bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Aflatoxin B1 in Baby Food (Infant Formula) by Immunoaffinity Column Cleanup Liquid Chromatography with Postcolumn Bromination: Collaborative Study
Authors: Stroka Joerg , Anklam Elke , Joerissen Urban , Gilbert John ,   Collaborators:, Barmark A , Brera C , Dias B , Felgueiras I , Gardikis J , Macho L , Michelet Y J , Noutio K , Pittet A , Reutter M , Spanjer C M , Strassmeier E , Szymanski L , Worswick R 
Published: February 2020

Abstract
A collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for determination of aflatoxin B1 in a milk powder based infant formula at a possible future European regulatory limit (0.1 ng/g). The test portion was extracted with methanol–water (8 + 2 [v + v]), filtered, diluted with water, and applied to an immunoaffinity column. The column was washed with water to remove interfering compounds, and the purified aflatoxin B1 was eluted with methanol. The separation and determination of the aflatoxin B1 was performed by reversed-phase LC and detected by fluorescence after postcolumn derivatization (PCD) involving bromination. PCD was achieved with either pyridinum hydrobromide perbromide (PBPB) or an electrochemical (Kobra) cell by addition of bromide to the mobile phase. The baby food (infant formula) test samples, both spiked and naturally contaminated with aflatoxin B1, were sent to 14 laboratories in 13 different European countries. Test portions were spiked at levels of 0.1 and 0.2 ng/g for aflatoxin B1. Recoveries ranged from 101 to 92%. Based on results for spiked test samples (blind pairs at 2 levels) and naturally contaminated test samples (blind pairs at 3 levels), the relative standard deviation for repeatability (RSDr) ranged from 3.5 to 14%. The relative standard deviation for reproducibility (RSDR) ranged from 9 to 23%. Nine participants used PBPB derivatization, and 5 particpants used the Kobra cell. There was no evidence of method performance depending on the derivatization method used. The method showed acceptable within- and between-laboratory precision for baby food matrix, as evidenced by HORRAT values, at the target levels of determination for aflatoxin B1.
Proposed Phytic Acid Standard Including a Method for Its Analysis
Authors: Brooks Stephen P J , Oberleas Donald , Dawson Brian A , Belonje Bartholomeus , Lampi Brian J 
Published: February 2020

Abstract
A method is described that accurately and rapidly quantifies the free and total phosphorous content of a commercially available, purified, phytic acid preparation. This allows its use as a standard for phytic acid determinations in foods. The method involves a wet ashing step followed by phosphorous measurement with a 1-amino-2-naphthol-4-sulfonic acid-molybdate reagent in a microplate reader at 660 nm. The procedure can be performed in 3 h with as little as 50 mg sample.
Determination of Clethodim and Its Oxidation Metabolites in Crops by Liquid Chromatography with Confirmation by LC/MS
Authors: Ishimitsu Susumu , Kaihara Akiko , Yoshii Kimihiko , Tsumura Yukari , Nakamura Yumiko , Tonogai Yasuhide 
Published: February 2020

Abstract
A method was developed for determination of the herbicide clethodim (C0) and its oxidation metabolites clethodim sulfoxide (C1) and clethodim sulfone (C2) in agricultural products. Upon extraction, both C0 and C1 were oxidized to C2 by m-chloroperoxybenzoic acid, and C2 was determined by liquid chromatography (LC). The C2 peak was confirmed by liquid chromatography/mass spectrometry (LC/MS) with electrospray ionization (ESI). Recoveries of C0 from radish, tomato, onion, sweet potato, kidney bean, carrot, cabbage, and lettuce ranged from 91 to 118% following fortification at 0.05–1.0 ppm. The detection limit of C2 in crops was 0.01 ppm (S/N &gt; 3). The fortified samples of onion, sweet potato, kidney bean, and carrot were confirmed by LC/MS (ESI), and the peak of C2 was detected.
Performance of a Proposed Determinative Method for p-TSA in Rainbow Trout Fillet Tissue and Bridging the Proposed Method with a Method for Total Chloramine-T Residues in Rainbow Trout Fillet Tissue
Authors: Meinertz Jeffery R , Stehly Guy R , Gingerich William H , Greseth Shari L 
Published: February 2020

Abstract
Chloramine-T is an effective drug for controlling fish mortality caused by bacterial gill disease. As part of the data required for approval of chloramine-T use in aquaculture, depletion of the chloramine-T marker residue (para-toluenesulfonamide; p-TSA) from edible fillet tissue of fish must be characterized. Declaration of p-TSA as the marker residue for chloramine-T in rainbow trout was based on total residue depletion studies using a method that used time consuming and cumbersome techniques. A simple and robust method recently developed is being proposed as a determinative method for p-TSA in fish fillet tissue. The proposed determinative method was evaluated by comparing accuracy and precision data with U.S. Food and Drug Administration criteria and by bridging the method to the former method for chloramine-T residues. The method accuracy and precision fulfilled the criteria for determinative methods; accuracy was 92.6, 93.4, and 94.6% with samples fortified at 0.5X, 1X, and 2X the expected 1000 ng/g tolerance limit for p-TSA, respectively. Method precision with tissue containing incurred p-TSA at a nominal concentration of 1000 ng/g ranged from 0.80 to 8.4%. The proposed determinative method was successfully bridged with the former method. The concentrations of p-TSA developed with the proposed method were not statistically different at p &lt; 0.05 from p-TSA concentrations developed with the former method.
Bioavailable Organochlorine Pesticides in a Semi-Arid Region of Eastern Oregon, USA, as Determined by Gas Chromatography with Electron-Capture Detection
Authors: Anderson Kim A , Johnson Eugene 
Published: February 2020

Abstract
A group of dissolved-bioavailable organochlorine (OC) pesticides and inorganic anions in water and total OC pesticides in sediments were measured in the Malheur Watershed, a semi-arid region in the western United States, over a 2-year period. OC pesticide levels were compared with those from a 1990 study of the lower section of the river, the most recent data available. After calculating the dissolved fraction from the 1990, study it seems that DDD and dieldrin levels have decreased in the water by 50–70%, while DDE and DDT have changed little. Although banned nearly 30 years ago, DDT is still persistent throughout the Malheur River basin/watershed because it was found in all water samples tested. All of the OC pesticides tested during the 2-year study are well below the criterion continuous concentration for aquatic community exposure as defined by the U.S. Environmental Protection Agency (EPA). OC pesticides appear to be decreasing, however, at lower Ontario there remains a human health risk (EPA Human Health Risk Water Quality Criteria) for DDT, because this criteria includes daily consumption of water and fish from the river. Overall, although the upper forest watershed sites have lower OC pesticide concentrations, they represent an important contribution to the total DDT load to this watershed, a source not previously acknowledged. The large increase in DDT and ΣDDT between the Ontario sites may indicate a possible historical point source of contamination or historical preferential deposition of contamination. Normalized sediment (ΣDDT/organic carbon) strongly correlates with dissolved water ΣDDT.
Multiresidue Determination of Pesticides in Drinking and Related Waters by Gas Chromatography/Mass Spectrometry after Solid-Phase Extraction: Interlaboratory Study
Authors: Hoof François van , Wiele Peter van , Bruchet Auguste , Schmitz Isabelle , Bobeldiji Ivana , Sacher Frank , Ventura Francesc , Marti Isabel , Monte Maria Helena Marecos Do , Costa Margarida Sa Da ,   Collaborators:, Alterova K , Barnier A , Hajslova J , Marti I , Martinez K , Planas C , Rivera J , Rörden O , Tejedor A , van der Kreeft R , Viana P , Werres F 
Published: February 2020

Abstract
As part of a project funded by the European Commission (EC) for the development and evaluation of multiresidue methods for analysis of drinking and related waters, 15 European laboratories evaluated a method using styrene–divinylbenzene copolymer solid-phase extraction followed by gas chromatography/mass spectrometry. The main aim of the study was to evaluate whether the method meets the requirements of EC Directive 98/83 in terms of accuracy, precision, and detection limit for 22 pesticides according to the following requirements: limit of detection, ≤0.025 μg/L; accuracy, expressed as recovery between 75 and 125%; and precision, expressed as repeatability relative standard deviation of the method of &lt;12.5% and as reproducibility relative standard deviation of the method of &lt;25%. Analyses for unknown concentrations were performed with fortified commercial bottled and tap waters. All laboratories were able to achieve detection limits of 0.01 μg/L for all pesticides except dimethoate and desisopropylatrazine (0.02 μg/L). The criteria for repeatability were met for all compounds except trifluralin, dimethoate, and lindane in bottled water and chlorpyrifos, dimethoate, and lindane in tap water. The criteria for reproducibility were met for all compounds except trifluralin, dimethoate, and lindane in bottled water and pendimethalin, chlorpyrifos, dimethoate, terbutryn, and lindane in tap water. In terms of accuracy, the method meets the requirements for all pesticides in both matrixes, except for lindane in bottled water and lindane and chlorpyrifos in tap water.
Fluorometric Determination of Ethanol in Liquor Samples by Flow-Injection Analysis Using an Immobilized Enzyme-Reactor Column with Packing Prepared by Coupling Alcohol Oxidase and Peroxidase onto Chitosan Beads
Authors: Taniai Tetsuyuki , Sukuragawa Akio , Okutani Tadao 
Published: February 2020

Abstract
A flow-injection system was developed for the determination of ethanol with an immobilized enzyme-reactor column. This system, which consisted of hand-made reactor columns packed with alcohol oxidase and horseradish peroxidase immobilized onto chitosan beads, and a fluorometric detector, was applied to the determination of ethanol in liquor samples. Under the recommended conditions, the ethanol, which was present in the pretreated samples, was converted to hydrogen peroxide when it was passed through the immobilized alcohol oxidase (AOD) column with 0.1 mol/dm3 phosphate buffer (pH 7.0). A sample can be analyzed with this system in &lt;10 min. The calibration curve for ethanol was linear from 2.0 to 0.1 mg/dm3. The determination limit, which was defined by the difference between the sample peak and blank peak, was estimated to be 50 μg/dm3 for ethanol. Interferences from some substances present in actual liquor samples decreased the analytical response and activity of the immobilized AOD-reactor column, but they were removed by dilution and pretreatment with an octyldecylsilane cartridge.
Estimation of Measurement Uncertainty in Pesticide Residue Analysis
Authors: Alder Lutz , Korth Wolfagang , Patey Alan L , Schee Henk A van der , Schoeneweiss Siegmar 
Published: February 2020

Abstract
Proficiency test results from 5 countries involving 61 separate interlaboratory proficiency tests for pesticide residues were examined in this study. A total of 24 different matrixes and 869 relative standard deviations of the mean (or median) pesticide residue concentration were statistically evaluated in relation to the Horwitz function. The aim was to determine whether or not the concentration-dependent relationship described by Horwitz would hold for the much narrower range of chemicals and concentrations covered in routine pesticide residue analysis. Although for fatty (animal-derived) matrixes the variability increased as the concentration decreased in line with the Horwitz equation, the between-laboratories relative standard deviations for nonfatty matrixes (fruit, vegetables, and grain) remained at 25% over the entire concentration range of 1 μg/kg to 10 mg/kg for the pesticides studied. Given these findings, the Horwitz equation remains valid for calculating uncertainties involving pesticide residues in fatty matrixes. However, for pesticide residue analyses involving nonfatty matrixes, a constant relative standard deviation of 25% is more appropriate for calculating uncertainties, particularly when a reported result is assessed against a regulatory limit.
Integrated Enzyme-Linked Immunosorbent Assay Screening System for Amnesic, Neurotoxic, Diarrhetic, and Paralytic Shellfish Poisoning Toxins Found in New Zealand
Authors: Garthwaite Ian , Ross Kathryn M , Miles Christopher O , Briggs Lyn R , Towers Neale R , Borrell Teresa , Busby Phil 
Published: February 2020

Abstract
Enzyme-linked immunosorbent assays (ELISAs) were developed for amnesic, neurotoxic, and diarrhetic shellfish poisoning (ASP, NSP, and DSP) toxins and for yessotoxin. These assays, along with a commercially available paralytic shellfish poisoning (PSP) ELISA, were used to test the feasibility of an ELISA-based screening system. It was concluded that such a system to identify suspect shellfish samples, for subsequent analysis by methods approved by international regulatory authorities, is feasible. The assays had sufficient sensitivity and can be used on simple shellfish extracts. Alcohol extraction gave good recovery of all toxin groups. The ease of ELISAs permits the ready expansion of the system to screen for other toxins, as new ELISAs become available.
Simultaneous Determination of Losartan and Hydrochlorothiazide in Combined Dosage Forms by First-Derivative Spectroscopy and High-Performance Thin-Layer Chromatography
Authors: Shah Shailesh A , Rathod Ishwarsinh S , Suhagia Bhanubhai N , Savale Shrinivas S , Patel Jignesh B 
Published: February 2020

Abstract
Losartan (LST) is the first orally active nonpeptide angiotensin-II receptor antagonist with an improved safety and tolerability profile. It is prescribed alone or in combination with hydrochlorothiazide (HCTZ) for the treatment of moderate-to-severe hypertension. This paper describes the development of 2 methods that use different techniques, first-derivative spectroscopy and high-performance thin-layer chromatography (HPTLC), to determine LST and HCTZ in the presence of each other. LST and HCTZ in combined preparations were quantitated by using the first-derivative responses at 271.6 nm for LST and 335.0 nm for HCTZ in spectra of their solutions in water. The linearity ranges are 30–70 μg/mL for LST and 7.5–17.5 μg/mL for HCTZ with correlation coefficients of 0.9998 and 0.9997, respectively. In the HPTLC method, a mobile phase of chloroform–methanol–acetone–formic acid (7.5 + 1.5 + 0.5 + 0.03, v/v) and a prewashed Silica Gel G60 F254 TLC plate as the stationary phase were used to resolve LST and HCTZ in a mixture. Two well-separated and sharp peaks for LST and HCTZ were obtained at Rf values of 0.61 ± 0.02 and 0.41 ± 0.02, respectively. LST and HCTZ were quantitated at 254.0 nm. The linearity ranges obtained for the HPTLC method are 400–1200 and 100–300 ng/spot with corresponding correlation coefficients of 0.9944 and 0.9979, for LST and HCTZ, respectively. Both methods were validated, and the results were compared statistically. They were found to be accurate, specific, and reproducible. The methods were successfully applied to the estimation of LST and HCTZ in combined tablet formulations.
Selective Liquid Chromatographic Method for Determination of Fluoxetine in Plasma
Authors: Zarghi Afshin , Kebriaeezadeh Abbas , Ahmadkhaniha Reza , Akhgari Maryam , Rastkari Nooshin 
Published: February 2020

Abstract
A selective and sensitive liquid chromatographic method was developed for the determination of fluoxetine (FLU) in plasma. FLU was isolated from plasma by liquid–liquid extraction. The chromatographic separation was performed on an analytical 250 × 3.9 mm id Novapak C18 column (4 μm particle size) with an isocratic mobile phase consisting of phosphate buffer–acetonitrile–methanol–triethylamine (58 + 30 + 10 + 2, v/v) adjusted to pH 7. Using UV detection at 226 nm, the detection limit for FLU in plasma was 3 ng/mL. No interferences were found with tricyclic antidepressant drugs, which allows this method to be used in clinical studies. The calibration curve was linear over the concentration range of 10–200 ng/mL. The average recovery was about 80% for plasma. The inter- and intraday assay coefficients of variation were &lt;8%.
Post Process Product Control of Rendering Plant Sterilization Conditions by ELISA
Authors: Holst Christoph von , Unglaub Wolfgang , Anklam Elke 
Published: February 2020

Abstract
Experiments were conducted in a laboratory autoclave and in a commercial rendering plant to set a limit for the R-value of an enzyme-linked immunosorbent assay (ELISA) to prove that animal meal had been sufficiently heat-treated. The immunoassay method is currently the only technique used to check for appropriate sterilization of animal meal. The results of these experiments were statistically assessed using operation characteristic curves and confirmed that insufficiently heat-treated animal meal has an R-value &gt; 2. Results of the trials also demonstrated that the main parameters of sterilization, temperature, and duration strongy influence the R-value, thus indicating that deviation from the target sterilization conditions is verifiable by the ELISA method.
Levels of Seven PCBs Used as Markers of Dioxin in Commercial Pork Meat in Spain
Authors: López-Leitón Teresa J López y , Piñeiro María E Alvarez , Yusty María A Lage , Daviña José L Cortizo 
Published: February 2020

Abstract
The levels of 7 PCBs used as markers of dioxin in 62 pork meat samples (head, loin, and dewlap) were determined by supercritical fluid extraction and gas chromatography with electron capture detection. Analytical limits of detection for the individual congeners ranged from 0.048 to 0.2 ng/g dry wt. PCB congeners 153 and 180 were detected in all samples. Among congeners in general, PCB 52, 101, and 153 were the most abundant. There was a linear relationship with a good correlation between PCB 101 and PCB 52.
Determination of Rendering Plant Sterilization Conditions Using a Commercially Available ELISA Test Kit Developed for Detection of Cooked Beef
Authors: Pallaroni Lea , Björklund Erland , Holst Christoph von , Unglaub Wolfgang 
Published: February 2020

Abstract
A commercially available enzyme-linked immunosorbent assay (ELISA) test kit developed for detection of cooked beef in meat samples was used to determine appropriate heat treatment of rendered materials. An improved extraction procedure increased the absolute difference in R-values between 2 rendered materials treated under different conditions (average temperature 129 and 134°C, respectively). To evaluate the influence of the main sterilization parameters on ELISA results, a factorial design approach was used. The parameters investigated were temperature, time, particle size, and meat composition. Lean meat samples containing beef and pork were sterilized under strictly controlled conditions in a laboratory autoclave. The experiments demonstrated that the R-values obtained with the ELISA test kit for beef are strongly influenced by temperature and time, whereas particle size has a minor influence. The proportion of bovine material did not have any impact on R-values. Autoclave-processed lean meat samples were analyzed by using an ELISA test kit for pork, which was validated in a collaborative trial. The ELISA test kit for pork proved to be more sensitive for the investigated parameters, thus verifying and extending previous investigations.
Spectrophotometric Determination of Ziram in a Commercial Sample and Wheat by Extraction of Its Copper Dimethyldithiocarbamate Complex into Molten Naphthalene
Authors: Malik Ashok Kumar , Rao Avasarla L J 
Published: February 2020

Abstract
A method was developed for the determination of zinc(II) dimethyldithiocarbamate by converting it into the copper(II) dithiocarbamate complex, which is then extracted into molten naphthalene. The absorbance is measured at 430 nm versus a reagent blank. Beer's law is obeyed for concentrations of 0.63 × 10−3 to 17.2 × 10−3 g/L in the final solution. The method is sensitive and was applied to the determination of ziram in a commercial sample and in wheat grain.
Employment of Peak Area as Instrumental Datum for Improving the Voltammetric Quantitative Analysis of Heavy Metals in Fresh and Sea Water in the Presence of Surfactants
Authors: Locatelli Clinio 
Published: February 2020

Abstract
Peak area instead of peak height is used for the simultaneous determination of Cu(II), Pb(II), Cd(II), and Zn(II) in fresh and sea water in the presence of anionic and cationic surfactants by differential pulse anodic stripping voltammetry. These species, if present, tend to make more irreversible the electrodic process of the metals. Because the employment of peak area for species having irreversible electrodic processes permits limits of detection about one or 2 orders of magnitude lower, this work shows the possibility of determining heavy metals at ultratrace level concentrations in the presence of surfactants, compounds which are always present in natural waters. The precision and accuracy of the analytical method were checked by the analysis of the standard reference materials (SRM) Fresh Water NIST-SRM 1643d, Sea Water BCR-CRM 403, and Estuarine Water BCR-CRM 505. The former, expressed as relative standard deviation (sr), and the latter, expressed as relative error (e), were satisfactory, being in all cases lower than 5%. The analytical procedure has been applied to fresh and sea water sampled in the Po river mouth area (Italy).
Enhanced Recovery of Salmonella from Apple Cider and Apple Juice with Universal Preenrichment Broth
Authors: Hammack Thomas S , Johnson Mildred L , Jacobson Andrew P , Andrews Wallace H 
Published: February 2020

Abstract
A comparison was made of the relative efficiencies of Universal Preenrichment (UP) broth and lactose broth for the recovery of a variety of Salmonella serovars from pasteurized and unpasteurized apple cider and pasteurized apple juice. Bulk portions of juice were contaminated with single Salmonella serovars at high and low levels of 0.4 and 0.04 CFU/mL, respectively. The juice was aged for a minimum of 5 days at 2–5°C. On the day analysis was initiated, each of 20 test portions (25 mL) of the contaminated juice was preenriched in UP broth and in lactose broth. The Bacteriological Analytical Manual Salmonella culture method was followed thereafter. For pasteurized apple cider, UP broth recovered significantly (p &lt; 0.05) more Salmonella-positive test portions than did lactose broth (112 and 75, respectively). For unpasteurized apple cider, UP broth recovered significantly more Salmonella-positive test portions than did lactose broth (326 and 221, respectively). For pasteurized apple juice, UP broth recovered more Salmonella-positive test portions than did lactose broth (93 and 81, respectively). However, this difference was not statistically significant. These results indicate that UP broth should replace lactose broth for the analysis of pasteurized and unpasteurized apple cider and pasteurized apple juice.