bluuebunny/crossref_metadata_2025 huggingface dataset:
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

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

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

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

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

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

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 < 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

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 <5 to 15 ng/L for E2, and from <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

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

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

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 >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

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

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

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

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

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

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).
Organochlorine Contaminants in Microlayer and Subsurface Water of Alexandria Coast, Egypt
Authors: Abd-Allah Aly Mohammed Aly
Published: February 2020

The surface microlayer of seawater is a potential enrichment site for hydrophobic organic compounds. Concentrations of pesticidesand congeners of polychlorinated biphenyls (PCBs) in the microlayer and subsurface waters of Alexandria coast were assessed. A 0.22 m2 screen was used to collect microlayer samples at 12 stations in June 1997. The samples were analyzed by gas chromatography with electron capture detection (GCECD) and confirmed by GC with mass spectrometry. Ten organochlorine pesticides and 10 PCB congeners were measured. The surface microlayer was enriched 2- to 3-fold in pesticides and PCBs. The most contaminated locations studied were Abu-Quir Bay and the Eastern Harbor. This study provides the first record of residues of PCB congeners in the studied areasand the first data about microlayer enrichment at Alexandria's Mediterranean Coast.
Determination of Four Fluoroquinolones in Milk by On-Line Immunoaffinity Capture Coupled with Reversed-Phase Liquid Chromatography
Authors: Holtzapple Carol K , Buckley Sandra A , Stanker Larry H
Published: February 2020

An automated, on-line immunoaffinity extraction method was developed for the analysis of 4 fluoroquinolones in milk: ciprofloxacin, difloxacin, enrofloxacin, and sarafloxacin. This method involves analyte extraction using an immunoaffinity capture column containing anti-fluoroquinolone antibodies coupled on-line with reversed-phase column chromatography. Liquid chromatographic analyses were performed by isocratic elution using a mobile phase of 2% acetic acid-acetonitrile (85 + 15) and an Inertsil phenyl column with fluorescence detection at excitation and emission wavelengths of 278 and 444 nm, respectively. No significant interferences from the sample matrix were observed, indicating good selectivity with the immunoaffinity column. Recoveries from fortified raw milk samples (5–50 ppb of each fluoroquinolone) ranged from 72 to 90%, with standard deviations of ≤8%.
Maternal Body Burden of Organochlorine Pesticides and Dioxins
Authors: Nakagawa Reiko , Hirakawa Hironori , Iida Takao , Matsueda Takahiko , Nagayama Junya
Published: February 2020

To investigate the body burden of organochlorine pesticides and dioxins in Japanese women,125 milk samples were collected from 41 mothers in 1994, 42 in 1995, and 42 in 1996. Ofthe 125 samples, 82 were from primipara mothers (first delivery) and 43 were from multipara mothers (second or later delivery). By using capillary gas chromatography with electron capture detection, β-HCH and p,p′-DDE were detected as the major chlorine pesticides in human milk. Average levels of β-HCH and p,p′-DDE were 475 and 368 ng/g lipid, respectively, in primipara breast milk, 314 and 259 ng/g lipid in multipara breast milk, and 420 and 330 ng/g lipid in total breast milk. Dieldrin, heptachor epoxide, oxychlordane, trans-chlordane, and cis-chlordane were detected at lower average levels of 3, 4, 34, 41, and 5 ng/g lipid, respectively. By using high-resolution gas chromatography with mass spectrometric detec tion, dioxins were detected in all samples. Average levels of total polychlorinated dibenzo-p-dioxin (PCDD), total polychlorinated dibenzofuran (PCDF), total PCDD + PCDF, total coplanar polychlorinatedbiphenyl (CoPCB), and total dioxin were 10.0, 7.8, 17.7, 9.9, and 27.5 TEQ (toxic equivalent) pg/g lipid, respectively, in primipara breast milk; 7.0, 5.8, 12.8, 7.3, and 20.1 TEQ pg/g lipid in multipara breast milk; and 8.9, 7.1, 16.1, 8.9, and 25.0 TEQ pg/g lipid in total breast milk. In primipara breast milk, significant correlations were found among levels of β-HCH, p,p’-DDE, total PCDD-TEQ, total PCDF-TEQ, total CoPCB-TEQ, and total TEQ except for less correlation between p,p’-DDE and total PCDF-TEQ. Levels of these analytes also significantly increased depending on mother’s age, except for total Co-PCB-TEQ. For the correlation with food habit, the only positive correlation was between total PCDF-TEQs and fish intake.
Spectrophotometric Determination of Fenpropathrin and Fluvalinate in Their Formulations
Authors: Kaushik Nutan , Handa Swadesh Kumar
Published: February 2020

An economical and precise method for spectrophotometric determination of fenpropathrin and fluvalinate pyrethroids is reported. The method involves alkaline hydrolysis of the pyrethroids to release HCN, which is converted to cyanogen bromide to form a colored complex with benzidine-pyridine reagent. This method can be used effectively to determine actual concentrations of these pyrethroids in their formulations. Results are comparable with results obtained by gas-liquid chromatography.
A Bridging Study for Oxytetracycline in the Edible Fillet of Rainbow Trout: Analysis by a Liquid Chromatographic Method and the Official Microbial Inhibition Assay
Authors: Stehly Guy R , Gingerich William H , Kiessling Connie R , Jeffrey H Cutting
Published: February 2020

Oxytetracycline (OTC) is a drug approved by the U.S. Food and Drug Administration (FDA) to control certain diseases in salmonids and catfish. OTC is also a likely control agent for diseases of other fish species and for other diseases of salmonids and catfish not currently on the label. One requirement for FDA to extend and expand the approval of this antibacterial agent to other fish species is residue depletion studies. The current regulatory method for OTC in fish tissue, based on microbial inhibition, lacks sensitivity and specificity. To conduct residue depletion studies for OTC in fish with a liquid chromatographic method, a bridging study was required to determine its relationship with the official microbial inhibition assay. Triplicate samples of rainbow trout fillet tissue fortified with OTC at 0.3,0.6,1.2,2.4,4.8, and 9.6 ppm and fillet tissue with incurred OTC at approximately 0.75,1.5, and 3.75 ppm were analyzed by high-performance liquid chromatography (HPLC) and the microbial inhibition assay. The results indicated that the 2 methods are essentially identical in the tested range, with mean coefficients of variation of 1.05% for the HPLC method and 3.94% for the microbial inhibition assay.
Glycoalkaloid Concentration in Alberta Potatoes Determined by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry
Authors: Driedger Darcy R , Sporns Peter
Published: February 2020

Matrix-assisted laser desorption and ionization (MALDI) mass spectrometry was used to determine concentrations of individual potato glycoalkaloids in tubers. Samples were extracted with methanol–water and deposited on 2,4,6-trihydroxyacetophenone crystals. Positive ions were analyzed with a MALDI time-of-flight mass spectrometer equipped with a 337 nm laser. Analyte ion intensities relative to an internal standard were used to determine chaconine and solanine concentrations. Calibration curves were prepared by standard additions to potato tuber material. The relative standard deviations (RSDs) of triplicate measurements ranged from 1 to 16%, with an average of 9%. The day-to-day RSD for replicate determinations was 11 %. Recoveries of analyst-prepared spikes (50 μg/g) averaged 104% for chaconine (RSD, 8%) and 98% for solanine (RSD, 4%). The method limit of detection was estimated to be 2 μg/g.
IUPAC Collaborative Trial Study of a Method To Detect Genetically Modified Soy Beans and Maize in Dried Powder
Authors: Lipp Markus , Brodmann Peter , Pietsch Klaus , Pauwels Jean , Anklam Elke ,   Collaborators:, Börchers T , Braunschweiger G , Busch U , Eklund E , Eriksen F D , Fagan J , Fellinger A , Gaugitsch H , Hayes D , Hertel C , Hörtner H , Joudrier P , Kruse L , Meyer R , Miraglia M , Müller W , Philipp P , Pöpping B , Rentsch R , Sawyer J , Schulze M , van Duijn G , Vollenhofer S , Wurtz A
Published: February 2020

This paper presents results of a collaborative trial study (IUPAC project No. 650/93/97) involving 29 laboratories in 13 countries applying a method for detecting genetically modified organisms (GMOs) in food. The method is based on using the polymerase chain reaction to determine the 35S promoter and the NOS terminator for detection of GMOs. Reference materials were produced that were derived from genetically modified soy beans and maize. Correct identification of samples containing 2% GMOs is achievable for both soy beans and maize. For samples containing 0.5% genetically modified soy beans, analysis of the 35S promoter resulted also in a 100% correct classification. However, 3 false-negative results (out of 105 samples analyzed) were reported for analysis of the NOS terminator, which is due to the lower sensitivity of this method. Because of the bigger genomic DNA of maize, the probability of encountering false-negative results for samples containing 0.5% GMOs is greater for maize than for soy beans. For blank samples (0% GMO), only 2 false-positive results for soy beans and one for maize were reported. These results appeared as very weak signals and were most probably due to contamination of laboratory equipment.
High-Performance Liquid-Phase Separation of Glycosides Analytical and Micropreparative HPLC Combined with Spectroscopic and Enzymatic Methods for Generating a Glucosinolate Library
Authors: Arguello Lino G , Sensharma Dilip K , Qiu Feng , Nurtaeva Aliya , El Rassi Ziad
Published: February 2020

Analytical and micropreparative high-performance liquid chromatographic (HPLC) methods assisted by spectroscopic and enzymatic tools were developed for generating a glucosinolate library from white cabbage. This involved the study of the chromatographic behavior of glucosinolates by reversed-phase chromatography (RPC) using octadecyl-silica (ODS) stationary phases and ion-exchange chromatography with strong an ion-exchange (SAX) columns. The glucosinolate extract from white cabbage was fractionated on a micropreparative Zorbax ODS column of 250 × 6.2 mm id. The collected fractions from the ODS column effluent were further purified by rechromatographing the early eluting fractions on a SAX column and the late-eluting peaks on the same ODS column under different elution conditions. These studies demonstrated the benefits of using more than one HPLC method in the isolation of pure glucosinolates. These chromatographic separation schemes combined with efficient sample cleanup provided pure glucosinolate fractions that were readily identified by high-field nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (MS), namely negative-ion liquid secondary ionization mass spectrometry (LSIMS). The structural determination of a given glucosinolate by 1- and 2-dimensional NMR was further confirmed by LSIMS, which gives the mass of the molecular anion of glucosinolates. In addition, the structure of a given glucosinolate fraction was readily assessed by performing RPC of the myrosinase digest of the particular glucosinolate and that of the standard degradation product that has a structure that is reflective of the parent glucosinolate. Also, through the myrosinase degradation products (e.g., isothiocyanates) under controlled conditions, the quantitative determination by RPC of the corresponding glucosinolates in the white cabbage extract was reliably achieved. By using the ability of myrosinase to hydrolyze the glucosinolates, it was possible to profile the glucosinolates in the cabbage extract quite rapidly. For the glucosinolates present at very low amounts in white cabbage, and also for the HPLC fractions containing more than one glucosinolate, the isothiocyanate degradation products resulting from the hydrolyzing effect of myrosinase were analyzed by gas chromatography/MS, and their structures were determined. This in turn allowed the determination of the structure of the parent glucosinolates. In summary, white cabbage seems to contain at least 8 glucosinolates.
Studies in Improvement of Official Method 996.06
Authors: DeVries Jonathan W , Kjos Lori , Groff Linda , Bob Martin , Kristi Cernohous , Patel Hasmukh , Payne Mark , Leichtweis Harry , Shay Mike , Newcomer Leo
Published: February 2020

Quantitation of fat in foods has been performed successfully with AOAC Official Method 996.06. A number of situations have been encountered that render the method note, “Note: For any unknown or uncalibrated peaks, use the nearest calibrated fatty acid response factors and conversion factors,” inaccurate. Identification of extraneous compounds and availability of additional standard fatty acid methyl esters combined with mass spectral data lead to the recommendation of modifications in Official Method 996.06. The stepwise performance of the method remains unchanged.
Analyses of Polychlorinated Biphenyls and Chlorinated Pesticides in Biota: Method and Quality Assurance
Authors: Cleemann Marianne , Paulsen Gudrun B , Storr-Hansen Eva , Fromberg Arvid
Published: February 2020

An analytical method for polychlorinated biphenyls (PCBs) and chlorinated pesticides in mussels, fish liver, bird liver, and seal blubber is described. Different calibration functions were tested to establish the optimal fit to the nonlinear response of all included compounds. Detection limits and within-batch variations were determined from standard deviations of duplicate analyses of real samples. Within-batch, between-batch, and total relative standard deviations were calculated from regular use of control material. Percentage recovery was estimated by spiking samples with 3 selected PCB congeners and by spiking selected samples with all compounds included in the procedure. Quality assurance is described, covering analysis of about 450 samples divided into 38 batches. Because between-batch variation was twice the within-batch variation, the use of in-house control material and control charts is considered to be mandatory for this type of analyses. Use of certified reference material and regular participation in intercomparison exercises have demonstrated the high quality of the method and the adequacy of the quality assurance applied.
Supercritical Fluid Extraction of Ten Chloracetanilide Pesticides and Pyriminobac-Methyl in Crops: Comparison with the Japanese Bulletin Method
Authors: Yoshii Kimihiko , Okada Mai , Tsumura Yukari , Nakamura Yumiko , Ishimttsu Susumu , Tonogai Yasuhide
Published: February 2020

In Japan, the maximum residue limit and an analytical bulletin method for alachlor and pyriminobac-methyl were recently published. Because this method has some problems, such as many interfering chromatographic peaks for some residues in certain crops, time-consuming sample preparation, etc., we have developed an alternative method. In the bulletin method, pesticides are extracted with acetone, reextracted with ethyl acetate, partitioned with hexane–acetonitrile, cleaned up on a Florisil column, and quantitatively determined by gas chromatography with flame thermionic detector (GC-FTD). In the developed method, pesticides are extracted by supercritical fluid extraction and directly cleaned up with a trap column consisting of Extrelut and Florisil (acetone–n-hexane, 3 + 7, as the eluent) or Bond Elut SAX and PSA (acetone–n-hexane, 1 +1, as the eluent). The test solution was quantitatively determined by GC with mass spectrometry. Alachlor, pyriminobac-methyl, and 9 other chloracetanilide pesticides were studied. Average recoveries of spiked samples (0.1 ppm) were between 52 and 104% with the bulletin method and between 68 and 106% with the developed method. By using the Japanese bulletin method, 3 pesticides from Japanese radish could not be measured because of many interfering peaks on the GC–FTD chromatogram, even on selected-ion monitoring (SIM) chromatograms. On the other hand, by using the developed method, SIM chromatograms had fewer interfering peaks than did the Japanese bulletin method.
A Pilot Study for the Statistical Treatment of Nutritional Parameters in the Quality Control of Canned Fishing Goods
Authors: Bartos-Lorenzo Marta , Calviño-López Alberto , Dalama-Iglesias Fernando , Torre-Lamosa Maria de la , Martín-Pardo Guadalupe , Andrade Jose M
Published: February 2020

This pilot study was derived as a consequence of European Directives 496/90 and 493/91 in which a regulation on the labeling of canned fishing goods was established. The study was intended primarily to assess whether different Spanish canned fishing goods might be differentiated by their basic nutritional composition (i.e., ash, chlorine as NaCl, fat, humidity, total proteins, and dry residue) and, second, to study each particular type of good. Accordingly, a univariate nonparametric statistical test and 2 multivariate chemometric techniques (factor and cluster analyses) were used. The pilot study revealed that (1) the basic nutritional variables did not allow a clear distinction among canned goods when different commodities were considered, but they seemed useful for obtaining information for only one type of good; and (2) the variables that gave the most useful information to visualize the appearance of groups in the data sets were humidity, dry residue, fat, and proteins, although their particular usefulness was found to be different when different species were considered.
Synergistic Extraction of Gold(III) by Mixtures of Adogen-464 and Neutral Donors
Authors: Biswas Samira , Basu Sukalyan
Published: February 2020

Synergism was observed in the extraction of gold(III) from aqueous hydrochloric acid media by mixtures of Adogen-464 neutral donors. Synergistic coefficients and adduct equilibrium constants were calculated from distribution data and correlated with the relative donor abilities of the added bases.
Cadmium Levels in Feed Components and Kidneys of Growing/Finishing Pigs
Authors: Lindén Anna , Olsson Ing-Marie , Oskarsson Agneta
Published: February 2020

Cadmium (Cd) concentrations in pig feeds (one control feed and one feed with reduced nitrogen content), straw, water, and pig kidney cortex were determined in 2 breeds of growing/finishing pigs (n = 96). The total Cd intake from feed was calculated. Feed mixtures and components, straw and kidney cortex samples, and certified reference samples were microwave-digested and analyzed by atomic absorption spectrometry with graphite furnace technique. Total Cd concentration in the control feed was 37.1 μg/kg wet weight (w.wt). The highest Cd levels were found in nonlocally produced feed components: vitamin-mineral mixture, lime, dicalcium phosphate, soybean meal, and rapeseed meal. These components contributed 70% of the Cd content in the feed. The main component, barley, which was locally produced, contributed 30% of the total Cd content in feed. The feed with reduced nitrogen content contained less soybean and rapeseed meal and a lower Cd level than the control feed. The Cd levels in kidney cortex varied from 38.0 to 105 μg/kg w.wt, with a mean level of 70.9 μg/kg. The levels differed between breeds and feeds, but not between gender. There was a significant correlation between Cd level in kidney cortex and age at slaughter, with an increase of 2.8 μg/kg w.wt in the kidney for each additional week of survival. The contribution of Cd from nonlocally produced feed components could have environmental effects through application of farmyard manure to local soils.
A New Spectrophotometric Method for the Determination of Dithianon in Commercial Formulations and Its Residues in Foodstuffs
Authors: Verma Balbir C , Thakur Hari K , Singh Jasvir , Sharma Devender K
Published: February 2020

A new, simple, and rapid spectrophotometric method for the microdetermination of dithianon, on the basis of its reaction with a dithiocarbamate, is described. The red color, which develops instantaneously when mixing the fungicide with the reagent in acetonitrile, is stable for at least 1 h and is measured at 520 nm. Beer's law is applicable up to 12 μg/mL dithianon concentration. The method has been successfully adapted to the analysis of the fungicide in commercial formulations and its residues on grains and apple (fruit and leaves). A photometric titration method for formulation analysis of the fungicide has also been developed.
Kjeldahl Nitrogen Analysis as a Reference Method for Protein Determination in Dairy Products
Authors: Lynch Joanna M , Barbano David M
Published: February 2020

Measurement of total nitrogen by Kjeldahl analysis is the historical reference method for determination of the protein content of dairy products and is used for both calibration and validation of alternative methods for protein determination. Accurate evaluation of alternative methods is not possible if there is large uncertainty regarding the reference values. When Kjeldahl analysis is used to establish reference values, the performance of the Kjeldahl testing must be verified and within established expectations. Advice is given for Kjeldahl system optimization, evaluation of test results, and troubleshooting. Techniques for successful Kjeldahl nitrogen analysis of dairy products other than milk are discussed.
Solid-Phase Extraction and Gas Chromatography with Mass Spectrometric Determination of Capsaicin and Some of Its Analogues from Chili Peppers (Capsicum spp.)
Authors: Manirakiza Philemon , Covaci Adrian , Schepens Paul
Published: February 2020

A rapid and accurate method has been developed for the quantitative determination of capsaicin and its most important analogues, dihydrocapsaicin and nordihydrocapsaicin in chili peppers. These components were extracted with methylene chlo ride and separated from interfering substances with activated charcoal. Further cleanup on Florisil cartridges and elution with ethyl acetate were performed before gas chromatographic with mass spectrometric quantitation. The concentrations found were 440 ± 64 μg/g capsaicin, 81 ± 10 μg/g dihydrocapsaicin, and 11 ± 2 μg/g nordihydrocapsaicin. The mean recovery values for triplicate analysis were between 85-94%.
Determination of Trace Metal Ions in Common Salt by Stripping Voltammetry
Authors: Ali Azza M M
Published: February 2020

Sensitive voltammetric methods using cathodic and anodic differential pulse stripping techniques were applied for determination of trace ions cadmium(II), cobalt(II), copper(II), lead(II), manganese(II), nickel(II), and zinc(II), which are usually found in different grades of common salt as contaminants. The optimal conditions, i.e., deposition time, preconcentration potential, supporting electrolyte, and ionic strength, were investigated for each metal ion. Concentration of the metal ion was determined by the standard addition method. Metal content varied according to the quality of the table salt.
Multiresidue Analysis of Pesticides in Fresh Fruits and Vegetables Using Procedures Developed by the Florida Department of Agriculture and Consumer Services
Authors: Cook Joanne , Beckett Mary Pat , Reliford Brian , Hammock Walter , Engel Marc
Published: February 2020

Improved quality and efficiency of pesticide residue analysis were achieved by examining all aspects of the laboratory process. In an effort to eliminate methylene chloride hazardous waste, an acetonitrile extraction method, originally developed by the California Department of Agriculture, was modified and adopted. Sample size and solvent consumption were reduced with the new method. Custom glassware racks and disposable supplies reduced overall analysis time. Gravity-fed, solid-phase extraction simplified sample preparation and provided cleaner extracts for gas chromatographic analyses. Modifications to the method were made to achieve the ruggedness needed to maintain quality objectives during routine analysis. Instrumental improvements, including new selective detectors, retention time locking, and mass spectrometry screening for all samples, provided the laboratory with efficient, reliable, and confirmed analytical results.
Alternative Methodologies for the Determination of Aldehydes by Capillary Electrophoresis
Authors: Pereira Elisabete Alves , Tavares Marina Franco Maggi , Cardoso Arnaldo Alves
Published: February 2020

This paper describes 2 alternative methodologies for the determination of selected aldehydes (form-aldehyde, acetaldehyde, propionaldehyde, acrolein, and benzaldehyde) by capillary electrophoresis (CE). The first approach is based on the formation of aldehyde-bisulfite adducts and employs free solution CE with reversed electroosmotic flow and indirect detection, using 10 mmol/L 3,5-dinitrobenzoic acid (pH 4.5) containing 0.2 mmol/L cetyltrimethylammonium bromide as the electrolyte. This novel methodology showed a fairly good sensitivity to concentration, with detection limits with respect to a single aldehyde on the order of 10-40 μg/L, a reasonable analysis time (separation was achieved in <8 min), and no need for sample manipulation. A second approach was proposed in which 2,4-dinitrophenylhydrazine derivatives of the aldehydes were detected in a micellar electrolyte medium (20 mmol/L borate buffer containing 50 mmol/L sodium dodecyl sulfate and 15 mmol/L β-cyclodextrin). This latter methodology included a laborious sample preconcentration step and showed much poorer sensitivity (0.5-2 mg/L detection limit, with respect to a single aldehyde), despite the use of sodium chloride to promote sample stacking. Both methodologies proved adequate to evaluate aldehyde levels in vehicular emissions. Samples from the tailpipe exhaust of a passenger car vehicle without a catalytic converter and operated with an ethanol-based fuel were collected and analyzed; the results showed high levels of formaldehyde and acetaldehyde (0.41-6.1 ppm, v/v). The concentrations estimated by the 2 methodologies, which were not in good agreement, suggest the possibility of striking differences in sample collection efficiency, which was not the concern of this work.
Identification of novel variants and candidate genes associated with porcine bone mineral density using genome-wide association study
Authors: Nan Jiuhong-H , Yin Lilin-L , Tang Zhenshuang-S , Xiang Tao , Ma Guanjun-J , Li Xinyun-Y , Liu Xiaolei-L , Zhao Shuhong-H , Liu Xiangdong-D
Published: February 2020

Pig leg weakness not only causes huge economic losses for producers but also affects animal welfare. However, genes with large effects on pig leg weakness have not been identified and suitable methods to study porcine leg weakness are urgently needed. Bone mineral density (BMD) is an important indicator for determining leg soundness in pigs. Increasing pig BMD is likely to improve pig leg soundness. In this study, porcine BMD was measured using an ultrasound bone densitometer in a population with 212 Danish Landrace pigs and 537 Danish Yorkshires. After genotyping all the individuals using GeneSeek Porcine 50K SNP chip, genetic parameter estimation was performed to evaluate the heritability of BMD. Genome-wide association study and haplotype analysis were also performed to identify the variants and candidate genes associated with porcine BMD. The results showed that the heritability of BMD was 0.21 in Landrace and 0.31 in Yorkshire. Five single-nucleotide polymorphisms on chromosome 6 identified were associated with porcine BMD at suggestive significance level. Two candidate quantitative trait loci (74.47 to 75.33 Mb; 80.20 to 83.83 Mb) and three potential candidate genes (ZBTB40, CNR2, and Lin28a) of porcine BMD were detected in this study.
Presentation and management of IVC and iliac vein encroachment by lumbar pedicle screws: a case-report
Authors: George Keith , Burke Shane , Park Sandra , Suarez Luis , Riesenburger Ron
Published: February 2020

Pedicle screws are commonly used in spinal surgeries and are relatively safe, with venous complications occurring rarely. We report a patient with imaging following a L4–5 fusion that showed indentation of the inferior vena cava and right common iliac vein by the right L4 and L5 pedicle screws. She underwent revision surgery in which the hardware was removed and no bleeding was observed. Intraoperative venogram confirmed vascular integrity and absence of indentation on the venous structures following screw removal. The patient recovered without complications. Venous contact by pedicle screws should be treated on a case-by-case basis in a multidisciplinary approach with vascular surgery. We discuss a treatment algorithm for the operative management of this problem.