bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variability Associated with Analytical Methods Used To Measure Aflatoxin in Agricultural Commodities
Authors: Whitaker Thomas , Horwitz William , Albert Richard , Nesheim Stanley 
Published: February 2020

Abstract
A total of 1019 analytical precision estimates obtained from method-performance (collaborative) studies for mycotoxins published through 1991 were sortedby type of variance measurement, type of analytical method, and type of agricultural commodity. Precision estimates for total aflatoxin were sorted into 2 precision measurements (among-labo ratories and with in-laboratory), 3 analytical methods (thin-layer chromatography [TLC], liquid chromatography [LC], and enzyme-linked immunosorbent assay [ELISA]), and 11 agricultural commodities. Sufficient data existed to study the analytical variability (precision) associated with 36 sorted combinations (of a possible 66). In all but one combination (within-laboratory, barley, and TLC), the variance (V) was a function of totalafla- toxin concentration (C). A power function of the form V = aCb, where a and b are constants, describes the relationship between variance and aflatoxin concentration. The coefficients a and b were determined from regression analysis. When results were pooled across all agricultural commodities, LC had the lowest analytical variability while ELISA had the highest. For a given method, among-labora tories variability was approximately double the with in-laboratory variability. These analytical variability estimates can be coupled with previously determined variability estimates of sampling and sample preparation to determine the performance associated with specific test procedures used to inspect agricultural commodities for aflatoxin.
Quantitative Analysis of 2-Aminoacetophenone in Off-Flavored Wines by Stable Isotope Dilution Assay
Authors: Dollmann Bettina , Wichmann Dominicus , Schmitt Alfred , Koehler Hans , Schreier Peter 
Published: February 2020

Abstract
Isotope dilution analysis was used to quantitate 2- aminoacetophenone in wines exhibiting the so- called untypical aging off-flavor. d3-Aminoacetophe- none was synthesized and used as isotopomeric internal standard. The method of quantitation was verified by several model experiments. In the off-flavored wines studied, amounts of 2-aminoacetophe none ranging from 0.7 to 12.8 μg/L were determined.
Gas Chromatographic Determination of Chlorothalonil in Leaves and Roots of Scrophularia and in Soil
Authors: Zhao Lan , Fan De-Fang 
Published: February 2020

Abstract
A gas chromatographic method is described for determination of chlorothalonil residues in leaves and roots of Scrophularia and in soil. Samples were extracted with acetone and cleaned up on a Florisil column. Chlorothalonil residues are chromatographed directly on a glass column of 1.5% OV-17 and 2% QF-1 coated on 80-100 mesh Chromosorb W (HP) support and measured with a 63Ni electron capture detector. Detection limits are 0.001 ppm for leaf, 0.005 ppm for root, and 0.001 ppm for soil.
Simultaneous Determination of Ascorbic, Dehydroascorbic, Isoascorbic, and Dehydroisoascorbic Acids in Meat-Based Food Products by Liquid Chromatography with Postcolumn Fluorescence Detection: A Method Extension
Authors: Ali M Sher , Phillippo Evan T 
Published: February 2020

Abstract
A simple and rapid liquid chromatographic (LC) method for determining ascorbic, dehydroascorbic, isoascorbic, and dehydroisoascorbic acids in mostly single-component food products was evaluated for use in analysis of multicomponent meatbased food products such as TV dinners. Groundbeef samples were used as blanks for repeatability studies. Samples were fortified with 5,10,20, and 40 ppm of mixed standards of ascorbic acid and isoascorbic acid. Means of 12 recoveries at 4 levels of fortification were 102.5 and 83.5%, respectively, for ascorbic acid and isoascorbic acid, with coefficients of variation of 6.7 and 15.2%, respectively. TV dinner products (21 samples) from a local grocery store were analyzed for vitamin C content. Samples prepared with a commercial food processor and a food grinder were compared. The commercial food processor was more capable than the food grinder in producing a homogeneous sample, which is critical to the method.
Simple HNMR Spectroscopic Method for Assay of Salts of the Contrast Agent Diatrizoate in Commercial Solutions
Authors: Hanna George M , Lau-Cam Cesar A 
Published: February 2020

Abstract
A simple, accurate, and specific 1H NMR spectroscopic method was developed for the assay of diatrizoate meglumine or the combination diatrizoate meglumine and diatrizoate sodium in commercial solutions for injection. A mixture of injectable solution and sodium acetate, the internal standard, was diluted with D20 and the 1H NMR spectrum of the solution was obtained. Two approaches were used to calculate the drug content, based on the integral values for the -N-CO-CH3 protons of diatrizoic acid at 2.23 ppm, the N-CH3 protons of meglumine at 2.73 ppm, and the CH3-CO-protons of sodium acetate at 1.9 ppm. Recoveries (mean ± standard deviation) of diatrizoic acid and meglumine from 10 synthetic mixtures of various amounts of these compounds with a fixed amount of internal standard were 100.3 ±; 0.55% and 100.1 ± 0.98%, respectively. In addition to providing a direct means of simultaneously assaying diatrizoic acid and meglumine, the proposed NMR method can also be used to identify diatrizoate meglumine and each of its molecular components.
Determination of Ceftiofur in Bovine Milk by Liquid Chromatography
Authors: Mcneilly Patrick J , Reeves Valerie B , Deveau E J Ian 
Published: February 2020

Abstract
A liquid chromatographic procedure is described for determination of ceftiofur (CEF) residues in milk. Milk samples were diluted with ammonium acetate solution and extracted on a C18 solid-phase extraction (SPE) column. After the analyte was eluted from the SPE column with methanol, extract volumes were reduced under nitrogen, diluted to 2.0 mL with acetate buffer, and filtered. CEF was determined after separation of milk components by reversed-phase chromatography with UV detection at 293 nm. Recoveries of CEF from bovine milk fortified at 25,50, and 100 ppb were 86.1,90.8, and 92.0%, respectively, with coefficients of variation (CVs) of 6.4, 7.3, and 3.9%, respectively. Values of CEF obtained from analysis of milk containing 2 levels of biologically incurred residues were 26.1 and 67.3 ppb with CVs of 3.8 and 4.4%, respectively. The limits of detection and quantitation were estimated to be 4 and 7 ppb, respectively.
Evaluation of a Rapid and Automated Enzyme-Linked Fluorescent Immunoassay for Detecting Escherichia coli Serogroup 0157 in Cheese
Authors: Cohen Alice E , Kerdahi Khalil F 
Published: February 2020

Abstract
The Vitek Immunodiagnostic Assay System (VIDAS) for Escherichia coli 0157, a rapid and fully automated test, was evaluated for use in detecting the foodborne pathogen E. coli 0157:H7 in soft, semisoft, and hard cheeses. Sixty-five cheese samples were artificially contaminated at low (2-4 colonyforming units [cfu]/25 g) and high (7-10 cfu/25 g) levels with one of 2 strains of enterohemorrhagic E. coli 0157:H7. Contamination at high levels was detected in all cheeses by VIDAS, whereas in 5 cheeses (7.7%) inoculated at low levels, contamination was not detected. In 15 additional cheeses inoculated with cold-stressed cells, both VIDAS and the Bacteriological Analytical Manual cultural assay detected all high and low levels of contamination. No false positives or interference from product background fluorescence was encountered in any of the cheeses tested by VIDAS.
Detection of Added Beet Sugar in Concentrated and Single Strength Fruit Juices by Deuterium Nuclear Magnetic Resonance (SNIF-NMR Method): Collaborative Study
Authors: Martin Gilles G , Wood Roger , Martin Gérard J ,   Collaborators:, Bigwood T , Blanch-Cortes A I , Cisero M , Cristoph N , Estoueigt M J , Guillou C , Hermann A , le Leuch A , Lindler P , Moussa I , Pavanello F , Reniero F , Serrini G , Wittkowski R , Zhang B 
Published: February 2020

Abstract
A collaborative study of the site-specific natural isotope fractionation-nuclear magnetic resonance (SNIF-NMR) method for detecting added beet sugar in fruit juices is reported. This method is complementary to the stable carbon isotope ratio analysis (SCIRA) (AOAC Official Methods 981.09 and 982.21), which can detect sugars derived from plants exhibiting C4 metabolism (corn and sugarcane). It is based on the fact that the deuterium content at specific positions of the sugar molecules is higher in fruit sugars than in beet sugar. The fruit juices are fermented, and the alcohol is distilled with a quantitative yield and analyzed with a highfield NMR spectrometer fitted with a deuterium probe and fluorine lock. The proportion of ethanol molecules monodeuterated on the methyl site is recorded. This parameter (D/H)i is lowered when beet sugar is added to a fruit juice or concentrate. The precision of that method for measuring (D/H)i was observed to be similar to that of other isotope ratio methods: sr values ranged from 0.19 to 0.25 ppm and SR values varied between 0.21 and 0.37 ppm. An excellent correlation was observed between the percentage of added beet sugar and the (D/H)i isotope ratio measured in this collaborative study. Consequently, all samples in which beet sugar was added were found to have a (D/H)i isotope ratio significantly below the normal value for authentic juice or concentrate of that fruit. The SNIF-NMR method for detection of added beet sugar in fruit juices has been adopted by AOAC INTERNATIONAL.
Use of Solid-Phase Extraction Disks for Analysis of Moderately Polar and Nonpolar Pesticides in High-Moisture Foods
Authors: Casanova John A 
Published: February 2020

Abstract
This study investigated the use of solid-phase extraction (SPE) disks in analysis of high-moisture (&lt;2% fat) foods for organophosphorus and organochlorinated pesticides with low (&lt;25 mg/mL) water solubilities. Five representative foods were each spiked with one of 18 pesticides at 2 levels. Gas chromatography with flame photometric and electrolytic conductivity detection was used to quantitate organophosphates and organochlorinated pesticides, respectively. Essentially complete recoveries (≥80%) suggest that use of SPE disks can complement traditional liquid-liquid extraction procedures.
Liquid Chromatographic Determination of Progestogens in Animal Fat
Authors: Andresen Michael T , Fesser Adrian C E 
Published: February 2020

Abstract
A liquid chromatographic method was developed for determination of 3 progestogens�melengestrol acetate, megestrol acetate, and chlormadinone acetate� found in edible tissue at concentrations between 10 and 1000 ppb. These progestogens are commonly used as feed additives to control herd estrus and to improve feed efficiency. Rendered fat was extracted with acetonitrile, washed with hexane, and dried. The remaining lipids were saponified with sodium hydroxide and precipitated with magnesium chloride. The progestogens were extracted from the basic solution with hexane, dried, and cleaned up on a cyanopropyl solid-phase extraction column in the normal-phase mode. The eluate was dried and reconstituted with acetonitrilewater (7 + 3, v/v). Chromatography was performed on a 5 μm high-carbon load C18 column with acetonitrile- water (7 + 3, v/v) at 1 mL/min and UV detection at 291 nm. Recoveries from fortified samples ranged from 84 to 116%. The limit of quantitation was 10 ppb for both beef and pork. The detection limit was 3 ppb.
Determination of Avermectin Bi in Biological Samples by Immunoaffinity Column Cleanup and Liquid Chromatography with UV Detection
Authors: Li Junsuo , Qian Chuanfan 
Published: February 2020

Abstract
A simple and specific procedure for determination of avermectin B1 in biological samples is described. A specific anti-avermectin B1 immunosorbent was developed. Avermectin B1 was extracted from cattle plasma, cattle meat, and pear samples. The extracts were cleaned up on a solid-phase extraction column (C18) and an immunoaffinity column. Avermectin B1 was determined by reversedphase liquid chromatography with UV detection at 245 nm. Recoveries of avermectin Bi from samples spiked at levels of 6 and 60 parts per billion (ppb) ranged from 80 to 86%, with coefficients of variation of 5-14%. The limit of detection was 2 ppb. The procedure provides a simple and sensitive method for monitoring avermectin B1 residues in biological matrixes.
TECRA Listeria Visual Immunoassay (TLVIA) for Detection of Listeria in Foods: Collaborative Study
Authors: Knight Michael T , Newman Melissa C , Benzinger M Joseph , Agin James R , Ash Megan , Sims Paul , Hughes Denise ,   Collaborators:, Arling V , Brock G , Bronstein A , Brooks R , Bucknavage M , Cirigliano M , Coles C , Farber J , Fisher B , George N , Heisick J , lannucci M , Koeritzer B , Lovett S , Mays J , McNally S , Menning C , Nelson T , Neufang K , Neuman S , O’Brien J , Rude R , Rudowski J , Singleton E , Sirivicha S , Turner S , VanderMeer J , Warburton D , Young S 
Published: February 2020

Abstract
A collaborative study involving 26 laboratories and 5 food types was performed to compare the TECRA Listeria Visual Immunoassay (TLVIA) with standard culture methods. Three foods (lettuce, ice cream, and fish fillets), under the jurisdiction of the U.S. Food and Drug Administration, and 2 foods (cooked chicken and cooked ground turkey), under the jurisdiction of the U.S. Department of Agriculture, were used to determine the effectiveness of the TLVIA. Of the 900 samples tested, 300 were inoculated with low levels (1-5 cells/25 g) of Listeria spp. and 300 were inoculated with high levels of Listeria spp. (10-50 cells/25 g). Method agreement between the conventional culture methods and TLVIA (visual) was 94.7%. Method agreement between the conventional culture methods and TLVIA (reader) was 93.6%. The colorimetric polyclonal enzyme immunoassay (TLVIA) for detection of Listeria in foods has been adopted first action by AOAC INTERNATIONAL.
Analysis of IHchothecene Mycotoxins in Contaminated Grains by Gas Chromatography/Matrix Isolation/Fourier Transform Infrared Spectroscopy and Gas Chromatography/Mass Spectrometry
Authors: Mossoba Magdi M , Adams Sarah , Roach John A G , Trucksess Mary W 
Published: February 2020

Abstract
Gas chromatography/matrix isolation/Fourier transform infrared (GC/MI/FTIR) spectroscopy and GC/mass spectrometry (MS) were used to confirm the identities of trimethylsilyl (TMS) derivatives of trichothecene mycotoxins in naturally contaminated grains. Infrared spectral bands observed in the fingerprint region were unique for 10 trichothecene standards. Characteristic absorption bands were observed for the ester (near 1750 cm-1) and ketone (near 1700 cm-1) carbonyl stretching vibrations, the acetate CH3 symmetric bend (1370 cm-1), the epoxide ring (1262 cm-1), the trimethylsilyl CH3 in-plane deformation (1253 cm-1), the ester (O)C-O asymmetric stretching vibration (near 1244 cm-1), and several other bands including intense features due to the TMS function. Infrared bands observed under cryogenic matrix isolation conditions were compared with those found at room temperature in a potassium bromide matrix for 5 of these standards. Identities of deoxynivalenol (DON) from barley and mixed feed, nivalenol from wheat and barley, and DON and fusarenon-x from sweet corn were confirmed by comparison of their infrared spectral bands with those of standards. The identity of DON in the same test samples of sweet corn was confirmed further by GC/MS. GC/MS was also used to quantitate the levels of DON (67-455 ppm) in sweet corn test samples.
Anatoxin B1 in Common Egyptian Foods
Authors: Selim Mustafa I , Popendorf William , Ibrahim Mahmoud S , Sharkawy Saleh El , Kashory El Syeda El 
Published: February 2020

Abstract
Samples of common Egyptian foods (17 nuts and seeds, 10 spices, 31 herbs and medicinal plants, 12 dried vegetables, and 28 cereal grains) were collected from markets in Cairo and Giza. A portion of each sample was extracted with chloroform, and the concentrated extract was cleaned by passing through a silica gel column. Aflatoxin Bi was determined by reversed-phase liquid chromatography with UV detection. The highest prevalence of aflatoxin B1 was in nuts and seeds (82%), followed by spices (40%), herbs and medicinal plants (29%), dried vegetables (25%), and cereal grains (21 %). The highest mean concentration of aflatoxin B1 was in herb and medicinal plants (49 ppb), followed by cereals (36 ppb), spices (25 ppb), nuts and seeds (24 ppb), and dried vegetables (20 ppb). Among nuts and seeds, the prevalence of aflatoxin B1 was highest (100%) in watermelon seeds, inshell peanuts, and unshelled peanuts. The lowest prevalence and concentrations were in hommos (garbanzo beans). The highest concentrations of aflatoxin B1 were detected in foods that had no potential for field contamination but required drying during processing and storage, such as pomegranate peel, watermelon seeds, and molokhia.
Comparison of Mouse Bioassay and Sodium Channel Cytotoxicity Assay for Detecting Paralytic Shellfish Poisoning Toxins in Shellfish Extracts
Authors: Truman Penelope , Lake Robin J 
Published: February 2020

Abstract
A neuroblastoma cell culture assay was used to analyze shellfish extracts for presence of paralytic shellfish poisoning toxins (saxitoxins). Results were compared with mouse bioassays performed as part of a screening program for shellfish toxins in New Zealand. Twenty-nine samples gave negative results in both assays. Fifty-seven samples gave positive results in at least one assay. The correlation between the assays for saxitoxin equivalent levels in shellfish was 0.867. In spiking studies on shellfish extracts, the neuroblastoma assay showed a good response to added saxitoxin. Although these results support use of the neuroblastoma assay as a screening procedure for shellfish toxicity, results close to regulatory limits should be confirmed by mouse bioassay.
Determination and Confirmation of Identities of Flumequine and Nalidixic, Oxolinic, and Piromidic Acids in Salmon and Shrimp
Authors: Pfenning Allen P , Munns Robert K , Turnipseed Sherri B , Roybal José E , Holland David C , Long Austin R , Plakas Steven M 
Published: February 2020

Abstract
A previously published liquid chromatographic (LC) method for determining residues of flumequine (FLU) and nalidixic (NAL), oxolinic (OXO), and piromidic (PIR) acids in catfish tissue was applied to salmon and shrimp muscle. Identities of all 4 residues in salmon and shrimp were confirmed by gas chromatography/mass spectrometry (GC/MS). The tissue is homogenized with acetone, the acetone extract is defatted with hexane, and the quinolones are extracted into chloroform. The extract is further purified by first partitioning into base and then back-extracting from a solution acidified to pH 6.0. Analytes are determined by LC with simultaneous UV and fluorescence detection. Muscle tissue was fortified with each quinolone at 5,10,20,40, and 80 ng/g. Average recoveries and relative standard deviations (RSOs) for salmon, which represent an average of the 5 levels for each analyte, ranged from 75.9 to 90.8% and from 2.25 to 6.40%, respectively. Average recoveries and RSDs for shrimp ranged from 81.3 to 91.2% and from 7.34 to 10.7%, respectively. Identities of OXO, FLU, NAL, and PIR were confirmed in extracts of salmon and shrimp tissue fortified at 10 ng/g by determination of decarboxylated quinolones by GC/MS. Four diagnostic ions were monitored for OXO, FLU, and PIR, and 5 ions were monitored for NAL. All ion relative abundances were within 10% of those calculated for standard decarboxylated quinolones. Optimum conditions for decarboxylation and GC/MS confirmation are given.
Determination of Diphenoxylate Hydrochloride and Atropine Sulfate in Combination Drug Formulations by Liquid Chromatography
Authors: Lehr Gary J 
Published: February 2020

Abstract
An isocratic, reversed-phase liquid chromatographic (LC) method was developed for simultaneous determination of diphenoxylate hydrochloride (I) and atropine sulfate (II) in pharmaceutical products. Analysis is conducted on a Spherisorb CN column (5 µm), with a mobile phase consisting of 47% 0.001 M pentanesulfonic acid sodium salt monohydrate, 53% acetonitrile, and 0.1 % phosphoric acid. The detection wavelength is 220 nm. Tablets are extracted with acetonitrile–water (50 + 50). Oral solutions are determined directly after dilution. The method is validated for linearity, precision, system reproducibility, and accuracy. Recoveries at 80-120% of label claim ranged from 98.7 to 101.0% and from 99.6 to 102.5% for I and II, respectively. Results were linear (r &gt; 0.9999) in the ranges 125–375 µg/mL and 1.25–3.75 µg/mL for I and II, respectively. Assay and content uniformity results for each ingredient, in both innovator products and generic formulations, are reported. Diphenoxylic acid, the principal degradation product and major metabolite of I, is separated and can be determined in tablets and oral solutions.
Immunoaffinity Column Cleanup and Liquid Chromatographic Method for Determining Ivermectin in Sheep Serum
Authors: Li Junsuo , Zhang Shiqin 
Published: February 2020

Abstract
A simple and sensitive method was developed for determining ivermectin in sheep serum. The sample is cleaned up on an immunoaffinity column and determined by liquid chromatography with detection at 245 nm. Recoveries ranged from 90.3 to 98.8% (93.9 ± 4.3%) for samples fortified with 2.0–50 ng ivermectin/mL. Coefficients of variation were 3.2–11.0%. The limit of detection was 1 ng/mL in 5.0 mL serum.
Comparison of Three Methods for Determining Aflatoxins in Melon Seeds
Authors: Diprossimo Vincent P , Malek Emil G 
Published: February 2020

Abstract
The suitability of 3 methods for determining aflatoxins in melon seeds was examined. The first 2 are the Contaminants Branch (CB) method and the Best Foods (BF) method, both official methods for determining aflatoxins in peanuts and peanut products. The third method, the modified CB method–Rapid Modification of the Cottonseed (CB-RCSMod) method, devised in this work, was derived by combining steps from the CB method and the Rapid Modification of the Cottonseed method. The CB method was superior to the other 2 methods for quantitation of aflatoxins. It gave better recoveries and cleaner extracts that exhibit less fluorescent interference for thin-layer chromatography (TLC) than the BF method. Also, its solvent efficiency was better than that of the CB-RCS-Mod method. With the CB method, recoveries from spiked samples were 85.0% for aflatoxin B1 and 90.0% for anatoxin B2. Recoveries of G1 aflatoxins were more variable, averaging 90.0% for aflatoxin d and 72.5% for aflatoxin G2. Total aflatoxin recovery was 86.5% for the CB method. At a low aflatoxin contamination level (8 μg B1/kg sample), aflatoxin B1 was detectable by the CB method but not by the BF method. Detection of aflatoxins in BF method sample extracts by TLC was not improved by the use of chloroform–acetone–water (88 + 12 + 1), benzene–ethanol–water, or ether–methanol–water (96 + 3 +1) in place of the standard chloroform–acetone (88 + 12) developer. Use of ether–methanol–water (96 + 3 + 1) for detecting aflatoxins by TLC in the CB method extracts increased interference compared with the standard chloroform–acetone (88 + 12) developer.