bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thin Layer Chromatography Reflectometric Determination of Benzoic and Sorbic Acids in Fruit Beverages
Authors: Mandrou Bernadette , Bressolle Francoise 
Published: February 2020

Abstract
A procedure is proposed for the quantitative determination of both benzoic and sorbic acids in fruit beverages. This method is carried out by direct ultraviolet spectrophotometric measurements in silica chromatoplates after development with chloroform-methanol-water (65+35+7) and makes use of an internal standard. Applied to samples spiked with benzoic and sorbic acids, this technique gives accurate and reliable results with good recoveries. The sensitivity (about 1 ppm) is particularly convenient for trace level determination.
Application of Sparging to the Automated Ion Selective Electrode Determination of Kjeldahl Nitrogen
Authors: Roy Ram B , Jansen John , Sahn Michael 
Published: February 2020

Abstract
An automated method has been developed for the determination of total Kjeldahl nitrogen. Sample digests are mixed with a NaOH solution and allowed to make contact with air flowing at 1000 mL/min. The mixture enters the inlet of a heating bath maintained at 75°C. On exit, ammonia gas separates from a sparging vessel and is trapped as ammonium sulfate in a dilute H2SO4 solution. An aliquot of the acid solution is resampled and made alkaline to generate ammonia, which is measured by an ammonia sensing probe. A comparison of this procedure with AOAC method 7.025 shows that the procedure is accurate and that there is no statistically significant difference between them. This procedure introduces a new approach to eliminate the interfering species present in sample digests after Kjeldahl digestion for automated ion selective electrode measurements of ammonia. Thirty samples/h can be analyzed by this method.
Study of Vacuum Oven Drying in Official Method for Moisture in Eggs and Egg Products
Authors: Taber Lawrence E 
Published: February 2020

Abstract
Discrepancies occur when moisture or solids determinations on eggs and egg products are done by the vacuum oven method as opposed to the atmospheric oven method. The vacuum oven method requires a temperature of 100°C to a point of constant weight (about 5 h) at 25 mm of Hg. When compared with the same samples dried to constant weight in an atmospheric oven at 100°C the vacuum dried product will show a 10 to 50% greater loss of weight depending on carbohydrate content. The difference in the product color from the 2 drying methods indicates a carbohydrate reaction in the vacuum dried product.
Extent of Microencapsulation in Pesticide Formulations of Diazinon, Methyl Parathion, and Ethyl Parathion
Authors: Argauer Robert J 
Published: February 2020

Abstract
A method is described that compares the amount of encapsulated pesticide and the amount of free pesticide as a percentage of the total pesticide content of a formulation. Formulations that contained pesticides encapsulated in a nylon-type polymer skin were more than 99% encapsulated. The method can be extended further to measure the amount of nonencapsulated pesticide (e.g., emulsifiable concentrates) in mixtures with encapsulated pesticides. The formulations studied were Knox-Out (encapsulated diazinon), Penncap-M (encapsulated methyl parathion), and Penncap-E (encapsulated parathion).
International Mycotoxin Check Sample Program. Part I. Report on the Performance of Participating Laboratories
Authors: Friesen Marlin D , Walker Ernest A , Castegnaro Marcel 
Published: February 2020

Abstract
Three aflatoxin-contaminated samples, raw peanut meal, finished peanut butter, and white corn meal, were analyzed by 139 laboratories in 34 countries. Sufficient data were obtained to permit a statistical comparison of the performance of laboratories using the BF, CB, and Pons methods and those using high performance liquid chromatography for quantification. A raw peanut meal sample showed no significant differences among means for laboratories using the four methods, and a white corn meal sample showed only one such significant difference; however, a finished peanut butter sample containing less than 10 μg total aflatoxins/kg showed 10 significant differences among means for laboratories using the 4 methods considered
Optimization of Chromatographic Conditions for the Separation of p,p´-DDE from Aroclor 1254 on Silica, Using Azulene as Indicator
Authors: Griffin Donald A , Marin Anna B , Deinzer Max L 
Published: February 2020

Abstract
Aroclor 1254 is separated from p,p´-DDE on a fully activated silica gel column with the aid of azulene as a visual marker. The azulene is useful in determining the best cutpoint for separating these compounds and has been valuable in characterizing the effects of several parameters of the separation system, such as the aromatic content of the eluting solvent, adsorbent activity, and lipid and pesticide load capacity. Several brands of silica are compared for their ability to separate these compounds.
Sample Preparation of Carbadox, Furazolidone, Nitrofurazone, and Ethopabate in Medicated Feeds for High Pressure Liquid Chromatography
Authors: Thorpe Virginia A 
Published: February 2020

Abstract
Medicated feeds (pelleted or mash) containing guarantees of carbadox, furazolidone, nitrofurazone, and ethopabate are pretreated with water, extracted with 95% dimethylformamide overnight at room temperature, cleaned up on a column of alumina, and injected into a high pressure liquid chromatograph for quantitative measurement. Carbadox, nitrofurazone, and furazolidone can be separated; chromatograms show excellent baseline resolution, and results are in good agreement with colorimetric methods. The same extraction and cleanup can be used to improve colorimetric methods for furazolidone and nitrofurazone.
Evaluation of Bacterial and Fungal Growth Media for Ability to Neutralize Cosmetic Preservatives
Authors: Littell Allan M , Palmieri Michael J , Bisciello Neil B 
Published: February 2020

Abstract
Standard methods agar (SMA) and letheen agar (essentially SMA plus lecithin and Tween 80) were compared for bacterial growth and ability to neutralize cosmetic preservatives. Potato dextrose and malt extract agars (each prepared with and without lecithin and Tween 80) were compared with letheen agar and SMA in similar studies with fungi. Twelve bacterial strains, representing 8 species, and 2 fungal species were used as inocula. Plate counts of bacterial cultures (no preservatives present) ranged from 0 to 50% higher on letheen agar than on SMA except for 3 strains of Staphylococcus, which were 8-29% lower. Fungal counts were about the same on all media. Cosmetics (10 g) representing 4 preservative systems (hexachlorophene, benzoin, formaldehyde, and parabens) were inoculated with diluted cultures. Counts at 10−1 and 10−2 dilutions were typically 10-200% higher on letheen agar; however, in one case (benzoin, S. aureus, 10−1) the count was 400 on SMA vs 20 000 on letheen agar. Although differences in fungal counts were not as great, letheen agar partially neutralized the preservatives’ action. Results show that product dilution does not sufficiently reduce the effects of preservative carryover and neutralizers should be incorporated into plating media for this purpose.
Improved Method for Gas-Liquid Chromatographic Determination of Clopidol in Chicken Tissues
Authors: Suzuki Etsuko , Matsuda Mihoko , Momose Atsushi , Namekata Masaya 
Published: February 2020

Abstract
A sensitive and specific gas-liquid chromatographic (GLC) method has been developed for determining low levels of clopidol in chicken tissues. Clopidol is extracted from the tissues with methanol, and cleaned up on an alumina column and an anion exchange resin column with 0.1% acetic acid–methanol as eluate. Clopidol is methylated with diazomethane, and then determined by GLC. 2,4-Dinitro-l-chlorobenzene is used as an internal standard. The method is applicable to levels as low as 2 ppb in chicken tissues. Recoveries of 2–20 ppb clopidol added to tissues averaged 87% for muscle, 84% for liver, 80% for kidney, and 76% for fat.
Influence of Extraction Techniques on Determination of α-Tocopherol in Animal Feedstuffs
Authors: Mcmurray Cecil H , Blanchflower William J , Rice Desmond A 
Published: February 2020

Abstract
Methods were compared for α-tocopherol determination involving saponification in the preparation of feed extracts for high performance liquid chromatography. The effects of antioxidant and saponification times used were also examined. The data obtained showed that saponification before solvent extraction more efficiently released natural α-tocopherol from the feedstuffs than extraction before saponification. Increases in α-tocopherol content of 0–144% were obtained for the range of feedstuffs examined. Ascorbic acid and pyrogallol used as antioxidants gave similar results, and extraction efficiency was independent of the time of saponification within the range 5–40 min.
High Pressure Liquid Chromatographic Determination of Aflatoxins in Soy Sauce and Fermented Soybean Paste
Authors: Wei Ru-Dong , Chang Shenq-Chyi , Lee Shiuh-Sheng 
Published: February 2020

Abstract
A procedure for the quantitative determination of aflatoxins B1, B2, G1, and G2 in soy sauce and fermented soybean paste is proposed using high pressure liquid chromatography with ultraviolet detection after CB extraction and SEP-FAK and preparative thin layer chromatographic cleanups. Recoveries of 71.3 to 89.3% were obtained for soy sauce spiked with 1, 5, 20, and 100 ppb aflatoxins. Similar recoveries (77.0 to 90.8%) were obtained with concentrated soy sauce and fermented soybean paste spiked at 20 and 100 ppb. In comparison with other procedures, the proposed procedure is relatively fast and precise and gives good recoveries. Aflatoxins were not stable in soy sauce. During storage, half of aflatoxins B1, and G1, were deteriorated at 60 and 120 days, respectively.
Mycotoxins in Coffee
Authors: Levi Colette 
Published: February 2020

Abstract
This report reviews studies concerning the susceptibility of green coffee beans to mycotoxin contamination. Included are investigations on normal mold flora, toxin production in inoculated beans, effect of experimental roasting on aflatoxin, ochratoxin, and sterigmatocystin, and survey on the presence of these toxins in commercial green coffee. Because of the extremely low frequency of findings, the low levels of toxins, and the experimental data showing 70–80% destruction by the roasting process of toxin added to green coffee, further study on this topic has been discontinued.
High Performance Liquid Chroma tographic Analysis of Dicofol Acaricide
Authors: Rothman Alan M 
Published: February 2020

Abstract
Kelthane Technical, a dicofol acaricide marketed by Rohm and Haas Co., and 18 impurity components can be resolved by a new reverse phase high performance liquid chromatographic (HPLC) method using a methanol-water-acetic acid (75+25+0.2) mobile phase, a high resolution C8 column in series with a short Cl8 s guard column, and detection at 254 nm. Relative elution volumes: and relative sensitivities for all known Kelthane Technical components are reported. This HPLC method has few co-elution problems, can be performed on a basic HPLC system, avoids the thermal degradation of Kelthane experienced in the previously established gas-liquid chromatographic (GLC) procedures, and can detect all impurity components to at least 0.1% level.
Quickfit Florisil Pesticide Trap for Use with Assisted Distillation Technique
Authors: Mcdougall Kerryn W 
Published: February 2020

Abstract
A quickfit Florisil pesticide trap is described for use with the assisted distillation technique for the cleanup of pesticide residues in fats. Recoveries of 80–100% were obtained for 9 pesticides. No cooling is needed and there is no measurable carryover of fat from this Florisil trap.
Gas-Solid Chromatographic Determination of Oxygen in Various Pharmaceutical Products
Authors: Lyma Gary W , Johnson Raymond N , Kho Boen T 
Published: February 2020

Abstract
A method is described for the gas chromatographic determination of oxygen at the low part per million level in both aqueous systems and nonaqueous systems such as creams, oils, and waxes. This method offers advantages over other popular assay procedures such as the Winkler and polarographic methods. The purging technique developed can be applied to any liquid or solid with a melting point of 75μC or less. Oxygen purged from the sample is passed through a molecular sieve 5A column where it is separated from nitrogen. Peaks obtained are compared to similarly prepared oxygen standards. The method is simple enough to be used routinely and up to 15 samples can be analyzed per day.
High Pressure Liquid Chromatographic Determination of β-Sitosterol and β-Sitosterol-D-Glucoside in Whisky
Authors: Byrne Kevin J , Reazin George H , Andreasen Arthur A 
Published: February 2020

Abstract
A high pressure liquid chromatographic method is presented for determining the oak wood steroids, β-sitosterol and β-sitosterol-D-glucoside, which contribute to floe formation in whisky. The steroids are extracted from whisky by using an adsorbent resin, Amberlite XAD-2, and are detected at 210 nm, orarederivatized to 2,5-dinitrobenzoate esters which are detectable over a wide ultraviolet wavelength range. Detection limits were less than 0.1 ppm for β-sitosterol and less than 0.2 ppm for β-sitosterol-D-glucoside in most whiskies, using the extraction procedure described. When the steroids were derivatized, the detection limits were decreased by about a factor of 10.
Comparison of Radioimmunoassay and Enzyme-linked Immunosorbent Assay for Determining Aflatoxin M1 in Milk
Authors: Pestka James J , Li Yaguan , Harder William O , Chu Fun S 
Published: February 2020

Abstract
Using a highly specific antibody against aflatoxin Mi, a radioimmunoassay (RIA) and an enzyme-linked immunosorbent assay (ELISA) were developed for the quantitation of Mi in milk. RIA was sensitive in the range of 5-50 ng per assay but was subject to interference by whole milk. Extraction and cleanup were therefore necessary for the detection of M1 in milk at 0.5 ng/mL. An ELISA procedure was developed by using an aflatoxin M1-carboxymethyl-horseradish peroxidase conjugate as the ligand. Competitive assays revealed that this system was relatively more sensitive for M1 than for B1, and had a much lower degree of cross-reactivity for aflatoxins B2, G1, G2, B2a, and aflatoxicol. As low as 0.25 ng M1/mL in artificially contaminated milk (raw, whole, skim) could be detected by ELISA in 3 h without extraction or cleanup. Because of its simplicity, sensitivity, and specificity, ELISA is the preferred method for monitoring aflatoxin M1 in milk.
High Pressure Liquid Chromatographic Method for Determination of Polynuclear Aromatic Hydrocarbons in Beer
Authors: Joe Frank L , Roseboro Emma L , Fazio Thomas 
Published: February 2020

Abstract
A high pressure liquid chromatographic (HPLC) method has been developed for the determination of some polynuclear aromatic hydrocarbons (PAHs) in beer. The PAHs are extracted into isooctane from a beer sample to which sodium hydroxide, ethanol, and acetone have been added. The isooctane extract is washed with acid and then base, and is purified by chromatography through deactivated neutral alumina. The eluate from the column is concentrated to dryness and the resulting residue is dissolved in methanol-acetonitrile (1 + 1) and subjected to reverse phase HPLC analysis. Both ultraviolet (UV) and fluorescence detectors are used to monitor the HPLC column effluent. Recovery of 4 PAHs, benz(a)anthracene, benzo(a)pyrene, benzo(g,h,i)perylene, and dibenzo(a,i)pyrene, ranged from 77 to 108% by UV measurement and 73 to 97% by fluorescence measurement.
Near-Infrared Reflectance Determination of Fat, Protein, and Moisture in Fresh Meat
Authors: Kruggel William G , Field Ray A , Riley Melvin L , Radloff Harold D , Horton Kristiina M 
Published: February 2020

Abstract
Near-infrared spectral absorption properties were determined for emulsified and ground meat samples. Six corrected log numbers associated with the optical responses of 6 filters in the InfraAlyzer were used as multiple independent variables in regression equations. Dependent variables for the equations were moisture, determined by oven-drying; fat, determined by Goldfisch extraction; and protein, determined by the Kjeldahl method. InfraAlyzer log values, replicated 4 times on each emulsified beef sample and 3 times on each ground lamb sample, increased as the samples were warmed from the heat generated in the sample drawer. Variation in temperature of the meat samples was partially responsible for differences in constant terms and in regression coefficients for equations developed on data from different replications of a sample. Multiple correlation coefficients for fat ranged from 0.91 to 0.94 in emulsified meat and from 0.83 to 0.85 in ground meat; for moisture, 0.90-0.94 and 0.83-0.85, respectively; and for protein, 0.80-0.85 and 0.72-0.77, respectively. Overall, near-infrared reflectance shows promise as a rapid method for determining composition of meat. Nevertheless, some aspects of near-infrared reflectance require further attention.
High Pressure Liquid Chromatographic Determination of Aldicarb, Aldicarb Sulfoxide, and Aldicarb Sulfone in Potatoes
Authors: Cochrane William P , Lanouette Monique 
Published: February 2020

Abstract
An ion-suppression reverse phase high pressure liquid chromatographic method is described for the determination of aldicarb, aldicarb sulfoxide, and aldicarb sulf one in potatoes. Samples are extracted with methylene chloride and Na2SO4, evaporated to dryness, and cleaned up using Sep-Pak silica and Sep-Pak-C18 cartridges. The extract can be successfully analyzed by high pressure liquid chromatography on either a μLiChrosorb RP-18 or μBondapak C18 column and quantitated using a variable wavelength ultraviolet detector set at either 220 or 247 nm. The mobile phase is acetonitrile-buffer (4 + 96) and (30 + 70), buffered to pH 7.6 and flowing at 2 mL/min. Recoveries ranged from 80 to 100%. The minimum detectable amount was 37.5 ng, which easily permitted the quantitation of 0.1 ppm aldicarb sulfone in 75 g sample. The recovery of aldicarb was low because of its rapid enzymatic oxidation to aldicarb sulfoxide and sulfone.
Paper and Micro Thin Layer Chromatographic Methods for Determination of Mercuric Chloride and Detection of Copper Sulfate
Authors: Nanda Kumar Nanguneri V , Devi Yalavarthi Prameela 
Published: February 2020

Abstract
A new simple, sensitive, and rapid method is described for the qualitative and quantitative determination of mercuric chloride by paper chromatographic-enzymatic and micro thin layer chromatographic-enzymatic methods. Mercuric chloride is detected by succinate dehydrogenase inhibition using 2-(4-iodophenyl)-3-(4-nitrophenyl) 5-phenyltetrazolium chloride and N-methylphenazonium methosulfate as the chromogenic reagent. From 0.5 to 5μg mercuric chloride may be estimated, and 50 ng may be detected. The method can be used for the quantitative determination of mercuric chloride in fresh and sea water without cleanup and for the detection of copper sulfate.
General Method for Determination of Pesticide Residues in Samples of Plant Origin, Soil, and Water. II. Thin Layer Chromatographic Determination
Authors: Ambrus Árpád , Hargitai Éva , Károly Gabriella , Ambrus András Fülöp , Ambrus János Lantos 
Published: February 2020

Abstract
o-Tolidine plus KI, p-nitrobenzene-diazoniumfluoroborate, bioassay with fungi and enzyme sources, AgNO3 plus UV radiation, and p-dimethyl-aminobenzaldehyde modes of detection have been selected for TLC screening of pesticide residues in extracts of samples of unknown origin. Single solvents were used for the elution. Coefficients of variation of Rf values were studied as a function of Rf and eluants. Indicator compounds were used for controlling the proper conditions of detection. The detectability of 188 pesticide compounds was tested, and the minimum detectable amounts were determined.
Brine Saturation Technique for Extraction of Light Filth from Rubbed and Ground Sage: Intralaboratory Study
Authors: Freeman Clarence C 
Published: February 2020

Abstract
An intralaboratory study was made of a new and widely applicable technique for isolating light filth from rubbed and ground sage. The technique eliminated the hazardous, costly, and lengthy pretreatment and isolation procedures of the current methodology and resulted in considerably better recoveries. Overall recovery of all filth elements introduced as spikes was 99.3% on the first trapping. The basic principle of the procedure is product saturation with brine, followed by trapping of the filth elements from tap water with olive oil.
High Pressure Liquid Chromatographic Determination of Methyl and Propyl p-Hydroxybenzoates in Comminuted Meats
Authors: Perfetti Gracia A , Warner Charles R , Fazio Thomas 
Published: February 2020

Abstract
A method was developed for determining methyl and propyl p-hydroxybenzoates (methyl and propyl parabens) in comminuted meats. The parabens were extracted from the meat sample with acetonitrile. After filtering, the extract was analyzed by reverse phase high pressure liquid chromatography, using a 254 nm absorbance detector. Samples of bologna, chicken roll, and chopped ham were fortified with approximately 100,200, and 400 ppm of each paraben. Average recoveries were 92% for methyl paraben and 94% for propyl paraben.
Separation and Characterization of Standard Propoxyphene Diastereomers and Their Determination in Pharmaceutical and Illicit Preparations
Authors: Soni Shiv K , Gelder Daniel Van 
Published: February 2020

Abstract
Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.
Evaluation of Laboratory Performance with Aflatoxin Methods by Means of the AOCS Smalley Check Sample Program
Authors: Mckinney John D 
Published: February 2020

Abstract
The American Oil Chemists’ Society Smalley Check Sample Program offers ongoing check sample series for determination of aflatoxins in peanut meal, cottonseed meal, and corn meal. Laboratories participating in this program represent a worldwide cross section of industry, regulatory, and commercial laboratories. Each annual series presently consists of 7 samples including a solution of an unknown mixture of aflatoxins B1, B2, G1, and G2 for direct spotting and quantitation. Participant analyses of the solution of aflatoxins resulted in coefficients of variation generally higher than those of any sample. Comparison of 4 years of results for analysts using BF and CB methods of analysis for peanut meal samples with aflatoxin B1 levels ranging from 2 to 56 ng/g resulted in higher aflatoxin B1 results for the CB method. The number of participants reporting results by HPLC methods is small; however, their results compare closely with those using TLC methods.