bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Aflatoxins in Peanut Butter, Using Two Liquid Chromatographic Methods: Collaborative Study
Authors: Campbell Alfred D , Francis Octave J , Beebe Roberta A , Stoloff Leonard ,   Collaborators:, Brown S , Cantafora A , Chang H L , Chin K S , Crosby N T , DeVries J W , Doeden W G , Duhart B T , Elliot L , Gorman L A , Gregory J F , Kronert W , Nesheim S , Routh J , Smiechowski R , Trantham A L , Webb N , Wilson D M 
Published: February 2020

Abstract
Two methods for determining aflatoxins in peanut butter, one using normal phase and the other reverse phase liquid chromatography (LC), were studied by 8 and 10 collaborators, respectively. Fluorescence detection was used for the determinative step in both methods. For reverse phase LC, aflatoxins B1 and G1 were converted to B2a and G2a; for normal phase LC, a silica gel-packed flow cell was placed in the irradiating light path of the detector. The samples included spiked and naturally contaminated peanut butter with total aflatoxin levels from about 5 to 20 ng/g and controls in a balanced pair design. For the normal phase LC method, recoveries of B1, B2, G1, and G2 from spiked samples averaged 79, 92, 74, and 88%, respectively; for the reverse phase method, the recoveries were 103, 104, 89, and 163%. For the normal phase LC method, pooled repeatabilities were 20, 23, 28, and 17% for B1, B2, G1, and G2, respectively; for the reverse phase method, the repeatabilities were 19, 22, 38, and 31%. For the normal phase method, pooled reproducibilities were 34, 33, 39, and 34% for B1, B2, G1, and G2, respectively; for the reverse phase method, the reproducibilities were 32, 46, 51, and 52%. Both methods show an improved limit of detection and better within-laboratory precision over current AOAC methods; however, between-laboratory precision is no better, and the reverse phase method shows evidence of interferences being measured. For these reasons and because of no benefits of present value, neither method was submitted for adoption as official first action.
Determination of Aflatoxicol and Aflatoxins B1 and M1 in Eggs
Authors: Trucksess Mary W , Stoloff Leonard 
Published: February 2020

Abstract
Procedures from 2 methods, one for aflatoxins B1 and M1 in eggs and one for aflatoxicol in milk, blood, and liver, have been combined to determine the 3 toxins in eggs. The sample is blended with sodium chloride-saturated water and this mixture is then blended with acetone. After separation from the solid residue, the aqueous acetone extract is defatted with petroleum ether. The toxins are next partitioned into chloroform and separated from interferences on a silica gel column. Aflatoxicol is determined by fluorescence measurement after separation on a C18 reverse phase liquid chromatographic column, and aflatoxins B1 and M1 are determined by fluorescence densitometry after separation on a silica gel thin layer chromatographic plate. In a recovery study with eggs, mean recoveries of aflatoxicol added at levels of 0.1, 0.05, and 0.025 ng/g were 87, 77, and 78%, respectively. Mean recoveries of aflatoxins B1 and M1 added at a level of 0.1 ng/g were 75 and 87%, respectively, and at an added level of 0.05 ng/g were 86 and 75%. The within-laboratory precision (repeatability) ranged from 2 to 13%.
Residues of Organochlorine Insecticides, Polychlorinated Biphenyls, and Heavy Metals in Biota from Apalachicola River, Florida, 1978
Authors: Winger Parley V , Sieckman Carol , May Thomas W , Johnson W Waynon 
Published: February 2020

Abstract
Seventy-seven composite samples composed of largemouth bass (Micropterus salmoides), channel catfish (Ictaluras punctatus), threadfin shad (Dorosoma petenense), Asiatic clam (Corbicula fluminea), burrowing mayfly (Hexagenia sp.), water snake (Natrix spp.), and little green heron (Butorides virescens) were collected from upper and lower reaches of the Apalachicola River, Florida, in 1978 for residue analysis of organochlorine insecticides, PCBs (polychlorinated biphenyls), and metals. Compared with data from the National Pesticide Monitoring Program and criteria recommended for the protection of aquatic life, residue concentrations were moderately high in the Apalachicola River. Biota from the upper river generally had higher organic and lower metal residues than those from the lower river. Highest residues in the biota were total DDT, total PCBs, and toxaphene. Although individual mean concentrations were below 2 μg/g and total organic contaminant residues never exceeded 5 μg/g, residue concentrations of DDT, PCBs, and toxaphene (particularly from the upper river) exceeded recommended permissible levels for the protection of aquatic life. Metal residues were generally below 1 μg/g. Exceptions were arsenic residues in threadfin shad (1.07 μg/g) and Asiatic clams (1.75 μg/g), and selenium in eggs of channel catfish (1.39 μg/g). The residues observed in the biota, particularly from the upper station, indicated moderate contamination of the Apalachicola River system at the time samples were collected.
ISO Working Group Studies on Filtration Problems in Crude Fiber Determinations
Authors: Holst David O ,   Members:, Crosby N T , Dordio A M , Harland B F , Hollman P , Kadijk F , Lutonska P , Martillott D F , Meer J M v d , Mudgal V D , Olah I , Pichl I , Rayner S E 
Published: February 2020

Abstract
A working group of individuals from International Organization for Standardization member nations studied the use of ceramic fiber to replace asbestos as a filter aid in crude fiber determinations in 8 samples: rolled oats, 48% solvent-extracted soybean meal, alfalfa meal, degermed corn meal, an all-bran cereal, hard red winter wheat, brussels sprouts, and soy fiber. Results obtained using ceramic fiber were accurate and precise, except for one laboratory which reported very high values. Results on 4 of these samples were compared with results obtained on the same 4 samples in an earlier collaborative study. There was good correlation between the studies. In addition, 2 laboratories reported data obtained using sea sand as filter aid, and 2 laboratories analyzed samples using no Alter aid.
Evolution of Analytical Methods for Fertilizers Through the AOAC Process
Authors: Johnson Frank J 
Published: February 2020

Abstract
A historical and scientific account is given of the evolution of chemical methods of analysis for fertilizers, as recorded in the annals of AOAC. Meetings that preceded the formation of AOAC are recalled with evidence of their domination by fertilizer chemists. The development, study, and adoption procedures of AOAC pertaining to primary, secondary, and micro plant nutrients are reported in chronological order. Only those changes in methods of analysis that had significant impact on future developments are noted. No attempt is made to present an exhaustive review of all AOAC analytical methods for fertilizer.
Liquid Chromatographic Determination of Chlorinated Phenol Impurities in Technical Pentachlorophenol Using Electrochemical Detection (Coulometric Mode)
Authors: Lanouette Monique , Cochrane William P , Singh Jojinder 
Published: February 2020

Abstract
Fourteen technical pentachlorophenol and 3 sodium pentachlorophenate samples were obtained from several manufacturers and analyzed for the presence of various chlorinated phenolic impurities. Reverse phase liquid chromatography with an electrochemical (coulometric mode) detector was used for qualitative and quantitative determinations. Nineteen chlorinated phenols were separated using a 50–70% methanol and 50–30% 0.02M KH2P04 (pH 4.0) 35 min gradient system on a Spheri-5 RP-18 column. 2,4-Dichlorophenol (average 0.07%); 3,5-dichlorophenol, 2,3,4-trichlorophenol, 2,4,6-trichlorophenol, 3,4,5-trichlorophenol (each &lt;0.03%); 2,3,5,6-tetrachlorophenol (average 0.009%); 2,3,4,6-tetrachlorophenol (average 4.47%); 2,3,4,5-tetrachlorophenol (&lt;0.025%) were detected as contaminants in the various samples. The minimum detectable amount ranged from 0.1 to 10 ng, depending on the chlorophenol.
Liquid Chromatographic Determination of Propoxur in Technical and Formulated Products: Collaborative Study
Authors: Slahck Stephen C ,   Collaborators:, Audino J B , Bennett O O , Folsom B D , Guenther P , Hodgins E , Jaworski J J , McDermott W H , Minyard J P , Noel R J , Polli R L , Teubert W E , Weisskopf C P 
Published: February 2020

Abstract
A liquid chromatographic method for the determination of propoxur in technical and formulated products has been subjected to a collaborative study with 8 participating collaborators. Formulations are extracted with acetonitrile and analyzed by reverse phase chromatography, with n-butyrophenone as an internal standard. Collaborators were furnished with samples of technical, 70% wettable powder, 1.5 emulsifiable, and 2% bait. Coefficient of variation values obtained on the 4 samples were 0.34, 0.68, 3.25, and 5.41%, respectively. The method has been adopted official first action.
Liquid Chromatographic Determination of Strychnine as Poison in Domestic Animals
Authors: Hunter R Tracy , Creekmur Robert E 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described, using a preliminary thin layer chromatographic (TLC) screen followed by LC quantitation of strychnine in biological specimens of domestic animals. The TLC solvent system is also used as the LC mobile phase. Samples are extracted using acidic acetone, followed by evaporation of the acetone. The aqueous residue is extracted with ethyl ether, made basic with ammonium carbonate, and back-extracted into methylene chloride before TLC-LC analysis. The method has been successfully applied to liver, kidney, and urine specimens, as well as stomach contents. Six replicates each of a 0.75 and 7.5 ppm strychnine standard were taken through the method; recoveries ranged from 94 to 104%. Six replicates of a naturally incurred canine liver sample had a mean value of 3.9 ppm strychnine, with a standard deviation of 0.138 and a coefficient of variation of 3.58 %.
Rapid Thin Layer Chromatographic Method for Determination of Zearalenone and Zearalenol in Grains and Animal Feeds
Authors: Swanson Steven P , Corley Richard A , White Donald G , Buck William B 
Published: February 2020

Abstract
A rapid and inexpensive method has been developed for the analysis of zearalenone and zearalenol in grains and animal feeds. The method involves extraction with 75% methanol, precipitation of pigments with lead acetate, and defatting with petroleum ether. The mycotoxins are subsequently partitioned into toluene–ethyl acetate, chromatographed on high performance thin layer chromatographic plates, and detected after treatment with Fast Violet B salt solution. Sensitivity of the method is better than 80 ng/g for zearalenone and 200 ng/g for zearalenol. Ten samples can be completed in less than 2 h. The method is applicable for zearalenone in corn, wheat, barley, millet, and swine feeds.
Evaluation of Cryogenic Impact Grinding Technique for Powdering Whole Fish for Metal Determinations
Authors: May Thomas W , Kaiser Millie L 
Published: February 2020

Abstract
A cryogenic grinding technique, which involves brittle fracture of samples by impact pressure, was evaluated for the final reduction of whole-fish samples for subsequent metal determinations. The technique incorporated a number of desirable features: protection of heat-labile components; incorporation of lyophilization to facilitate handling and storage; requirement of few procedural steps; short grinding time per sample; and easy, rapid cleanup of equipment. Particle size in the ground powder was &lt;100 μm. Problems associated with the technique were contamination of fish samples with Cr, Fe, Mo, and Ni; limited size of the grinding container; and powder clumping caused by the presence of lipids. Approaches to alleviate these problems are discussed.
Improved Liquid Chromatographic Method for Determination of Aflatoxins in Peanut Butter and Other Commodities
Authors: Tarter Edward J , Hanchay Jean-Pierre , Scott Peter M 
Published: February 2020

Abstract
A combination of the extraction and cleanup procedures of Pons and Franz with the liquid chromatographic (LC) derivatization technique of Beebe is proposed as an accurate, precise, and sensitive method for determination of aflatoxins B,, B2, G,, and G2 in various foodstuffs. Mean recoveries of total aflatoxins added in the range 15–34 ng/g to peanut butter were 86–94% in 2 laboratories. Recovery of total aflatoxins (30 ng/g) from shelled peanuts, shelled Brazil nuts, pistachios, cashews, walnuts, and filberts exceeded 86% and from pumpkin seeds was 80%. Coefficients of variation for total aflatoxins were less than 7% for spiked samples and 15% for peanuts naturally contaminated with 16.7 ng/g of total aflatoxin (B1 + B2). Analyses of peanut meal, yellow corn meal, and peanut butter check samples (AOCS Smalley Series 1980/81 and 1981/82, IARC Series 1982/83) by this method compared favorably with reported averages. The detection limit is about 0.3 ng/g for each aflatoxin.
Automated Determination of α-Tocopherol in Food and Feed. Part 2. Continuous Flow Technique
Authors: Bourgeois Claude F , George Philippe R , Cronenberger Lucien A 
Published: February 2020

Abstract
The proposed determination of α-tocopherol is a continuous flow method with fluorometric detection. The only cleanup necessary is the usual saponification. A solution of the unsaponifiable matter in isooctane is automatically assayed. Isooctane is the carrier solvent and extractions are inserted between steps. These steps are selective reactions which render the method very specific. The natural homologs of α-tocopherol (α-T) do not interfere in the determination. A procedure for blank assays allows selective inhibition of α-T conversions and measurement of interfering fluorescence. The method is highly sensitive, which allows the determination of α-T in very dilute solutions. This in turn suppresses matrix effects and renders the results reliable. The time interval between 2 peaks is 6 min, washing included, and it is possible to carry out 50 determinations per day (sample preparation not included). The system is robust and maintenance is easy. Parallel determinations of foods and feeds have been carried out with a conventional thin layer chromatographic method.
Liquid Chromatographic Determination of Prednisolone in Tablets and Bulk Drugs: Interlaboratory Study
Authors: Brower James F 
Published: February 2020

Abstract
A normal phase liquid chromatographic (LC) method for the determination of prednisolone in tablets and bulk drugs was studied by 7 analysts. An LC system, consisting of a methanol-water-ethylene dichloride- acetic acid mobile phase and a silica column, was used to analyze bulk drugs, individual tablets, and composite samples. Analysts were supplied with 16 samples, including simulated formulations, composites of commercial tablets, intact tablets, and bulk drug substances. Results agreed with those obtained by the author. The coefficients of variation of the analysts' results ranged from 1.34% for bulk drugs to 2.14% for tablet composites. The LC method is suggested as an alternative to the official AOAC and USP XX blue tetrazolium colorimetric methods.
Liquid Chromatographic Determination of Sodium Salinomycin in Feeds, with Post-Column Reaction
Authors: Goras John T , Lacourse William R 
Published: February 2020

Abstract
A method for the detection and quantitation of sodium salinomycin in feeds by a liquid chromatographic, post-column reaction system is presented. Sodium salinomycin is leached from feed with hexane, isolated as a dried residue, and dissolved in mobile phase for analysis. The drug is separated from interfering substances on a silica LC column, combined with vanillin reagent in a mixing tee, reacted with vanillin at elevated temperature in a coil, and detected in the effluent stream at 527 nm. Response, as peak area, is linear with concentration. Feed components, other common veterinary drugs, and closely related compounds do not interfere. Average recovery and coefficient of variation (CV) values for liquid spiked feeds and supplements were 101 ± 3.5% and 100 ± 0.3%, respectively. Results for laboratory blends and commercial scale feeds were within 6% of intent with CV values ranging from 0.4 to 5.1%.
Confirmation of N-Nitrosodimethylamine and N-Nitrosopyrrolidine in Foods By Conversion to their Nitramines with Pentafluoroperoxybenzoic Acid
Authors: Kimoto Walter I , Silbert Leonard S , Fiddler Walter 
Published: February 2020

Abstract
Amethod is presented, wherein concentrated dichloromethane extracts from malt, beer, and nonfat dried milk powder containing N-nitrosodimethylamine (NDMA), and fried dry-cured and pump-cured bacon containing NDMA and iV-nitrosopyrrolidine (NPYR) undergo 3N HC104- Celite microcolumn cleanup followed by peroxidation with pentafluoroperoxybenzoic acid, a stable solid peroxyacid, to N-nitrodimethylamine and N-nitropyrroIidine, as an aid to nitrosamine confirmation. The nitramine-containing solution underwent further cleanup with 6N HC104-Celite and acid alumina-6 % H2O microcolumns for subsequent analysis by gas chromatography interfaced with thermal energy analyzer and 63Ni electron capture detectors. With a 20 g sample, 1 ppb NDMA and 2.5 ppb NPYR could be confirmed by this method. The extract can be concentrated further before analysis, so the detection level can be reduced to &lt;1 ppb NDMA and 1 ppb NPYR.
Headspace Gas Chromatographic Determination of Methylene Chloride in Decaffeinated Tea and Coffee, with Electrolytic Conductivity Detection
Authors: Page B Denis , Charbonneau Claudette F 
Published: February 2020

Abstract
A headspace gas chromatographic procedure is described for the determination of methylene chloride (MC) in decaffeinated tea and coffee. The tea or coffee sample, with added methylene bromide (MB) internal standard, is equilibrated for 1.5 h at 100°C in aqueous sodium sulfate before manual headspace sampling. MC and MB are separated on a Porasil A column at 160°C and detected by using a Coulson electrolytic conductivity detector. For coffee and tea samples spiked at 1.3 ppm MC, as well as commercially decaffeinated teas and coffees containing up to 8 ppm MC, coefficients of variation were 10% or less. For decaffeinated teas, problems involving sample homogeneity and loss of MC before sealing the headspace vial had to be overcome. Similar problems with decaffeinated instant and ground coffees were minimal. The headspace procedure was superior to a previously reported distillation technique. MC was readily detected at 0.05 ppm. Fourteen decaffeinated teas and 15 decaffeinated coffees were analyzed; MC was detected at levels that ranged up to 15.9 and 4.0 ppm, respectively.
Thin Layer Chromatographic Detection and Spectrophotometric Determination of the Trisodium Salt of 1,3,6-PyrenetrisuIfonic Acid in D&C Green No. 8
Authors: Richfield-Fratz Naomi 
Published: February 2020

Abstract
A thin layer chromatographic method is presented for separating the reaction by-product 1,3,6-pyrenetrisuIfonic acid (trisodium salt) (PTS) from D&C Green No. 8 (8-hydroxy-l,3,6-pyrenetrisulfonic acid). PTS is detected visually, extracted from the adsorbent, and determined spectrophotometrically. Recoveries of PTS added at 0.75-6.73% levels to 8-hydroxy-l,3,6-pyrenetrisuIfonic acid ranged from 80.0 to 94.8%.
Liquid Chromatographic Determination of Nitrogen Derived from Urea and Water-Soluble Methylene Ureas in Urea Formaldehyde Fertilizers: Collaborative Study II
Authors: Davidson Allan D ,   Collaborators:, Barry C , Carmany J , Grigor A F , Hastings R E , Hendricks T A , Morris H F , Thorpe V A 
Published: February 2020

Abstract
A second collaborative study with 6 collaborators was conducted on the AOAC official first action method for measuring nitrogen derived from urea, methylenediurea (MDU), and dimethylenetriurea (DMTU). No variations were made. The collaborators made single determinations on 2 separate days on 5 sets of paired samples. The mean coefficients of variation for the completed study were 4.22% for urea, 5.08% for MDU, and 5.48% for DMTU, which are only slightly higher than the values reported in the first study: urea, 3.24%; MDU, 3.48%; and DMTU, 6.56%. The method has been adopted official final action.
Gas Chromatographic Methods for Determination of γ-BHC in Technical Emulsifiable Concentrates and Water-Dispersible Powder Formulations and in Lindane Shampoo and Lotion: Collaborative Study
Authors: Miles James W , Mount Dwight L ,   Collaborators:, Beckmann T J , Carrigan S K , Galoux I M , Hitos P , Hodge M C , Kissler K , Martijn A , Sanchez-Rasero F , Weeren R D , Zi-Hou Z 
Published: February 2020

Abstract
Although the gas chromatographic separation of the isomers of BHC was demonstrated two decades ago, the present AOAC method of analysis of BHC for gamma-isomer (lindane) content is based on a separation carried out on a liquid chromatographic partition column. A method of analysis has been developed that uses an OV-210 column for separation of the gamma-isomer from the other isomers and impurities in technical BHC. Di-n-propyl phthalate was chosen as an internal standard. The same system allows quantitation of lindane in lotion and shampoo after these products are extracted with ethyl acetate-isooctane (1 + 4). The analytical methods were subjected to a collaborative trial with 10 laboratories. The coefficient of variation for technical BHC was 2.83%. For the water-dispersible powder and emulsifiable concentrate, the coefficients of variation were 2.89% and 4.62%, respectively. Coefficients of variation for 1% lindane lotion and shampoo were 4.36% and 11.92%, respectively. The method has been adopted official first action.
Liquid Chromatographic Assay of Ascorbic Acid, Niacinamide, Pyridoxine, Thiamine, and Riboflavin in Multivitamin-Mineral Preparations
Authors: Lam Fuk-Luen , Holcomb Ira J , Fusari Salvatore A 
Published: February 2020

Abstract
A simple and rapid method is presented for the liquid chromatographic assay of ascorbic acid, niacinamide, pyridoxine, thiamine, and riboflavin from a single chromatogram. Ion-pair chromatography with a reverse phase C18 cartridge in a radial compression system is used. Quantitation is excellent with a total analysis time of less than 20 min. A mobile phase of methanol-water (15 + 85) (0.005M heptanesulfonic acid) with 0.5% triethylamine at pH 3.6 and a flow rate of 2.0 mL/min gives the most satisfactory separation of the 5 water-soluble vitamins. By using 2 detectors in series set at different wavelengths and sensitivities, all 5 vitamins, with peak heights on scale, can be measured from a single injection; peak elution order is ascorbic acid, niacinamide, pyridoxine, thiamine, and riboflavin. Ascorbic acid is measured at 254 nm and the other vitamins, at 280 nm. The amount of amine modifier in the mobile phase is critical to the separation of niacinamide and pyridoxine. Recoveries of 5 water-soluble vitamins from spiked placebos were in the range of 98.2-102.0%. Confidence limits, ± 3 SD, were in the range of 1.0-5.4%. Overall, the results obtained using the liquid chromatographic method show excellent agreement with manual methods and automated analysis.
Liquid Chromatographic Determination of Zoalene in Medicated Feeds
Authors: Morawski John , Kyle Glenn 
Published: February 2020

Abstract
A rapid, reliable separation and quantitation of zoalene (3,5-dinitroo-toluamide) from feeds is accomplished by using reverse phase liquid chromatography (LC) and ultraviolet detection. An extraction technique which is similar to the present AOAC official colorimetric method is used before chromatographic analysis. This extraction is followed by an activated alumina cleanup and LC to separate zoalene from feed matrix. The methodology was applied to a variety of spiked feed matrices, and yielded good recoveries. Liquid chromatographic results were shown to correlate with colorimetric determinations.