and internal standards. The accuracy of the quantitative determination measured in terms of average percentage recovery of 143 compounds in 13 crop samples was 92% with a relative standard deviation of 22%.
Determination of Oxolinic Acid Residues in Salmon Muscle Tissue by Liquid Chromatography with Fluorescence Detection
Authors: Larocque Lyse , Schnurr Mary , Sved Stephen , Weninger Andrea 
Published: February 2020

Abstract
The present paper describes a method for determination of oxolinic acid in salmon muscle tissue. Tissue (0.5-2 g) mixed with 2 g anhydrous sodium sulfate is extracted twice with ethyl acetate, centrlfuged, and the extract evaporated. The residue is partitioned in a mixture of hexane and 0.01M oxalic acid and the aqueous phase chromatographed using fluorescence detection at 327 nm excitation and 369 nm emission. Calibration and standard curves are linear from 10-200 ppb and 100-2000 ppb at different sensitivity settings. Recoveries ranged from 71-83% in spiked blanks, with a CV of 4-10.3% over a 2-week period. Preliminary results in treated salmon were variable, possibly because some fish refused to eat medicated feed.
Lipid Globule Staining to Aid in Differentiating Bacillus Species
Authors: Harmon Stanley M , Kautter Donald A , Lancette Gayle 
Published: February 2020

Abstract
The use of the lipid globule stain to aid in differentiating the Bacillus cereus group (i.e., B. cereus, B. cereus var. mycoldes, and B. thurlnglensls) from other Bacillus species was investigated. Smears from colonies grown on suitable agar were made on precleaned slides, stained, and examined microscopically for characteristic deep blue lipid globules. The study included a total of 649 cultures of Bacillus species plus 143 Incompletely characterized Bacillus isolates from food. Only B. cereus, B. cereus var. mycoldes, B. thurlnglensls, B. megaterlum, and B. sphaerlcus were consistently positive for lipid globules, although at times, a few cells of B. aneurlnolyilcus and B. thlamlnolytlcus were also positive. The lipid globule stain procedure Is of value In differentiating Bacillus species, especially when performed by an experienced analyst and used in conjunction with tests for cell and spore morphology.
Clostridium perfringens
Authors: Labbé Ronald G 
Published: February 2020

Abstract
In the United States and Canada, Clostridium perfringens remains a leading cause of bacterial food poisoning in humans. It has been primarily associated with meat and poultry products prepared in food service establishments. Fecal spore levels of 104 or more per g are considered indicative of a food poisoning outbreak. However, elevated spore levels of this organism are frequently seen in healthy elderly individuals, an observation that complicates investigations of suspected outbreaks. Recent studies with this population indicate that fecal enterotoxin levels are a valuable and effective assay for confirming outbreaks due to this organism. With regard to the toxin itself, a membrane protein of 50 000-70 000 molecular weight has been isolated as a possible enterotoxin-receptor site. It is the subsequent action of the toxin on membrane structure that results in the loss of ions and fluid associated with illness. In addition, the enterotoxin gene has been cloned in E. coil and sequenced. Using toxin-specific DNA probes, only 6% of non-symptomatic farm animals were found to possess the enterotoxin gene, disproving the hypothesis that all strains of this organism can produce the toxin.
Efficiency of Two Commercial ELISA Kits Compared with the BAM Culture Method for Detecting Listeria in Naturally Contaminated Foods
Authors: Noah Charles W , Ramos Nora C , Gipson Virginia M 
Published: February 2020

Abstract
The efficiency of 2 commercial enzyme-linked Immunosorbent assay (ELISA) kite (Listeria-Tek™ and Tecra™) for detecting Listeria in naturally contaminated foods was evaluated and compared with that of the culture method described in the Bacteriological Analytical Manual (BAM). Both ELISAs use modified University of Vermont (UVM-1) medium as a primary enrichment; the BAM method uses Listeria enrichment broth. Secondary enrichments for Llsterla-Tek and Tecra, respectively, were Fraser broth and UVM-2, which contains additional acriflavln-HCI. When ELISA test results differed, secondary enrichments were tested against the other ELISA; Fraser broth was used to determine recovery rates because of Its superiority over UVM-2. Of the 178 food samples examined, the presence of Listeria was detected and culturally confirmed in 38, 37, and 40 samples by the BAM, Llsterla- Tek, and Tecra methods, respectively. Differences in results of the EUSAs compared with those of the BAM method were not statistically significant; however, differences between results of the 2 ELISA methods were significant. It was concluded that as rapid screening methods, the Llsteria-Tek and the Tecra kits qualify as alternative methods to the BAM cultural method.
Recovery of Salmonella from Shell Eggs
Authors: Stephenson Patricia , Satchell Felicia B , Allen Geraldine , Andrews Wallace H 
Published: February 2020

Abstract
A preenrlchment procedure and a direct selective enrichment procedure were compared for recovery of Salmonella artificially inoculated into liquid whole egg, egg yolk, and egg albumen. For liquid whole egg and egg yolk, the 2 procedures were comparable. With egg albumen, however, preenrlchment In lactose broth gave significantly higher recoveries than did direct selective enrichment in either selenite cystine or tetrathionate broths. The lactose preenrlchment procedure was used to determine the survival of S. enterltldla in egg yolk and egg albumen over a period of 7 days. As shown by most probable number determinations, counts of S. enterltldla Inoculated Into egg albumen decreased by 3 log units, whereas those in egg yolk did not change significantly. It is recommended, therefore, that only the egg yolk be examined for this pathogen. In a comparison of 5 different preenrlchment media (lactose broth, brain heart Infusion broth, trypticase soy broth, buffered peptone water, and nutrient broth), lactose broth was somewhat less productive than the other 4 media for the recovery of Salmonella from egg yolks. Trypticase soy broth gave the highest recovery.
Liquid Chromatographic Determination of Paralytic Shellfish Poisons in Shellfish After Prechromatographic Oxidation
Authors: Lawrence James F , Ménard Cathie 
Published: February 2020

Abstract
A liquid chromatographic method for quantitating paralytic shellfish poison toxins in shellfish has been developed in which the toxins are converted to fluorescent purines by prechromatographic oxidation under mildly basic conditions with hydrogen peroxide or periodate. The addition of ammonium formate to the periodate oxidation reaction greatly improved the yield of fluorescent derivatives for neosaxitoxin, gonyautoxin-1, B-2, and C-3 compared to the same reaction without ammonium formate. As little as 3-6 ng of each of the nonhydroxylated toxins and 7-12 ng of the hydroxylated compounds per gram of shellfish could be detected. Reversed-phase chromatography using ammonium formate in the mobile phase improved the chromatography of neosaxitoxin and B-2 compared to results obtained earlier. Because the oxidation products of neosaxitoxin and B-2 could not be separated, parent compounds were separated before oxidation by using an SPE-COOH ion exchange cartridge. The repeatability coefficient of variation for the oxidation reactions ranged from 3 to 8% for the peroxide reaction, and from 4 to 11 % for the periodate reaction, depending upon the individual toxin determined and its concentration in the extract (0.04-0.55 μg/g). The method was compared to the mouse bioassay and the postcolumn oxidation method. In most cases, results were comparable.
Simple Colorimetric Determination of Carrageenan in Jellies and Salad Dressings
Authors: Yabe Yoshie , Ninomiya Takahiro , Tatsuno Takashi , Okada Taro 
Published: February 2020

Abstract
A simple, rapid colorimetric method is described for the determination of carrageenan (CAR) in foods such as jellies and salad dressings. Alcian blue reagent is added to the sample solution prepared from these foods, then CAR is precipitated selectively as a CAR-alcian blue complex. The precipitate is dissolved in monoethanolamine and determined colorimetrically at 615 nm. Overall recovery for jelly was 93.3% with a coefficient of variation (CV) of 5.8%. Overall recovery for salad dressing was 91.9% with a CV of 3.0%. The detection limit was 0.05%. The results obtained by the proposed method were similar to those obtained by a capillary gas chromatography method.
Bacillus stearothermophilus Disk Assay for Determining Ampicillin Residues in Fish Muscle
Authors: Plakas Steven M , DePaola Angelo , Mox Michael B 
Published: February 2020

Abstract
The Bacillus stearothermophilus disk assay for penicillin in milk (AOAC official method) was adapted for the determination of ampicillin in fish muscle. The method was evaluated in 2 species of cultured fish: channel catfish and striped bass. Recoveries of ampicillin ranged from 99 to 104% when muscle specimens from both species were spiked at concentrations of 0.025-1.00 μg/g. The lower limit of determination (LOD) was 0.025 μg/g. The assay was applied to monitor the elimination of ampicillin from the muscle of striped bass after intravascular administration (dosage of 10 mg/kg body weight). The mean concentrations in the muscle declined from 1.160 μg/g at 2 h to 0.063 μg/g at 18 h. The half-life of ampicillin in the muscle was 3.6 h. Ampicillin concentrations were below LOD at 24 h. No inhibitory activity was observed in the muscle of control fish.
Sensitive and Rapid Reversed-Phase Liquid Chromatography–Fluorescence Method for Determining Bisphenol A Diglycidyl Ether in Aqueous–Based Food Simulants
Authors: Losada P Paseiro , Mahia P López , Odériz L Vázquez , Lozano J Simal , Gándara J Simal 
Published: February 2020

Abstract
A method has been developed for determination of bisphenol A diglycidyl ether (BADGE) in 3 aqueous-based food simulants: water, 15% (v/v) ethanol, and 3% (w/v) acetic acid. BADGE is extracted with C18 cartridges and the extract Is concentrated under a stream of nitrogen. BADGE is quantltated by reversed-phase liquid chromatography with fluorescence detection. Relative precision at 200 μg/L was 3.4%, the detection limit of the method was 0.1 μg/L, and recoveries of spiking concentrations from 1 to 8 μg/L were nearly 100%. Relative standard deviations for the method ranged from 3.5 to 5.9%, depending on the identity of the spiked aqueousbased food simulant.
Analysis of Organochlorine Pesticide Residues Using Simultaneous Injection of Two Capillary Columns with Electron Capture and Electrolytic Conductivity Detectors
Authors: Hopper Marvin L 
Published: February 2020

Abstract
A system has been developed that will allow low level screening of 31 organochlorine pesticide residues using simultaneous injection on 2 dissimilar capillary columns. An electron capture detector was attached to a DB-1701 column, and an electrolytic conductivity detector in the halogen mode was attached to a DB-5 column. Chlorinated pesticide amounts ranging from 0.05 ng for γ-BHC to 1.5 ng for decamethrin can easily be quantitated and confirmed. The system can be used in either the column programmed mode or the isothermal column mode. Good reproducibility was obtained for injections in both modes. This system can easily be retrofitted to any gas chromatograph using on column or split/splitless injectors.
GC/MIP/AED Method for Pesticide Residue Determination in Fruits and Vegetables
Authors: Ting Keh-Chuh , Kho Peng 
Published: February 2020

Abstract
This research describes the results of a gas chromatography/microwave induced plasma/atomic emission detection (GC/MIP/AED) method performed on a Hewlett-Packard 5921A system for pesticide residue analysis in fruits and vegetables. Atotal of 6 experiments were conducted: (1) sensitivity and linearity studies for elements S, P, CI, and N by analyzing dursban; (2) a study of instrument response to CI concentration in pesticide molecules; (3) organochlorinated pesticide recoveries; (4) organophosphate pesticide recoveries; (5) carbamate pesticide recoveries; and (6) investigation of metallic pesticides with pllctran and vendex as standards. The rank according to sensitivity and linearity was found to be as follows: S-181&gt;P-178&gt;CI-479&gt;N-174. Instrument response to the concentration of chlorine atoms in the pesticide molecule was linear, with a correlation coefficient of 0.89. Recoveries of organochlorinated pesticides were 91.7-109.3%, with the exception of citrus, whose recovery was affected by coeluting Interferences. Organophosphate recoveries were 73.2% or higher, except for the cygon oxygen analog, which degraded in the GC system under all circumstances. Carbamate recoveries were inconsistent quantitatively; however, the information generated from elements N and S were useful for qualitative confirmation of other methods, such as LC postcolumn derivatization analysis. Overall, the GC/MIP/AED method is powerful for qualitative confirmation in pesticide residue analysis. The instrument’s capability of acquiring multi-elements (CI and P) selectively and accurately is an alternative method for organochlorinated and organophosphate pesticide residue analyses. In addition, the GC/MIP/AED system is easy to use, simple to maintain, and its chromatograms can be interpreted by any chromatography analyst without much prior training.
CI-906 and CI-925 Cyclization in Rodent Chow Using Liquid Chromatography for Detection and Assay
Authors: Spurlock Carola H 
Published: February 2020

Abstract
Two ACE inhibitors, CI-906 and CI-925, cyclize rap- Idly to the corresponding dlketopiperazlnes PD109 488 and PD 114 009, respectively, in admixture with 5002 rodent chow. After 2 weeks storage at ambient temperature, 90% of the admixed CI-925 and 68% of the admixed CI-906 cyclized. Liquid chromatography (LC) was used to quantitate both parent drugs and cyclized products. Absence of fat and fish meal from the chow affects the reaction. With CI-925 as the test compound, 90% cyclized after only 3 days In fat-free chow, and 80% cyclized after 3 days In chow free of both fat and fish meal. Chow pre-extracted with methanol has less effect than does whole chow. After 2 weeks, 87% CI-925 remained. Cyclization of CI-925 in methanol solution Is also enhanced by the presence of chow extractables. After 2 weeks, 21-25% PD 114 009 was produced in fat-free diet extract, fat- and fish meal-free diet extract, and whole 5002 diet extract, compared to 4-5% produced in methanol alone. We concluded that 5002 chow contains one or more extractable components that promote cyclization of CI-906 and CI-925.
Soxtec Fat Analyzer for Determination of Total Fat in Meat:
Collaborative Study
Authors: Foster Max L , Gonzales Sharon E 
Published: February 2020

Abstract
A new method for determination of total fat in meat and meat products, which uses a commercially available extraction system, was collaboratively studied by 11 laboratories. The study compared the new Soxtec solvent extraction with the Soxhlet method. The new method reduces extraction time, enables recovery of 60-70% of the solvent, and improves safety through external heating. Each laboratory received 6 samples: canned ham, ground beef, frankfurters, fresh pork sausage, hard salami, and beef patties with added soy. Laboratories were Instructed to analyze each sample In duplicate on each of 2 days by both the Soxhlet and Soxtec methods. In general, results for the Soxtec system showed Improved performance. For all samples used in Soxtec analysis, ranges of values for repeatability and reproducibility were Sr, 0.106-0.764; RSDr, 1.01-2.44%; SR, 0.112- 0.799; and RSDR, 1.53-2.84%. The method was adopted first action by AOAC International.
Comparison of Monoclonal Antibody-Based Enzyme-Linked Immunosorbent Assay with Thin-Layer Chromatography and Liquid Chromatography for Aflatoxin B1 Determination in Naturally Contaminated Corn and Mixed Feed
Authors: Hongyo Ken-Ichi , Itoh Yukikatu , Hifumi Emi , Takeyasu Akira , Uda Taizo 
Published: February 2020

Abstract
A 1-step enzyme-linked Immunosorbent assay (EUSA) method, using a highly sensitive and specific monoclonal antibody to aflatoxin B1 (AFB1), was evaluated by comparison with other methods, Including liquid chromatography (LC) and thinlayer chromatography. The detection limit of the ELISA was as low as 100 pg/assay. AFB1 contents of naturally contaminated corn samples were determined by the 3 methods. The relationships among the methods were Investigated, and good correlations were observed. Mixed feeds were also subjected to AFB1 determination by the 3 methods. For our ELISA system, 3 types of sample preparations were tested. For analysis of mixed feed by ELISA, samples must first be purified by column chromatography. When the relationship between LC and ELISA was also investigated, results were found to have a good correlation coefficient.
Liquid Chromatographic Determination
of Fumonisins B1, B2, and B3 in Foods and Feeds
Authors: Sydenham, Eric W , Shephard, Gordon S , Thiel Peter G 
Published: February 2020

Abstract
Three recently described and toxlcologlcally Important Fusarlum mycotoxins, fumonisln B1 (FB1), fumonisln B2 (FB2), and fumonisln B3 (FB3), are the major fumonisins produced In cultures of F. monlllforme, a fungus that occurs worldwide on corn. Contamination of food and feed with F. monlllforme has been associated with a number of diseases In both animals and humans. Aspects of a recently reported liquid chromatographic method for the determination of FB1 and FB2 in corn, including Initial extraction, extract purification, and stability of derivatives, were Investigated and, where necessary, optimized further both to reduce the analysis time and to include the co-determlnatlon of FB3. The method was applied for the determination of FB3, in a series of U.S. feed samples associated with outbreaks of equine leukoencephalomalacla, which were shown previously to contain both FBi and FB2. Twelve of the 13 feed samples contained FB3 at levels ranging between 50 and 2650 ng/g, corresponding to 2.2-18% of the total fumonisln concentrations present in the FB3-posltlve feed samples. This is the first report of the natural occurrence of FB3.
Matrix Solid-Phase Dispersion Isolation and Liquid Chromatographic Determination of Oxolinic Acid in Channel Catfish (Ictalurus punctatus) Muscle Tissue
Authors: Jarboe Herman H , Kleinow Kevin M 
Published: February 2020

Abstract
Matrix solid-phase dispersion Isolation and liquid chromatographic techniques were developed to quantify oxolinic acid (OA) and OA-related metabolites in channel catfish (Ictalurus punctatus) muscle tissue and bile. Mean percent recovery, correlation coefficient, and inter- and intra-assay variabilities were 82.8 ±15.0%, 0.996 ±0.004,12.5 ±8.9%, and 1.22%, respectively, for OA Isolated from fortified muscle tissue. Using the methodologies described in the current study, incurred OA In muscle tissue and 4 OA-related metabolites were Isolated In the bile of dosed catfish.
Solid-Phase Extraction Method for Volatile N-Nitrosamines in Hams Processed with Elastic Rubber Netting
Authors: Pensabene John W , Fiddler Walter , Gates Robert A 
Published: February 2020

Abstract
A method was developed for the determination of volatile N-nitrosamines in hams processed In elastic rubber nettings. The method was based on a modification of a solid-phase extraction (SPE) procedure used in the past to determine selected nitrosamines in different types of cured meat products. The nitrosamines detected in ham most likely originate from the amine precursors in rubber and from the nitrite commonly used in the meat curing process. The method was compared with 2 established procedures for N-nitrosodibutylamine (NDBA) analysis in cured meat products: the mineral oil distillation procedure (MOD) and the low temperature vacuum distillation procedure (LTVD). All 3 methods used the same gas chromatographic/chemlluminescent detection conditions and system. No significant difference was found between the MOD and LTVD methods. These methods were found to yield significantly higher NDBA levels than the SPE procedure. When 2,6-dimethylmorpholine was added to the sample before analysis in the MOD and LTVD procedures, artifactual nitrosamines were formed. No artifactual formation was noted in the SPE method. We propose that the new SPE method replace the current methods being used for analysis of netted, cured meat products.