bluuebunny/crossref_metadata_2025_split huggingface dataset:
NBS Plant Tissue Standard Reference Materials
Authors: Alvarez Robert 
Published: February 2020

Abstract
NBS issues 6 Standard Reference Materials for use in determining nutrient and contaminant elements in plant tissues and agricultural food products. They are SRM 1571, Orchard Leaves; SRM 1573, Tomato Leaves; SRM 1575, Pine Needles; SRM 1570, Spinach; SRM 1567, Wheat Flour; and SRM 1568, Rice Flour. These SRMs are used to calibrate instrumentation, to determine accuracy of existing analytical methods, and to develop more accurate methods. The Certificate of Analysis for each SRM details the homogeneity of the powdered material, the minimum sample size to be used, the certified values for the elements with their uncertainties, and the noncertified values. A certified value is based either on concordant results by independent analytical methods or on results by a definitive method, i.e., an accurate method having identified, systematic errors. These certified values can serve as common reference points for comparison of data acquired over a long period by various investigators using a variety of methods.
Trace Element Analysis of Bovine Liver: Interlaboratory Survey in Australia and New Zealand
Authors: Koh T S , Benson T H , Judson G J 
Published: February 2020

Abstract
An interlaboratory survey of the determination of trace elements in bovine liver was undertaken. Thirty-three laboratories from Australia and 15 from New Zealand returned results. Moisture determination results were variable despite the use of a recommended drying procedure. For the 10 trace elements determined, the mean values (μg/g) with their interlaboratory coefficients of variation (CV) were: cadmium, 1.2 (42.5%); cobalt, 0.21 (9.5%); copper, 110 (6.0%); iron, 276 (11.0%); lead, 0.6 (48.9%); manganese, 8.6 (13.9%); mercury, 0.03 (30.0%); molybdenum, 2.5 (45.6%); selenium, 1.0 (17.5%); zinc, 219 (8.2%). The intralaboratory CV for determining each of these elements was less than 9% except for the lead CV which was 20.2%. Results for the determination of sodium, potassium, calcium, and magnesium were also reported. The survey shows that while the use of a standard reference material can improve the performance of laboratories in trace element analysis, it may also introduce analytical bias.
Paper Chromatographic Determination of Phosphorus Species
Authors: Trimm Joe R , Stumpe Louis A , Lawrence Edward J , Duncan Russell D , Johnson Frank J 
Published: February 2020

Abstract
Ascending paper chromatographic methods are described to identify and quantify phosphorus species present in polyphosphates, metaphosphates, fluorophosphates, and phosphites. After interfering cations are removed or complexed, samples are chromatographed, and the individual species are leached from the paper, hydrolyzed to orthophosphate, and determined by the heteropoly blue method. Different solvents and techniques are used for the various phosphate compounds.
Thin Layer Chromatographic Detection and Fluorometric Determination of the Preservative cis-l-(3-Chloroallyl)-3,5,7-triaza-lazoniaadamantane Chloride (Quaternium-15) in Cosmetics
Authors: Wisneski Harris H 
Published: February 2020

Abstract
The preservative cis-l-(3-chloroallyl)-3,5,7- triaza-1-azoniaadamantane chloride (quaternium-15) was detected and differentiated from other formaldehyde-releasing preservatives such as 2-bromo-2-nitropropane-l,3-diol, l-hydroxymethyl-5,5-dimethylhydantoin, and imidazolidinyl urea in cosmetics by thin layer chromatography. A minimum of 0.1 μg quaternium-15 was detected by fluorescence of the lutidine derivative formed from a buffered 2,4-pentanedione indicator spray and formaldehyde liberated from this preservative. Another indicator spray, a modified Dragendorf reagent, provided additional confirmation at lower sensitivity. The fluorometric determination of quaternium-15 was based on its quantitative release of formaldehyde to form the fluorescent 3,5-diacetyl-1,4-dihydrolutidine. Close to the theoretical value of 6 moles of formaldehyde per mole of quaternium-15 was verified experimentally (5.8–6.3). Average recoveries of quaternium-15 from a bath oil and lotion ranged from 91.7 to 103%.
Infrared Spectrophotometric Determination of Encapsulated Methoprene in Poly (lactic Acid) Formulations
Authors: Giang Paul A , Jaffe Howard 
Published: February 2020

Abstract
A simple infrared spectrophotometric method is described for determination of the percentage methoprene (isopropyl (E,E)-11-methoxy-3,7,11-trimethyl-2,4-dodecadienoate, Altosid, ZR-515) in a microcapsule sample of lactic acid polymer material. In the analysis, a weighed microcapsule sample was extracted with toluene–isopropanol in an Erlenmeyer flask, and the solvent mixture was evaporated in a rotary vacuum evaporator. For cleanup, the extract was dissolved in methanol and chromatographed through a column composed of sodium sulfate, silica gel, and aluminum oxide. The solvent was again completely evaporated, the dried eluate was dissolved in an appropriate volume of carbon tetrachloride, and the infrared absorption was scanned. The response can then be related by a standard curve to mg methoprene/mL.
High Performance Liquid Chromatographic Determination of α-Tocopherol in Fish Liver
Authors: Hung Silas S O , Cho Young C , Slinger Stanley J 
Published: February 2020

Abstract
A simple method is described for the determinatio n of α-tocopherol in fish liver by high performance liquid chromatography. This method does not involve saponification or thin layer chromatography and thus avoids the destruction of α-tocopherol during sample preparation. The homogenized liver sample is extracted twice with dioxane–isooctane (20+80, v/v), and the combined extracts are dried under vacuum. The residue is extracted 3 times with acetonitrile from which α-tocopherol is then extracted with isooctane. The residue from the dried isooctane solution is dissolved in methanol–water (90+10, v/v) which is injected directly onto a micro Bondapak C18 high performance liquid chromatograph. The detection response to α-tocopherol at 280 nm was measured by peak height which was linear from 1 to 10 μg/25 μL injection. The coefficients of variation for retention time and peak height for 5 replicate analyses of the standard during 2 weeks were 1.4 and 2.4%, respectively. Recovery of α-tocopherol added to the sample before homogenization was 80–92% with a mean of 86.2% and a coefficient of variation of 4.9%. The minimum amount of sample and the concentration of α-tocopherol that can be accurately determined by the method are 0.5 g liver and 1 μg α-tocopherol/g liver, respectively.
Survey for Zearalenone, Aflatoxin, and Ochratoxin in U.S. Grain Sorghum from 1975 and 1976 Crops
Authors: Shotwell Odette L , Bennett Glenn A , Goulden Marion L , Plattner Ronald D , Hesseltine Clifford W 
Published: February 2020

Abstract
Grain sorghum samples (197) from 10 States harvested in 1975 and 1976 were analyzed for zearalenone, aflatoxin, and ochratoxin by the Eppley procedure. Zearalenone was detected in 56 samples (28%) at levels of 200–6900 ng/g (the detection limit was 100–200 ng/g). Zearalenone identity was confirmed in representative samples by gas chromatography–mass spectroscopy of the trimethylsilyl derivatives. No ochratoxin was detected in any sample (the detection limit was about 50 ng/g). Aflatoxin was detected in 4 samples at levels of 54, 6, 10, and 7 ng total aflatoxin/g (the detection limit was ca 3 ng/g). The identity of aflatoxin B1 in the samples was confirmed by formation of the water adduct on thin layer chromatographic plates.
Gas Chromatographic and Mass Spectrometric Characterization of Impurities in Technical Methoxychlor
Authors: Lamoureux Carolejean H , Feil Vernon J 
Published: February 2020

Abstract
The impurities in technical methoxychlor were concentrated by removing most of the 1,1,1-trichloro-2,2-bis(4-methoxyphenyl)ethane by recrystallization. Analysis of the impurities by gas chromatography–mass spectrometry provided evidence for more than 50 compounds. Twenty-five of these were identified through interpretation of mass spectra and synthesis.
Rapid High Pressure Liquid Chromatography of Patulin in Apple Juice
Authors: Möller Tord E , Josefsson Egon 
Published: February 2020

Abstract
A rapid method has been developed for screening patulin in apple juice. The sample is extracted with ethyl acetate and the extract is cleaned up by extraction with a sodium carbonate solution. Patulin is determined after high pressure liquid chromatography on a Spherisorb 5 μm ODS column with an ultraviolet detector set at 276 nm. The detection limit of the method is 5 μg/L and recovery is 70–75%.
Gas-Liquid Chromatographic Determination of Pentachlorophenol in Mason Jar Lids and Home Canned Foods
Authors: Heikes David L , Griffitt Kenneth R 
Published: February 2020

Abstract
A method was developed for the determination of pentachlorophenol (PCP) in the seals and enamel of Mason lids. After extraction with acidic CH2Cl2 and methylation, the resulting pentachloroanisole was determined by gas-liquid chromatography (GLC) with electron capture detection (EC). Three of the 9 brands of lids examined contained PCP. Levels were as high as 198 μg/lid. Recoveries from fortified samples ranged from 92 to 103%. Six fruits and vegetables were canned by home canning techniques, using lids shown to contain PCP. PCP in these foods was determined by a procedure specifying extraction with acidic CH2Cl2 and gel permeation chromatography cleanup. Extracts were methylated and determined by GLC-EC. PCP was found in all the canned foods. Levels were as high as 16 μg/qt. Recoveries from foods fortified with PCP ranged from 85 to 94%. The presence of PCP was confirmed by GLC-mass spectrometric determination of the derivative, pentachloroanisole.
Rapid High Performance Liquid Chromatographic Method for Determination of Gelatin-Coated Supplemental Vitamin E in Feeds
Authors: Eriksen Svend 
Published: February 2020

Abstract
A rapid method is described for determining supplemental vitamin E in feeds by means of high performance liquid chromatography (HPLC) using isocratic elution with methanol-water. The sample is mixed with water and left on a water bath to dissolve the coating. The released vitamin E is extracted, the solvent is evaporated, and the sample is redissolved in methanol for injection. The method is applicable to gelatin-coated vitamin preparations. Standard deviations for 2 ranges of supplemented vitamin E, 10–50 ppm and 50–200 ppm, are 1.6 and 5.7, respectively.
Determination of Low Levels of Vitamin D3 in Animal Feeds, Using Sephadex LH-20 and Normal Phase High Pressure Liquid Chromatography
Authors: Cohen Huguette , Lapointe Michel 
Published: February 2020

Abstract
A procedure has been developed for the purification and quantification of vitamin D3 at levels of 4000 down to 500 IU/kg from a variety of animal feeds. The method involves initial extraction with dichloromethane followed by filtration through a Sep-Pak cartridge. The D3 fraction from the Sep-Pak is further purified by using a 45 × 1.6 cm Sephadex LH-20 column followed by a Partisil-10 PAC cleanup column. Final analysis is performed by high pressure liquid chromatography (HPLC) using a LiChrosorb NH2 10 μm column and a variable wavelength UV detector set at 264 nm. The detection response curve for a vitamin D3 standard was linear over the range 5 to 100 ng, using both peak area and peak height measurements; the minimum detectable amount was 5 ng. The average percent recovery of vitamin D3 in animal feeds was 94.16 ± 5.2%.
High Pressure Liquid Chromatographic Determination of Vitamin D3 in Instant Nonfat Dried Milk
Authors: Cohen Huguette , Wakeford Bryan 
Published: February 2020

Abstract
Vitamin D3 was determined in commercially fortified instant nonfat dried milk by using normal phase high pressure liquid chromatography (HPLC). The sample was extracted with dichloromethane with sodium phosphate tribasic solution added. The sample was cleaned up by using a Sep-Pak silica cartridge and then a microparticulate column containing 10 μm Partisil-10 PAC packing material. The final analysis was performed by using a normal phase HPLC system with a 10 μm LiChrosorb NH2 column. Recovery of vitamin D3 at levels as low as 1000 IU/kg was 97.7% with a standard deviation of 3.9%.
Analytical Reference Materials. III. Preparation and Homogeneity Test of Large Quantities of Wet and Dry Sediment Reference Materials for Long Term Polychlorinated Biphenyl Quality Control Studies
Authors: Chau Alfred S Y , Lee Hing-Biu 
Published: February 2020

Abstract
This paper describes the preparation of large quantities of wet and dried lake sediments to be used as analytical reference materials for long term polychlorinated biphenyl (FCB) quality control studies. Five hundred and forty subsamples (15–20 g each) of wet sediment spiked with PCBs and more than 4900 subsamples (25–30 g each) of naturally contaminated dried sediment were prepared. Evidence of homogeneity between subsamples in each group is presented.
Quantitative Determination of Individual Chlorinated Biphenyls in Milkfat by Splitless Glass Capillary Gas Chromatography
Authors: Tuinstra Louis G M T , Traag Wim A , Keukens Henk J 
Published: February 2020

Abstract
A method is described for determining individual polychlorinated biphenyls (PCBs) in milkfat at the ppb level. Extraction and major cleanup are done simultaneously by saponification of the milkfat. After final cleanup on basic alumina, the concentrated extract is injected under splitless conditions on a capillary column coated with CPSil 7 stationary phase. The recovery of several individual PCBs from milkfat at a level of 25 ppb is better than 80%. The reproducibility for duplicates analyzed on several days showed standard deviations from 0.2 to 0.9 ppb for 19 individual chlorinated biphenyls. Some preliminary results for 165 samples of milkfat are reported.
Simultaneous Spectrophotometric Determination of Nifuroxime and Furazolidone in Pharmaceutical Preparations
Authors: Elsayed Laila , Hassan Sayed M , Kelani Khadiga M , El-Fatatry Hamed M 
Published: February 2020

Abstract
Two spectrophotometric methods have been developed for the simultaneous determination of nifuroxime and furazolidone in their pharmaceutical preparations. No preliminary separation step is required in either method. The first, a modified Vierordt method, gives accurate and reproducible results for both drugs. Mean percent recoveries for nifuroxime and furazolidone were 99.50 ±1.59 and 100.20 ±1.16 (P = 0.05), respectively. This method also gives accurate and reproducible results for the determination of nifuroxime and furazolidone in their pharmaceutical preparations: Tricofuran vaginal suppositories and powder. The second method, which involves the use of the first-derivative curves, gives unreliable results; the reasons for these are discussed.
Quantitative Determination of Steroid Acetates in Pharmaceutical Preparations by High Performance Liquid Chromatography
Authors: Van Dame Halver C 
Published: February 2020

Abstract
A high performance liquid chromatographic method is described for the rapid, quantitative determination of corticosteroid acetates in a variety of pharmaceutical preparations. The method not only separates the steroids from other ingredients in tablets, creams, ointments, lotions, or suspensions, but also from their probable degradation products. The steroid acetate is extracted from a tablet matrix or from a suspension with water and acetonitrile (50+50), or from a hexane suspension of a cream, ointment, or lotion with acetonitrile. A liquid chromatogi aph equipped with an accurate flow controller, a variable wavelength detector capable of measurement at 240 nm, and a 10 μL loop injector was used. Components were separated on a μBondpak C18 column with acetonitrile-water as the mobile phase. K’ values of 10 commonly used steroid acetates are shown and compared with Rf values from thin layer chromatographic systems. Results were equivalent for cortisone acetate tablets assayed by both the proposed and the official USP methods. Other pharmaceutical preparations were assayed to test the method, with satisfactory results.
High Performance Liquid Chromatography of Furfural and Hydroxymethylfurfural in Spirits and Honey
Authors: Jeuring Hans J , Kuppers Frans J E M 
Published: February 2020

Abstract
Furfural (2-Jfuraldehyde) and hydroxymethylfurfural (S-hydroxy-2-furaIdehyde, HMF) are determined in brandy and honey by reverse phase high performance liquid chromatography. Brandies and other spirits are injected without sample preparation; honey is diluted with water and the solution is filtered before injection onto a reverse phase column with detection at 285 nm. The mobile phase is methanol–water (10+90) and the effluent flow rate is maintained at 1.0 mL/min. External standardization is used for quantitative determination. Recoveries from cognac and honey spiked at different levels ranged from 95 to 99% (furfural) and 95 to 100% (HMF). The furfural content of the brandies was also determined by the existing colorimetric method of the Bureau National Interprofessionel du Cognac. The HMF content of the honey was correlated to the results of the classic method of Winkler.
Isotachophoretic Determination of Ethylenediaminetetraacetate in Salad Dressing, Mayonnaise, and Margarine
Authors: Ito Yoshio , Toyoda Masatake , Suzuki Hideyo , Iwaida Masahiro 
Published: February 2020

Abstract
An isotachophoretic method was developed for the determination of EDTA in foods imported by Japan. Skimmed samples of dressings, mayonnaise, or margarine were chromatographed on an anion exchange column, and interfering organic acids were eluted with water and 0.01N HC1. EDTA was eluted with 0.2N HC1 and reacted with ferric chloride to form a stable EDTA-Fe complex. Electrophoresis was carried out with dilute HCl containing 0.05% Triton and β-alanine (pH 3.5) as the leading electrolyte and 0.01M caproic acid as terminating electrolyte. Since uncoupled EDTA showed more than one zone, it was reacted with ferric chloride to form EDTA-Fe complex which showed only a single zone on an isotachopherogram. More than 90% of EDTA spiked at 100 or 1000 ppm level as disodium salt was recovered from the above mentioned three types of food. Detection limit was 10 ppm as disodium EDTA.
Identification of Hazardous Organic Chemicals in Fish from the Ashtabula River, Ohio, and Wabash River, Indiana
Authors: Kuehl Douglas W , Leonard Edward N , Welch Kenneth J , Veith Gilman D 
Published: February 2020

Abstract
Composite fish samples from the Wabash River, IN, and the Ashtabula River, OH, were analyzed by conventional pesticide procedures for PCBs, DDTs, chlordane components, and hexachlorobenzene. Additional aliquots of each sample were processed by gel permeation chromatography and were analyzed with gas chromatography–mass spectrometry by using both electron impact and negative chemical ionization modes. These analyses resulted in the identification of a series of chlorinated alkanes, chlorinated alkenes, chlorinated alkylamines containing 2–5 carbons, and polychlorinated styrenes in the Ashtabula River sample, and a series of chlorinated norbornenes, pentachlorobenzyl alcohol, and pentachlorophenol in the Wabash River sample.
Laboratory Screening for Zearalenone Formation in Corn Hybrids and Inbreds
Authors: Shannon Gail M , Shotwell Odette L , Lyons Allister J , White Donald G , Garcia-Aguirre Genoveva 
Published: February 2020

Abstract
Grains from 14 corn inbreds and 4 single cross hybrids were inoculated with 3 isolates of Gibber ella zeae to determine their inhibition of zearalenone production. The corn hybrids: Pa762 × A632 (50 mg/kg zearalenone production), A619 × A632 (17 mg/kg zearalenone production), H95 × Mol7 (132 mg/kg zearalenone production), and B73 × Mol7 (33 mg/kg zearalenone production) appear to have less resistance than the inbreds to toxin formation. Inbred H95 (64 mg/kg zearalenone production) supported the highest toxin production of all inbreds. The remaining 13 inbreds did not exceed 15 mg/kg zearalenone production. The inbreds A632 (4 mg/kg zearalenone production) and Pa762 (2 mg/kg zearalenone production) demonstrated some resistance; the resulting cross, hybrid Pa762 × A632 (50 mg/kg zearalenone production), does have greater resistance than hybrid H95 × Mol7 (132 mg/kg zearalenone production). Analysis of variance indicated highly significant variation between corn varieties and fungal isolates. The coefficient of variation for 29 fermentations run in duplicate on inoculated control corn to produce zearalenone (212 mg/kg) was 37%, which would include variation in both the fermentation and analysis. Isolate and variety interaction is not significant.
GasChromatographic-Mass Spectrometric Analysis, Identification, and Detection of Adulteration of Perfumery Products from Bitter Orange Trees
Authors: Prager Manfred J , Miskiewicz Michael A 
Published: February 2020

Abstract
A gas chromatographic procedure was developed for identifying and detecting adulteration of several perfumery products from the bitter orange tree. Components present to the extent of about 1% or more were determined quantitatively in reference and commercial samples of petitgrain oil, petitgrain absolute from water, neroli oil, orange flower absolute from water, and orange flower absolute. About 20 major components were common to these materials. These compounds were identified by mass spectrometric analysis following chromatographic separation and included β-pinene, limonene, γ-terpinene, linalool oxide, linalool, linalylacetate, α-terpineol, neryl acetate, geranyl acetate, nerol, geraniol, phenethyl alcohol, benzyl cyanide, nerolidol, methyl anthranilate, farnesol, and indole.
Application of Azulene as Visual Aid to Monitor Column Chromatographic Fractionation of Samples for Pesticide and Polychlorinated Biphenyl Determination
Authors: Nowicki Henry G 
Published: February 2020

Abstract
Environmental samples are cleaned up by Florisil column chromatography, using azulene as a visual aid to monitor column performance. Azulene migrates as a blue band in the 6% ethyl ether-hexane fraction, and the gas chromatograph electron capture detector (GC-ECD) is nonresponsive at the use concentration. This method complements the standardization of Florisil columns by weight adjustment based on adsorption of lauric acid. Spiking of sample with azulene provides a convenient real-time monitor for column channeling, mistakes in polarity of mobile phases, particular sample composition, column overloading, and dynamic changes in the adsorptivity of the stationary phase between lauric acid calibration and use. Using this visual aid, the analyst is alerted to unexpected column behaviors. Normally, polychlorinated biphenyls (PCBs) elute in the 6% fraction, in front of the blue indicator. Experiences with azulene and industrial effluent samples demonstrated that PCBs can elute in the 100% hexane fraction. GC-ECD analysis of the hexane eluate revealed a PCB characteristic chromatogram, not observed with the original extract. Thus, monitoring column performance avoided reporting a false negative result, i.e., no PCBs in the 6% ethyl ether-hexane fraction.
High Pressure Liquid Chromatographic Determination of Cholesterol in Foods
Authors: Newkirk David R , Sheppard Alan J 
Published: February 2020

Abstract
A high pressure liquid chromatographic method that uses the benzoate ester of cholesterol has been developed for the measurement of cholesterol in foods. A 300 × 3.9 mm id μBondapak C18 column and a variable wavelength ultraviolet detector are used with a 100% methanol mobile phase. Amounts as low as 10 ng cholesterol benzoate can be detected. The results from the analyses of a variety of foods are given and compared with results from gas-liquid chromatographic analyses. The comparison of the 2 chromatographic techniques is favorable.