bluuebunny/crossref_metadata_2025 huggingface dataset:
Abundance of the Sugarcane Borer (Lepidoptera: Crambidae) and Foraging Ants (Hymenoptera: Formicidae) in Sugarcane Grown on Organic and Mineral Soils in Florida
Authors: Roldán Erik L , Beuzelin Julien M , VanWeelden Matthew T , Cherry Ronald H
Published: February 2020

A study was conducted in Florida to determine sugarcane borer, Diatraea saccharalis (F.), injury and infestation levels in sugarcane (Saccharum spp. hybrids), D. saccharalis parasitism rates, and ant foraging activity in 32 commercial fields as affected by soil type (shallow organic vs deep organic vs mineral). In 2017 and 2018, each field was sampled four times during the summer for D. saccharalis by inspecting 100 sugarcane stalks and for foraging ants using plastic tubes baited with hot dog at 12 locations. One non-parasitized D. saccharalis larva was collected in 2017 and in 2018 out of 12,100 and 12,600 stalks sampled, respectively. Additional sampling of 50 stalks per field in October showed that 0.6% (2017) and 0.1% (2018) of the sugarcane stalks had bored internodes, and one Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) cocoon mass was observed. Seven ant species foraged in sugarcane fields, including the red imported fire ant, Solenopsis invicta Buren, which was the most abundant ant. Solenopsis invicta was not affected by soil type; however, sugarcane fields on shallow organic soils might represent a more suitable environment. The third most abundant foraging ant, Nylanderia bourbonica (Forel), was more abundant in mineral soil fields than in shallow and deep organic soil fields. Results suggest that D. saccharalis population levels in Florida sugarcane are extremely low under current production conditions regardless of soil type. In addition, the observation of C. flavipes, S. invicta, and six other ant species suggest that biological control contributes to these low D. saccharalis population levels.
Difficult diagnosis of cardiac haemochromatosis: a case report
Authors: Sudmantaitė Vaida , Čelutkienė Jelena , Glaveckaite Sigita , Katkus Rimgaudas
Published: February 2020

Background

Primary iron overload cardiomyopathy is an important and potentially preventable cause of heart failure (HF), usually manifesting in the 4–5th decade of life. Patients may be asymptomatic early in the disease with hidden progression of cardiac dysfunction. The challenge of timely detection is an awareness of this systemic disorder and an adequate degree of clinical vigilance.

Case summary

A 48-year-old man was referred to the university clinic due to the episode of atrial fibrillation. The specific features of bronze skin and yellow eyes together with a combination of syndromes (cardiomyopathy, cirrhosis, ascites and portal hypertension, diabetes mellitus, and chronic kidney disease) stimulated the testing of iron metabolism markers, which were far above the normal range. Echocardiography and cardiac magnetic resonance (CMR) showed the dilatation of all cardiac cavities and biventricular systolic dysfunction. CMR T2* mapping was consistent with the diagnosis of myocardial and hepatic siderosis. Hereditary Type I haemochromatosis was confirmed by a genetic test. After 6 months of standard HF treatment, chelation therapy with deferiprone and regular phlebotomies imaging tests showed a reduction of ventricular and atrial volumes, an improvement in the cardiac systolic function and a decrease of iron accumulation.

Discussion

In this case, complicating syndromes were detected earlier than underlying disease of primary haemochromatosis. Cardiac haemochromatosis should be considered in any patient with unexplained HF, especially in the case of a positive family history, abnormal liver enzymes, endocrinopathies, or evidence of involvement of other organ systems. Screening for systemic iron overload with transferrin saturation and serum ferritin is the first step. Further non-invasive imaging tests should be done to confirm organ involvement.
Operationalizing triple bottom line harvest strategies
Authors: Dichmont Catherine M , Dowling Natalie A , Pascoe Sean , Cannard Toni , Pears Rachel J , Breen Sian , Roberts Tom , Leigh George M , Mangel Marc
Published: February 2020

Over the past 50 years, the diversity of fisheries types being actively managed has changed from mainly data-rich, industrial sectors to more socially, economically, and environmentally complex multispecies and multisector fisheries. Accompanying this change has been a broadening of management objectives to include social and economic considerations with traditional resource sustainability objectives, the so-called triple bottom line, and the need to include these considerations into harvest strategies. The case of a line fishery in Australia’s Great Barrier Reef is used as a demonstration of the first steps in implementing triple bottom line harvest strategies. This fishery has several disparate sectors including commercial, tourism, and recreation; targets multiple but important reef species; and is undertaken in a World Heritage Site. This work highlights the need for a much-expanded set of objectives elicited from stakeholders that are either included in the trade-off analyses of the different harvest strategies or directly in an optimization. Both options demonstrated that a paradigm shift is required to emphasize representative participatory management systems that assemble teams from quite different backgrounds and viewpoints; use much broader set of objectives; and modify tools and (especially) the data collected within revised monitoring programmes to underpin these tools.
The Elliptic Tail Kernel
Authors: Cuenca Cesar , Gorin Vadim , Olshanski Grigori
Published: February 2020

We introduce and study a new family of $q$-translation-invariant determinantal point processes on the two-sided $q$-lattice. We prove that these processes are limits of the $q$–$zw$ measures, which arise in the $q$-deformation of harmonic analysis on $U(\infty )$, and express their correlation kernels in terms of Jacobi theta functions. As an application, we show that the $q$–$zw$ measures are diffuse. Our results also hint at a link between the two-sided $q$-lattice and rows/columns of Young diagrams.
Disposable Cartridge Extraction of Retinol and Alpha-Tocopherol from Fatty Samples
Authors: Bourgeois Claude Fernand , Ciba Nadine
Published: February 2020

A new approach is proposed for liquid/solid extraction of retinol and α-tocopherol from samples, using a disposable kieselguhr cartridge. The substitution of the mixture methanol-ethanol-n-butanol (4 + 3 + 1) for methanol in the alkaline hydrolysis solution makes it now possible to process fatty samples. Methanol is necessary to solubilize the antioxidant ascorbic acid, and a linear chain alcohol such as n-butanol is necessary to reduce the size of soap micelles so that they can penetrate into the kieselguhr pores. In comparisons of the proposed method with conventional methods on mineral premixes and fatty feedstuffs, recovery and accuracy are at least as good by the proposed method. Advantages are increased rate of determinations and the ability to hydrolyze and extract retinol and α-tocopherol together from the same sample.
Determination of Ammonium Ion in Povidone by Derivatization and Square Wave Voltammetry
Authors: Ianniello Robert M
Published: February 2020

A rapid and precise method is described for the determination of residual ammonium ion in povidone (polyvinylpyrrolidone). Formaldehyde reacts with ammonium ion at pH 4 to yield hexamethylenetetramine, which is reducible at ca −0.9 V vs Ag/AgCl. The derivative is detected using square wave voltammetry and is quantitated by the method of standard additions.
Rapid Determination of Aflatoxins in Raw Peanuts by Liquid Chromatography with Postcolumn Iodination and Modified Minicolumn Cleanup
Authors: Dorner Joe W , Cole Richard J
Published: February 2020

A method is described for rapid cleanup followed by reverse-phase liquid chromatographic (LC) quantitation of aflatoxins in raw peanuts. A modified minicolumn cleanup is used for sample preparation, and a preliminary estimation of aflatoxin content by minicolumn can be made so that highly contaminated samples can be diluted before LC analysis. The use of the simple, quick minicolumn cleanup eliminates the need for further column or cartridge cleanup, thus greatly reducing sample preparation time. Sensitive quantitation is achieved using a phenyl column, a mobile phase of water-tetrahydrofuran (80 + 20, v/v), and postcolumn derivatization with water-saturated iodine followed by fluorescence detection. The recoveries of aflatoxins B1, B2, G1, and G2 from peanut meal spiked at 3 levels ranged from 71.7 to 88.3% (average 80%) with coefficients of variation from 2.7 to 10.4%.
Spectrophotometric Method for the Microdetermination of Bendiocarb Standard Residues in Water
Authors: Handa Swadesh K
Published: February 2020

A spectrophotometric method has been developed for the microdetermination of bendiocarb in water. The method is based on the reaction of bendiocarb phenol resulting from the hydrolysis of bendiocarb with nitric acid to form a yellow complex with an adsorption maximum at 420 nm. The method is applicable for estimation of residues of bendiocarb in the range of 10-100 μg/5 mL solution.
Bacterial Numbers on Penicylinders Used in Disinfectant Testing: Use of 24 Hour Adjusted Broth Cultures
Authors: Cole Eugene C , Rutala William A
Published: February 2020

The current AOAC use-dilution methods of disinfectant efficacy testing require the use of 48-54 h unadjusted broth cultures of Salmonella choleraesuis, Staphylococcus aureus, and Pseudomonas aeruginosa for the inoculation of stainless steel penicylinders. The use of unadjusted broth cultures contributes to noncomparable numbers of organisms on penicylinders among the test strains due to relative efficacy of bacterial attachment to penicylinders and to bacterial numbers in broth. To achieve comparable numbers of cells on the penicylinders among the 3 test strains, the cell densities of S. aureus and P. aeruginosa in broth culture were visually adjusted. Growth studies were conducted using S. choleraesuis and P. aeruginosa to determine the numbers of cells in broth at timed intervals and the corresponding numbers of cells attaching to the penicylinders. Results showed that the use of the 24 h broth cultures for all 3 test strains, with adjustment of S. aureus and P. aeruginosa broths, contributes to more comparable numbers of organisms attached to the penicylinders used in disinfectant testing.
Ion-Pair Reverse-Phase Liquid Chromatographic Determination Of Amprolium
In Complete Feeds And Premixes
Authors: Kentzer Elzbieta J , Cottingham Layna S , Smallidge Robert L
Published: February 2020

Amprolium is extracted with methanol-water (2 + 1) containing 5mM dioctylsulfosuccinate (DOSS) and lOmM CaCl2. The analyte is separated from coextracted materials by isocratic ion-pair reversephase liquid chromatography, following removal of late-eluting materials on an acid alumina cleanup column, and is detected at 270 nm. The mobile phase contains 4mM DOSS with 0.3% diethylamine and 1% acetic acid in 40% acetonitrile. Linearity is satisfactory over the range of 2.5-50 /xg/mL. Mean recovery, as determined by standard addition to commercial samples, is 100.1%. Accuracy was further tested in studies comparing the LC method to the official AOAC colorimetric method, using commercial samples, and was found to be satisfactory. Studies show that common poultry feed additives, grass meals, and some pelletization aids do not interfere with the analysis; however, when bentonite is present, recovery is decreased. The precision of the method, measured over several experiments on commercial samples, is satisfactory as indicated by coefficients of variation ranging from 1 to 4.5. A ruggedness test resulted in an overall CV of 3.2%, indicating the probable success of the method in a collaborative study.
Simultaneous Determination of Diazinon and Chlorpyrifos Pesticide Formulations
by Liquid Chromatography
Authors: Bushway Rodney J , Perkins L Brian , Joan King M
Published: February 2020

A liquid chromatographic (LC) method has been developed to analyze simultaneously separate formulations of diazinon and chlorpyrifos. Samples of each formulation were mixed in a Polytron mixer with the internal standard butylated hydroxytoluene and were diluted with acetonitrile. An aliquot was injected into an Ultremex LC column. The mobile phase was acetonitrile-water-tetrahydrofuran-glacial acetic acid-monoethanolamine (480 + 230 + 55 + 2 + 0.75); all 3 compounds were monitored at 230 nm. Total analysis time was 11 min. Combinations of 11 different samples of each formulated pesticide were analyzed 9 times for coefficients of variation generally less than 3%. Purity of the diazinon, chlorpyrifos, and butylated hydroxytoluene was checked by using a photodiode array detector in the spectrum and absorbance ratio modes. No interferences were noted at 230 nm.
Analysis of Rotenone in Cube and Derris Root Powders and Formulations by Liquid
Chromatography
Authors: Bushway Rodney J , Yang Angela , AL-Yamany Ali
Published: February 2020

A modified liquid chromatographic (LC) procedure, including an improved extraction, has been developed to analyze rotenone in root powders of derris and cube. The procedure is also applicable to formulations. Samples are sonicated for 5 min in chloroform or a mixed solvent of tetrahydrofuran-acetonitrile-water-glacial acetic acid, followed by liquid chromatography. Rotenone content of 4 lots of root powder samples showed good agreement between the new extraction and the AOAC official extraction; coefficients of variation ranged from 5 to 1.2%. Five formulations were also analyzed and showed good agreement with results for methanol extraction. Coefficients of variation were 4.5% or less. Purity of the rotenone peaks was tested by using a photodiode array detector in the spectrum and UV ratio modes. It is recommended that the new method be tested collaboratively.
Gas Chromatographic Determination of N-Nitrosodialkanolamines in Herbicide Di- or
Trialkanolamine Formulations
Authors: Wigfield Yuk Y , Lacfloix Mario D , Lanouette Monique , Gurprasad Narine P
Published: February 2020

A modified method is presented to determine trace quantities of N-nitrosodiethanolamine (NDE1A) and yV-nitrosodiisopropanolamine (NDiPlA) in the triisopropanolamine (TiPlA) formulation of a mixture of picloram and 2,4-D. Aqueous sample is extracted with dichloromethane to remove organic interferences, and then the aqueous layer is passed sequentially through chloride anion exchange column, hydrogen cation exchange column, and Clin-Elut extraction tube. The final eluate, 10% acetone in ethyl acetate, is concentrated. The isolated nitrosamines are converted to the corresponding trimethylsilyl (TMS) derivatives and determined by gas chromatography (GC) on a DB1 column coupled with a thermal energy analyzer (GC-TEA). Eight samples of commercial TiPlA formulations are analyzed. Maximum detected levels of NDE1A and NDiPlA were 0.6 and 0.9 ppm, respectively, expressed relative to total weight of active ingredients. Analysis of 13 samples of herbicide DEIA formulation using a previously established method and a DB225 column gave NDE1A results of 0.7-6.0 ppm. NDiPlA was not detected in those samples. Results are confirmed by GC-mass spectrometry (GC/MS) with oxygen negative chemical ionization (ONCI) detection. Dectection limits for both nitrosamines are 0.05 or 0.07 ng (0.1 or 0.17 ppm) for GC-TEA detection, depending on the analytical columns used, and 20 pg (0.04 ppm) for GC/MS detection. Recoveries of NDE1A are 87-109% for DEIA formulation spiked at 2.6 and 3.9 ppm and 90-115% for TiPlA formulation spiked at 0.2-0.3 ppm. Similarly, recoveries of NDiPlA are 95.7-100% for the DEIA formulation spiked at 0.24 and 0.48 ppm, and 82-118% for the TiPlA formulation spiked at 0.2-0.3 ppm.
Determination of Residual Cephalexin in Chick Tissues by Bacillus stearothermophilus Paper
Disc Assay
Authors: Okada Junya , Higuchi Ikuji , Kondo Sadao , Saito Bun-Ichi
Published: February 2020

A paper disc method is described for determination of residual cephalexin (CEX) in chick tissues. A trichloroacetic acid extract of plasma and tissues is chromatographed on a macroreticular resin (Diaion HP-20) column to remove endogenous antibacterial substances interfering with the assay. The eluate is evaporated to dryness and the residue, dissolved in methanol-water (1 + 2), is subjected to a paper disc assay using Bacillus stearothermophilus var. calidolactis C953 NIZO as a test organism. The detection limit was 0.0375 ppm in tissue; the average recovery of CEX ranged from 72.4% in skin to 90.4% in plasma. Water containing 200 or 500 mg/L of CEX was given ad libitum to 2-week-old chicks for 10 days; the highest levels of CEX were found in the kidney, and the lowest were found in muscle at 0 h of withdrawal. CEX disappeared from most tissues at 24 h after withdrawal except from skin of chicks given 500 mg/ L. However, the drug was not detected in the skin at 48 h after withdrawal.
Evaluation of Abbreviated Enzyme Immunoassay Method for Detection of Salmonella in Low-Moisture Foods
Authors: Flowers Russell S , Klatt Mary Joan , Robison Barbara J , Mattingly Jerome A
Published: February 2020

A modified enzyme immunoassay method (EIA) utilizing an 18 h pre-enrichment, a 6-8 h selective enrichment, and a 14 h M-broth post-enrichment is compared to the standard culture method (AOAC/ BAM) on selected low-moisture foods. Tested samples included 238 inoculated, 30 naturally contaminated, and 30 uninoculated foods. By EIA, 235 samples were positive (optical densities greater than 0.2 at 405 nm), 233 of which were confirmed culturally. By the culture methods, 221 samples were positive. The EIA method was more productive in detecting salmonellae in inoculated samples of dry cheese powder, chocolate, and nonfat dry milk, whereas the culture method gave better recovery from naturally contaminated meat and bone meal. The modified EIA could be completed in 40 h and required no centrifugation.
Single-Laboratory Evaluation of EPA Method 8080 for Determination of Chlorinated Pesticides and Polychlorinated Biphenyls in Hazardous Wastes
Authors: Avila Viorica Lopez , Schoen Sarah , Milanes June , Beckert Werner F
Published: February 2020

Method 8080, as published in the Second Edition of "Test Methods for Evaluating Solid Waste," EPA Manual SW-846, has been evaluated in a single-laboratory study. The Florisil procedure recommended in Method 8080 for sample cleanup does not separate organochlorine pesticides (OCPs) from the polychlorinated biphenyls (PCBs). Consequently, gas chromatographic analysis of OCPs on the packed column recommended in the method may result in false identifications or in no identifications at all when PCBs are present. Therefore, silica gel was substituted for Florisil, a capillary column was substituted for the packed column, and a sulfur cleanup procedure was incorporated in the method. The revised method was evaluated with samples spiked at 3 concentrations. Precision and accuracy indicate that the revised method can be reliably applied to the determination of OCPs and PCBs in liquid and solid matrixes. Detection limits for liquid matrixes range from 0.02 to 0.09 μg/L for OCPs and from 0.5 to 0.9 (μgL for PCBs. Detection limits for solid matrixes range from 1 to 6 μg/kg for OCPs and from 60 to 70 μg/kg for PCBs
Gas Chromatographic-Mass Spectiometric Determination of Adipate-Based Polymeric
Plasticizers in Foods
Authors: Castle Laurence , Mercer Angela J , Gilbert John
Published: February 2020

A method for the quantitative determination of adipate-based polymeric plasticizers in foods is described. The procedure involves extraction from the food and transmethylation of the polymeric plasticizer to form dimethyladipate (DMA). The derivative is cleaned up by size-exclusion chromatography and determined by capillary gas chromatography-mass spectrometry with selected on monitoring. The use of a deuterated internal standard at the extraction stage enables quantitation by stable isotope dilution. A detection limit of 0.1 mg/kg of the polymeric plasticizer in foods and a relative standard deviation of 4% have been achieved routinely. The method has been applied successfully to the analysis of cheese, sandwiches, meat, biscuits, and cake that have been in contact with polymeric plasticized polyvinyl chloride) films.
Direct Gas Chromatographic Analysis of Trichlorfon for Its Decomposition Products
Authors: Slahck Stephen C
Published: February 2020

The analysis of trichlorfon by direct gas chromatography is discussed. A procedure is described for the determination of impurities in trichlorfon by using a fused silica capillary column and cold on-column injection. Attempts at quantitating trichlorfon using this system were unsuccessful due to problems with irreproducibility of the peak area. Although no derivatization was performed, there was no decomposition of the analyte as confirmed by mass spectrometry
Rapid Identification of Color Additives, Using the C18 Cartridge: Collaborative Study
Authors: Young Mary L
Published: February 2020

Nine laboratories collaboratively studied a method for the separation and identification of the 7 permitted FD&C color additives (Red Nos. 3 and 40; Blue Nos. 1 and 2; Yellow Nos. 5 and 6; Green No. 3) and the banned FD&C Red No. 2 in foods. The method is based on use of a commercial C18 cartridge and spectrophotometry or thin layer chromatography. Collaborators analyzed 5 commercial products (noodles, candy, carbonated soda, flavored gelatin, and powdered drink) and 2 dye mixtures (one containing FD&C Red Nos. 2,3, and 40; the other containing FD&C Green No. 3 and Red No. 3). All of the colors were identified with little or no difficulty by 8 collaborators. The method has been adopted official first action.
Simultaneous Determination of D- and L-Malic Acids in Apple Juice by Gas Chromatography
Authors: Agarwal Vipin K
Published: February 2020

A gas chromatographic (GC) method was developed for the simultaneous determination of D- and L-malic acids in apple juice. D-Malic- (R)-(-)-2-butyl ester and L-malic-(R)-(-)-2-butyl ester are prepared with (R)-(-)-2-butanol. These diastereomers are separated and quantitated by gas chromatography on a Carbowax 20M (30 m x 0.25 mm) fused silica capillary column. This procedure does not involve any extraction or cleanup step.
Liquid Chromatographic Methodology for the Characterization of Orange Juice
Authors: Perfetti Gracia A , Joe Frank L , Fazio Thomas , Page Samuel W
Published: February 2020

Liquid chromatographic (LC) methodology potentially useful for the characterization of orange juice, with particular regard to detecting adulteration of orange juice by computer pattern recognition analysis, has been developed. After dilution with methanol the juice is extracted with hexane to remove the carotenoids, which are chromatographed on a C18 column with an acetonitrile-methanol-methylene chloride mobile phase and detection at 450 nm. Further extraction of the juice with methylene chloride isolates the methoxylated flavones, which are chromatographed by reverse phase LC with an acetonitrile-methanol-water mobile phase and detection at 280 nm. The flavanone glycosides remaining in solution are chromatographed on a C18 column with an acetonitrile-water mobile phase and detection at 280 nm. The precisions of the heights of the 32 LC peaks selected for pattern recognition analysis were determined from 5 replicate analyses of a single juice. Coefficients of variation of the replicates ranged from 0.3 to 4.5%, with an average of 2.1%. Adulteration of products with sodium benzoate-fortified pulpwash or grapefruit juice can be detected by this method. Pattern recognition analysis of the data obtained for 80 authentic and 19 adulterated orange juices showed that the method is potentially useful for distinguishing between authentic and adulterated products.
High-Speed Liquid Chromatographic Determination of Monensin, Narasin, and Salinomycin in Feeds, Using Post-Column Derivatization
Authors: Lapointe Michel R , Cohen Huguette
Published: February 2020

A high-speed liquid chromatographic (LC) method using post-column derivatization is described for the determination of monensin, narasin, and salinomycin in a variety of animal feeds. The ionophores are extracted with hexane-ethyl acetate (90 + 10). A portion of the sample is evaporated, diluted to a known volume, and analyzed using a 6 cm 3 μm C18 column and an absorbance detector after post-column reaction with vanillin. The method has been applied to poultry and swine feeds with levels of 3-100 ppm added antibiotic. A comparison was also carried out with medicated poultry feed and beef feed lot supplement samples previously analyzed by 2 separate bioassay methods for monensin and salinomycin, respectively. Recoveries for the LC method ranged from 92.1 to 103% with an average recovery of 98.1% and a coefficient of variation of 3.65%.
Gas Chromatographic Screening Method for T-2 Toxin, Diacetoxyscirpenol, Deoxynivalenol, and Related Trichothecenes in Feeds
Authors: Rood Harold D , Buck William B , Swanson Steven P
Published: February 2020

A gas chromatographic method for screening trichothecene mycotoxins in feeds is described. Feed is extracted with acetonitrile-water, and the toxins are purified with charcoal-alumina-Celite, Florisil, and silica mini-columns. Deoxynivalenol (DON), nivalenol (NIV), diacetoxyscirpenol (DAS), T-2 toxin, and their fungal metabolites are hydrolyzed to their corresponding parent alcohols (DON, NIV, scirpentriol, or T-2 tetraol) by alkaline hydrolysis. After derivatization to their pentafluoropropionyl analogs, they are quantitated by capillary gas chromatography with electron capture detection. Identity can be confirmed and sensitivity can be increased by using negative chemical ionization mass spectrometry with no additional sample workup. Recoveries of DAS, DON, and T-2 toxin averaged, respectively, 80, 65, and 85% in corn; 84, 65, and 88% in soybeans; and 70, 57, and 96% in mixed feeds at concentrations ranging from 0.1 to 2.0 ppm. Recoveries of 15-monoacetoxyscirpenol (MAS), HT- 2, NIV, and T-2 tetraol were 97, 97, 86, and 56%, respectively, in corn at a concentration of 0.25 ppm. A detection limit of 0.02 ppm in corn, soybeans, and mixed feeds, and 0.05 ppm in silages is estimated.
Gas Chromatographic Determinatiion of Monoethylene Glycol and Diethylene Glycol in
Chocolate Packaged in Regenerated Cellulose Film
Authors: Castle Laurence , Cloke Helen R , Startin James R , Gilbert John
Published: February 2020

A method for the quantitative determination of monoethylene glycol (MEG) and diethylene glycol (DEG) in chocolate is described. The procedure involves dissolving the chocolate in hot water, defatting with hexane, removing sugars by precipitation, and analyzing as trimethylsilyl (TMS) ether derivatives by capillary gas chromatography. The use of butan-l,4-dioI as an internal standard corrects for recovery, which is between 50 and 60%, to give a relative standard deviation of 10 -11 % for the determination of both glycols at the level of 50 mg/kg. The presence of MEG and DEG in chocolate is confirmed by full scanning gas chromatography/mass spectrometry of the TMS derivatives
Liquid Chromatographic Determination of Scopoletin in Hydroalcoholic Extract of Oak Wood
and in Matured Distilled Alcoholic Beverages
Authors: Puech Jean-Louis , Moutounet Michel
Published: February 2020

A liquid chromatographic (LC) method is described for determination of the coumarins esculin, umbelliferone, scopoletin, and 4-methyl umbelliferone in hydroalcoholic extracts of oak wood and in matured distilled alcoholic beverages. Samples were injected directly into the LC column (30 m, 5μm C18) and detected by fluorescence detector. Under these experimental conditions, only scopoletin (detection limit, 200 pg) was found in hydroalcoholic oak wood extracts and in spirits matured in oak wood. Applications of this method to spirits distilled from wine, grain, and sugar cane aged in oak barrels showed that amounts varied from 0.026 to 1.57 ppm
Determination of Reserpine and Hydrochlorothiazide in Commercial Tablets by Liquid
Chromatography with Fluorescence and UV Absorption Detectors in Series
Authors: Cieri Ugo R
Published: February 2020

A procedure is presented for the determination of reserpine and hydrochlorothiazide in commercial tablets by liquid chromatography (LC). Reference and sample solutions are prepared in methanol. For LC, a normal phase column is used, methanol is the eluting solvent, and 2 detectors are arranged in series. A fluorescence detector set at an excitation wavelength of 280 nm and emission wavelength of 360 nm quantitates reserpine, and a UV absorption detector set at 345 nm determines hydrochlorothiazide. Several synthetic mixtures containing the 2 ingredients in the amounts approximately present in commercial tablets were analyzed by the proposed method. Two samples of commercial tablets were also analyzed; for each sample, 5 determinations were made on a ground composite of 20 tablets; 10 individual tablets were also analyzed. For comparison, some of the solutions were analyzed for each ingredient by an alternative procedure.
Liquid Chromatographic Determination of Carbamazepine in Tablets
Authors: Walker Ella S
Published: February 2020

A simple and rapid liquid chromatographic method is described for the qualitative and quantitative determination of carbamazepine in tablet composites and individual tablets, using the internal standard technique. Analyses were performed on a C-18 reverse-phase column with tetrahydrofuran-methanol-water (8 + 37 + 55) as the mobile phase. A linear relationship was obtained between detector responses at 254 nm and amounts of carbamazepine injected ranging from 0.2 to 1.7 ng. The coefficient of variation for 10 consecutive injections of a standard preparation was 0.4%. Recoveries of carbamazepine from 100 and 200 mg tablets averaged 101.4 and 99.7%, respectively. Assay results for commercial tablets analyzed by the proposed method agreed favorably with those obtained by the method of USP XXI. The assay results for individual tablets indicated that deviations from the average value and the range of individual values are much wider with the compendial method than with the proposed method
Simplified Multiresidue Method for Liquid Chromatographic Determination of /V-Methyl
Carbamate Insecticides in Fruits and Vegetables
Authors: Chaput Daniel
Published: February 2020

A simplified method is described for determining 7 N-methyl carbamates (aldicarb, carbaryl, carbofuran, methiocarb, methomyl, oxamyl, and propoxur) and 3 related metabolites (aldicarb sulfoxide, aldicarb sulfone, and 3-hydroxy carbofuran) in fruits and vegetables. Residues are extracted from crops with methanol; coextractives are then separated by gel permeation chromatography (GPC) or GPC with on-line Nuchar-Celite cleanup for crops with high chlorophyll and/or carotene content (e.g., cabbage and broccoli). Carbamates are separated on a reverse-phase liquid chromatography column, using a methanol-water gradient mobile phase. Separation is followed by postcolumn hydrolysis to yield methylamine, and the formation of a fluorophore with o-phthalaldehyde and 2-mercaptoethanol prior to fluorescence detection. Recovery data were obtained by fortifying 5 different crops (apples, broccoli, cabbages, cauliflower, and potatoes) at 0.05 and 0.5 ppm. Recoveries averaged 93% at both fortification levels except for the very polar aldicarb sulfoxide for which recoveries averaged around 52% at both levels. The coefficient of variation of the method at both levels is <5% and the limit of detection, defined as 5 times baseline noise, varies between 5 and 10 ppb, depending on the compound
Comparison of Values Derived from Selected Flours by Fat Acidity Methods of the American
Association of Cereal Chemists and the International Organization for Standardization
Authors: Lane Ralph H , Erickson Richard L
Published: February 2020

Fat acidity values were determined on 8 commercially available flours by the American Association of Cereal Chemists method (AACC- 02-01 A) and by the International Organization for Standardization method (ISO-7305). Comparisons of means obtained by these 2 methods indicated that the ISO method produced results that were 1.4- 2.5 times greater (P < 0.001) than those for the AACC method. These data are consistent with a previous report which indicated that acidic materials (phosphates and amino acids) other than fatty acids are extracted by 95% alcohol (ISO method), whereas fatty acids alone are extracted by petroleum ether (AACC method). Fat acidity values obtained by AACC methodology employing Soxhlet and continuous extraction were also compared. No difference in fat acidity means existed with respect to extraction technique except for an aged whole wheat flour sample which produced a higher value (P = 0.05) by continuous extraction.
Identification of Escherichia coli from Shellfish and Related Environments by Automicrobic
System
Authors: TardiÓ Joseph L , O'brien Kevin , Latt Thomas
Published: February 2020

A total of 463 fecal coliform positive isolates obtained from shellfish and related samples gave typical Escherichia coli IMViC reactions. E. coli identifications for 458 (99%) of these isolates were confirmed using a combination of the Automicrobic System (AMS) and the API 20E system (reference system). The AMS (test system) identified 433 isolates as E. coli; the remaining 25 (5%) isolates were identified as E. hermanii by the test system and as E. coli by the reference system. Additional tests performed on the isolates identified as E. hermanii confirmed those AMS identifications to be incorrect
Liquid Chromatographic Method for Analysis of Elemental Sulfur in Pesticide Formulations
Authors: Bushway Rodney J , Brian Perkins L
Published: February 2020

A nonaqueous reverse-phase liquid chromatographic (LC) method has been developed to determine elemental sulfur in pesticide formulations. Samples were extracted in 50 mL of stabilized tetrahydrofuran (THF) by gentle swirling while sonicating for 1 min. A 5 pL aliquot was injected into the LC instrument equipped with a Vydac 218 TP 54 column. The mobile phase was methanol-acetonitrilestabilized tetrahydrofuran (58.5 + 40 + 1.5). Sulfur was monitored at 280 nm. Retention time was approximately 5 min with total analysis time of 7 min. For 6 different products analyzed 12 times each, the coefficients of variations were all less than 3.5%. Purity of each sulfur peak was checked by using a photodiode array detector in the spectrum and absorbance ratio modes. No impurities were observed at the monitoring wavelength
Listeria Methods Development Research at the Eastern Regional Research Center,
U.S. Department of Agriculture
Authors: Buchanan Robert L , Smith James L , Stahl Heidi G , Archer Deborah L
Published: February 2020

Listeria methods research at the U.S. Department of Agriculture, Eastern Regional Research Center, has concentrated on 2 areas during the past year. The first was development of techniques for assessing isolation methods for their ability to detect sublethally stressed cells. It appears that a number of widely used media do not accurately detect Listeria that have been injured by thermal processing or acidification. The second was development of improved plating media. One, modified Vogel-Johnson agar, shows promise; it is highly selective and quantitative, and eliminates the need to select colonies on the basis of a blue color when illuminated with reflected light
Comparative Studies of Nucleic Acid Hybridization Assay for Listeria in Foods
Authors: Klinger Jeffrey D , Johnson Andrew , Croan Daniel , Flynn Pauline , Whippie Kevan , Kimball Margaret , Lawrie Jonathon , Curiale Michael
Published: February 2020

A nucleic acid hybridization assay has been developed for Listeria spp. in dairy foods and environmental samples. The assay is based on detection of unique Listeria 16S rRNA sequences by using a 32Plabeled synthetic DNA probe. Inclusivity and exclusivity of the probe were confirmed with 139 Listeria isolates representing all known species, and 73 non-Listeria bacterial strains. In this paper, we present results from our preliminary studies comparing the hybridization assay with conventional culture on a total of 575 specimens that represent a variety of inoculated and uninoculated foods and environmental samples. The assay, which is done in a filter manifold format after 2 days of cultural enrichment, requires a total assay time of less than 2.5 days. The false-negative rate for all sample groups tested using the GENE-TRAK hybridization assay was less than the rate for culture. Thus, the new assay allows rapid screening of the indicated product groups and provides reliable numerical results
Identification and Enumeration of Beta-Hemolytic Listeria monocytogenes in Naturally
Contaminated Dairy Products
Authors: Datta Atin R , Wentz Barry A , Hill Walter E
Published: February 2020

A DNA probe was used to identify hemolytic Listeria monocytogenes in naturally contaminated dairy products: unpasteurized milk, ricotta cheese, and imported semisoft cheeses. Of 34 milk samples, 12 were suspected to contain hemolytic L. monocytogenes; 1 contained >6000 viable organisms/g. The ricotta cheese, although temperature-abused, had a titer of 3.6 x 10-6 beta-hemolytic L. monocytogenes cells/g, whereas the semisoft cheeses reached a maximum of 5.6 x 10-6 cells/g. Pure cultures of L. monocytogenes isolated from both types of cheese were found positive by the CAMP test and the DNA probe
Rapid Determination of Fumigant and Industrial Chemical Residues in Food
Authors: Daft James L
Published: February 2020

A gas chromatographic (GC) method is described for the determination of 22 fumigant and industrial chemical residues in a variety of foods. The fumigants and industrial chemicals determined are methyl bromide, methylene chloride, carbon disulfide, chloroform, 1,1-dichloroethane, ethylene dichloride, methyl chloroform, carbon tetrachloride, methylene bromide, propylene dichloride, 2,3-dichloropropene, trichloroethylene, 1,3-dichloropropylene, 1,1,2-trichloroethane, chloropicrin, ethylene dibromide, tetrachloroethylene, propylene dibromide, l,l,2,2-tetrachloroethane,j»-dichlorobenzene, o-dichlorobenzene, and l,2-dibromo-3-chloropropane. Except for the latter three, the fumigants are determined at 90°C on 3.6 m 20% loaded OV-101 columns with electron-capture and Hall-electroconductivity detectors. The other 3 compounds (o-dichlorobenzene, p-dichlorobenzene, and l,2-dibromo-3-chloropropane), which elute beyond 30 min on the above columns, are determined at 90°C on 1.8 m 5% loaded OV-101 columns with the same detectors. The ng/g-level fortifications have an overall mean analyte recovery of 70% and a coefficient of variation of 40%. The variety of foods examined includes both fatty and nonfatty food types (e.g., off-the-shelf cooked and uncooked grain-based items, dairy products, fresh and canned fruits and vegetables, and meats). Samples are extracted and cleaned up according to fat content and food type. Samples containing less than 71% fat are extracted by using an aqueous: nonaqueous shakeout (20% acetone solution under isooctane). Most extracts (isooctanes) are analyzed directly. Extracts from samples containing from 21 to 70% fat (e.g., ground beef, pecans, and corn chips) are cleaned up further on micro-Florisil columns to remove excess fat. A few other samples containing more than 71% fat or oil (e.g., butter, salad dressing, and vegetable oil) are diluted directly in isooctane and, depending on the degree of dilution, can be cleaned up further on micro-Florisil columns. Also, clear beverages (e.g., soda and tea) are extracted directly with isooctane. These extraction and cleanup techniques were tested on 231 different table-ready foods. Three-hundred incurred residues of 10 different fumigants were found in 138 items examined; 93 items had no detectable residues. The main advantage of the method is rapid semiquantitative determination of multiple fumigants from all food types.
Liquid Chromatographic Determination of Propranolol Hydrochloride in Various Dosage Forms
Authors: Olsen Carolyn S , Scroggins Henry S
Published: February 2020

A simple and rapid liquid chromatographic method is described for the determination of propranolol hydrochloride in pharmaceutical preparations. The separation was achieved on a reverse-phase octylsilane (C8) column by using a mobile phase composed of a mixture of 0.5 g dodecyl sodium sulfate in 18 mL (0.15 M) H3P04 plus 90 mL methanol, 90 mL acetonitrile, and 52 mL water. Detector response was linear for 0.03-3.1 mg/mL of propranolol. Recoveries from synthetic mixtures ranged from 99.6 to 101.7%. The results obtained by the proposed method were similar to those obtained by the USP XXI method.
Determination of Novobiocin Residues in Milk, Blood, and Tissues by Liquid Chromatography
Authors: Moats William A , Leskinen Laura
Published: February 2020

Residues of novobiocin in milk, blood, and tissues can be detected by microbiological tests but cannot be distinguished from other antibiotics. A simple liquid chromatographic (LC) method was developed for identification of residues. Tissues were blended and milk and blood serum were mixed with 0.2M NH4H2P04. The mixture was deproteinized by adding aqueous methanol and filtering. The LC apparatus consisted of a variable wavelength detector, set at 340 nm, an automatic loop injector, and a C,8 column with guard cartridge. The flow rate was 1 mL/min and the solvent mixture of 0.01M H3P04-acetonitrile-methanol was programmed from 50 + 0 + 50 (0-1 min) to 20 + 80 + 0 (20 min). Novobiocin was concentrated directly by solid-phase extraction on the analytical column. Five or more 200 11L aliquots of the filtrate in water-methanol (1 + 1) (adjusted if necessary) were injected with the column solvent at 50 + 0 + 50. After the final injection, the program was run to completion. Recoveries were 90-100% with sensitivities of 0.05 ppm or less. The procedure should be adaptable for use with formulations and feeds
Determination of Ethyl Carbamate in Distilled Alcoholic Beverages by Gas Chromatography with Flame Ionization or Mass Spectrometric Detection
Authors: Pierce William M , Clark Adora O , Hurst Harrell E
Published: February 2020

Quantitative methods are detailed for determination of ethyl carbamate in distilled alcoholic beverages by capillary gas chromatography with flame ionization detection (GC/FID) and by packedcolumn gas chromatography/mass spectrometry (GC/MS) using selected ion monitoring. Five g samples of distillate of known ethanol concentration are diluted with water to 25% ethanol (v/v), washed with petroleum ether, and extracted with dichloromethane prior to GC/FID or GC/MS analysis. As necessary, sample extracts that exhibit GC/FID interference are passed through alumina for additional cleanup. When internal standards (ferf-butyl carbamate and n-butyl carbamate for GC/FID, or ethyl ,3C-,sN-carbamate for GC/ MS) were used for quantitation, the limit of detection for ethyl carbamate was in the range of 5-25 ppb. Coefficients of variation ranged from 3.5 to 6.0% for GC/FID determinations, and from 1.4 to 3.2% for GC/MS. Correlation between methods for 22 random distillate samples ranging in concentration from approximately 40 to 800 ppb gave a correlation coefficient (r) of 0.996.
Simple Method for Derivatization of Monoglycerides and Diglycerides
Authors: Lee Theresa , Hastilow Christine , Smith Katrina
Published: February 2020

A method has been developed for derivatization of monoglycerides and diglycerides to their propyl esters by using propionic anhydride in the presence of pyridine. The derivatives are volatile and thus can be separated and identified by gas chromatography (GC). Completion of the reaction is monitored by thin-layer chromatography. Monoglyceride propyl esters were positively identified by gas chromatography and by gas chromatography/mass spectrometry. No side products were observed in the derivatization reaction which requires 35 min at 75°C. GC analysis of the mono- and diglyceride propyl esters can be completed in approximately 30 min.
Laboratory Procedures for Detoxification of Equipment and Waste Contaminated with
Brevetoxins PbTx-2 and PbTx-3
Authors: Poli Mark A
Published: February 2020

Procedures are presented for the detoxification of laboratory equipment contaminated with brevetoxins PbTx-2 and PbTx-3. An in vivo bioassay using the Japanese madaka Oryzias latipes monitored toxin activity. Incubation for 10 min with 0.1N NaOH detoxified a lethal dose of either PbTx-2 or PbTx-3 to levels below the detection limit of the assay (<10 ng/mL). Decreasing the NaOH concentration required correspondingly longer incubation times. The potency of both toxins was also destroyed by incubation forlO-15 min at 500°C. Steam autoclaving 30 min at 122°C (18 psi) was not sufficient to detoxify brevetoxins. These results show that laboratory equipment will be decontaminated and rendered safe for normal handling by washing or soaking it in a dilute NaOH solution. Disposable waste can be either soaked in an NaOH solution prior to disposal or burned in an incinerator with a combustion chamber of at least 500°C. Steam autoclaving, however, is not a viable method of decontamination.
Liquid Chromatographic Determination of Lake Red C Amine and
2-Naphthol in D&C Red No. 8
Authors: Scher Alan L , Calvey Robert J
Published: February 2020

A method is described for the determination of the intermediates in D&C Red No. 8 by reverse-phase liquid chromatography (LC). The pigment is dissolved in boiling 95% ethanol-water (1 + 1) and then precipitated. The filtrate is chromatographed by gradient elution. Calibrations from peak areas at 254 nm for Lake Red C Amine sodium salt (LRCA-Na) and at 229 nm for 2-naphthol were linear, with prediction limits of 0.200 ± 0.006% and 0.200 ± 0.003%, respectively, for the maximum permitted levels. Calibration limits of determination were 0.01% for LRCA-Na and 0.006% for 2-naphthol. A 99% confidence level was used. Recoveries were 100.0-100.4% for LRCA-Na and 97.1-101.8% for 2-naphthol, each added at levels of 0.025-0.2%. Certified lots of D&C Red No. 8 that were analyzed by the LC method contained higher levels of LRCA-Na but the same levels of 2-naphthol when compared to results obtained previously by a cellulose column method, in which the pigment is not dissolved. The solubilities of D&C Red No. 8 in hot and room temperature solutions of 95% ethanol-water (1 + 1), water, and 95% ethanol were estimated.
Pesticide Residue Findings by the Luke Method in Domestic and Imported
Foods and Animal Feeds for Fiscal Years 1982-1986
Authors: Hundley, Harvey K , Cairns Thomas , Luke Milton A , Masumoto Herbert T
Published: February 2020

Nearly 20 000 samples of food and feed commodities were analyzed for pesticide residues by the U.S. Food and Drug Administration Los Angeles District Laboratory during the 5-year study period 1981- 1986. The resultant data base has been summarized to provide separate residue information for domestic and imported samples. The overall violation rates for domestic and imported samples collected on a surveillance basis were 3.0 and 2.6%, respectively. For domestic and imported samples collected on a compliance basis, the overall violation rates were 19.7 and 17.5%, respectively.
Quantitation of Ochratoxin A: Use of Reverse Phase Thin-Layer Chromatography for Sample
Cleanup Followed by Liquid Chromatography or Direct Fluorescence Measurement
Authors: Frohlich Andrzej A , Marquardt Ronald R , Bernatsky Aniko
Published: February 2020

An improved procedure for sample preparation and quantitation of ochratoxin A in moldy grain was developed. Grain samples were acidified and extracted, and extracts were subjected to reverse phase thin-layer chromatography (RPTLC). The separated spots, which were identified under UV light, were scraped and collected into recovery devices. Ochratoxin A was eluted from the adsorbent and analyzed by either liquid chromatography with fluorescence detection or direct spectrofluorometric measurement. The method yielded values that were proportional to the concentrations of toxin in the sample, had relatively high levels of recovery (94%), and required considerably less volume of solvents and preparation time than a standard packed column method.