bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matrix Solid-Phase Dispersion (MSPD) Isolation and Liquid Chromatographic Determination of Oxytetracycline, Tetracycline, and Chlortetracycline in Milk
Authors: Long Austin R , Hsieh Lily C , Malbrouh Marsha S , Short Charles R , Barker Steven A 
Published: February 2020

Abstract
A multlresldue method for the isolation and liquid chromatographic determination of oxytetracycline (OTC), tetracycline (TC), and chlortetracycllne (CTC) antibiotics In milk Is presented. Blank and tetracycline (OTC, TC, and CTC) fortified milk samples (0.5 mL) were blended with octadecylsllyl (C18, 40 /an, 18% load, endcapped, 2 g) derivatized silica packing material containing 0.05 g each of oxalic acid and dlsodlum ethylenedlamlnetetraacetlc. A column made from the C18/milk matrix was first washed with hexane (8 mL), following which the tetracyclines were eluted with ethyl acetate-acetonltrlle (1 + 3; v/v). The eluate contained tetracycline analytes that were free from Interfering compounds when analyzed by liquid chromatography with UV detection (photodiode array, 365 nm). Correlation coefficients of standards curves for Individual tetracycline isolated from fortified samples were linear (from 0.982 ± 0.009 to 0.996 ± 0.004) with average percentage recoveries from 63.5 to 93.3 for the concentration range (100,200,400,800,1600, and 3200 ng/ mL) examined. The Inter-assay variability ranged from 8.5 ± 2.4% to 20.7 ± 13.0% with an Intra-assay variability of 1.0- 9.3%.
Automation Of Dihydroxyaluminum Sodium Carbonate Analysis In Antacid Tablets By Energy Dispersive X-Ray Fluorescence
Authors: Georgiades Constantine A 
Published: February 2020

Abstract
A sensitive, specific, automated energy dispersive X-ray fluorescence (EDXRF) method for determination of anhydrous dihydroxyaluminum sodium carbonate in antacid tablets has been developed. The compound was quantltated by Impact grinding, palletizing at 10 tons pressure, and monitoring the aluminum by using a rhodium anode X-ray tube, high resolution thermoelectrlcally cooled SI(LI) detector with sample spinning, and computer data processing. The assay procedure was validated with spiked laboratory-prepared samples at 100 ± 20% levels. The average recovery was 100.6% with a relative standard deviation of 1.6% (n = 14). Instrument precision was determined and found to have an average relative standard deviation of 1.0% (n = 16). In addition, analysis precision by the EDXRF method was compared to that for titration and autoanalyzer methodologies and found to be statistically comparable. The sample precision had an averaged relative standard deviation of 2.7% (n = 16) by X-ray methodology. The advantages of this EDXRF method Include Increased sample throughput with excellent precision and accuracy, no solvent usage, and automated data handling.
Diagnostic Data Evaluation. Part III. Collaborative Study Evaluation: Standard Deviation Considered To Be A Constant
Authors: Malanoski Anthony J 
Published: February 2020

Abstract
The diagnostic evaluation of the crude protein collaborative study Identified possible problems with a standardized Interval for the Kjeldahl digestion, with sample preparation, and with excess sample weights. The standard deviations for the ham and the beef samples cannot be considered to be representative of the method because of these problems. The standard deviations for the frankfurter and the pork sausage samples for all analysts met the performance standard of 0.24. There was no evidence of analyst bias.
Comparative Study of Colorimetric DNA Hybridization Method and Conventional Culture Procedure for Detection of Salmonella in Foods
Authors: Chan Samuel W , Wilson Stephen G , Vera-Garcia Marcela , Whippie Kevan , Ottaviani Margaret , Whilby Anna , Shah Alpa , Johnson Andrew , Mozola Mark A , Halbert Donald N 
Published: February 2020

Abstract
A second generation nucleic acid hybridization assay has been developed and evaluated against the conventional culture method for detection of salmonellae In foods. The assay Involves a liquid hybridization with Sa/mone/fo-speclflc oligonucleotide probes, capture of probe:target hybrids onto a solid support (plastic dipstick), and a colorimetric end point detection. The assay can be completed In 2.5 h, following approximately 44 h of culture enrichment. One thousand samples representing 20 food types were analyzed in parallel by both methods. Samples Included unlnoculated test product, and product Inoculated with Salmonella at 2 levels. Eighteen Salmonella serotypes were used as Inocula. The data demonstrate that the colorlmetric hybridization method and the conventional culture method are equivalent In their ability to detect Salmonella contamination of foods.
Liquid Chromatographic Method for Determination of Oxydemeton-Methyl in Formulated Products: Collaborative Study
Authors: Slahck Stephen C 
Published: February 2020

Abstract
A liquid chromatographic method has been developed for the determination of oxydemeton-methyl (Metasystox-RR) In formulated products. Samples are dissolved In acetonltrile and analyzed by reverse-phase chromatography using methyl paraben as an Internal standard. Twelve laboratories participated In a collaborative study of the method. Each collaborator was furnished with reference standard, Internal standard, and blind duplicate samples of Metasystox-R 50% concentrate (MSR 50 Cone), Metasystox-R spray concentrate (MSR SC), and DYLOXR/MSR 1.5-0.5 formulations. Collaborators were instructed to use peak area measurements for quantitation. Relative standard deviations for reproducibility (RSDR) were 1.44, 2.14, and 3.63%, respectively. The method has been approved Interim official first action by AOAC.
Extraction Methods for Quantitation of Gentamicin Residues from Tissues Using Fluorescence Polarization Immunoassay
Authors: Brown Scott Anthony , Newkirk David R , Hunter Robert P , Smith Gary G , Sugimoto Kyoko 
Published: February 2020

Abstract
Sodium hydroxide digestion of unhomogenlzed kidney and skeletal muscle for 20 min at 70°C was a superior method for extracting gentamicin from tissues, compared with simple homogenlzatlon, trichloroacetic acid precipitation of homogenized tissue, and sodium hydroxide digestion of homogenized tissue. Fluorescence polarization Immunoassay was used to quantltate gentamicin. Sodium hydroxide digestion of unhomogenlzed tissue allowed for the recovery of 90.0 ± 5.9% (Ẋ ± SD) from renal cortex and 79.9 ± 3.5% from skeletal muscle. The limit of sensitivity was 17.4 ng/g kidney tissue, 15.8 ng/g digested muscle, and 39.0 ng/g digested heart. The wlthin-assay coefficient of variation (CV) at 100 ng/g kidney was 9.2%; at 500 ng/g kidney, the CV was 2.5%; and at 2000 ng/g kidney, the CV was 1.5%. The between-assay coefficient of variation was &lt;7.5% for all concentrations from kidney, and the 99% confidence Interval at 100 ng/g kidney was 71.7-112.4 ng gentamlcin/g kidney. The wlthln-assay coefficient of variation (CV) at 100 ng/g muscle was 15%; at 500 ng/g muscle, the CV was 2.6%; and at 2000 ng/g muscle, the CV was 2.3%. The between-assay coefficient of variation was &lt;15% for all concentrations from muscle, and the 99% confidence interval at 100 ng/g muscle was 72.5-136.8 ng gentamlcin/g muscle. Gentamlcln-free milk could be distinguished from milk containing gentamicin concentrations of 10 ng/mL milk with 95 % confidence, and from milk containing concentrations of 30 ng gentamicin/mL milk with 99% confidence. Quantitative results at or below the tolerance level can be obtained within 90 min of sample acquisition using these extraction and assay methods
Liquid Chromatography-EIectrochemical Detection of Furazolidone and Metabolite in Extracts of Incurred Tissues
Authors: Parks Owen W , Kubena Leon F 
Published: February 2020

Abstract
One-day-old chicks were raised to maturity on a diet fortified with 0.0055% furazolidone. Analyses of tissue extracts by a liquid chromatographic-electrochemlcal detection screening procedure for nltro-contalning drugs disclosed, in addition to the parent drug, an unidentified metabolite in the liver and breast tissue of the mature birds sacrificed while on the fortified feed. No evidence of residues of the drug or metabolite was found In birds removed from the medicated feed 48 h prior to sacrifice. In view of the rapid In vivo and postmortem metabolism of the parent drug In liver tissue, the metabolite can serve as an alternative means of detecting furazolidone residues In chicken tissues.
Confirmation of Identity by Gas Chromatography/Tandem Mass Spectrometry of Sulfathiazole, Sulfamethazine, Sulfachloropyridazine, and Sulfadimethoxine from Bovine or Swine Liver Extracts after Quantitation by Gas Chromatography/Electron-Capture Detection
Authors: Matusik Jean E , Sternal Richard S , Barnes Charlie J , Sphon James A 
Published: February 2020

Abstract
Four sulfonamide veterinary drug residues were quantltated by electron-capture detection (ECD) after separation by gas chromatography (GC). The Identities of sulfathiazole (ST), sulfamethazine (SM), sulfachloropyridazine (SCP), and sulfadimethoxine (SDM) were confirmed In bovine or swine liver residues by tandem mass spectrometry (MS/MS). Bovine or swine liver tissues were extracted by using either the Tlshler or the Manuel-Steller cleanup. The methylated residues containing ST, SM, SCP, and SDM were separated by GC prior to MS/MS daughter ion analysis. Control tissue, control tissue fortified at 0.1 ppm, and Incurred tissue residues at approximately 0.1 ppm were analyzed for these 4 sulfonamides. A Flnnigan Model TSQ-46 operating in the chemical ionization mode was used to perform the MS/MS daughter Ion experiments. The Identities of all 4 sulfonamides were confirmed In a single GC/MS/MS analysis.
Comparison of Postcolumn Derivatization-Liquid Chromatography with Thin-Layer Chromatography for Determination of Aflatoxins in Naturally Contaminated Corn
Authors: Beaver Rodney W , Wilson David M , Trucksess Mary W 
Published: February 2020

Abstract
Quantitation of aflatoxins by liquid chromatography with postcolumn iodine derlvatization (LC-PCD) and fluorescence detection was compared with quantitation by the AOAC CB method, 968.22. Thirty-seven naturally contaminated corn samples were ground and then divided. One portion was extracted, and the extract was cleaned up and analyzed by thin-layer chromatography according to the CB method. The second portion was extracted and cleaned up In a similar fashion, but quantitation was by the LC-PCD method. For aflatoxin B1, concentrations ranging from 0 to 150 ng/g, results obtained by the 2 methods were fitted to a linear equation with the LC-PCD results as the dependent variable. The correlation coefficient was 0.99, the Intercept was near 0, and the slope was near 1. For aflatoxin B2, the correlation coefficient was 0.97, and the Intercept was near 0. However, the slope of the equation relating LC-PCD concentration to TLC concentration was only 0.5. We believe that this lack of equivalence between the methods for determination of aflatoxin B2 is due to overestlmatlon by the TLC method because the low levels present are near the TLC detection limit for B2.
Cigarette Smoke Composition. Part 1. Limitations of FTC Method When Applied to Cigarettes That Heat Instead of Burn Tobacco
Authors: Borgerding Michael F , Hicks Richard D , Bodnar James E , Riggs Dennis M , Nanni Edward J , Fulp George W , Hamlin William C , Giles J A 
Published: February 2020

Abstract
The design of a new cigarette that heats rather than burns tobacco calls for modifications to the Federal Trade Commission (FTC) method for analytical smoking. These changes Include eliminating sample conditioning at 75 °F and 60% RH, exercising greater care In lighting cigarettes, and smoking cigarettes to self-extinguishment rather than to a predetermined butt length as a measure of complete consumption. By several gross analytical measures, smoke condensate from the new cigarette differs substantially from that of tobacco-burning cigarettes. This Is Inferred from the lack of coloration of smoke condensate collected on Cambridge filters. Elemental analysis demonstrates reduced carbon and nitrogen content concurrent with Increased hydrogen. Thermogravlmetrlc analysis shows almost quantitative weight loss at Tmax = 220 °C. Ultraviolet (UV) spectrophotometrlc analysis shows greatly reduced levels of tobacco-derived smoke components and qualitative differences In chemical entitles being measured. By design, the heat required for smoke formation Is supplied by a carbon heat source embedded In the cigarette tip. Tobacco contained In the cigarette Is not burned and Is exposed to temperatures less than 300 °C. Thus, It Is apparent (1) that smoke from the new cigarette contains little or no "tar" as tar Is classically defined, and (2) that the FTC method even as modified to account for cigarette design differences Is appropriate only for determination of nicotine and carbon monoxide yielded from this cigarette.
Cigarette Smoke Composition. Part 2. Method for Determining Major Components in Smoke of Cigarettes that Heat Instead of Burn Tobacco
Authors: Borgerding Michael F , Milhous L Arthur , Hicks Richard D , Giles J A 
Published: February 2020

Abstract
A method Is described for determining major constituents In the smoke of a cigarette that heats, but does not burn, tobacco. Dual, simultaneous separations are performed in a single gas chromatographic oven to determine water, glycerol, nicotine, and propylene glycol in a rapid and cost-effective manner. A materials balance of new cigarette smoke total particulate matter was attempted from both Cambridge filter and electrostatic precipitation smoke collection data. Serious deficiencies were found when Cambridge filter smoke collection was applied for this purpose. Electrostatic precipitation smoke collection eliminated these problems. The data obtained by electrostatic precipitation smoke collection Indicate that water, glycerol, nicotine, and propylene glycol make up about 94% of new cigarette smoke total particulate matter.
Rapid Method for Determination of Leucogentian Violet in Chicken Fat by Liquid Chromatography with Electrochemical Detection
Authors: Munns Robert K , Roybal Jose E , Hurlbut Jeffrey A , Shimoda Wilbert 
Published: February 2020

Abstract
The metabolite leucogentian violet (LGV) was found In chicken fat obtained from chickens dosed with gentian violet (GV); however, no residues of the parent compound, GV, and Its oxidized metabolites were found. Therefore, a rapid method was developed for the specific determination of LGV In chicken fat. Chicken fat containing LGV Is separated from the cellular protein with methylene chloride. LGV Is then separated from the fat by partition extraction with an aqueous acid phase In which LGV Is protonated, and the fat Is discarded with the methylene chloride layer. The aqueous solution Is neutralized, LGV Is re-extracted Into methylene chloride, and the methylene chloride Is evaporated. An acetonltrlle- water solution containing LGV Is filtered before liquid chromatography using a cyano column, an acetate buffer- acetonltrile mobile phase, and an electrochemical detector set at a potential of +1.000 V. Average recoveries of LGV from chicken fat were 83.9% with a coefficient of variation (CV) of 12.9 % for the 5 ppb level; 82.8 % with a CV of 13.5 % for the 10 ppb level; and 77.7 % with a CV of 2.56 % for the 20 ppb level. Levels of Incurred LGV in chicken fat averaged 49.3 ppb with a CV of 2.43%
Typical Phthalate Ester Contamination Incurred Using EPA Method 8060*
Authors: Lopez-Avila Viorica , Milanes June , Constantine Franklin , Beckert Werner F 
Published: February 2020

Abstract
Methods for determination of trace levels of phthalate esters In environmental samples require procedures that avoid the Introduction of laboratory contaminants. Because It Is difficult to avoid contamination of samples with phthalate esters from laboratory reagents, materials, and glassware, we have undertaken a study to determine the sources, extent of contamination, and conditions under which background contamination can be minimized. Solvents such as acetone, hexane, diethyl ether, isooctane, and methylene chloride, and reagent water samples from various commercial suppliers were analyzed for 11 phthalate esters. Florlsll, alumina, silica gel, anhydrous sodium sulfate, filter paper, paper thimbles, glass wool, and aluminum foil were washed with organic solvents and the solvent washings were analyzed for 11 phthalate esters. Finally, we addressed the likelihood of contamination of laboratory glassware subjected to common laboratory cleanup procedures and the likelihood of contamination of hexane and Isooctane stored In sample vials of different sizes. The present study was conducted in conjunction with the single-laboratory evaluation of U.S. Environmental Protection Agency (EPA) method 8060 for determination of phthalate esters in environmental samples.
Gas Chromatographic Determination of Systemic Fungicide Tricyclazole in Soil and Water
Authors: Yunxiang Xiao , Defang Fan , Hexin Chen 
Published: February 2020

Abstract
A method Is described for determination of tricyclazole residues In soil and water. Tricyclazole is extracted from soil by refluxlng with ethyl acetate-acetone (80 + 20 v/v) and from water by partitioning Into dlchloromethane. The soil extract Is purified by coagulation. The compound Is detected and measured by gas chromatography using a flame photometer operated In the sulfur mode. Detection limits are 8 ppb for soil and 0.8 ppb for water. Recoveries for control samples fortified with tricyclazole at 0.1-5.0 ppm averaged 97.1 % for soil and 108.1% for water.
Simple Analytical Method for Organophosphorus Pesticide Residues in Milk
Authors: Toyoda Masatake , Adachi Kazuhiko , Ida Tadakazu , Noda Katsuhiko , Minagawa Norio 
Published: February 2020

Abstract
A simple method for determination of organophosphorus pesticide residues at the parts per million level In milk was developed. Pesticide residues were extracted with acetonitrlle added to aqueous milk, fat was removed by zinc acetate addition and dichloromethane partition, and analytes were concentrated and analyzed by wide-bore capillary column gas chromatography. Recoveries of 6 pesticides spiked in milk samples at levels of 0.1 and 1.0 μg/mL were 82.1- 93.8% and 79.7-96.6%, respectively. Triplicate samples spiked with 6 pesticides at 1 itg/mL were analyzed independently by 3 laboratories. Average recoveries were greater than 80%, and the mean coefficients of variation for the complete study were 2.9% for diazlnon, 5.4% for dimethoate, 4.6% for malathlon, 4.6% for parathlon, 4.9% for EPN, and 6.1% for phosalone.
Development of Milk Powder Reference Materials BCR-CRM 187,188. Part I. Preparation, Homogeneity, and Stability
Authors: Quirijns Jan K , Van Der Paauw Kees G , Mulders Ed J , Griepink Bernard 
Published: February 2020

Abstract
Two milk powders were prepared and tested as reference materials for 9 organochlorlne pesticides and metabolites: hexachlorobenzene, HCH Isomers (a-HCH, jS-HCH, 7-HCH), 0-heptachlor epoxide, dleidrin, endrln, p.p'-DDE, and p,pf- DDT. The reference materials, a natural milk powder (CRM 187) and a spiked milk powder (CRM 188), contain the analytes at concentrations of 1.5 to 69 /ig/kg on a dry weight basis. Preparation and testing for homogeneity and stability of the powders are discussed. The mean coefficient of variation In the homogeneity tests was about 4.5%, which indicates that the homogeneity of the samples Is very good. Stability data over 12 months do not show any trend that suggests lack of stability
Homogenization Methods for Analysis of Foodstuffs
Authors: Lichon Michael J , James Keith W 
Published: February 2020

Abstract
Methods for homogenlzatlon of food matrixes are examined. Determinations Involving foods homogenized by noncryogenlc methods were found to have relative standard deviations varying Inversely with the subsample mass used for determination. Each method could only be used for sampling at the milligram level on a very limited range of foods. Cryogenic homogenlzatlon methods were effective on the majority of foods, allowing milligram subsample masses to be used for analysis. A noncryogenlc pretreatment was generally necessary to obtain a subsample suitable for cryogenic homogenlzatlon
Determination of Pentachlorophenol in Animal Tissues: A Canadian Perspective
Authors: Macneil James D , Patterson John R , Fesser Adrian C , Martz Valerie K 
Published: February 2020

Abstract
Analytical methods for pentachlorophenol (PCP) residues In edible animal tissue have been reviewed, with particular reference to gas chromatographic methods of analysis. Results of analyses demonstrate that significant residues of PCP can persist for several weeks In animals exposed to contaminated bedding. National surveys In Canada have found that the incidence of PCP residues In pork in excess of 0.1 ppm was reduced from 32% of survey samples In 1981- 1982 to 6.6% of samples tested In 1987-1988. An Interlaboratory sample exchange among Canadian laboratories demonstrated that the PCP analytical method currently used by Agriculture Canada could be successfully transferred to other laboratories. An exchange of samples between regulatory laboratories of Agriculture Canada and the Food Safety and Inspection Service of the U.S. Department of Agriculture (USDA) demonstrated equivalency of results for the 2 methods currently used in the respective laboratories, with relative standard deviations for analytical results ranging from 4.4 to 22.2%.
Matrix Solid Phase Dispersion Isolation and Liquid Chromatographic Determination of Oxytetracycline in Catfish (Ictalurus punctatus) Muscle Tissue
Authors: Long Austin R , Hsiesh Lily C , Malbrough Marsha S , Short Charles R , Barker Steven A 
Published: February 2020

Abstract
A method for Isolation and liquid chromatographic determination of oxytetracycllne In catfish (Ictalurus punctatus) muscle tissue Is presented. Blank control and oxytetracycllne- fortlfied fish muscle tissue samples (0.5 g) were blended with octadecylsilyl (C18, 40 μm, 18% load, endcapped) derlvatized silica packing material (2 g) containing 0.05 g each of oxalic acid and disodlum ethylenedlamlnetetraacetate. A column made from the C18/fish tissue matrix was first washed with hexane (8 mL), following which the oxytetracycllne was eluted with acetonltrile-methanol (1 + 1, v/v) containing 0.06% w/v each of butylated hydroxyanlsole and butylated hydroxytoluene. The eluate contained oxytetracycllne analyte that was free from Interfering compounds when analyzed by liquid chromatography with UV detection (photodlode array set at 365 nm). Standard curves for oxytetracycllne Isolated from fortified samples were linear (0.998 ± 0.002) with an average absolute percentage recovery of 80.9 ± 6.6% for the concentration range (50,100,200, 400, 800, 1600, and 3200 ng/g) examined. The Interassay variability was 11.3 ± 5.2% with an Intra-assay variability of 1.1%.
Liquid Chromatographic Determination of Cephapirin Residues in Milk
Authors: Macintosh Agnes I 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was developed for quantitative determination of cephapirin residues In milk that also resolved cephapirin from amplcillln, cloxaclllin, and penicillin G. Diluted milk was passed through a C18 cartridge on which the cephapirin was adsorbed; then, Interfering material was removed by washing with water and methylene chloride and cephapirin residues were eluted with methanolacetonitrlle (25 + 75). After drying, residues were dissolved in the mobile phase for Injection. The LC system had an ultrasphere-ODS column with RP-18 Spherl-10 guard column and a UV detector with a 254 nm filter. The mobile phase was 85% sodium acetate (0.01M) and 15% methanol-acetonltrile (25 + 75) with a flow rate of 1 mL/mln. Sensitivity was 20 ppb or less with a recovery of 61-80% in the range studied. Other βlactam antibiotics tested did not Interfere with detection of cephapirin. Analysis of 30 samples of commercial homogenized milk obtained for a survey of antibiotics in consumer milk In Canada revealed no detectable cephapirin residues.