bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental Screening of Acidic Compounds Based on Capillary Zone Electrophoresis/Laser-Induced Fluorescence Detection with Identification by Gas Chromatography/Mass Spectrometry and Gas Chromatography/High-Resolution Mass Spectrometry
Authors: Brumley William C , Grange Andrew H , Kelliher Virginia , Patterson Dennis B , Montcalm Alice , Glassman Jack , Farley John W 
Published: February 2020

Abstract
This paper describes the application of capillary zone electrophoresis/laser-induced fluorescence detection (CZE/LIF) to the discovery of acidic compounds in environmental matrixes or the screening of extracts for acidic components. Published studies indicate that coal-derived materials contain a significant fraction of acidic compounds relative to materials derived from petroleum and shales. Such compounds may be useful as marker compounds for site assessment and source apportionment issues, and their identification may be important in toxicological and other health issues. We used deep-UV light from the frequency-doubled Ar ion laser at 244 and 257 nm to study extracts of samples. The CZE/LIF technique possesses good sensitivity and therefore overcomes one of the limitations of CZE with UV detection. The present work depends on high pressure/temperature solvent extraction of polynuclear aromatic hydrocarbon (PNA)-contaminated soil, followed by separation using CZE. The anionic analytes were separated by using borate or phosphate buffer (pH 9.2–12.3) after a chemical class separation. Samples were also characterized by gas chromatography/mass spectrometry (GC/MS) using full scans at low resolution, and elemental compositions were determined unequivocally by GC/high-resolution MS (GC/HRMS) using mass peak profiling (MPP). The similarity of low-resolution electron ionization mass spectra for a standard, 1-hydroxypyrene, and for a series of compounds in a contaminated-soil extract suggested that several types of phenolic and hydroxy-PNAs were present, including hydroxylated derivatives of fluorenes, fluoranthenes, and pyrenes. GC/HRMS using MPP confirmed the elemental compositions of the hydroxyfluorenes and hydroxypyrenes (and presumably hydroxyfluoranthenes) as [C13H10O] and [C16H10O], respectively. A new version of the MPP software was written for the Finnigan-MAT 900S-Trap and was similar to that developed previously for the VG 250SE. Inclusion of a calibration ion in addition to a lock mass ion in the multiple-ion detection descriptor provided errors of &lt;1 ppm for the 3 partial profiles of the analytes. A mass resolution of 31 000 was used to resolve the analyte signals from interferences evident in the full M+1 and M+2 profiles in the case of the hydroxyfluorenes. Derivatization was also performed to form the tert-butyldimethylsilyl derivatives of phenolic hydroxy groups as a further confirmation of structure.
Sensitivity and Specificity of the Test Kit BAX® for Screening/ E. coli O157:H7 in Ground Beef: Independent Laboratory Study
Authors: Hochberg Alan M , Gerhardt Paul N M , Cao Thoa K , Ocasio Wilfredo , Barbour W Mark , Mrozinski Peter M 
Published: February 2020

Abstract
An independent laboratory study of the BAX® for Screening/E. coli O157:H7 kit was conducted at the National Food Laboratory, Inc., Dublin, CA, to complete AOAC® Performance Tested MethodSM certification. The BAX system kit was compared with the BAM culture method and a modified BAM culture method for detection of E. coli O157:H7 in ground beef. The BAX system kit detected the target organism at levels approximately 10-fold lower than those that gave positive BAM results. This study validated product claims, and Performance Tested Method status was granted.
Liquid Chromatographic Preparative Method for Isolating Ergot Alkaloids, Using a Particle-Loaded Membrane Extracting Disk
Authors: Ware George M , Price Gina , Carter Lawrence , Eitenmiller Ronald R 
Published: February 2020

Abstract
A liquid chromatographic method is described for the determination of ergot alkaloids in wheat. Ergonovine, ergotamine, ergocornine, α-ergocryptine, and ergocristine are extracted from wheat with methanol–0.25% concentrated H3PO4 (40 + 60) pH 2.2, cleaned up by using a solid-phase extraction (SPE) disk, and separated by reversed-phase liquid chromatography with fluorescence detection. Ergot alkaloids are basic compounds that form water-soluble salts in acidic aqueous solution. Because ergot alkaloid salts are positively charged, they can be easily and selectively trapped on a negatively charged strong cation-exchange SPE disk. A strong wash solvent, methanol–0.25% concentrated H3PO4 (40 + 60) was used to remove matrix interferences not bonded by ionic interactions with the cation-exchange column. The ergot alkaloids were eluted from the ion-exchange column by adjusting the pH of the elution solvents to slightly basic conditions (pH 9). The SPE disk concentrated and cleanly separated the ergot alkaloids from matrix interferences. Standard calibration curves for ergot alkaloids for the concentration range 0.1–2.0 μg/mL were linear. The SPE disk had a column capacity equivalent to about 1 g extracted wheat. At spiking levels of 2.3–46 ng/g for ergonovine and 20–400 ng/g for ergotamine, ergocornine, α-ergocryptine, and ergocristine, the mean recovery was 88.1% with a coefficient of variation (CV) of 5.33%. The recovery data ranged from 79.1 to 95.9%. Ergonovine had the lowest overall recovery and the largest CV. The method has an estimated reliable limit of detection and limit of quantitation of &lt;5 and &lt;20 ng/g, respectively, for each ergot alkaloid tested.
Fluorescence Spectra Measurement of Olive Oil and Other Vegetable Oils
Authors: Kyriakidis Nikolaos B , Skarkalis Paulos 
Published: February 2020

Abstract
Fluorescence spectra of some common vegetable oils, including olive oil, olive residue oil, refined olive oil, corn oil, soybean oil, sunflower oil, and cotton oil, were examined in their natural state, with a wavelength of 360 nm used as excitation radiation. All oils studied, except extra virgin olive oil, exhibited a strong fluorescence band at 430–450 nm. Extra virgin olive oil gave a different by interesting fluorescence spectrum, composed of 3 bands: one low intensity doublet at 440 and 455 nm, one strong at 525 nm, and one of medium intensity at 681 nm. The band at 681 nm was identified as the chlorophyll band. The band at 525 nm was at least partly derived from vitamin E. The low intensity doublet at 440 and 455 nm correlated with the absorption intensity at 232 and 270 nm of olive oil. The measurements of these fluorescence spectra were quick (about 5 min) and easy and could possibly be used for authentification of virgin olive oil.
Spectrophotometric Determination of Saponin in Yucca Extract Used as Food Additive
Authors: Uematsu Yoko , Hirata Keiko , Saito Kazuo , Kudo Ichiro 
Published: February 2020

Abstract
A spectrophotometric method was developed for the determination of saponin in Yucca extract or its preparation for food additive use. A saponin fraction of Yucca extract was prepared by column chromatography with porous polymer, and hydrolyzed with a 2 mol/L mixture of hydrochloric acid–ethanol (1 + 1) to generate sapogenin. Sapogenin amounts were determined by measuring absorbance at 430 nm, based on the color reactions with anisaldehyde, sulfuric acid, and ethyl acetate. Recoveries from Yucca extracts were 91.5–95.1%, and the detection limit was 10 mg/kg. Commercial Yucca extracts for food additive use were composed of 5.6–6.4% (w/w) saponin, making it a minor component.
Determination of 1,3-Benzodioxanes in Piper mullesua by High-Performance Thin-Layer Chromatography
Authors: Srivastava Shaifali , Gupta Madan M , Verma Ram K , Kumar Sushil 
Published: February 2020

Abstract
A new, simple, precise, and rapid high-performance thin-layer chromatographic method was developed for the determination of 6 benzodioxanes in Piper mullesua extract: 1′,3′-benzodioxole-5′-(2,4,8-triene-isobutyl nonanoate), 1′,3′-benzodioxole-5′-(2,4,12-triene-isobutyl tridecanoate), fargesin, sesamin, asarinin, 1′,3′-benzodioxole-5′-(2,4,8-triene-methyl nonanoate). The ingredients were separated on a precoated Silica Gel 60 F254 plate with a solvent system of toluene–acetone (92 + 8). The 6 benzodioxanes were well separated and easily identified in this chromatographic system. The separated benzodioxanes were visualized by color development with a spray reagent consisting of 1 g vanillin dissolved in 100 mL H2SO4–ethanol (5 + 95, v/v). Quantitation was performed by scanning the spots and comparing the integrated areas of compounds in samples with those of standards. Recoveries from samples spiked with known amounts of the benzodioxanes were excellent. The results were comparable with those estimated by liquid chromatography.
Assay of Naproxen in Rat Serum by High-Performance Thin-Layer Chromatography/Densitometry
Authors: Guermouche Moulay-Hassane , Atik Nadia , Chader Hocine 
Published: February 2020

Abstract
A simple, sensitive, and reproducible high-performance thin-layer chromatographic method using densitometry is presented for the determination of naproxen in rat serum. Only 0.1 mL serum was used for extraction. Separations were performed on 10 × 10 cm plates coated with silica gel, with toluene–ethyl acetate–acetic acid (82 + 15 + 3) as the mobile phase. Benzophenone was used as the internal standard. Quantification was performed by densitometry at 260 nm. The response for naproxen was linear ( r = 0.992) over the range 2–100 mg/L. Method validation demonstrated good recoveries (92–96%), sensitivity (limit of quantitation, 1 mg/L), repeatability of sample application (4%), repeatability of the method (8%), and intermediate precision (5%). The procedure was applied to the quantitation of naproxen in rat serum.
Validation of a High-Performance Thin-Layer Chromatographic Method for Trace Analysis for Some Generic Drugs Affecting Gastrointestinal Function
Authors: Novaković Jasmina 
Published: February 2020

Abstract
To prevent cross-contamination between pharmaceutical products manufactured with the same equipment, cleanup procedures must be introduced before the manufacture of a new product begins. From an analytical point of view, it is crucial to select and validate a suitable analytical method to determine contaminants in the rinse water, swabs, and the placebo of the next product. High performance thin-layer chromatography (HPTLC) was chosen in our laboratory for this purpose and was optimized to meet the requirements of trace determination. The method was validated in terms of the limit of detection, limit of quantitation (LOQ), linearity close to the LOQ, sample preparation from the swab media and from the placebo of the next product made with the same equipment (recovery), precision, selectivity (interference from the swab and placebo matrixes), resolution (from related compounds), and robustness. The HPTLC method was applied to 2 different generic drugs affecting gastrointestinal function—the water-soluble H2-receptor antagonist ranitidine hydrochloride (RHCl) and the water-insoluble choleretic drug ursodeoxycholic acid (UDCA). Chromatography was performed on silica plates by using toluene–methanol–diethylamine (9 + 1 + 1, v/v/v) and n-heptane–ethyl acetate–glacial acetic acid (5 + 5 + 1, v/v/v) as the mobile phases for RHCl and UDCA, respectively. RHCl was measured in situ at 320 nm, whereas the detection of UDCA was performed at 502 nm after postchromatographic derivatization. The method was used for the determination of RHCl and UDCA in the swabs, the final rinse water, and the placebo batch after the cleanup process.
Immunochemical Applications in Environmental Science
Authors: Emon Jeanette M Van 
Published: February 2020

Abstract
Immunochemical methods are based on selective antibodies combining with a particular target analyte or analyte group. The specific binding between antibody and analyte can be used to detect environmental contaminants in a variety of sample matrixes. Immunoassay methods provide cost-effective, sensitive, and selective analyses for many compounds of environmental and human health concern. Immunoaffinity chromatography methods have been integrated with chromatographic methods and are also being used as efficient sample preparations prior to immunochemical or instrumental detection. Immunosensors show promise in obtaining rapid online analyses. These and other advancements in immunochemical methods continue the expansion of their role from field screening methods to highly quantitative procedures that can be easily integrated into the environmental analytical laboratory.
Sensitive Determination of n-Hexane and Cyclohexane in Human Body Fluids by Capillary Gas Chromatography with Cryogenic Oven Trapping
Authors: Kondo Kei , Lee Xiao-Pen , Kumazawa Takeshi , Sato Keizo , Watanabe-Suzuki Kanako , Seno Hiroshi , Suzuki Osamu 
Published: February 2020

Abstract
A sensitive method was developed for determination of n-hexane and cyclohexane in human body fluids by headspace capillary gas chromatography (GC) with cryogenic oven trapping. Whole blood and urine samples containing n-hexane and cyclohexane were heated in a 7.5 mL vial at 70°C for 15 min, and 5 mL of the headspace vapor was drawn into a glass syringe. All vapor was introduced through an injection port of a GC instrument in the splitless mode into an Rtx-Volatiles middle-bore capillary column at an oven temperature of −40°C for trapping volatile compounds. The oven temperature was programmed to 180°C for GC with flame ionization detection. These conditions gave sharp peaks for both n-hexane and cyclohexane, a good separation of each peak, and low background impurities for whole blood and urine. The extraction efficiencies of n-hexane and cyclohexane were 13.2–30.3% for whole blood and 12.7–20.7% for urine. The coefficients of within-day variation in terms of extraction efficiency of both compounds were 5.0–9.5% for whole blood and 3.8–10.8% for urine; those of day-to-day variationfor the compounds were not greater than 16.6%. The regression equations for n-hexane and cyclohexane showed good linearity in the range of 5–500 ng/0.5 mL for whole blood and urine. The detection limits (signal-to-noise ratio = 3) for both compounds were 1.2 and 0.5 ng/0.5 mL for whole blood and urine, respectively. The data on n-hexane or cyclohexane in rat blood after inhalation of each compound are also presented.
Charm Safe-Level β-Lactam Test for Amoxicillin, Ampicillin, Ceftiofur, Cephapirin, and Penicillin G in Raw Commingled Milk
Authors: Salter Robert S , Legg David , Ossanna Nancy , Boyer Cheryl , Scheemaker Joan , Markovsky Robert , Saul Steven J 
Published: February 2020

Abstract
The Charm Safe-Level β-Lactam Test was evaluated by a U.S. Food and Drug Administration (FDA) test protocol administered by the AOAC–Research Institute. The sensitivity and selectivity of the test were evaluated with &gt;800 negative raw commingled and drug-fortified milk samples by the manufacturer and an independent laboratory. Probit analysis by the independent laboratory determined the following 90% positive levels with 95% confidence: amoxicillin, 5.6 ppb; ampicillin, 8.5 ppb; cephapirin, 13.7 ppb; ceftiofur, 46.2 ppb; and penicillin G, 3.6 ppb. These values were within a range of ±20% of the manufacturer's data. Selection of negative samples met confidence specifications. Ruggedness parameters were studied and defined, and the stability of frozen milk was verified. There were no interferences from somatic cells (1 000 000 somatic cell count/mL) or bacteria (300 000 colony-forming units/mL), or from 27 other non-β-lactam animal drugs. Test performance with raw milk samples containing incurred penicillin, ampicillin, and amoxicillin was consistent with the dose responses determined with fortified milk samples. Incurred cephalosporin in raw milk samples was detected at lower levels than was cephalosporin in fortified milk samples, presumably because of the presence of metabolite, as verified by other test methods. Quality control data support consistency in manufacture between batches and the stability of refrigerated test reagents for up to 1 year. Successful fulfillment of these criteria led to FDA certification of the test when used with a reader in U.S. milk testing programs.
TECRA® Unique™ Test for Rapid Detection of Salmonella in Food: Collaborative Study
Authors: Hughes Denise , Dailianis Angela E , Hill Louise , McIntyre Deborah A , Anderson Aimee ,   Collaborators:, Anderson A , Barrat C , Battista K , Beatty S , Blanch T , Briones D , Brooks R , Brown J , Burnie A , Clark T , Dailianis A , Destro C , Dijs B , Dombroski P , Fyfe R , Gebler J , Gerry A , Graham T , Hadjimichael D , Heaton S , Hetrick S , High E , Hill L , Hirt B , Hulett B , Hussain Z , Kalinowski R , Kerr D , Matouchi N , Maycock L , Munyard S , Murphy M , Remes A , Ristov K , Robbins R , Rodriquez R , Shebuski J , Simes V , Smith K , Vanderpoel S , Wang D 
Published: February 2020

Abstract
The TECRA® Unique™ Salmonella test uses the principle of immunoenrichment to allow rapid detection of Salmonellae in food. A collaborative study was conducted to compare the TECRA Salmonella Unique test with the reference culture method given in the U.S. Food and Drug Administration's Bacteriological Analytical Manual. Three food types (milk powder, pepper, and soy flour) were analyzed in Australia and 2 food types (milk chocolate and dried egg) were analyzed in the United States. Forty-one collaborators participated in the study. For each of the 5 foods at each of the 3 levels, a comparison showed no significant differences (p ≥ 0.05) in the proportion of positive test samples for Unique and that for the reference method using the Chi-square test for independence with continuity correction.
Variables Affecting Simulated Use Determination of Residual Ethylene Oxide in Medical Devices
Authors: Centola Duane T , Ayoub Kamal I , Lao Nelson T , Lu Hollington T C , Page Barry F J 
Published: February 2020

Abstract
In autumn 1993, AAMI/ST/WG 63, Sterilization Residuals Working Group undertook the task of studying factors involved in determining the amount of residual ethylene oxide in medical devices after sterilization and developing a protocol for controlling the relevant variables. The protocol was evaluated by conducting a round robin study consisting of 8 participating laboratories from around the country. Results of this round robin study demonstrated the range over which results may vary despite controls placed on the time and temperature at which determinations were conducted. The data from the study suggest that small, random variations in technique during short sample extraction times can lead to variability in the results. Variables such as initial water temperature, oven temperature, weighing of sample, and length of extraction should be carefully controlled. Inherent variations in the material composition of similar devices are possible contributing factors. The efforts of this working group and the subsequent evaluation and discussion of its findings are presented.
Determination of Moisture in Cheese and Cheese Products
Authors: Bradley Robert L , Vanderwarn Margaret A 
Published: February 2020

Abstract
Variables related to oven-drying samples of cheese and cheese products to determine moisture content were examined to provide more efficient and reproducible methods. Over 6500 samples of cheese were analyzed in an effort to modify the current AOAC procedure. The gravity atmospheric oven was unsuitable for use in accurate moisture analysis because of wide temperature differentials within the oven cavity. Use of this for oven moisture determination resulted in higher variance, which corresponded to the high temperature variation within the oven. Cheese sample preparation using an Oster blender yielded consistently lower variance in final moisture content than did preparation of cheese samples with a hand grater, rotary grater, and plug and plunger. Sample size of 3 ± 0.25 g maximized surface area-to-volume ratios and yielded a lower error in final moisture content because of better control of ambient weight loss rates. Use of combination of disposable 5.5 cm diameter aluminum sample pans with 5.5 cm diameter glass fiber filter pads for covers produced a smaller standard deviation for moisture analysis than did the AOAC pan and insert cover and filter paper covers. All pans must be pre-dried for at least 3 h at 100°C, and the glass fiber covers should be pre-dried for 1 h under the same conditions. All dried pans and covers must be stored in a desiccator with active desiccant. Equipment upgrades from the existing AOAC standard methods provide safer more efficient methods of analysis.
Determination of Phytase Activity in Feed by a Colorimetric Enzymatic Method: Collaborative Interlaboratory Study
Authors: Engelen Adrianus J , van der Heeft Fred C , Randsdorp Peter H G , Somers Wim A C , Schaefer Jan , van der Vat Bianca J C 
Published: February 2020

Abstract
Fourteen laboratories participated in a collaborative study (coded fyt9404) and 13 laboratories participated in a study (coded fyt9410) to validate a colorimetric assay for determination of microbial phytase activity in feed. For each study, all laboratories received 6 laboratory samples provided by one commercial supplier (phytase activity levels within the range of 200–400 per kg) to be analyzed in duplicate. Method performance was calculated and statistical calculations were executed according to AOAC guidelines. Results from 3 laboratories for study fyt9404 and from one laboratory for study fyt9410 were excluded from statistical analysis because of invalid data determined during initial review by Youden pair, value versus laboratory. For study fyt9404, repeatability relative standard deviation (RSDr) values ranged from 6.2 to 8.6%, and reproducibility relative standard deviation (RSDR) values ranged from 14.1 to 27.6%. No outliers were identified. For study fyt9410, RSDr values ranged from 3.9 to 7.9%, and RSDR values ranged from 14.0 to 20.5%. With outliers excluded, RSDr values ranged from 2.5 to 7.9%, and RSDR values ranged from 14.0 to 20.5%.
Determination of Coumarin in Fragrance Products by Capillary Gas Chromatography with Electron Capture Detection
Authors: Wisneski Harris H 
Published: February 2020

Abstract
A gas chromatographic (GC) method is described for the determination of coumarin in fragrance products. Coumarin was tentatively identified by retention time and confirmed by GC/mass spectrometry. The amount of coumarin was determined by external standard. The method was validated by conducting recovery studies from fortified fragrance products at several concentrations. Recoveries of coumarin ranged from 99 to 110%, with a relative standard deviation of 3.24. The method was used to survey a variety of fragrance products purchased in the metropolitan Washington, DC area, for coumarin. Seventy one percent of the products were found to contain coumarin at concentrations ranging from 0.002 to 0.61%.