bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stable Carbon Isotope Ratio Analysis of Honey: Validation of Internal Standard Procedure for Worldwide Application
Authors: White Jonathan W , Winters Kenneth , Peter Martin , Rossmann Andreas 
Published: February 2020

abstract
Stable carbon isotope ratio analysis (SCIRA) of honey for undeclared presence of cane or corn sugars has been available for 20 years. Its use with domestic and imported honeys is reviewed. Six years of data from the internal standard isotope ratio analysis (ISCIRA) method support its worldwide validity for honey analysis. The ISCIRA database of pure honeys has been increased from 64 U.S. samples to 224 by addition of data from Germany, United Kingdom, Mexico, Italy, and Spain. ISCIRA analyses of 131 commercial honeys from the United States, Mexico, and Spain found that 17 are adulterated. Analyses of 303 Chinese honeys proves that they should have carbon isotope values similar to honeys from other areas, contrary to claims that the observed differences are intrinsic because of the variability of environmental conditions and of plants used in honey production in China. Addition of corn or cane (C4) sugars to honeys in amounts that do not produce a δ13C value greater than -23.5%o for the mixture cannot be detected by the original 1978 SCIRA procedure. Such adulteration however is detected by ISCIRA procedure from the δ13C value of the protein contained in the honey, which shows the isotopic composition of the honey before addition of C4 sugars. Fortythree percent of 98 honeys received in the United States in 1994-1997 with δ13C &lt; -23.5%o were suspected and found to be adulterated.
Liquid Chromatographic Determination of Methylxanthines and Catechins in Herbal Preparations Containing Guaraná
Authors: Carlson Marvin , Thompson Richard D 
Published: February 2020

Abstract
Herbal preparations derived from the dried seeds of guarana (Paullinia cupana) have become a popular nutritional supplement used for stimulatory purposes. Once considered a drug substance in the United States, guaraná currently is classified as a food additive and dietary supplement. The pharmacological activity of guaraná-containing products is primarily due to methylxanthine alkaloids. For guaraná preparations, methylxanthine levels and, more significantly, the presence of several polyphenol compounds (i.e., catechins) provide phytochemical markers of authenticity. Methylxanthines and polyphenols are extracted from sample matrix with a heated phosphate buffer-methanol solution, the cooled extract is filtered, and the extract is injected into the liquid chromatographic (LC) system. A Nova-Pak C18 column eluted with phosphate buffer-methanol mobile phase (pH = 3.50) and monitored at 272 nm gave satisfactory resolution for the methylxanthines theobromine, theophylline, caffeine and the polyphenols (+)-catechin and (−)-epicatechin. Twenty-four products including dried seeds, dried paste, seed powders, tablets, and capsule formulations were assayed and conclusions were drawn about their authenticity. The LC system responded linearly to methylxanthines over the 100-fold range in concentration from 0.043 to 4.30 μg/mL for theobromine and caffeine and from 0.041 to 4.10 μg/mL for theophylline. Precision data for the 3 methylxanthines obtained from 10 different products (n = 5) gave relative standard deviation (RSD) values of 1.18-15.52% within a concentration range of 0.01-52.28 mg/g. Recoveries of methylxanthines from fortified products varied from 87.5 to 120.0%. The response for catechins was linear over a 200-fold range in concentration of 0.05-10.0 μg/mL. Precision data from 5 products (n = 5) gave RSD values of 1.08-5.54% within a concentration range of 0.34-32.65 mg/g. Recoveries from these products ranged from 87.7 to 109.7%. Results and chromatographic profiles for 14 commercial products in solid dosage form indicate that a number of these products may not contain authentic guaraná as an active ingredient or contain less than the declared quantity of guaraná. The proposed procedure also was applied to 2 carbonated soft drinks and a sample of mate.
Microwave-Assisted Extraction Coupled with Gas Chromatography with Nitrogen-Phosphorus Detection or Electron Capture Negative Chemical Ionization Mass Spectrometry for Determination of Dimethomorph Residues in Soil
Authors: Stout Steven J , Babbitt Brion W , Dacunha Adrian R , Safarpour Maximilian M 
Published: February 2020

Abstract
Dimethomorph, a cinnamic acid derivative, is a crop protection product for the control of fungi in grapes, tomatoes, potatoes, and tobacco. Of the extraction techniques evaluated, microwave-assisted extraction (MAE) gave the best extractability of the analyte at trace levels from soil. After an appropriate cleanup, dimethomorph residues could be determined by gas chromatography (GC) with either nitrogen-phosphorus detection (NPD) or mass spectrometry with electron capture negative chemical ionization (ECNCI). The sensitivity and specificity of the latter detection technique made it possible to use a greatly simplified cleanup procedure. The limit of quantitation of both procedures was 10 ppb. Soils fortified over a range of 10 to 500 ppb gave an average recovery of 88%, with a standard deviation of 11% by GC-NPD and an average recovery of 99%, with a standard deviation of 8.8% by GC/ECNCI. Control soils generally showed apparent residues of less than 1 ppb
Determination of Micronutrients in Feed Products by Inductively Coupled Plasma Mass Spectrometry
Authors: Mcguire James S , Hite Douglas A 
Published: February 2020

Abstract
Micronutrients are widely used in feed products and are very important to the health and productivity of farm and domestic animals. It is imperative to have analytical capabilities for rapid and accurate results. By using a simple nitric acid digestion of the feed coupled with inductively coupled plasmamass spectrometry (ICP/MS), rapid and accurate results can be obtained. ICP/MS has many advantages over classical wet chemical methods, atomic absorption methods, and other ICP methods: speed of analysis, reduced standards preparation, reduced waste stream, and qualitative scan capabilities. One gram portions of feed products were placed into 250 mL volumetric flasks and digested with 30 mL concentrated high-purity nitric acid for about 20 min. They were then brought to volume with ultra-high-purity water, shaken, and filtered. Ten milliliter portions were taken, and 0.5 mL internal standards were added. Standards were made up in concentrations to agree with the expected range of the desired element. Analysis of check samples from the Association of American Feed Control Officials shows that this method is comparable with other methods of choice
Development and Implementation of an Automated Sample Preparation Procedure for Frenolicin-B in Poultry Feed
Authors: Walstead Mark M , Yapchanyk Ed , Haroon Yacoob 
Published: February 2020

Abstract
The Zymark Tablet Processing Workstation II (TPWII) provides a versatile, cost-effective alternative to manual sample preparation for extracting drugs from medicated animal feed (Type C medicated articles). Routine manual assays require samples to be ground, extracted, filtered, diluted, and analyzed by liquid chromatography. The TPW II uses computer-controlled homogenization, a liquid management system, an internal 4-place analytical balance, and a 3-place top-loading balance to consistently provide accurate results. The TPW II is also equipped with a robotic arm articulated by 4 degrees of freedom. The relative standard deviation of the precision assays for automated versus manual extraction were 7.4 and 8.1, respectively. The workstation also provides a gravimetric audit trail for all sample weights and sample volumes transferred. Few papers have been published concerning automated extraction of drugs in feeds. We report the successful development and routine implementation of a robotically automated procedure for extracting frenolicin-B, an anticoccidial and feed efficiency enhancer, from poultry feed
Determination of Cephapirin and Ceftiofur Residues in Bovine Milk by Liquid Chromatography with Ultraviolet Detection
Authors: Schermerhorn Patricia G , Chu Pak-sin , Ngoh Maureen A 
Published: February 2020

Abstract
A method capable of quantitating cephapirin at a level of 20 ng/mL and ceftiofur at a level of 50 ng/mL was developed for raw bovine milk. Raw bovine milk is deproteinated with acetonitrile. The supernatant is collected and then acetonitrile is removed under reduced pressure while warming in a water bath at 40°-50°C. The extract is mixed with water and loaded onto a conditioned C18 solidphase extraction column. Analytes are eluted with acetonitrile, which is removed completely under a stream of nitrogen gas. Analytes are separated from coextractives by gradient elution with an ion-pair mobile phase on a reversed-phase column and are detected by ultraviolet absorbance at 290 nm. Mean recoveries from fortified milk samples ranged from 79 to 87% for cephapirin and from 76 to 86% for ceftiofur, with intralaboratory coefficients of variation ranging of 6-10% and 7-14%,respectively.
Identification of β-Lactam Antibiotics in Tissue Samples Containing Unknown Microbial Inhibitors
Authors: Moats William A , Romanowski Robert D , Medina Marjorie B 
Published: February 2020

Abstract
Antibiotic residues in animal tissues can be detected by various screening tests based on microbial inhibition. In the 7-plate assay used by the U.S. Department of Agriculture's Food Safety and Inspection Service (FSIS), penicillinase is incorporated into all but one plate to distinguish β-lactam antibiotics from other types. However, β-lactams such as cloxacillin and the cephalosporins are resistant to degradation by penicillinase. They may not be identified as β-lactams by this procedure, and thus, they may be identified as unidentified microbial inhibitors (UMIs). However, these penicillinase resistant compounds can be degraded by other β-lactamases. The present study describes an improved screening protocol to identify β-lactam antibiotics classified as UMIs. A multiresidue liquid chromatographic procedure based on a method for determining β-lactams in milk was also used to identify and quantitate residues. The 2 methods were tested with 24 tissue FSIS samples classified as containing UMIs. Of these, 3 contained penicillin G, including one at a violative level, and 5 contained a metabolite of ceftiofur. The others were negative for β-lactam antibiotics.
Immunoaffinity Column as Cleanup Tool for a Direct Competitive Enzyme-Linked Immunosorbent Assay of Cyclopiazonic Acid in Corn, Peanuts, and Mixed Feed
Authors: Yu Wanjun , Dorner Joe W , Chu Fun S 
Published: February 2020

Abstract
An immunoaffinity column (IAC) for cyclopiazonic acid (CPA) was prepared by coupling a CPA-specific monoclonal antibody to CNBr-activated sepharose 4B. A direct competitive enzyme-linked immunosorbent assay (dc-ELISA) was used to study the chromatographic behavior of a 0.2 ml_ gel column with a binding capacity of 4 μg CPA/column as well as to evaluate its efficacy as a cleanup tool for analysis of naturally occurring CPA. Sample extract either in buffer solution or in a solution containing up to 35% methanol could be loaded onto the column. After the column is washed with 5 ml_ deionized water and 5 ml_ 50% methanol, CPA could be quantitatively eluted with 2 ml_ 100% methanol. The column could be regenerated at least 10 times by washing with 10 mL equilibrating buffer and then storing in a cold room overnight before reuse. Recoveries of CPA added to corn, peanut, and mixed feed extracts in the range 10-200 ng/g were 88-105,86-100, and 90-110%, respectively. Detection limits were 2.0,4.4, and 4.7 ng/g for corn, mixed feed, and peanuts, respectively. Twenty-two peanut samples naturally contaminated with CPA were subjected to both IAC and solvent partition cleanup followed by dc-ELISA. Although a good correlation between data obtained from lAC-dc-ELISA and from SP-dc-ELISA (r = 0.75, p &lt; 0.0001) was obtained, the slope of the linear regression was low (0.67), indicating loss during solvent partition cleanup. The overall data showed that the combination of IAC and dc- ELISA is an effective method for CPA analysis.
Determination of 17β-Estradiol and Its Metabolites in Sewage Effluent by Solid-Phase Extraction and Gas Chromatography/ Mass Spectrometry
Authors: Lee Hing-Biu , Peart Thomas E 
Published: February 2020

Abstract
The paper describes a simple and quantitative method for monitoring non-conjugated 17β-estradiol (E2) and its metabolites estrone (E1) and estriol (E3) as environmental contaminants in municipal sewage effluents. Estrogens were preconcentrated and cleaned up by solid-phase extraction using a reversed-phase c18cartridge. They were derivatized with pentafluoropropionic acid anhydride, and the products were analyzed by gas chromatography/mass spectrometry. Recoveries from spiked distilled water and sewage were better than 87% at fortification levels of 100 and 20 ng/L. For a 1 L sewage sample and a concentration factor of 5000, detection limits were 5 ng/L for E1 and E2 and 10 ng/L for E3. In a brief survey of Canadian wastewater, these estrogens were detected in many raw sewage and effluent samples at concentrations ranging from 6 to 109 ng/L for E1, from &lt;5 to 15 ng/L for E2, and from &lt;10 to 250 ng/L for E3.
Automated Method for Cleanup and Determination of Benomyl and Thiabendazole in Table-Ready Foods
Authors: Levine Robert A , Luchtefeld Ronald G , Hopper Marvin L , Salmon Garrett D 
Published: February 2020

Abstract
An automated solid-phase extraction (SPE) cleanup with on-line liquid chromatographic (LC) analysis was developed to determine residues of benomyl (as carbendazim) and thiabendazole in table- ready food items from the U.S. Food and Drug Administration Total Diet Study (TDS). A strong-cation- exchange cleanup of an acetone extract replaces the methylene chloride solvent partitioning steps in the procedure described in the Pesticide Analytical Manual(PAM). LC analysis is accomplished with a Cs analytical column and tandem fluorescence and UV detection. Recoveries of both analytes from 32 representative TDS foods fortified at 0.05 and 0.5 μg/g were determined. Method precision was evaluated with triplicate recovery assays on 11 foods fortified at both levels. Accuracy was tested further by assaying 47 foods for incurred residues in parallel with the validated PAM procedure for comparison, and good agreement was found. The automated SPE method reduces solvent consumption, analysis time, and labor.
Monitoring Chlorinated Pesticides and Toxic Elements in Tissues of Food-Producing Animals in Yugoslavia
Authors: Spiric Aurelija , Saicic Snezana 
Published: February 2020

Abstract
According to the established monitoring program in Yugoslavia, 941 swine, 561 cattle, and 358 lamb samples collected during a 5-year period were analyzed for chlorinated pesticide residues. Less than 10% of the examined samples contained residues of HCB (hexachlorobenzene), HCH (hexachlorocyclohexane), lindane (ɤ-hexachlorocyclohexane), and total DDT (p,p′-DDT and metabolites) at concentrations greater than the lowest detectable limit. None of the swine and cattle samples exceeded the residue limit (RL). Among lamb samples, 2.5% contained lindane residues exceeding the RL, with a mean of 4.75 mg/kg. This finding suggests lindane's improper use as a veterinary pesticide, probably as a sheep-dip for destroying ectoparasites. During the same period, 849 swine, 584 cattle, and 350 lamb samples also were analyzed for toxic elements (Pb, Cd, Hg, and As). In the majority of samples, toxic elements were present at levels less than 50% of RLs. Only Cd and Pb RLs were exceeded in several cases. Differences in trace element contents of samples from different animals were not significant. The data indicate that residues in tissues of food-producing animals do not have a great potential impact on public health.
Improvement in the Multiresidue Liquid Chromatographic Analysis of Residues of Mono- and Dibasic Penicillins in Bovine Muscle Tissues
Authors: Boison Joe O , Keng Lily J -Y 
Published: February 2020

Abstract
A recently developed multiresidue method using gradient liquid chromatographic conditions for analysis of residues of (β-lactam drugs in bovine muscle tissues after precolumn derivatization with acetic anhydride was modified to permit isocratic analysis. The modification included replacing the acylating reagent, acetic anhydride, with benzoic anhydride and increasing sample size for extraction from 2 to 3 g. The modifications have reduced analysis time per sample from &gt;1 h to about 22 min without loss in detection sensititivities for the (β-lactam s, resulting in a significant increase in the number of samples that can be analyzed in 1 day from 1 to 8. The modifications make the multiresidue LC method more suitable than the original method for use in regulatory programs for routine analysis of these veterinary drug residues in bovine muscle tissues.
Fat Contents of Cereal Foods: Comparison of Classical with Recently Developed Extraction Techniques
Authors: Zou Wei , Lusk Chris , Messer Dale , Lane Ralph 
Published: February 2020

Abstract
Eight cereal products ranging from a fat-free ready- to-eat (RTE) cereal (frosted flakes) to a full-fat high- ratio cake mix were subjected to analyte separation by anhydrous diethyl ether extraction (EE), acid hydrolysis/mixed ether extraction (AH), solid-phase extraction (SPE), and supercritical fluid extraction (SFE) with CO2 and with CO2 modified with 15% ethanol (SFEmod). Gravimetric analyses of extracts indicated higher (P ≤ 0.05) crude fat values by AH than by EE, SFE, or SFEmod. Extractions followed by fatty acid methyl ester analysis also produced higher (P ≤ 0.05) triglyceride means by AH than by other methods used for heat-treated RTE cereals and for ready-to-cook (RTC) cream of wheat. Therefore, for labeling purposes, AH seems most appropriate because in most cases it achieves higher triglyceride values than extraction with solvent(s) alone. SFE and SPE, on the other hand, yield fat values similar to those obtained by EE and offer the advantages of reduced solvent volume, short extraction times, and ease of laboratory automation.
Teaching the Basics of Pharmaceutical Analysis by Thin-Layer Chromatography and High-Performance Thin-Layer Chromatography to Undergraduate Students—Laboratory Practicals
Authors: Salo Jukka-Pekka , Salomies Hannele 
Published: February 2020

Abstract
As part of the renewal of the pharmacy students’ curriculum, we planned a 2-day program with 9 exercises in thin-layer chromatography to teach the basics of the technique. Written reports with proper presentation ofresults were required. Related issues such assimple experimental design were integrated into the program. The results and difficultiesin their interpretation are described from a teacher’s point of view. As in real life, some exercises do not allow simple conclusions or complete solutions to a problem. The mostly positive feedback about the program suggests the program served its purpose well.
Determination of Neomycin in Animal Tissues by Liquid Chromatography
Authors: Reid Jo-Ann , MacNeil James D 
Published: February 2020

Abstract
Tissue samples are digested under hot alkaline conditions after initial conditioning atroom temperature with phosphate-buffered saline. The cooled digest is deproteinated with concentrated perchloric acid. After centrifugation and pH adjustment, the clear supernatantis applied to an ion-ex change cartridge, andafter the cartridge is washed, the neomycin is eluted with dilute perchloric acid. This eluate is derivatized with 9-fluorenylmethyl chloroformate prior to liquid chromatography using a wide-pore spherical silica C4 column and fluorescence detection.Recovery and repeatability are calculated from tissue extract standard calibration curves produced from the same assay. Recoveries ranged from80to 120% for fortifications of 0.25-1.00 mg/kg for muscle tissue and from 80 to 100% for fortifications of 0.50-10.0 mg/kgfor kidney tissue. Limits of quantitationwere0.25 and 0.50 mg/kg, respectively, formuscle and kidneytissues. Limits of detection were 0.125 and 0.20 mg/kg, respectively, for muscleand kidney tissues.
Validation of the LacTek Test Applied to Spiked Extracts of Tissue Samples: Determination of Performance Characteristics
Authors: Mitchell John M , Yee Arlene J , McNab William B , Griffiths Mansell W , McEwen Scott A 
Published: February 2020

Abstract
LacTekTM tests are competitive enzyme-linked immunosorbent assays intended for rapid detection of antimicrobial residues in bovine milk. In this study, the LacTek test protocol was modified for use with extracts of bovine tissue to detect β-lac-tam, tetracycline, and sulfamethazine residues. Testperformance characteristics—precision, accuracy, ruggedness, practicability, and analytical specificity and sensitivity—were investigated. Results suggest that LacTek tests can be easily adapted to detect antimicrobial residues in extracts of lean ground beef. However, positive samples may not contain residues at violative concentrations (i.e., Canadian maximum residue limits), and therefore, additional analysis would be required for final confirmation and quantitation (e.g., chromatography).
Preparative Method for Isolating α-Zearalenol and Zearalenone Using Extracting Disk
Authors: Ware George M , Zhao Yuhong , Kuan Shia S , Carman Allen S 
Published: February 2020

Abstract
A liquid chromatographic method is described for the determination of zearalenol and zearalenone in corn. Zearalenol and zearalenone are extracted from corn with methanol–water (1+1) and cleaned up using a solid-phase extraction (SPE) disk, separatedon a reversed-phase analytical column, and detected with a fluorescence detector. The SPE disk concentrated and cleanly separated zearalenol and zearalenone from sample interferences. Standard calibration curves for zearalenol and zearalenone for the concentration range 25–500 ng/mL were linear. The small extract disk had a column capacity equivalent to 1 g extracted corn. Zearalenol and zearalenone were added at levels ranging from 10 to 2000 ng/g to a control sample that contained no detectable levels of zearalenol and zearalenone. Both toxins were recovered from spiked samples at 106.3 and 103.8%, with coefficients of variation of 7.6 and 13.0%, respectively. The method has an estimated reliable limit of detection and limit of quantitation around 10 and 40 ng/g for each toxin, respectively.
Degradation of Parathion Methyl on Field-Sprayed Apples and Stored Apples
Authors: Pappas Christos J , Kyriakidis Nikolaos B , Athanasopoulos Panagiotis E 
Published: February 2020

Abstract
Residue levels of parathion methyl on field-sprayed Granny-Smith apples were studied. The pesticide was applied according to producer recommendations. Apples received a single spraying at a rate of 40 g active ingredient/100 L. Residues were determined with a simple gas chromatographic method. Recovery of parathion methyl was88-108%, and the limit of determination was 0.002 mg/kg. Decomposition of parathion methyl was studied in apples remaining on trees after spraying and in apples harvested and stored under ambient-temperature, refrigerated- room, and controlled-atmosphere conditions. During post harvest storage, parathion methyl degrades more slowly than on apples remaining on the trees. Best-fit curves were determined, and kinetic equations, rate constants, and half-lives were calculated. Half-lives found were 8 days for apples on trees, 45 days for apples stored at ambient conditions, 68 days for apples stored in control led-atmosphere room, and 62 days for apples stored in a refrigerated room. Under storage conditions, levels of parathion methyl residues need a longtime to become lower than the legal limit (0.2 mg/kg).