bluuebunny/crossref_metadata_2025_split huggingface dataset:
Niacin II: Identification of Isonicotinic Acid in Niacin by Liquid Chromatography with Diode Array Detection
Authors: Kirchhoefer Ross D 
Published: February 2020

Abstract
Isonicotinic acid impurity in bulk niacin was detected and identified by comparison with a reference material by liquid chromatography with a diode array detector. The niacin was dissolved in dilute hydrochloric acid and chromatographed on an amine column with a mobile phase of methanol and water acidified with formic acid. Isonicotinic acid has a relative retention time of 1.5 compared with niacin (nicotinic acid), and the wavelengths of maximum ultraviolet (UV) absorbance for isonicotinic acid and niacin are 270 and 260 nm, respectively. The amount of impurity found in the niacin sample was 0.3%. Twelve formulations, including sustained-release products, one bulk material, and the United States Pharmacopeia (USP) reference standard were tested. The impurity was detected in only the bulk and USP reference material samples.
Gas Chromatographic Determination of Chloramphenicol Residues in Shrimp: Interlaboratory Study
Authors: Munns Robert K , Holland David C , Roybal José E , Storey Joseph M , Long Austin R , Stehly Guy R , Plakas Steven M 
Published: February 2020

Abstract
An interlaboratory study of a gas chromatographic method for determining chloramphenicol (CAP) residues in shrimp was conducted. An internal standard (Istd), the meta isomer of CAP, was added to the shrimp, and the treated shrimp were homogenized with ethyl acetate. The ethyl acetate extract was defatted with hexane, and the CAP was partitioned into ethyl acetate from an aqueous salt solution. The ethyl acetate was evaporated, and the dried residue was treated with Sylon, a trimethyl-silyl derivatizing agent, to yield the trimethylsilyl derivative of CAP. A portion of the solution containing the derivative was injected into a gas chromatograph equipped with an electron capture detector. Levels of fortified and incurred CAP were calculated from the peak area ratio of standard CAP to Istd. Recoveries of CAP from tissue directly fortified at 5 ppb were 102% (within-laboratory relative standard deviation [RSDr] = 5.6%), 104% (RSDr = 5.5%), and 108% (RSDr = 6.3%) from Laboratories 1, 2, and 3, respectively. Incurred-CAP residues at 5 and 10 ppb levels were also determined, with the following results: Laboratory 1: composite A, 4.56 ppb (RSDr = 14.0%); composite B, 8.38 ppb (RSDr = 11.6%); Laboratory 2: composite A, 4.17 ppb (RSDr = 12.5%); composite B, 8.90 ppb (RSDr = 5.60%); Laboratory 3: composite A, 4.66 ppb (RSDr = 14.9%); composite B, 11.0 ppb (RSDr = 11.8%).
Determination of Volatile Organic Contaminants in Bulk Oils (Edible, Injectable, and Other Internal Medicinal) by Purge-and-Trap Gas Chromatography/Mass Spectrometry
Authors: Thompson Don W 
Published: February 2020

Abstract
Purge-and-trap gas chromatography/mass spectrometry is evaluated for the quantitation of part-per-billion levels of volatile organic contaminants in bulk vegetable oils. Results using 2 purge techniques (direct purging of the heated oil and purging after dispersing the oil on an aluminum oxide powder) and 2 quantitative methods (standard curve and deuterium-labeled internal standard addition) are reported. Twenty volatile compounds and 8 vegetable oils were investigated. Recovery data and estimated detection limits for each compound are reported for each purge technique. Generally acceptable recoveries (70-130% for more than 90% of the analyte spikes) and acceptable detection levels (approximately 4-10 ppb) were obtained for all compounds using either the external standard curve or the deuterium-isotope-labeled internal standard. The use of a dispersant (such as alumina) for sample purging resulted in poor recoveries of the highly volatile contaminants.
Enzyme-Linked Immunosorbent Assay of Total Aflatoxins B1, B2, and G1 in Corn: Follow-up Collaborative Study
Authors: Trucksess Mary W , Stack Michael E 
Published: February 2020

Abstract
A direct competitive enzyme-linked immunosorbent assay screening method for af latoxins at 20 ng/g in corn was studied by 15 collaborating laboratories. Test samples of corn were extracted by blending with methanol-water (8 + 2). The extracts were filtered and the filtrates were diluted with buffer to a final methanol concentration of &lt;30%. Each diluted filtrate was applied to a test device containing a filter with immobilized polyclonal antibodies specific to aflatoxins B1, B2, and G1. Aflatoxin Bi-peroxidase conjugate was added, the test device was washed with water, and a mixture of hydrogen peroxide and tetramethylbenzidine was added. A test sample was judged to contain ≥20 ng af latoxins/g when, after exactly 1 min, no color was observed on the filter; if a blue or gray color developed, the test sample was judged to contain &lt;20 ng aflatoxins/g. All laboratories correctly identified naturally contaminated corn test samples. Only one false positive was found for controls containing no aflatoxins. The correct responses for positive test samples spiked at levels of 10,20, and 30 ng aflatoxins/g (the ratio of B1:B2:G1 was 15:1:3) were 67,97, and 100%, respectively. This method was adopted first action by AOAC INTERNATIONAL as a change in method for 990.34 for screening for aflatoxins B1, B2, and G1 in corn at total aflatoxin concentrations of ≥20 ng/g.
Determination of Soluble Dietary Fiber in Foods and Food Products: Collaborative Study
Authors: Prosky Leon , Asp Nils-Georg , Schweizer Thomas F , Devries Jonathan W , Furda Ivan , Lee Sungsoo C 
Published: February 2020

Abstract
A collaborative study was conducted to determine the soluble dietary fiber (SDF) content of foods and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that employed for determining total dietary fiber (TDF), 985.29, and the method for insoluble dietary fiber (IDF), 991.42. Ten laboratories were each sent 13 test samples (6 blind duplicates and 1 standard [green beans] containing 29-33% TDF, 19-23% IDF, and 8-13% SDF) and were instructed to assay for IDF, SDF, and TDF independently. Included in the package were the 3 enzymes, namely alpha-amylase, amyloglucosidase, and protease, and the filter aid Celite, which was thought to be the major cause of high reproducibility relative standard deviation (RSDR) values for SDF obtained in a previous collaborative study. The foods to be analyzed were apricots, carrots, chickpeas, onions, raisins, and the sugar beet fiber Fibrex™. IDF, TDF, and SDF were calculated as the weight of residue minus the weight of protein and ash on a dry weight basis. RSDR values of the IDF results averaged 8.02%, with only 1 food having an RSDR &gt;10%. The RSDR values for the TDF results averaged 4.97%, and all foods had an RSDR &lt;7%. Although the RSDR values for SDF averaged 14.17%, 4 of the 6 foods had an RSDR &lt;10%, and 1 of the 2 remaining foods that had a high RSDR had an SDF content of only 1.2%. In all cases, the RSDR values of the SDF content of the foods were less than the values for the same foods analyzed in a previous collaborative trial. The enzymatic-gravimetric method for the determination of SDF was adopted first action by AOAC INTERNATIONAL.
Accuracy and Precision of Fossomatic 250/300/360 Series of Somatic Cell Counters Compared to Fossomatic 215: Collaborative Study
Authors: Mckenna David 
Published: February 2020

Abstract
AOAC method 978.26, Somatic Cells in Milk—Optical Somatic Cell Counting Method (Fossomatic), using Fossomatic 215 was adopted first action in 1978 and final action in 1984. The method specifying a second-generation cell counter, the Fossomatic 90, was approved final action in 1989. This demonstrates that the method has been well tested and has satisfied all the requirements of the Association. Since then, the manufacturer, Foss Electric, has introduced a third generation of equipment, which is being distributed as 3 different models. These are the Fossomatic 250, Fossomatic 300, and Fossomatic 360. The models differ only in their packaging and the speed at which they perform analyses.
Gel-Permeation Liquid Chromatographic Method for Determination of Polymerized Triglycerides in Oils and Fats: Summary of Collaborative Study
Authors: Firestone David 
Published: February 2020

Abstract
The IUPAC Commission on Oils, Fats and Derivatives undertook development of a method and collaborative study for determination of polymerized triglycerides in oils and fats. Two collaborative studies were carried out by IUPAC in 1985 and 1986. Both studies consisted of 4 materials, including animal fat, frying oil with average content of polymers, and blends of frying oil containing varying amounts of polymers. Thirteen and 17 laboratories were included in the first and second IUPAC collaborative studies, respectively. Another collaborative study conducted by Inspectorate for Health Protection, Food Inspection Service, The Netherlands, included 13 laboratories. Six heat-processed fat samples (3 pairs of split samples) containing 14–28% (w/w) of polymerized triglycerides were studied. The method was adopted by AOAC INTERNATIONAL as an IUPAC–AOCS–AOAC method.
Normative Data for Commercial Pineapple Juice from Concentrate
Authors: Low Nicholas H , Brause Allan , Wilhelmsen Eric 
Published: February 2020

Abstract
Normative data for pineapple juice from concentrate were determined for 19 samples, including 5 that had been aseptically processed and representing 4 of the major pineapple growing regions of the world. Values are reported for sugars, organic acids, including isocitric acid, metals (specifically potassium, sodium calcium, and magnesium), δ13C, and oligosaccharides. Although geographical variation existed, the observed ranges and variances were small enough to be useful in describing authentic pineapple juice. Two concentrates (one aseptically and one nonaseptically processed) were intentionally adulterated (individually) with 3 commercially available inexpensive sweeteners (high fructose corn syrup, cane invert syrup, and beet medium invert syrup). Oligosaccharide analysis of these samples either by liquid chromatography or by capillary gas chromatography yielded oligosaccharide patterns that were useful for the detection of these sweeteners at 10% levels. Principal-component analysis (PCA) was used to represent graphically both the pure and adulterated samples based on their measured chemical parameters.
Determination of Bacitracin-MD in Complete Feed by Microbiological Plate Assay: Collaborative Study
Authors: Desai Anil D , Desai Anil D , Muir Larry A 
Published: February 2020

Abstract
Eleven laboratories evaluated the double extraction procedure for the determination of bacitracin methylene disalicylate in swine and poultry feeds at 22, 44, and 88 g/2000 lb. Bacitracin activity was determined on each of 2 days using blind duplicates in a random order. All collaborators submitted their data for statistical evaluation. No significant difference was found between the assay results and the label claim at 22,44, and 88 g/2000 lb for swine and poultry feed. For both feed types, reported ranges at 95% confidence limit for 22,44, and 88 g/2000 lb were 17-30 g/2000 lb, 29-61 g/2000 lb, and 64-112 g/2000 lb, respectively. The microbiological plate assay procedure for determination of BMD in complete feed was adopted first action by AOAC INTERNATIONAL.
Simultaneous Multiresidue Analysis of (β-Lactam Antibiotics in Bovine Milk by Liquid Chromatography with Ultraviolet Detection and Confirmation by Electrospray Mass Spectrometry
Authors: Tyczkowska Krystyna L , Voyksner Robert D , Straub Rolf F , Aronson Arthur L 
Published: February 2020

Abstract
A multiresidue analytical method was developed for the simultaneous determination of amoxicillin, cephapirin, procaine penicillin G, ampicil-lin, cloxacillin, and ceftiofur in bovine milk. The method involved ultrafiltration of milk diluted with an equal volume of 50% acetonitrile through a 10 000 dalton molecular mass cutoff filter. Separation of these β-lactam antibiotics from other milk components was performed by ion-paired (octane- and dodecanesulfonate) liquid chromatography using a phenyl column eluted with acetonitrile-water solution. Ultraviolet ab-sorbance of the column effluent was monitored in the 200-350 nm range of a photodiode-array detector. For quantitation, the chromatograms were acquired at λ210 nm for penicillin G, am-picillin, and cloxacillin; λ230 nm for amoxicillin; and λ290 for cephapirin, procaine, and ceftiofur. The limit of detection for the simultaneous determination of these antibiotics was estimated to be 100 ppb. Liquid chromatography/electrospray mass spectrometry could be used to confirm these antibiotics for quantities down to 100 pg entering the mass spectrometer.
Extraction of Light Filth from Bean Paste: Collaborative Study
Authors: Bryce John R , Glaze Larry E 
Published: February 2020

Abstract
Bean paste is a popular Asian food frequently imported to the United States. The main varieties are: hot bean and blackbean, which are used in pastry fillings; and soybean paste, which is usually used as a condiment. A new method was developed for the extraction of light filth from bean pastes containing beans and flour, and from hot bean paste containing red pepper. A100 g test portion is boiled in tap water containing Igepal DM-710 and CO-730 and washed with hot tap water on a No. 230 sieve. The residue is transferred to a beaker and boiled in isopropanol in a reflux apparatus. The mixture is transferred to a No. 230 sieve. The residue is washed again, transferred to a 2 L trap flask with 40% isopropanol, boiled with magnetic stirring, cooled, and trapped off with flotation liquid [mineral oil-heptane (85 + 15, v/v)]. Ten laboratories participated in a collaborative study validating the extraction method for the detection of light filth. Average recoveries were 94.9 and 82.8% for insect fragments and rat hairs, respectively. The method has been adopted first action by AOAC INTERNATIONAL.
Quantitation and Stability of Fumonisins B1 and B2 in Milk
Authors: Maragos Chris M , Richard John L 
Published: February 2020

Abstract
The well-documented presence of fumonisin myco-toxins B1 and B2 (FB1 and FB2) in corn raises the possibility that these toxins are carried over into the milk of animals fed with contaminated feed. The presence of FB1 and FB2 in milk has not been assessed because of the lack of sensitive analytical techniques for this matrix. Two methods, liquid chromatography (LC) and enzyme-linked immunosorbent assay (ELISA), were adapted for the analysis of milk. The ELISA, produced commercially for screening corn, required no sample preparation and was reproducible but was of low sensitivity [concentration that inhibits color development by 50% (IC50), 1200-1600 ng FB1/mL]. The more sensitive LC method involves serial extraction of milk with methanol-acetone and strong anion exchange followed by derivatization with naphthalene-2,3-dicarboxaldehyde. Recoveries of 50 ng FB1 and FB2/mL from unpasteurized and un-homogenized milk were 84 and 83%, respectively (limit of detection, 5 ng/mL). Recoveries of FB1 from whole homogenized milk (76%) were slightly lower. Heating milk for 30 min at 62°C, to mimic pasteurization, did not significantly reduce FB1 or FB2 recovery, nor did storing milk for 11 days at 4°C. The LC method was applied to 165 samples of milk, only 1 of which was positive. This finding suggests that exposure of humans to FB1 and FB2 from milk is low.
Determination of the Sum of Dimer and Polymer Triglycerides and of Acid Value of Used Frying Fats and Oils by Near Infrared Reflectance Spectroscopy
Authors: Boot Andries J , Speek Andrbes J 
Published: February 2020

Abstract
Near infrared reflectance spectroscopy (NIRS) in the transaction mode was applied to determine the sum of dimer and polymer triglycerides (DPTG) contents and acid value of used frying fats and oils. A filter instrument and a calibration sample set were used to determine DPTG content and acid value. For each parameter, a 7-wavelength calibration was developed using multiple linear regression analysis. For a validation set comprising 44 samples for the NIRS-DPTG determination in the range of 2.2 to 32.7% m/m, the correlation coefficient between NIRS and liquid chromatography (LC) was 0.976, with a standard error of prediction (SEP) of 1.8% m/m. For a validation set comprising 36 samples for the NIRS-acid value determination in the range of 0.30 to 18.8 mg potassium hydroxide per gram of sample (mg KOH/g), the correlation coefficient between NIRS and titration was 0.996, with a SEP of 0.33 mg KOH/g. Validation after routine operation for 1 year provided SEPs of 2.3% m/m and 0.44 mg KOH/g for DPTG and acid value determination, respectively. NIRS screening of 1400 samples collected during 1992 precluded the need for 1149 DPTG determinations by LC (82.1%) and 1033 acid value determinations by titration (73.8%), which are methods the judicature in The Netherlands accepted, because those samples appeared to comply with legislation.
Determination of Cholesterol by p-Nitrobenzoate Derivatization and Liquid Chromatography
Authors: Hamill Thomas W , Soliman Abdel M 
Published: February 2020

Abstract
The method involves direct saponification and formation of the sterol p-nitrobenzoate (PNB) derivatives or lipid extraction with methylene chloride and isopropyl alcohol, saponification, fatty acid methylation, and formation of the sterol PNB derivatives. The sterol PNB derivatives are separated on a C8 column with a mobile phase of acetonitrile-hexane-water (250 + 30 + 3) and quantitated by UV detection at 280 nm. The limit of detection for cholesterol is 2 ng. The response was linear over a range of 4 to 250 ng (r = 0.999). Assays of NIST SRM 1845 and 1563 by this method gave results that were closer to the certified values than were results obtained by the AOAC gas chromatographic method. Reproducibility was evaluated by using foods containing low, medium, and high levels of cholesterol. The % coefficient of variation ranged from 1.8 to 6.7. Studies on a wide variety of food products (using lipid extraction and saponification-methylation) gave a mean recovery of 87.5 ± 10.1%. Direct saponification of poultry and dairy products gave a mean recovery of 101.3 ± 15.8%. Peak purity was determined by diode array spectrophotometry.
Detection of Milk Fat Adulteration by Linear Discriminant Analysis of Fatty Acid Data
Authors: Ulberth Franz 
Published: February 2020

Abstract
Analysis of the fatty acid (FA) profile of milk fat (MF) by gas-liquid chromatography is widely used to detect adulteration with foreign fats. On the basis of the FA spectra of 352 genuine Austrian MF samples collected over a 4-year period, the effectiveness of concentration ranges of the major FA of MF and of certain FA ratios to identify non-MF/MF mixtures was tested. FA ratios proved useful for the detection of coconut fat in MF and admixture of vegetable oils rich in linoleic acid down to a level of 2%. This approach failed to identify non-MF/MF blends containing beef tallow, lard, olive oil, or palm oil at a level less than 10% commingling. Linear discriminant analysis applied to FA data was successful in distinguishing pure MFfrom adulterated MF. Computer-simulated data were used to derive the discriminant functions. Saturated and un-saturated FA with 18 C atoms were the most useful discriminating variables selected by a stepwise variable selection procedure. More than 95% of a data set composed of pure MF, and non-MF/MF blends containing 3% of either tallow, lard, olive oil, or palm oil were correctly classified. The validity of the classification rule was also tested by 206 gravimetrically prepared fat mixtures. Mixtures containing &gt;3% foreign fat were detected in all cases.
Determination of Amino Acids in Feeds: Collaborative Study
Authors: Llames Cynthia R , Fontaine Johannes 
Published: February 2020

Abstract
A total of 28 laboratories (including authors’ laboratories) participated in a collaborative study for determination of amino acids in feeds using 3 complementary procedures. Each collaborator analyzed 5 blind duplicate samples of feed and ingredients used in the poultry industry. The amount of amino acids in these materials ranged from 0.10 to 8.50%. Twenty-three laboratories conducted analyses using performic acid oxidation with acid hydrolysis—sodium metabisulfite method, 16 laboratories performed analyses using performic acid oxidation with acid hydrolysis—hydrobromic acid method, and 15 laboratories used acid hydrolysis method. The repeatability relative standard deviation values for all amino acids for all 3 procedures ranged from 1.1 to 5.6% for broiler finisher feed, 1.1 to 4.73% for starter feed, 1.3 to 9.6% for corn, 0.8 to 3.96% for fishmeal, and 0.8 to 12.7% for poultry meal. The reproducibility relative standard deviation values for all amino acids ranged from 3.71 to 19.80% for broiler finisher feed, 4.1 to 16.93% for starter feed, 4.4 to 28.2% for corn, 3.46 to 18.96% for fishmeal, and 3.73 to 24.1% for poultry meal. The performic acid oxidation with acid hydrolysis—sodium metabisulfite and hydrobromic acid methods, and acid hydrolysis method for determination of amino acids in feeds have been adopted first action by AOAC INTERNATIONAL.
Determination of Antimony in Environmental Samples by Hydride Generation–Inductively Coupled Plasma Spectrometry
Authors: Anderson Kim A , Isaacs Brandon 
Published: February 2020

Abstract
Total antimony was determined by inductively coupled plasma atomic emission spectrometry (ICP AES) using hydride vapor generation. A1 g wet, 0.25 g dry, or 10 mL water sample was digested by one of 2 distinct methods in a 10 mL graduated Kimax culture tube on a programmed heating block by heating with nitric acid and then boiling in a mixture of sulfuric acid and perchloric acid. For soils, a 0.25 g sample was digested in a 10 mL volumetric culture tube with hydrochloric acid. After digestion, the samples were treated with hydrochloric acid and potassium iodide. The antimony was then reduced by sodium borohydride to stibine (SbH3) in a simplified, continuous-flow manifold. A standard pneumatic nebulizer effected the gas–liquid separation of SbH3, which was then quantified by ICP AES at 231.147 nm. The instrument detection limit was 0.41 μg/L. Recoveries from 10 matrixes were 80 to 100%, with a typical relative standard deviation of 5.3%. The digestion and analysis methods demonstrated statistical control for samples of environmental and biological interest and are especially well suited to analysis of small samples. This method requires no additional apparatus for hydride generation or sample introduction.
Determination of Organophosphorus Nematicide Residues in Banana-Field Soils by Gas Chromatography/Mass Spectrometry
Authors: Cooper Jean-François , Zheng Shan-Qiang , Wynn Nigel R , Palcy Louis 
Published: February 2020

Abstract
Gas chromatographic/mass spectrometric (GC/MS) methodology is presented for the determination, in banana-field soils, of the 4 most used organophosphorus nematicides in Martinique (French West Indies): cadusafos (Rugby), ethoprophos (Mocap), isazophos (Miral), and fenamiphos (Nemacur). After extraction with 2 successive solvent mixtures, ethyl acetate–dichloromethane (8 + 2, v/v) and ethyl acetate–acetone (7 + 3, v/v), cleanup was performed using solid-phase extraction cartridges (silica SPE). Fenamiphos and its metabolites were separated in the second eluate and then oxidized to sulfone. Analysis was performed by GC/MS in fragmentometric mode. Recoveries varied from about 75 to 90%. Limits of quantitation varied from 4 to 20 μg/kg fresh soil sample, depending on the nematicide.