bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Four Commercially Available Rapid Test Kits with Liquid Chromatography for Detecting Penicillin G Residues in Bovine Plasma
Authors: Boison Joe O , Korsrud Gary O , Papich Mark G , Macneil James D 
Published: February 2020

Abstract
Four commercially available rapid tests (Brilliant Black reduction test, LacTek test, Charm Farm test, and Charm Test II receptor assay) were compared with a liquid chromatographic (LC) method (lowest quantitatable level of 5 ng/mL) in their efficiency, reliability, and sensitivity to detect penicillin G in bovine plasma. Samples were obtained from 16 steers treated with procaine penicillin G alone or in combination with its long-acting form, benzathine penicillin G. The steers were injected intramuscularly with penicillin G doses ranging from label dose to about 9 times label dose. When results of the Brilliant Black reduction, LacTek, Charm Test II, and Charm Farm tests for penicillin G in plasma (with detection sensitivities of 5,10,20, and 30 ng/mL, respectively) were compared with results of LC, none of the rapid tests gave false-positive results. Each rapid test elicited a positive response when used to test bovine plasma containing penicillin G residues at concentrations above the test’s detection sensitivity. The simplicity, selectivity, and sensitivity of the rapid tests, coupled with rapidity with which results are obtained, make them suitable for use in large-volume preslaughter screening of penicillin-treated cattle.
Fully Automated Solid-Phase Extraction Cleanup and On-Line Liquid Chromatographic Determination of Benzimidazole Fungicides in Fruit and Vegetables
Authors: Hiemstra Maurice , Joosten Jeannette A , de Kok Andre 
Published: February 2020

Abstract
A liquid chromatographic (LC) method using fully automated solid-phase extraction (SPE) sample cleanup and on-line LC analysis was developed for determination of the benzimidazole fungicides car-bendazim and thiabendazole in various crops. Preparation of food samples involved extraction with acetone followed by solvent partitioning with dichloromethane–petroleum ether to draw the analytes into the organic phase. The laborious liquid–liquid partitioning cleanup procedure described in the literature was replaced with a fast SPE cleanup using diol-bonded silica cartridges. Automation of the total procedure was achieved by using a commercially available SPE cleanup apparatus (ASPEC). The cleaned-up extract was injected on-line into an LC system with UV and fluorescence detection in tandem. Chromatographic separations were performed with a methanol–phosphate buffer mobile phase (pH = 7) and different polymeric stationary phases. The polymer-based columns performed better than silica-based columns in separating benzimidazole fungicides, and different columns were compared. Results of validation studies with fortified lettuce and citrus fruit are presented. Shewhart control charts of analytical results of control samples demonstrated good performance of the complete system. Sample throughput (extraction, automated SPE, and on-line LC analysis) was about 50 samples per 24 h. Residues of carbendazim and thiabendazole found during our pesticide residue monitoring program in 1992–1994 are reported.
Total, Free, and Glucose-Conjugated Acid Metabolites from Permethrin and Cypermethrin in Foods by Gas Chromatography-Electron Capture Detection
Authors: Mortimer Richard D , Shields J Brian 
Published: February 2020

Abstract
A method was developed to determine the combined amount of residual free pyrethroid metabolite acids and their glucosides on fruit and vegetables after application of permethrin or cypermethrin insecticides. Samples were spiked with glucose-conjugated acid metabolites, extracted, derivatized, and cleaned up for gas chromatography (GC) with electron capture detection. Limits of detection in the various matrixes were approximately 0.01 ppm, expressed as free acids. In addition, 2 field-grown crops were analyzed over 21 days after spraying with permethrin. Three commercial food samples known to contain parent pyrethroid were also analyzed. In general, the amounts of acid metabolites found were small; commercial samples of grapes, lettuce, and spinach analyzed by GC/mass spectrometry contained 0.005–0.02 ppm.
Comparison of Liquid Chromatography–Atmospheric Pressure Chemical Ionization/Mass Spectrometry and Liquid Chromatography–Postcolumn Fluorometry for Determination of Carbamates in Food
Authors: Newsome W Harvey , Lau Benjamin P-Y , Ducharme Dean , Lewis David 
Published: February 2020

Abstract
Two detection methods, postcolumn derivatization with fluorescent detection and atmospheric pressure chemical ionization/mass spectrometry (MS) were compared for determination of N-methyl carbamates in food by liquid chromatography. Five commodities were spiked with 11 carbamates at levels from 10 to 100 ppb, extracted, and cleaned up by using a method based on the AOAC official method. With each detection method, sample blanks showed false-positive responses, indicating that neither method alone provides definitive identification. Except for aldicarb sulfoxide determined by MS, recoveries were linear between 10 and 100 ppb. Agreement between the 2 methods was good for determination of recoveries at 25 ppb. Coefficients of variation were 11–33% for fluorescence detection and 9–26% for MS.
Rapid Ultratrace Analysis of Tributyltin in Aqueous Matrixes by Purge-and-Trap Gas Chromatography with Flame Photometric Detection
Authors: Sharron Daniel , Swami Kamal , Jansing Robert L 
Published: February 2020

Abstract
A simplified purge-and-trap technique for detecting subnanogram amounts of the biocide tributyltin (TBT) and its degradation products dibutyltin (DBT) and monobutyltin (MBT) in aqueous environmental samples is described. Butyltin chlorides present in the sample were derivatized to volatile butyltin hydrides with NaBH4 and simultaneously purged by drawing ambient air through the purge vessel. Butyltin hydrides were trapped on a Porapak-N cartridge, eluted with dichloromethane, and analyzed by gas chromatography with flame photometric detection. Recoveries of the butyltin species ranged from 46 to 101%. Method detection limits for MBT, DBT, and TBT were 1.28, 0.39, and 0.24 ng/L, respectively. The major advantages of this technique are sensitivity, reduced analysis time, and a significant reduction in the amount of dichloromethane used. Results from the analysis of various surface water samples collected in New York are presented.
Practical Application of Thin-Layer Chromatography for Detection of Polyphosphates in Seafood
Authors: Krzynowek Judith , Panunzio Laurie J 
Published: February 2020

Abstract
The practical application of previously published thin-layer chromatographic (TLC) methods to polyphosphate detection in seafood was determined. Exogenous polyphosphates are distinguishable from naturally occurring phosphates by using TLC; their detection can be enhanced by sampling techniques. Polyphosphates will eventually hydrolyze to monophosphates and make detection virtually impossible. Hydrolysis and therefore, nondetection, is accelerated by certain commercial practices. Results indicate that TLC detection of added phosphates can be used as an inspection tool for fresh products and for frozen products stored about 1 year.
Bacillus Stearothermophilus Disc Assay: A Review
Authors: Katz Stanley E , Siewierski Marie 
Published: February 2020

Abstract
The literature on the Bacillus stearothermophilus disc assay was reviewed and evaluated. The history of the assay development; data on applicability, sensitivity, interferences, and cowside screening; potential for the future; and limitations are presented and discussed.
On-line Steam Distillation/Purge and Trap Analysis of Halogenated, Nonpolar, Volatile Contaminants in Foods
Authors: Page B Denis , Lacroix Gladys M 
Published: February 2020

Abstract
An on-line, steam distillation/purge and trap gas chromatographic procedure is described for determination of halogenated analytes in foods and beverages. Recoveries were generally &gt;80% (versus aqueous standards) from vegetable oil, flour, root beer, cream (10% butter fat), and milk spiked at 1 - 3 μg/kg for each of the 32 analytes studied. Analytes ranged in volatility from vinyl chloride to 1,2,3,4-tetrachlorobenzene. Repeatabilities from aqueous standards were &lt;10% for most analytes. For a 1 g food sample, method detection limits ranged from 0.02 to 0.2 μg/kg for the 32 analytes. Reduced recoveries for less volatile analytes, however, occurred when steam-distillable, nonpolar food components were carried to the sparger. This effect was observed for citrus beverages containing steam-volatile limonene, roasted and ground coffees, and some salad dressings. The method was applied to a variety of foods.
Determination of Extractable, Apparent Total N-Nitroso Compounds in Cured-Meat Products
Authors: Fiddler Walter , Pensabene John W , Doerr Robert C , Gates Robert A 
Published: February 2020

Abstract
The modification of a newly developed method for determination of apparent total N-nitroso compounds by chemical denitrosation and chemiluminescence detection of nitric oxide (thermal energy analysis) is described. The minimum level of reliable measurement was 0.1 ppm, and the repeatability of the method was 0.2 ppm, based on the response of N-nitrosoproline (NPro). Seventy-three samples of cured-meat products, including frankfurters, bacon, and ham, were examined; 50 samples contained less than 1 ppm. The largest amounts, up to 24.8 ppm, were detected in canned corned beef. This method has several advantages over other methods.
Determination of Total Dietary Fiber in Foods and Food Products by Using a Single-Enzyme, Enzymatic-Gravimetric Method: Interlaboratory Study
Authors: Li Betty W 
Published: February 2020

Abstract
A simplified enzymatic-gravimetric method for total dietary fiber (TDF) determination has been published and used in the Food Composition Laboratory of the U.S. Department of Agriculture since 1988. This method gives comparable results to AOAC Official Methods 985.29 and 991.43 but the AOAC methods use 100°C (water bath) to gelatinize the sample and a combination of α-amylase and an amyloglucosidase to hydrolyze starches, whereas the simplified method incorporates an autoclaving step (121°C) for gelatinization followed by incubation with only amyloglucosidase. The simplified method omits protease hydrolysis and does not require any pH adjustment. Overall, the simplified method cuts cost and is less labor intensive. An interlaboratory study was conducted to validate this method. Blind duplicates of six sample (baked beans, corn bran, roasted peanuts, cooked potatoes, white bread with reduced calories, and cooked white rice) were sent to 11 laboratories. The reproducibility relative standard deviations of the TDF values (without outliers) ranged from 3.46 to 27.6%. The repeatability standard deviations ranged from 0.91 to 14.6%.
Importance of Cooking Temperature and Pancreatic Amylase in Determination of Dietary Fiber in Dried Legumes
Authors: Mongeau Roger , Brassard René 
Published: February 2020

Abstract
Total dietary fiber (TDF) was measured in large lima, roman, black turtle, light red kidney, white navy, pinto, black-eyed, and soya beans and in chick peas by the Mongeau rapid method (A), the Prosky method (B), and the Lee method (C). When the samples were soaked and cooked according to package instructions (gentle boiling, 95°C), TDF values by method A were all within 19.7-22.1%, except for black-eyed beans (9.9%) and chick peas (11.3%) (g/100 g, cooked dry matter). For large lima beans (20.0-21.3%) and soya beans (19.2-19.7%), TDF values by methods A, B, and C were in agreement. For 7 samples, however, TDF values were up to 81% higher by method B (17.4-34.7%) and up to 122% higher by method C (21.1-39.8%) than those by method A (P ≤ 0.01). For 6 legumes, TDF values by method C were 15-28% higher (P ≤ 0.013) than by method B. White navy beans were analyzed also after different cooking conditions, varying from no cooking to autoclaving for 15 min at 120°C. TDF values by method A were independent from cooking conditions and remained between 20.2 and 22.4%. For navy beans cooked at 95°C, TDF values by method B (up to 34.7 ± 1.4%) and C (up to 39.8 ± 0.3%) were unpredictable, but autoclaving at 120°C reduced them to about 22%. Incorporation of a pan-creatic amylase in methods B and C consistently decreased the aforementioned analytical discrepancies, as did the absence of cooking. Only autoclaving (for at least 15 min at 120°C) fully restored agreement among methods A-C.
Multiresidue Liquid Chromatographic Method for Simultaneous Determination of Pyrethroid Insecticides in Fruits and Vegetables
Authors: Pang Guo-Fang , Chao Yan-Zhong , Liu Xie-Shan , Fan Chun-Lin 
Published: February 2020

Abstract
A simple and rapid liquid chromatographic (LC) method has been developed for simultaneous determination of 9 pyrethroid insecticides (biphenthrin, cypermethrin, fenpropathrin, fenvalerate, flucythrinate, methothrin, permethrin, py-115, and tetramethrin) in fruits and vegetables. Residues are extracted from crops with methanol and partitioned with toluene. Extracts are cleaned up by Florisil–charcoal column chromatography. LC separation is performed on a μBondapak C18 stainless steel column with acetonitrile–deionized water as mobile phase. The insecticides are detected at 206 nm with 0.03 absorbance unit full scale. Recoveries of 9 pyrethroid insecticides from 6 crops (cucumbers, tomatoes, cabbages, apples, pears, and peaches) fortified at 0.5–5.0 mg/kg were 62.7–129.2%. Detection limits were about 0.05 mg/kg, except for py-115, for which detection limit was 0.10 mg/kg.
Multiresidue Method for Determination of Organophosphorus Insecticide Residues in Fatty Processed Foods by Gel Permeation Chromatography
Authors: Sannino Anna , Mambriani Paola , Bandini Mirella , Bolzoni Luciana 
Published: February 2020

Abstract
A multiresidue method for quantitative determination of 39 organophosphorus compounds (parent pesticides and their major metabolites) in 7 fatty processed foods is described. Samples are extracted with methylene chloride and cleaned up by automated gel permeation chromatography with a Biobeads SX3 column and a methylene–chloridecyclohexane (15 + 85) eluant. Organophosphorus compounds are quantitated by capillary gas-liquid chromatography with flame photometric detection using OV-1701 and DB-5 columns. Average recoveries from samples fortified at 0.025–1 mg/kg ranged from 50.6% for dichlorvos to 185% for malaoxon. Determination limits were between 0.005 and 0.040 μg/mL. Results were confirmed by gas chromatography/mass spectrometry with selected-ion monitoring.
Alternative Catalyst to Mercury for Kjeldahl Determination of Nitrogen in Water and Wastewater Samples
Authors: Anderson Kim A , Möller Gregory 
Published: February 2020

Abstract
A non-polluting alternative catalyst was used in a U.S. Environmental Protection Agency (EPA) Kjeldahl digestion procedure for water and wastewater samples. The colorimetric semiautomated block digestion method (EPA Method 351.2) was essentially unchanged except that 1 mL of a saturated solution of titanium dioxide was added to the digestant mixture, instead of 2 g mercuric oxide. Titanium dioxide is a nontoxic compound, which makes an excellent replacement in total Kjeldahl nitrogen (TKN) determination. Samples were digested and then placed on a flow injection autoanalyzer for ammonia determination. All other digestion and analysis procedures were the same as in the original method. Detection limit for TKN was 0.1 mg/L. Recovery of glutamic acid averaged 96.2%. Recoveries of standard reference water samples over a 9 month period averaged &gt;95%.
Effect of Extraction Systems on Clomazone Recovery from Aged Soil Samples
Authors: Kirksey K Bruce , Mueller Thomas C 
Published: February 2020

Abstract
Seven extraction methods were examined to determine which one provided a simple, efficient clomazone extraction from aged soil. The method selected involved adding 80 mL acetonitrile to moist soil and shaking for 16 h. The extract was filtered, and an additional 80 mL acetonitrile was added, equilibrated for 1 h, and filtered. Filtrates were combined and concentrated with a rotary evaporator. Clomazone concentrations were then determined by reversed-phase liquid chromatography with UV detection at 220 nm. Recovery with this method was equal to a 16 h + 1 h extraction with methanol, but acetonitrile was selected as extraction solvent because of its ease of removal with a rotary evaporator. The recovery from fortified soil samples was &gt;80%, and a conservative lower limit of detection was 40 ng/g soil.
Detection of Salmonella spp. in Eggs: DNA Analyses, Culture Techniques, and Serology
Authors: Burkhalter Paul W , Müller Christoph , Lüthy Jürg , Candrian Urs 
Published: February 2020

Abstract
A polymerase chain reaction (PCR) method for direct detection of Salmonella spp. in whole-shell eggs is described. The method does not require isolating strains. Preenrichment, rapid DNA isolation, and a nested PCR system targeting the invA gene enabled detection of the genus Salmonella. The specific nested PCR product of 283 base pairs was formed from all 21 serovars, including 43 Salmonella strains tested. No PCR product was formed from 56 non-Salmonella enterobacteriacea and other bacterial strains tested. Experiments with artificially contaminated eggs showed a detection limit of about 103–104 colony-forming units (cfu)/egg before and about 1–10 cfu/egg after preenrichment. In analysis of 180 single eggs from 4 flocks and 36 pools of 5 eggs each from another 4 flocks from the same producer, Salmonella spp. were detected in 5 of 90 eggs from 2 different flocks. Determination of anti-Salmonella antibodies in eggs yielded positive results for 2 additional and the 2 PCR-positive flocks. In contrast, classical selective culture detected Salmonella spp. in only 1 of 100 eggs in one flock when 100 eggs from each flock were analyzed.
Performance-Based Field Methods for Analyses of Substituted Phenols by Thermal Desorption Gas Chromatography/Mass Spectrometry
Authors: Jiao Kaisheng , Robbat Albert 
Published: February 2020

Abstract
Performance-based field methods that provide qualitative and screening level data for phenol and its substituted (chloro, methyl, and nitro) analogues were developed for soil analysis. The methods give results in under 5 min/sample. A more quantitative field method for soil and water also was developed. The method can provide data in under 20 min/sample inclusive of sample preparation. Measurement performance of thermal desorption gas chromatography/mass spectrometry (TDGC/MS) for both soil and water samples are presented. MS with selective ion monitoring and a compound-specific data analysis algorithm provides data with measurement precision and accuracy of about 40%. The more quantitative method yields data comparable with those obtained by U.S. Environmental Protection Agency standardized methods, with measurement precision and accuracy of ± 30%.
Effects of Sodium Sulfite on Recovery and Composition of Detergent Fiber and Lignin
Authors: Hintz Rodney W , Mertens David R , Albrecht Kenneth A 
Published: February 2020

Abstract
Use of sodium sulfite to reduce nitrogenous contamination in fiber analysis was evaluated. The effects of sodium sulfite on analytical accuracy and precision were examined for amylase-treated neutral detergent fiber (aNDF), sequentially determined acid detergent fiber (sADF), and acid detergent lignin (sADL) in animal feeds. In one experiment, 0.5 g sodium sulfite was added per sample during neutral detergent (ND) extraction. The treatment consistently reduced aNDF, sADF, and sADL values of 180 alfalfa samples and improved precision (decreased within-sample variance of replicated analyses). The greatest effect was on precision of sADL analysis, with within-sample variance reduced by more than 50%. In a second experiment, 24 animal feeds were analyzed for aNDF, sADF, and sADL with and without addition of 0.5 g sodium sulfite per sample during ND extraction. Nitrogen contents of the recovered fiber fractions were determined. Sodium sulfite reduced fiber and lignin values and decreased nitrogen concentration in residues. Within-sample variance was lower in all analyses. In a third experiment, 23 animal feeds were analyzed for aNDF with sodium sulfite at 0, 0.25, 0.5, and 1.0 g per sample. Average aNDF of feeds was reduced by each additional increment of sodium sulfite; however, 1.0 g sodium sulfite resulted in only a slight reduction in aNDF compared with 0.5 g. Therefore, 0.5 g sodium sulfite per sample should be added to samples prior to aNDF analysis.
Vitamin D in Infant Formula and Enteral Products by Liquid Chromatography: Collaborative Study
Authors: Sliva Matthew G , Sanders James K ,   Collaborators:, Arendsen M , Baars A , Bhandari S , Boerma B , Broge J , Bueno M , Cherix G , Gates G , Hollembaek J , Kaufman M , Kraft C , Oerl L , Santos A , Schuep W , Wehrmann J 
Published: February 2020

Abstract
Results from a collaborative study of a new liquid chromatographic (LC) method for determination ofvitamin D in infant formulas and enteral products are presented. Each of 15 laboratories was provided with 11 blind duplicate samples covering a range ofapproximately 200-500 International Units/quart (normal dilution), a system suitability sample, and the U.S. Pharmacopeia ergo- and cholecalciferol standards. Product types included liquid and powder forms of milk (whey and casein), soy, and hydrolyzed protein-based infant formulas and enteral products. The method includes a single liquid-liquid extraction following saponification, solid-phase extraction,and then concentration by evaporation. An isocratic, nonaqueous, chromatographic system with reversed-phase, zero end- capped C18 column, and UV detector set at 265 nm are used. Statistical evaluation ofdata from participating laboratories showthe average reproducibility and repeatability of the method across all samples to be excellent, with RSDR and RSDr values of 13.48 and 9.44, respectively, after elimination of out liers. The LC method for determination of vitamin D in infant formulas and enteral products has been adopted by AOAC INTERNATIONAL.
Determination of Shell Content in Palm Kernel Cake
Authors: Wai-Lin Siew 
Published: February 2020

Abstract
A method for determining shell in palm kernel cake (PKC) is described. This simple and rapid method requires little pretreatment compared with the method currently used in PKC trade, in which the sample undergoes defatting, acid and alkali digestion, and washing, before a chloroform-alcohol solution is used to separate the shells. In the proposed method, only defatting the sample is required. The shells are separated by the density difference between the shell and PKC in a potassium iodide solution. Recoveries of at least 93% were obtained, and the correlation coefficient between the actual shell content and the determined shell content was 0.999, with gradients of 0.97 and 0.98 for fine and coarse shell, respectively.
Rapid Liquid Chromatographic Determination of Fatty Acids as 2-Nitrophenylhydrazine Derivatives
Authors: Miwa Hiroshi , Yamamoto Magobei 
Published: February 2020

Abstract
Direct derivatization of saponified fats and oils with 2-nitrophenylhydrazine hydrochloride produced corresponding fatty acid hydrazides without timeconsuming sample cleanup and/or extraction steps. Hydrazides were injected directly into a liquid chromatograph. Improved isocratic separation was achieved within only 22 min for 29 saturated and mono- and polyunsaturated fatty acids (C8:0- C22:6), including cis-trans isomers and doublebond positional isomers. The technique has good quantitative accuracy while reducing analysis time, cost, and labor.