bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Pressure Liquid Chromatographic Method for Indole in Shrimp: Development of Method and Collaborative Study
Authors: Chambers Theodore L , Staruszkiewicz Walter F ,   Collaborators:, Bohm G , Bond J F , Carr R , Edge D J , Everett R L , Illuminati J C , Rose J La , Mcmurtrey K , Miller G , Panaro K W , Smith B H 
Published: February 2020

Abstract
A collaborative study on the determination of indole in shrimp was conducted in which a high pressure liquid chromatographic (HPLC) method and a spectrofluorometric method were compared with the AOAC gas-liquid chromatographic (GLC) method (18.075–18.078,13th ed.). In the HPLC method, 10 g shrimp was blended with methanol, an internal standard was added, and the extract was filtered. Indole was separated on an octadecylsilane reverse phase column, using 60% MeOH-H2O, and quantitated with a fluorescence detector (excitation 280 nm, emission 330 nm) by comparing the indole peak height with that of an internal standard, 2-methylindole. Recoveries at a 25 μg/100 g level averaged 104% with a range of 90–127%, and at a level of 35 μg/100 g averaged 102% with a range of 93–112%. In the spectrofluorometric method, 25 g shrimp was extracted with 2% EtOAc-hexane. After several washes, indole was partitioned into a saturated NaCl-MeOH solution and its fluorescence was measured (excitation 280 nm, emission 332 nm). Recoveries at a 25 μg/100 g level averaged 93% with a range of 0–255% and at a level of 35 μg/100 g averaged 64% with a range of 0–107%. Recoveries obtained by the AOAC-GLC method at a level of 25 μg/100 g averaged 96% with a range of 81–116% and at a level of 35 μg/100 g averaged 101% with a range of 81–119%. The coefficients of variation were 20,10, and 64% at a 25 μg/100 g level for the GLC method, the HPLC method, and the spectrofluorometric method, respectively. The HPLC method was adopted as official first action for indole levels in shrimp exceeding 1 μg/100 g.
Comparison of Modified A-1 Method with Standard EC Test for Recovery of Fecal Coliform Bacteria for Shellfish
Authors: Hunt Daniel A , Lucas John P , Mcclure Foster D , Springer Janet , Newell Richard 
Published: February 2020

Abstract
This study is one of a series in which variations of the A-1 method for the detection and enumeration of (ecal coliforms and Escherichia coli in seawater and foods were evaluated. The tests were conducted jointly by the Food and Drug Administration and state and provincial laboratories that support shellfish control programs in the United States and Canada as part of the National Shellfish Sanitation Program’s Microbiology Task Force activities. Results showed significantly higher recovery of fecal coliforms from naturally contaminated shellfish by the AOAC official A-l-M method than by the American Public Health Association standard method. There was no significant difference in recovery of E coii by the 2 methods.
Identification of Trialkyl and Triaryl Phosphates in Distilled and Super-Q Water
Authors: Williams David T , Lebel Guy L , Benoit Frank M 
Published: February 2020

Abstract
An unknown compound detected in an extract from water purified through a Millipore Super-Q system has been identified as tributoxyethyl phosphate by gas chromatographic retention times and by gas chromatography/mass spectrometry. Purified water from distillation systems also contained trialkyl/aryl phosphate plasticizers/flame retardant additives: Tris(l,3-dichloropropyl) phosphate and triphenyl phosphate were formally identified and isopropylphenyl diphenyl phosphate was tentatively identified from mass spectra interpretation and from GC retention times on 2 chromatographic columns.
Minicolumn Detection Methods for Aflatoxin in Raw Peanuts: Collaborative Study
Authors: Shotwell Odette L , Holaday Charles E ,   Collaborators:, Athnasios A K , Ayres J L , Baxley J R , Bean G A , Chisholm T , Edds G T , Erickson R , Holaday C E , Johnson H S , Lowie D M , Minyard J P , Nesheim S , Rashmawi K J , Romer T R , Shannon G M , Soloman W , Teague R T , Wilson D M 
Published: February 2020

Abstract
The Holaday-Velasco method and a modified Holaday method have been compared. The former method combines the speed and simplicity of the Holaday extraction and cleanup with the sensitivity of the minicolumn originally described by Velasco. The combination method has been approved by the AOAC and the AACC for determining aflatoxin in corn. The Holaday method was modified by substituting toluene for benzene in the solvent partition, and methylene chloride for chloroform in the minicolumn development to eliminate use of hazardous solvents. The neutral alumina in the Holaday minicolumn was changed from activity V to activity III to provide a more stable column. At aflatoxin levels in raw peanuts of 13-20 ng/g, the presence of aflatoxin was missed by the modified Holaday method in 4 analyses (3 laboratories) of 42 reported. There were no misses in this contamination range by the Holaday-Velasco method. There were no misses by either method with samples containing &gt;20 ng total anatoxins/g. Analysis of uncontaminated raw peanuts by the modified Holaday method resulted in 2 false positives of 14 reports; the Holaday-Velasco method produced no false positive reports from 15 analyses of uncontaminated peanuts. The Holaday-Velasco method was adopted official first action for peanuts.
Spectrophotometric Determination of Dicumarol in Sweet Clover
Authors: Casper Howard H , Benson Margaret E , Kunerth Wallace 
Published: February 2020

Abstract
A procedure is described for the purification and quantitation of dicumarol in sweet clover. The toxin is extracted by refluxing the sweet clover with 1,2-dichloroethane and 1M NaH2PO4, and partially purifying the extract by base partitioning. The extract is examined by thin layer chromatography, and then the dicumarol band is eluted and quantitated by ultraviolet spectrometry. All interferences are removed when the procedure is applied to moldy and nonmoldy sweet clover. The estimated limit of detection is 1 mg dicumarol/kg sweet clover. At the 10 mg/kg level the procedure standard recovery is 91 ± 1%. The recovery of a dicumarol standard addition (10mg/kg) from a moldy (15 mg dicumarol/kg) sweet clover pool was 95 ± 1%.
General Method for Determination of Pesticide Residues in Samples of Plant Origin, Soil, and Water. I. Extraction and Cleanup
Authors: Ambrus Árpád , Lantos János , Visi Éva , Csatlós Imre , Sárvári Lászlo 
Published: February 2020

Abstract
Acetone extraction followed by partition into methylene chloride is used to extract organophosphate, organochlorine, carbamate, thiocarbamate, urea, triazine, and other types of pesticides. The efficiency of acetone extraction is demonstrated with different samples and compounds. A general extraction scheme is presented which is suitable for the determination of parent compounds and many of their metabolites. Different samples are divided into 8 groups according to the extraction process and cleanup on mixed adsorbent (active carbon, magnesia, diatomaceous earth), alumina, or silica gel columns. Maximum possible loads, depending on sample type and mode of detection, are given for each adsorbent. The method is suitable for 143 of the 257 pesticides used in Hungary.
Automatic Incubator for Use with Modified A-l Test for Enumerating Fecal Coliform Bacteria in Shellfish Growing Waters
Authors: Cook David W 
Published: February 2020

Abstract
An automatic water bath incubator which can be constructed from easily obtainable materials is described. This incubator provides temperatures necessary for both the 35 ± 0.5°C resuscitation period and the 44.5 ± 0.2°C final incubation period as required in the AOAC method for enumerating fecal coliforms by the modified A-l test. Statistical analysis of experimental data indicated no significant differences (P&gt; 0.50) in fecal coliform counts obtained by using the automatic incubator and the AOAC incubation method.
Microdiffusion and Fluoride-Specific Electrode Determination of Fluoride in Infant Foods: Collaborative Study
Authors: Dabeka Robert W , Mckenzie Arthur D ,   Collaborators:, Baetz R A , Bingham D W , Bohm G , Brown L C , Cavlovic P , Fee S A , Goul J , Hall R J , Hancha J -P , Helle L , Jacobso J S , Johnson R D , Keashly R , Mankotia M , Mietz J L , Nixon G , Peters T , Shreve M , Smith B F 
Published: February 2020

Abstract
Twelve laboratories analyzed (1 replicate) 12 samples of infant foods – milk, pears, and peas – containing 0.2-5 ppm F. There was one laboratory outlier. Mean coefficients of variation were 7.06% for intralaboratory determination of 3 sets of blind duplicates and 21.6% for interlaboratory determination of 12 samples. Variance analysis for all samples yielded a reproducibility standard deviation of 0.41 ppm; for 3 sets of blind duplicates, repeatability standard deviation was 0.26 ppm and reproducibility standard deviation was 0.32 ppm.
High Pressure Liquid Chromatographic-Thermal Energy Determination of N-Nitrosodiethanolamine in Cosmetics
Authors: Ho Julia L , Wisneski Harris H , Yates Ronald L 
Published: February 2020

Abstract
Methods for the determination and confirmation of N-nitrosodiethanolamine (NDELA) in cosmetic products were developed. The NDELA fraction was isolated from a cosmetic product by a series of solvent extractions which were designed to concentrate the NDELA and remove ingredients deleterious to the analytical system. The isolated fraction was then analyzed for NDELA using a high pressure liquid chromatograph (HPLC) interfaced with a thermal energy analyzer (TEA). The compound was measured by comparison of detector response with those of known standards. NDELA was verified by gas chromatography-mass spectrometry of the silyl derivative after preliminary cleanup of the sample by gradient elution HPLC on a Partisil 10 PAC column. The limit of detection of NDELA by TEA is 2-3 ng, which corresponds to 20-30 ppb in the cosmetic product. Analysis of an emulsion cream and a hair grooming gel spiked at 3 and 4 ng concentration levels, respectively, yielded recoveries ranging from 71 to 103% (average 88%).
High Performance Liquid Chromatographic Determination of Lactose in Milk
Authors: West Leslie G , Llorente Marie A 
Published: February 2020

Abstract
A rapid and simple high performance liquid chromatographic method for the determination of lactose in milk was developed. Samples were diluted with 0.5% perchloric acid and centrifuged, and an aliquot of the supernate was mixed with acetonitrile. Lactose was separated on a 10 μm particle-size silica column with aqueous acetonitrile as the mobile phase. The recovery of lactose from whole, skim, and chocolate milk averaged 99.2, 101.1, and 100.4%, respectively. Coefficients of variation for routinely performed duplicate determinations are between 1.0 and 1.5%.
Spectrophotometric Determination of Phosphorus in Certifiable Straight Color Additives: Collaborative Study
Authors: Brammell Wallace S ,   Collaborators:, Arozarena C , Hunter J , Kiernan H G , King J H , Leon M , Schoneker D R , Zyren J 
Published: February 2020

Abstract
A simple and rapid spectrophotometric method was developed for determining the total phosphorus content of certifiable straight color additives. The dye sample is mixed with a cellulose powder and MgO mixture, and ashed at 500°C in a small Pyrex beaker in a muffle furnace. The ash is dissolved in vanadomolybdic acid reagent and filtered through glass wool, and the absorbance of the resulting yellow molybdovanadophosphoric acid solution is measured at 400 nm. The total phosphorus content of the sample, expressed as percent Na3PO4, is determined from a standard curve. Recovery of phosphorus added as KH2PO4 to 39 different dyes in amounts equivalent to 0.300% Na3PO4 ranged from 95.3 to 106.8%, averaging 100.6%. In the collaborative study, 7 laboratories successfully performed duplicate analyses of 6 different dyes (D&C Orange No. 5, D&C Yellow No. 8, FD&C Blue No. 2, FD&C Red No. 3, FD&C Red No. 40, and FD&C Green No. 3). The mean values found ranged from 0.325 to 6.86% Na3PO4. In general, the accuracy and reproducibility of the method were satisfactory, with single determination coefficients of variation ranging from 3.76 to 9.60%. The method was adopted official first action.
Gas-Liquid Chromatographic Determination of Tetradif on Technical and Formulations: Collaborative Study
Authors: Rossum Bram Van , Martijn Albertus , Launer James E ,   Collaborators:, Calamita E C , Oliva M De , Prima S Y Di , Gassola L , Gotz G , Hitos M P , Magallanes M , Pavel K , Poulingue P , Povlsen H H , Rasero F Sanchez , Zeiser O 
Published: February 2020

Abstract
The gas-liquid chromatographic determination of tetradifon technical and formulations was collaboratively studied in duplicate with 12 laboratories. Six samples were dissolved in dichloroethane with n-hexacosane as the internal standard, chromatographed on a column of 3% SE-52, and detected by flame ionization. The average coefficients of variation were 1.2% for the 2 technical samples, 1.6% for the 2 wettable powders, and 1.5% for the 2 emulsifiable concentrates. The method has been adopted official first action.
Spectrophotometric Determination of Atropine Sulfate in the Presence of Phenylmercury (II) Acetate
Authors: Wahbi Abdel Aziz M , Barary Magda 
Published: February 2020

Abstract
Two-component spectrophotometric method of analysis using 2 wavelengths, the method of least squares using absorbances, the method using 2-orthogonal function coefficients, and the method of least squares using orthogonal function coefficients have been applied to the determination of atropine sulfate in the presence of phenylmercury (II) acetate, compounds whose spectra overlap. The first method gave erroneous results; the second method gave satisfactory results for synthetic mixtures. The fourth method was superior, especially in the presence of irrelevant absorption. It has been successfully used for determining atropine sulfate in injection solutions in which a cubic irrelevant absorption was present. Results were in good agreement with those obtained by the official method.
High Performance Liquid Chromatographic Determination of Methapyrilene Hydrochloride in Feed and Sleep Aid Tablets
Authors: Shaikh Badaruddin , Hallmark Margarette R 
Published: February 2020

Abstract
Methapyrilene hydrochloride (MP·HCl) was extracted from feed with methanol and determined by reverse phase partition chromatography in less than 15 min, using isocratic elution with acetonitrile-1.1% ammonium carbonate (1 + 1) as the mobile phase. This procedure was tested on feed treated with MP·HCl at levels of 125,500, and 2000 ppm. Recoveries were 104,95, and 96% with coefficients of variation of 2.4,1.6, and 0.6%, respectively. MP·HCl in feed was stable for 14 days. This method was also successfully used to determine MP·HCl in 3 sleep aid tablets.
Comparative Efficiency of Brilliant Green, Bismuth Sulfite, Salmonella-Shigella, Hektoen Enteric, and Xylose Lysine Desoxycholate Agars for the Recovery of Salmonella from Foods: Collaborative Study
Authors: Andrews Wallace H , Poelma Paul L , Wilson Clyde R ,   Collaborators:, Abeyta C , Chu G S , Cruz L , Dorrett L , English L , Estela L A , Guarino P , Hayden M A , Haymond R E , Heagy J , Hoffman C D , Kallander K , Krout D J , Landry W L , Latt T , Ludwig S G , Martinez E E , McDonald R L , McKee C R , Melanson D E , Otto L A , Palmieri M J , Roderick C N , Sado P N , Sawai E , Stout D K , Tardio J L , Tom J , Twohy C W , Wagner D , White W D , Wong P 
Published: February 2020

Abstract
The relative efficiency of brilliant green (BG), bismuth sulfite (BS), Salmonella-Shigella (SS), xylose lysine desoxycholate (XLD), and Hektoen enteric (HE) agars for the recovery of Salmonella from 5 foods was collaboratively studied in 11 laboratories. The analytical efficiency of various paired combinations of the 5 agars was statistically compared according to 3 parameters: (1) productivity or recovery of Salmonella, (2) rate of enumeration of cultures that were false positive for Salmonella, and (3) rate of enumeration of false-negative reactions. In descending order of productivity, the sequential rankingwasBS, XLD, HE, BG, and SS agars. In ascending order, the rates of false-positive reactions based on a statistical analysis of paired agar combinations was HE, BS, BG and XLD (tie), and SS agars. Analogously, in ascending order, the sequence of false-negative reaction rates was BS, XLD, HE, BG, and SS agars. The combination of BS, XLD, and HE agars is more efficient for recovery of Salmonella from foods than is the present official combination of BG, BS, and SS agars. The revision of official final action method 46.054 to replace the combination of BG, BS, and SS agars with a combination of BS, XLD, and HE agars has been adopted official first action.
X-Ray Powder Diffraction Data for Nine Medicinal 2-Imidazolines
Authors: Owen John T R , Kountourellis John E , Underwood Frank A 
Published: February 2020

Abstract
X-ray powder diffraction data for nine 2-imidazolines have been obtained by the powder dif f ractometer and by the photographic Debye-Scherrer techniques. The data for individual 2-imidazolines are tabulated in terms of lattice spacings (d in Å) and the relative intensities of lines. The best method of packing for powder diffraction was investigated. It was advantageous to use chromium K∝ radiation in the Debye-Scherrer technique.
Spectrophotometry Determination of Procaine Hydrochloride in Presence of 4-Aminobenzoic Acid, Using a Combined Polynomial Method
Authors: Wahbi Abdel-Aziz M , Belal Saied , Bedair Mona , Abdine Hassan 
Published: February 2020

Abstract
A method is presented for the determination of procaine hydrochloride without prior separation from degradation products, using the combined polynomial method. Thus, pw (= 3p2 + 4p3) calculated over the wavelength range 272-316 nm at 4 nm intervals, using 12-point orthogonal polynomials, was linearly related to concentration (0.3-1.3 mg/100 mL), reproducible (rel. std dev. 0.88%), and independent of degradation products. Mean percent recovery for 6 mixtures of procaine hydrochloride and degradation products was 100.49 ± 1.33. The relationship log c% vs time for a solution in pH 10 buffer was linear with aslope of −0.171/day.
Gas-Liquid Chromatographic and Gas-Liquid Chromatographic-Mass Spectrometric Determination of Fenvalerate and Permethrin Residues in Grasshoppers and Duck Tissue Samples
Authors: Reichel William L , Kolbe Elizabeth , Stafford Charles J 
Published: February 2020

Abstract
A procedure is described for determining fenvalerate and permethrin residues in grasshoppers and duck tissues. Samples are Soxhlet-extracted with hexane and cleaned up by gel permeation chromatography with an in-line alumina column. Samples are analyzed by gas-liquid chromatography with electron capture detection, and confirmed by gas-liquid chromatography-mass spectrometry. The average recovery from fortified tissues was 97%.
Rapid Cleanup Procedure for Gas-Liquid Chromatographic Determination of Chlorpyrifos-Methyl Residues in Cat Food
Authors: Simonaitis Richard A , Cail R Spencer , Zehner James M 
Published: February 2020

Abstract
A simple and rapid gas-liquid chromatographic (GLC) method was developed for the determination of residues of chlorpyrifos-methyl in dry cat food. Cat food fortified with chlorpyrifos-methyl was extracted with acetone and cleaned up on a modified acetonitrile-on-Florisil partitioning column. The chlorpyrifos-methyl was determined by GLC with a flame photometric detector. Results were compared with those for known standards that had undergone the same cleanup procedure. The quantitative electronic integration limit of determination was 0.03 ppm. Average recoveries for 5 analyses at fortification levels from 0.052 to 51 ppm ranged from 90 to 102% and averaged 97%.
Volatile N-Nitrosamines in Dried Foods
Authors: Sen Nrisinha P , Seaman Stephen 
Published: February 2020

Abstract
An investigation was carried out to determine the levels of volatile Af-nitrosamines in several dried food commodities such as malt, instant skim milk powder, infant formula containing milk powder, instant coffee, soup and soup bases, and baby cereals. The method involves vacuum distillation of the sample from 3N KOH or 1% sulfamic acid, followed by extraction of the aqueous distillate with dichloromethane. The dichloromethane extract is then washed with an acidic buffer (to remove amines), dried over anhydrous sodium sulfate, concentrated in a Kuderna-Danish concentrator, and analyzed by gas-liquid chromatography, using a thermal energy analyzer. Detection limit is 0.1-0.5 ppb. Of the samples analyzed thus far, all malts (22 samples) and instant skim milk powders (11 samples) were positive for Af-nitrosodimethylamine (NDMA); average levels were 7.4 ppb (1.3-67.0 ppb) and 0.4 ppb (0.3-0.7 ppb), respectively. Traces of NDMA and/or JV-nitrosopyrrolidine were also detected in 3 of 20 dried soups and 5 of 10 instant coffees analyzed. Traces of NDMA and/or AT-nitrosopiperidine (NPIP) were detected in 3 of 8 powdered infant formulas. All 4 baby cereal samples were negative. The identity of NDMA in 14 samples of malt and that of NDMA and NPIP in an infant formula was confirmed by gasliquid chromatography-mass spectrometry; identity of N-nitrosamines in 3 instant coffees and 1 infant formula was independently verified by high pressure liquid chromatographic analysis.
Anomalies in the Mass Spectrum of N-Nitrosopyrrolidine
Authors: Libbey Leonard M , Scanlan Richard A 
Published: February 2020

Abstract
Several anomalies in the published standard mass spectrum of JV-nitrosopyrrolidine (NPYR) were pointed out and a new standard spectrum was presented. It was suggested that the published standard was partially thermally degraded, perhaps by an overheated inlet line or interface to the mass spectrometer. Specific anomalies thought to be due to overheating included a marked decrease in the relative intensity of m/z 100 (M+) and a concomitant increase in m/z 30 and m/z 69. The large ion at m/z 28 could not be attributed to overheating, nor to an air leak; rather it is part of the normal spectrum for NPYR.
Analysis of Laboratory Animal Feed for Toxic and Essential Elements by Atomic Absorption and Inductively Coupled Argon Plasma Emission Spectrometry
Authors: Blakemore William M , Billedeau Stanley M 
Published: February 2020

Abstract
Analytical procedures are described for the determination of arsenic, cadmium, calcium, copper, lead, mercury, selenium, and zinc in animal feed. Mercury is determined by digesting the feed sample in a mixture of concentrated nitric and sulfuric acids with vanadium pentoxide added as an oxidation catalyst, reducing with stannous chloride, and sweeping the elemental mercury into an absorption tube for measurement by atomic absorption (AA) spectrophotometry. Arsenic and selenium are determined simultaneously by digesting the sample with a mixture of concentrated nitric, sulfuric, and perchloric acids; the hydrides of arsenic and selenium, which are formed with the addition of sodium borohydride, are swept into an argon-hydrogen flame for analysis by AA. A low temperature ash is prepared and dissolved in 1N HNO3 for the analysis of calcium, copper, and zinc by emission spectroscopy using the inductively coupled argon plasma source; the same solution is used for the determination of cadmium and lead by flameless AA. Animal feed spiked with 3 levels of each of the 8 elements gave recoveries that ranged from 80 to 107%.