bluuebunny/crossref_metadata_2025 huggingface dataset:
Automated High Performance Liquid Chromatographic Determination of Intermediates and Side Reaction Products in FD&C Red No. 3
Authors: Goldberg Allen L , Calvey Robert J
Published: February 2020

A rapid, sensitive, reproducible method that uses high performance liquid chromatography in the reverse phase mode is described for the determination of intermediates and side reaction products in FD&C Red No. 3. With this method, 2 intermediates, phthalic acid and resorcinol, and 2 side reaction products, 2-(2',4'-dihydroxybenzoyl)benzoic acid and 2-(2',4'-dihydroxy-3',5'-diiodobenzoyl)benzoic acid, are eluted in a reproducible pattern as a gradient increases the organic nature of the buffered mobile phase. Fhthalic acid and the 2 side reaction products are quantitated. The intermediate resorcinol is detected but not quantitated. Recoveries averaged 99.4-102.8% for phthalic acid and the 2 side reaction products added to samples of FD&C Red No. 3 at levels ranging from 0.02 to 0.22%.
Improved Radioimmunoassay of Staphylococcai Enterotoxin A
Authors: Dickie Nester , Mumtaz Akhtar Syed
Published: February 2020

A simple solid-phase radioimmunoassay was developed for detecting staphylococcai enterotoxin A (SEA) in food. The method detected 85-100% SEA added to extracts of 6 kinds of foods, and 52-100% SEA added directly to foods at a concentration of 1 ng/g. Assay sensitivity is about 0.3 ng toxin/mL extract. The method is specific for SEA; results are only marginally affected by staphylococcai enterotoxins B and C2 present at concentrations as high as 500 ng/mL extract
Differential Pulse Polarographic Determination of Total Iodine in Milk
Authors: Ralph Curtis A , Hamming Percy
Published: February 2020

A differential pulse polarographic method for total iodine in milk is presented. Samples are ashed, sodium hypochlorite is added to oxidize iodide to iodate, and the product is mixed with sodium sulfite solution and measured by differential pulse polarography at μ90 V against SCE. The standard deviation for 53 duplicate samples was 0.011. Average recovery for 10 or more samples at different levels was 98.6% with a standard deviation of 2.9%.
Reverse Phase High Pressure Liquid Chromatographic Determination of Arprinocid in Animal Feeds
Authors: Thorpe Virginia A
Published: February 2020

A simple method is presented for determination of arprinocid in finished feeds by reverse phase high pressure liquid chromatography. The sample is extracted with 95% DMF, the major feed interferences are removed by alumina chromatography, and arprinocid is separated from the remaining interferences on the HPLC column. The peak height detected at 254 nm can be quantitated by direct comparison with the working standard.
Radioimmunoassay for Hygromycin B in Feeds
Authors: Foglesong Mark A , Lefeber Debra S
Published: February 2020

A radioimmunoassay developed for the determination of hygromycin B in feed gave a coefficient of variation of 3%. Results showed 97-103% recovery of the antibiotic from various feed mixtures. Specificity studies with rabbit-anti-hygromycin B antibody showed insignificant cross reactivity with other antibiotics commonly used in combination with hygromycin B.
High Pressure Liquid Chromatography of Zearalenone and Zearalenols in Rat Urine and Liver
Authors: James Lynda J , McGirr Larry G , Smith Trevor K
Published: February 2020

A high pressure liquid chromatographic technique with internal standardization has been developed for determining zearalenone and metabolites in rat urine and liver. Following extraction with methylene chloride and solvent partition, samples are cleaned up by applying the extract to a Sephadex LH-20 column and eluting with a mixture of benzene-methanol (85 + 15). Compounds were resolved on 2 Partisil- 10 columns (25 cm × 4.6 mm id) in series with a mobile phase of isooctane-chloroform-methanol (35 + 25 + 3), and detected at 280 nm. The internal standard was 6'αa-acetoxyzearalane. Limits of detection were about 2.0 ng for zearalenone and 5.0 ng for zearalenols (6'-hydroxyzearalane). Zearalenone and zearalenols were excreted mainly in free form with relatively little glucuronide conjugation. Metabolism of zearalenone to free zearalenol was minor compared with formation of bound forms.
Fluorometric Determination of Dehydroacetic Acid in Mascara Products
Authors: Demers Francois X , Yates Ronald L
Published: February 2020

A fluorometric method tor the determination of dehydroacetic acid in mascara products was developed. The method is based on the formation of the fluorophore γ-pyroxonium borate, which occurs when dehydroacetic acid is reacted with sulfuric and boric acids. Fluorescence intensity is measured and the amount of dehydroacetic acid is determined from a standard calibration curve. Studies were conducted at the 0.1,0.05, and 0.01% levels. Recoveries ranged from 88 to 106% with an overall average of 99%.
Rapid High Performance Liquid Chromatographic Determination of Monosodium Glutamate in Food
Authors: Sporns Peter
Published: February 2020

A rapid, accurate high performance liquid chromatographic method is described for determination of glutamic acid in food. Average recovery of added glutamic acid was 99.2% by this method. The method could be used to analyze samples such as soy sauce, which contain a large amount of other potentially interfering soluble compounds.
Collaborative Evaluation of Rolling Ball Viscometer for Measuring Somatic Cells in Abnormal Milk
Authors: Richardson Gary H , Brown Rodney J , Case Ron , Ginn Roy E , Kasandjieff Ted , Norton Rick C
Published: February 2020

The Ruakura rolling ball viscometer was evaluated in 3 laboratories along with currently approved instrumental methods for measuring somatic cells in milk and the Wisconsin mastitis test. Replacement of the Teepol reagent with Wisconsin mastitis test reagent in the rolling ball viscometer was also evaluated. Both repeatability and reproducibility were satisfactory for all methods evaluated. The instrumental methods each gave higher readings than the other 3 methods. Use of Wisconsin mastitis test reagent in the rolling ball viscometer improved both repeatability and reproducibility. Additional work on standardization is suggested to match rolling ball viscometer readings with those of the instrumental methods.
Chemiluminescence Detection of Nitrite in Nonfat Dried Milk Powders
Authors: Doerr Robert C , Gates Robert A , Fiddler Walter
Published: February 2020

Determination of nitrite in nonfat dry milk powders by chemiluminescence detection was compared with a colorimetric method specifying Griess reagents. The chemiluminescent technique requires no sample preparation, is free from apparent interferences, and is sensitive to 25 ppb nitrite. Statistical analysis shows no difference at P = 0.05 between the colorimetric and chemiluminescent methods, based on the analysis of 16 commercial nonfat dry milk samples.
Application of the AOAC Multi-Residue Method to Determination of Synthetic Pyrethroid Residues in Celery and Animal Products
Authors: Braun Heinz E , Stanek Jana
Published: February 2020

A procedure based on current multi-residue methodology is described for the determination of synthetic pyrethroid residues in vegetable and animal tissues. Permethrin, cypermethrin, and fenvalerate are extracted from celery, egg yolk, beef muscle, and milk with acetonitrile, partitioned into hexane, and cleaned up on Florisil for quantitation by electron capture gas chromatography. Recoveries of the 3 pyrethroids averaged 94-103% from celery and 82- 97% from animal products. Minimum detectable levels of <5 ng/g are readily attainable. The method also allows for the simultaneous extraction and cleanup of the organochlorine hydrocarbon insecticides which have been routinely analyzed in the past.
High Performance Liquid Chromatographic Determination of Clocapramine in Feed and Plasma
Authors: Geahchan Aziz , Chambon Paul , Genoux Pierre
Published: February 2020

A high performance liquid chromatographic method is described for the determination of clocapramine in animal feed and plasma. Samples are made alkaline and then extracted with chloroform containing opipramol as internal standard. For plasma samples, the organic phase is evaporated to dryness under a stream of nitrogen, and the residue is dissolved in dichloromethane-methanol. Extracts are chromatographed on silica gel with dichloromethane-methanol-ammonia (100 + 10 + 0.25) as eluant, and quantitated using an internal standard. Within-day precision for plasma extracts (n = 15) was 3.39, 5.7, and 4.13% at 5,10, and 15 mg clocapramine/L plasma, respectively, and day-to-day precision was 4.6, 6.8, and 4.4% at the same levels. The detection limit was 0.5 mg/L. Recovery from feed over the concentration range 2-6 g/kg was >96%.
Isolation, Identification, and Determination of Food Dyes Following Ion-Pair Extraction
Authors: Puttemans Marc L , Dryon Louis , Massart Désiré L
Published: February 2020

Food dyes are extracted as ion-pairs with tri-n-octylamine and tetrabutylammonium. Extraction from aqueous solutions to chloroform is quantitative with 0.1M counter ion concentrations. The dye may be back-extracted to an aqueous phase with chloride, bromide, iodide, nitrate, or perchlorate ions; perchlorate is most successful. The method is applied to the qualitative analysis of dyes in grenadine, pickles, and milk desserts, and quantitative analysis in alcoholic beverages. Commercial samples are analyzed by using a standard addition method.
Evaluation of Tabarie’s Formula
Authors: Alvarez-Nazario FabiÁn
Published: February 2020

A strict derivation of an empirical formula, long used in the wine industry for the determination of extract, shows its inherent limitations.
Sample Preparation in Determination of Lead in Garden Vegetables by Flame Atomic Absorption Spectrophotometry
Authors: Preer James R , Stephens Bernard R , Bland Cynthia Wilson
Published: February 2020

Dry and wet ashing methods have been used in the analysis of garden vegetables for Pb. The reliability of wet ashing has been verified by the method of standard additions. Comparison of dry and wet ashing showed good agreement for a variety of garden vegetables. Sample size was more strictly limited for the wet-ashed samples, which led to lower sensitivity. Vegetable samples are commonly analyzed for a number of trace elements, which introduces additional constraints on sample preparation, notably because of Cd loss on dry ashing. Pretreatment with HNO3/H2SO4 ash aid eliminated Cd loss. Reliability of dry ashing with pretreatment was shown with NBS SRM Orchard Leaves, Pine Needles, Spinach, and Tomato Leaves. The analysis was insensitive to ashing temperature in the range 480-625°C. A practical detection limit for the method is about 2 ppm Pb, dry weight basis (DWB). Care must be exercised to avoid contamination of the sample with lead at this level by improper handling. Segregation and acid washing of glassware and protection of the sample from contact with any object not demonstrably clean was necessary. No evidence was found of Pb contamination at this level from tap water washing of fresh vegetables, forced-air oven drying, or grinding with mortar and pestle. No special clean room facilities or laboratory air purification measures were used. Sensitivity was increased 3-fold by extraction with dithizone in CHCI3 followed by back-extraction into dilute HC1. Detection limits were not improved, however, because of variation in the extraction results. The instrumental method for assessing effective correction for background absorbance showed adequate compensation, although comparison of direct and extractive determinations showed a small but significant difference between the methods of about 1 ppm Pb (DWB).
Simultaneous Determination of Total Boron, Calcium, Copper, Iron, Magnesium/Manganese, Phosphorus, Potassium, and Zinc in Fertilizers by Inductively Coupled Argon Plasma Emission Spectroscopy
Authors: Jones J Benton
Published: February 2020

Nine elements (B, Ca, Cu, Fe, Mg, Mn, P, K, and Zn) were determined in 34 Magruder fertilizer standards by inductively coupled argon plasma (ICAP) emission spectroscopy. The total elemental concentrations found for each of the 9 elements compared favorably with known concentrations. Seventeen of the fertilizer samples were also extracted with ammonium citrate, and the phosphorus in the extract was determined by ICAP emission spectroscopy with good results compared with the known Magruder concentration for available phosphate. Concentrations of other elements (Al, Ba, Cd, Co, Cr, Na, Ni, Pb, Si, and Sr) were also obtained but were not verified.
Liquid Chromatographic Determination of Natamycin in Cheese at Residue Levels
Authors: Tuinstra Louis G M T H , Traag Wim A
Published: February 2020

A high performance liquid chromatographic method, with special reference to the cleanup procedure, is described for the measurement of natamycin in cheese. Co-extracted fats and proteins are removed by cooling the methanol extract of the cheese. Amounts as low as 1 ng natamycin can be detected; the limit of determination is better than 0.05 mg/kg. Recovery at the 1 mg/kg level is better than 90%. Reproducibility at the 0.4 mg/kg level shows a coefficient of variation of 10%. Some results obtained with Dutch cheese samples from the local market are reported.
Evaluation of Three Methods for Recovery of Sulfamethazine Metabolites from Swine Tissue
Authors: Matusik Jean E , Barnes Charlie J , Newkirk David R , Fazio Thomas
Published: February 2020

Recent investigations have clearly established the presence of desaminosulfamethazine (I), N4-acetyl-sulfamethazine (II), and N4-D-glucosyl sulfamethazine (III) in the tissues of swine which have been dosed with sulfamethazine (V). N4(l-Deoxy-DglucuronyDsulfamethazine (IV) has frequently been found in the urine and feces of animals. These metabolites have generally not been investigated in current sulfamethazine methods; therefore, it is not clear to what extent they might be measured by these procedures. Metabolites I, II, III, and IV were synthesized and characterized by several chemical and physical measurements. These metabolites and their parent, V, were added to swine tissue and recoveries were measured by a gas-liquid chromatographic (GLC), a colorimetric, and a gas chromatographic/ mass spectrometric method with electron ionization- selected ion monitoring (GC/MS EI-SIM). With modifications of the gas chromatographic parameters, the GLC method can quantitate compounds I, II, and V simultaneously. If a hydrolysis step is added, all 3 methods can quantitate compound II as V and, in addition, the GC/MS EI-SIM and colorimetric methods can quantitate III as V. In none of these methods do metabolites I, II, III, or IV interfere in the determination of V.
International Mycotoxin Check Sample Program: Part II. Report on Laboratory Performance for Determination of Aflatoxin M1 in Milk
Authors: Friesen Marlin D , Garren Liliane
Published: February 2020

A sample of aflatoxin M1-contaminated lyophilized cow's milk was analyzed by 80 laboratories in 30 countries. Sufficient data were obtained to permit a statistical comparison of the performance of laboratories using AOAC methods I and II and those using high performance liquid chromatography for quantitation. A significant difference was noted between means for laboratories using AOAC method I as opposed to those using HPLC methods. Overall reproducibility (between- plus within-laboratory precision) was best for laboratories using HPLC methods and poorest for those using AOAC method II.
Reverse Phase Liquid Chromatographic Determination of Chlorophacinone and Diphacinone in Bait Formulations
Authors: Bennett Brian R , Grimes Gregory S
Published: February 2020

Chlorophacinone and diphacinone are extracted at the 0.005% level from grain or paraffinized baits with glacial acetic acid. The target concentration is 0.01 mg/mL. The filtered supernate is chromatographed on a Partisil PXS ODS10/25 liquid chromatography column with premixed and degassed glacial acetic acid-tetrahydrofuran-water (14 + 2 + 9) and detected at 288 nm. The concentration is calculated by using an external standard. The recovery from spiked samples averaged 96.6% for both analytes. The response is linear from 0.001 to 0.040 mg/mL. The coefficient of variation of within-day replicates ranged from 1.1 to 2.5%.
Infrared Spectrophotometric Determination of Dioxathion in Cattle Dipwashes
Authors: Luguru Stephen M , Saidi A B
Published: February 2020

Infrared (IR) spectrophotometric determination of dioxathion in cattle dipwashes was checked for its suitability as a routine method. Two calibration curves constructed from absorbances of a series of solutions of dioxathion in carbon tetrachloride and a series of extracts of equivalent quantities of dioxathion from aqueous emulsions were similar (slope 1.8). Several determinations of a field sample gave a mean concentration of 292 ppm or 0.029% and a coefficient of variation of 1.6%. Two determinations of an aqueous emulsion of dioxathion of approximately 400 ppm gave concentrations of 440 and 404 ppm.
Crude Fiber Determination Using Ceramic Fiber to Replace Asbestos
Authors: Knox Randy L , Engvall David S , Ginther Burton E
Published: February 2020

Crude fiber was determined in a wide range of feed products by a method which specifies ceramic fiber as a filter medium instead of the more hazardous and difficult to obtain asbestos. Results correlated well with those obtained by using AOAC official final action method 7.061-7.065 (correlation coefficient, 0.9994). For 8 samples, the coefficients of variation ranged from 0.74 to 4.80%. Compared with the AOAC method, the proposed method showed a slight negative bias of 0.1%. Compared with asbestos, ceramic fiber was easier to prepare for use, filtering was faster, and samples bumped less.
Influence of Various Solvent-Water Mixtures on the Extraction of Dieldrin and Methomyl Residues from Radishes
Authors: Wheeler Willis B , Thompson Neal P , Edelstein Robert L , Littell Ramon C , Krause Richard T
Published: February 2020

The effect of organic solvent/water ratios on the extraction of field-incurred residues of dieldrin and methomyl from radishes was determined. 14CDieldrin and 14C-methomyl were applied separately to radishes in commercial formulations at rates of 0.2 and 0.9 kg/ha, respectively. Fourteen days post-application, the radishes were harvested and fresh root tissues were extracted using a Polytron homogenizer. Acetone, acetonitrile, and methanol containing 0,10, 20, 30, 40, and 50% water were used as extraction solvents. For methomyl residues, the optimum water content of acetonitrile-water extraction mixtures was 40-50%; less than 40% water reduced the ability of acetonitrile to extract carbon- 14. Methanol and acetone were nearly as efficient as 50% acetonitrile-water and were apparently not influenced by solvent/water ratios. For dieldrin, low water content slightly reduced the extraction efficiency of acetonitrile, with the optimum water content also being 40-50%. Percentage of water appeared to have little overall effect on methanol extraction efficiency. The extraction efficiency of acetone was lower than that of the other 2 solvents, and this effect was independent of the acetone/water ratio. Approximately 20% of the 14C-dieldrin residue was bound to radish roots 14 days post-application.
Gas-Liquid Chromatographic Determination of 4-Chlorophenoxyacetic Acid Residues in Mung Bean Sprouts
Authors: Wong Yew-Sin
Published: February 2020

A gas-liquid chromatographic (GLC) method is described for determining 4-chlorophenoxyacetic acid (CPA) residues in mung bean sprouts. The residues were extracted from samples by using ethyl acetate followed by liquid-liquid partition into 5% NaHCO3 solution. After acidification and reextraction with ethyl acetate, CPA was reacted with pentafluorobenzyl bromide (PFB-Br) to form the PFB derivative. The reaction mixture was separated on a silica gel column to remove excess reagent, and the derivative was eluted with a solution of 75% toluene in hexane. GLC separations were performed on a 3% OV-1 column at 230°C. As low as 10 pg CPA could be quantitated, which is equivalent to about 0.05 ppm at residue level, using an electron capture detector. Recoveries of CPA from fortified mung bean sprouts (0.05, 0.20, and 0.50 ppm) ranged from 71 to 107%. The PFB derivative was further identified by gas chromatography-mass spectrometry.
Hydride Generation and Condensation Flame Atomic Absorption Spectroscopic Determination of Antimony in Raw Coffee Beans and Processed Coffee
Authors: Kuennen Roy W , Hahn Mark H , Fricke Fred L , Wolnik Karen A
Published: February 2020

A method was developed for determining Sb at nanogram per gram levels in raw coffee beans and processed coffee. The procedure uses either total acid digestion or extraction with 6M HCl followed by hydride generation/condensation with subsequent revolatilization of stibine (SbH3) and detection by flame atomic absorption spectroscopy. The lowest quantifiable level, based on a 2 g (dry weight) sample, is 2 ng Sb/g. The results of recoveries on spiked samples, precision studies on composited coffee samples, and the analysis of National Bureau of Standards Standard Reference Materials demonstrate the reliability and accuracy of the procedure. Sb concentrations in coffee samples were verified by neutron activation analysis and inductively coupled plasma atomic emission spectroscopy. Advantages of the method compared with the AOAC colorimetric procedure and hydride generation without condensation are discussed.
Transfer of Reports from an Automated Gas Chromatographic System to a Large Computer for Final Processing
Authors: Clower Marion
Published: February 2020

An automated gas chromatographic system consisting of a Hewlett-Packard 5710 gas chromatograph, a Varian 8000 autosampler, and a Spectra-Physics 4000 laboratory data system has been interfaced to FDA's large, central computer facility by using a Tektronix 4923-01 digital cartridge tape recorder. The autosampler provides single or multiple injections of up to 60 samples. The data system is preprogrammed with appropriate sample and standard information in addition to parameters for proper peak integration. A chromatogram is traced and a report of integration area counts for each peak detected is prepared by the data system after each chromatographic analysis. A duplicate of each report is recorded on the data cartridge. After analysis of all samples, the quality of chromatography is examined for acceptability. The chromatographic reports contained on the data cartridge may then be entered into the computer via a terminal equipped with a similar digital cartridge tape recorder. Translation of the reports, correlation of responses from sample and standard solutions, all calculations, and a complete report of each sample analysis are obtained by using the computer programming language APL. The data system-cartridge tape recorder interface, as well as data reduction using the large computer, is discussed.
Development of a Chemical Information System
Authors: Milne G W A
Published: February 2020

The 10-year history of the development of the NIHEPA Chemical Information System is described. The System grew from the cooperative efforts of several agencies of the federal government and now is publicly available on a fee-for-service basis on computers in the private sector.
Design of an Ail-Metal Syringe Heating Mantle
Authors: Page B Denis , Charbonneau Claudette F
Published: February 2020

The design and fabrication of a simple, robust, all-metal heating mantle, readily adaptable to different sizes of gas-tight (or other) syringes, is described.
Determination for and from Analyst Performance Standards: Collaborative Studies
Authors: Malanoski Anthony J
Published: February 2020

With the increased emphasis on quality assurance in all phases of regulatory analysis, it has become necessary to establish standards of performance for the analyst. The technique discussed is one that should be considered for use and the performance standard should become an integral part of the method.
Volatile Organic Compounds in Water at Thirty Canadian Potable Water Treatment Facilities
Authors: Otson Rein , Williams David T , Bothwell Peter D
Published: February 2020

A static headspace technique and previously developed and evaluated dynamic headspace and liquid-liquid extraction techniques were applied in a survey of volatile organic compounds in water at 30 Canadian potable water treatment facilities. Of the 43 compounds investigated, 27 compounds were detected in the water samples. Chloroform and bromodichloromethane occurred most frequently in treated water, and trichloroethylene, tetrachloroethylene, 1,2-dichloroethane, dichloromethane, benzene, toluene, ethylbenzene, and the xylenes occurred frequently in both treated and raw water. Only chloroform occurred frequently at levels above 10 μg/L in treated water. Generally, higher levels of organic compounds were found during August-September than during November-December.
Gas-Liquid Chromatographic Derivatization and Chromatography of N-Methylcarbamate Methoxy Derivatives Formed with Trimethylanilinium Hydroxide
Authors: Ogierman Leonard
Published: February 2020

Carbamate insecticides injected into a gas-liquid chromatograph react with trimethylanilinium hydroxide to give derivatives that have good gas-liquid chromatographic properties. The substituted phenyl N-methylcarbamates give methoxy derivatives by this procedure. Chromatographic response was linear with increased concentration for the synthetic standard and the on-column methylation products of the examined substances. The standards obtained were identified by ultraviolet and infrared absorption spectroscopy, as well as by nuclear magnetic resonance and mass spectral analysis.
Infant Formula Physical Stability
Authors: Miles J Preston
Published: February 2020

The physical nature of liquid infant formula products is characterized in terms of emulsion, suspension, and solution processes. Such mixtures inevitably undergo phase separation. A variety of physical and chemical phenomena govern the gradual changes in the appearance of these products. The consequent loss of physical elegance is primarily a question of consumer acceptance. Only in the most extreme cases do the physical characteristics deteriorate to the point that swallowing and digestion are affected. Recently, both public and regulatory attention has been focused on the physical characteristics of liquid infant formula products. Formula appearance is the product aspect most readily evaluated by the consumer. The design and manufacture of products that will have consistent appearance over extended periods is a difficult technical problem. This presentation summarizes the phenomena responsible for changes in the physical characteristics of liquid infant formula products. Product defects are discussed and methods for product evaluation are described. Representative data on the effect of storage on product physical elegance also are presented.
Nutrient Overages and Methodology Trends
Authors: Mays David L
Published: February 2020

Because infant formula provides the sole dietary intake for many infants, it is important that the nutrient composition be carefully controlled. Establishing nutrient levels depends on laboratory testing. Current testing methods have certain limitations, some of which can be overcome by modern trends in analytical technology.
Survival and Movement of Clostridium perfringens in Sewage-Treated Soil
Authors: John WILLIAM D S T , Matches Jack R
Published: February 2020

The survival and movement of Clostridium perfringens in soil were studied. Fresh dewatered sewage sludge was added to 2 plots of tilled soil. During analyses for 24 weeks, some movement of spores from surface sludge into soil was obtained but little movement through the soil took place. In laboratory studies, columns of soil with a surface layer of sludge were subjected to the equivalence of 67 in. of rain. During this treatment, slow movement through the soil was obtained, but organisms were not detected in column effluents. These data show that C. perfringens will survive for at least 24 weeks in soil, with little movement. The application of sewage sludge increases the total numbers of C. perfringens in soil, but should have little effect on food poisoning from foods grown in treated soil.
High Pressure Liquid Chromatographic Determination of Zearalenone in Chicken Tissues
Authors: Turner G Vincent , Phillips Timothy D , Heidelbaugh Norman D , Russell Leon H
Published: February 2020

A method is reported for the extraction and analysis of zearalenone in chicken fat, heart muscle, and kidney tissue by using high pressure liquid chromatography (HPLC). Zearalenone is extracted with acetonitrile, cleaned up with hexane, and extracted further with ethyl acetate. Zearalenone is determined by HPLC using a reverse phase radial compression separation system, an ultraviolet absorbance detector, and a mobile phase of acetonitrile-water (60 + 40) (v/v). Recoveries of zearalenone added at levels from 50 to 200 ng/g are in the range 82.6-95.1%.
Colorimetric Determination of Propoxur and Its Residues in Vegetables
Authors: Appaiah Kalapanda M , Kapur Omprakash , Nagaraja Krishnarajpet V
Published: February 2020

A method has been developed for the determination of propoxur (o-isopropoxyphenyl N-methylcarbamate) based on the hydrolysis of propoxur with methanolic potassium hydroxide to its phenol and coupling with diazotized 4,4-diaminodiphenyl sulfone. The orange complex formed has an absorption maximum at 500 nm and obeys Beer’s law in the range 0.25-5.0 μg/mL. The method can be applied to levels as low as 0.5 ppm propoxur from vegetables.
Improved Method for Determination and Identification of Serotonin in Foods
Authors: García-Moreno Concepcion , Rivas-Gonzalo Julian C , Peña-Egido M Jesus , Mariné-Font Abel
Published: February 2020

A previously described method to identify and quantitate serotonin in foods has been improved. The extraction and separation of serotonin from interfering substances has been improved, and the scope of material to which the method may be applied has been widened. The relative standard deviation (RSD) for repeated determinations of serotonin in canned fried tomato puree and the average recovery of serotonin added to the same sample was 6.25 and 89.9%, respectively. The method showed the presence of serotonin in apricots, cherries, and peaches
Selected Ion Mass Spectrometric Identification of Chlorophenol Residues in Human Urine
Authors: Hargesheimer Erika E , Coutts Ronald T
Published: February 2020

A method is presented for the detection and confirmation of trace chlorophenol residues in environmental and biological samples by mass spectrometry with selected ion monitoring (SIM). Propionate and acetate ester derivatives of phenol, cresols, mono-, di-, tri-, and tetrachlorophenols, pentachlorophenol, as well as the internal standard 4,6-dibromo-o-cresol, were prepared directly in aqueous solution, using the appropriate anhydride reagent. The acetate or propionate esters were quantitatively extracted and then separated by gas-liquid chromatography using either an SP-1240DA or OV-101 packed column. Electron impact SIM was carried out by simultaneously monitoring up to 4 diagnostic fragment ions of each chlorinated phenol. The use of SIM eliminated background interference encountered using flame ionization or electron capture detectors, and allowed identification of chlorophenol residues in extracts of urine samples collected from individuals without known exposure to chlorophenols. Phenol concentrations as low as 1.0 pmol/mL urine gave peaks that were readily discernible by SIM.
Optimum Conditions for Hydride Generation of Selenium and Its Determination by Atomic Absorption Spectrophotometry
Authors: Brooks Robert R , Willis Janine A , Liddle John R
Published: February 2020

Instrumental parameters and other variables were studied to establish the optimum indicators for determination of selenium by atomic absorption spectrophotometry using the hydride generation procedure with cold-trapping. Optimum conditions were established by consideration of the following variables: volume of reaction solution, acid concentration in the reaction mixture, lapse of time after last addition of borohydride, method of addition of borohydride, carrier gas flow rates, position of source beam in the flame cell, oxidation state of selenium, and effect of drying the cold trap between successive determinations. This latter procedure greatly improved the reproducibility of the technique (from ±28% to ±2%. The limit of detection was about 2 ng selenium.
Determination of Penicillin G, Ampicillin, and Cephapirin Residues in Tissues
Authors: Vilim Arnost B , Larocque Lyse
Published: February 2020

A cylinder plate microbiological method was developed for the rapid, quantitative determination of penicillin G, ampicillin, and cephapirin in animal tissues. The method uses agar plates seeded with stable spores of Bacillus stearothermophilus var. calidolactis and incubated 4 h at 64°C. Standard curves were obtained for the following ranges of concentration of antibiotics in tissues: 0.02-0.32 IU penicillin G/g, 0.0125-0.2 μg ampicillin/g, and 0.02-0.32 μg cephapirin/g. The proposed method is suitable not only for penicillin residue analysis, for which the sensitivity has been greatly improved compared with the Sarcina lutea method, but also for depletion studies on these antibiotics, which are commonly used to treat diseases in food-producing animals.
Turbidimetric Assay of Penicillin in Feeds: Addition of Magnesium Sulfate to Eliminate Chlortetracycline Interference
Authors: Chiang Tom , Hanks Alan R , Melton James R , Hoover William L
Published: February 2020

The official AOAC method for extracting penicillin from feeds allows some chlortetracycline to be coextracted if the latter is also present in the sample. This can cause a high bias in results obtained by using the turbidimetric assay in which the test organism is sensitive to both antibiotics. In this report, we show that magnesium ions can be used to circumvent the interference of chlortetracycline in the turbidimetric assay for penicillin.
Treatment of Freshly Harvested 1980 Georgia Dent Corn Samples Collected for Aflatoxin Analysis
Authors: Shotwell Odette L , Bennett Glenn A , Kwolek William F , Hesseltine Clifford W
Published: February 2020

In 1980, corn was harvested from six 15-ft rows in each of 67 fields in Georgia for aflatoxin analysis. Every sixth ear from each field was placed in a sample bag to be dried the day of collection. The rest of the corn was husked and shipped to Peoria in cardboard boxes. When undried ear samples arrived in Peoria, each sample was randomly separated into 5 equivalent subsamples. One set of 67 subsamples was shelled and dried as soon as possible to avoid further aflatoxin formation. Two other sets of 67 subsamples were stored 3 and 6 weeks before shelling and drying. The remaining 2 sets of ear samples were placed in plastic bags with 5% Monoprop (1 part propionic acid plus 1 part versite) and stored 3 and 6 weeks before shelling and drying. The samples dried in Georgia before shipping had an average total aflatoxin level of 217 ng/g. Samples shelled and dried immediately after arrival had an average level of 202 ng/g. Samples shelled and dried after 3 and 6 weeks of storage had average total aflatoxin levels of 417 and 387 ng/g, respectively. Samples stored 3 and 6 weeks in the presence of 5% Monoprop (2.5% propionic acid) had average total aflatoxin levels of 120 and 157 ng/g, respectively.
High Performance Liquid Chromatographic Determination of Nonvolatile Phenolic Compounds in Matured Distilled Alcoholic Beverages
Authors: Lehtonen Matti
Published: February 2020

Gallic acid, vanillic acid, syringic acid, vanillin, syringaldehyde, and ferulic acid were determined in matured spirits by reverse phase high performance liquid chromatography. Concentrations varied from 0 to 11 ppm depending on the compound and the beverage. Gallic acid and syringaldehyde were the main components. Vanillic acid, vanillin, and, especially, gallic acid were the most important in distinguishing the different classes of spirit. Discriminate analysis gave 2 factors, which, however, could not be used to classify the samples with any great confidence: 61% of the whiskies, 33% of the rums, and 52% of the brandies were correctly assigned in this way.
Nitro Musk Fragrances as Potential Contaminants in Pesticide Residue Analysis
Authors: Yurawecz Martin P , Puma Bart J
Published: February 2020

Synthetic nitro musks, fragrance ingredients of soaps, lotions, and other products commonly used in the home and laboratory, are potential interferences in analyses of foods for pesticide residues. These fragrances are recovered by extraction-cleanup procedures of the AOAC multiresidue method for fatty and nonfatty foods and have electron capture gas-liquid chromatographic properties similar to the organochlorine residues for which the method has official status. This report presents the analytical evidence that led to the identification of musk xylol (1-[1,1-dimethylethyl]-3,5-dimethyl-2,4,6-trinitrobenzene) as a contaminant in a sample of fish; mass spectra and data on the behavior in the AOAC multiresidue method of musk xylol, musk ambrette (1-[1,1-dimethylethyl]-2-methoxy-4-methyl - 3,5 - dinitrobenzene), musk tibetene (1-[1,1-dimethylethyl]-3,4,5-trimethyl-2,6-dinitrobenzene), and musk ketone (1-[4-(1,1-dimethylethyl)-2,6-dimethyl - 3,5 - dinitrophenyl] ethanone); and information on some sources of these chemicals in the laboratory environment.
Gas-Liquid Chromatographic Determination of Trace Amounts of Nitrite in Egg, Egg White, and Egg Yolk
Authors: Tanaka Akio , Nose Norihide , Masaki Hiroyuki , Kikuchi Yoshinori , Iwasaki Hisao
Published: February 2020

A simple, sensitive, and practical method is described for determination of nitrite in egg, egg white, and egg yolk. Egg is deproteinized by adding a mixture of ammonium thiocyanate, mercuric chloride, and zinc acetate, and centrifuged. Nitrite in the supernate is converted to tetrazolophthalazine by reaction with hydralazine in acidic solution and then determined by gas-liquid chromatography with an electroncapture detector (GLC-ECD) and a column of OV-225 on Chromosorb W(HP). Nitrite concentrations from 5 to 50 ng/mL are calculated from peak height; the detection limit is 3 ng/mL extract. Recoveries from eggs, egg whites, and egg yolks ranged from 91.7 to 98.0%. The mean nitrite concentration in 50 egg samples was 0.04 ppm (0.01-0.11 ppm) with a detection limit of 4 ng nitrite/g.
Diagnosis of Ethylene Glycol (Antifreeze) Intoxication in Dogs by Determination of Glycolic Acid in Serum and Urine with High Pressure Liquid Chromatography and Gas Chromatography-Mass Spectrometry
Authors: Hewlett Tracy P , Ray Allen C , Reagor John C
Published: February 2020

A relatively fast and sensitive high pressure liquid chromatographic (HPLC) and gas chromatographicmass spectrometric (GC/MS) method was developed for determination of glycolic acid, one of the major metabolites of ethylene glycol, in extracts of canine urine and serum. The procedure involves extraction of glycolic acid with methyl ethyl ketone and derivatization with O-p-nitrobenzyl-N,N'-diisopropylisourea (PNBDI) in ethyl acetate solution. Recovery was greater than 94% from spiked samples. Ethylene glycol and commercial antifreeze were administered to experimental dogs at different dosage levels to reproduce the naturally occurring toxicosis associated with the consumption of commercial antifreeze. Glycolic acid was determined in either the urine or serum or both from these dogs by HPLC and GC/MS. 1,3-Butanediol, a competitive inhibitor of ethylene glycol biotransformation, was administered to one dog concurrently with antifreeze. In that experiment, it was effective in decreasing glycolic acid formation and prevented acute metabolic acidosis, kidney damage, and death.
Evaluation of Urea-Acid System as Medium of Extraction for the B-Group Vitamins. Part II. Simplified Semi-Automated Chemical Analysis for Niacin and Niacinamide in Cereal Products
Authors: Roy Ram B , Merten John J
Published: February 2020

Efficiency of a urea-acid system was evaluated as medium of extraction for niacin and niacinamide from cereals and other selected food products. Samples were treated with IN HC1 in the presence of urea and autoclaved 30 min at 15 psi. Extracts were diluted to a known volume, filtered, and analyzed. The analytical results obtained for niacin were compared with values obtained by AOAC method 43.044. In general, the urea-acid extraction system was simple and straightforward with an efficiency comparable to the AOAC method. The analytical manifold designed uses fewer modules, gives net absorbance readings from sample and blank, and is capable of analyzing 50 samples per hour.
High Performance Liquid Chromatographic Determination of Malondialdehyde in Vegetable Oils
Authors: Hirayama Teruhisa , Yamada Naohide , Nohara Motoshi , Fukui Shozo
Published: February 2020

A simple high performance liquid chromatographic (HPLC) method has been developed for determining malondialdehyde (MDA) in vegetable oils. MDA was reacted with dansyl hydrazine in an acidic medium, and the product, 1-dansyl-pyrazole, was determined by HPLC, using a Zorbax sil column with mixed mobile phase of n-hexane-methylene chloride. MDA can be determined as 1-dansyl-pyrazole by f luorometric detection at a level of 0.01 ppm in vegetable oils.
Automated Analysis of Flour Extracts for Uric Acid and Its Correlation With Degree of Insect Defilement
Authors: Galacci Raymond R
Published: February 2020

An automated method is described for quantitating uric acid in a sodium acetate extract of flour. The difference in color intensity developed in a flour extract treated with the enzyme uricase and one that is not treated is measured spectrophotometrically. A mean recovery of 97.1% was obtained for 50 g flour samples spiked with 1 mg uric acid. The method can measure as little as 50 ng uric acid in 50 g flour and is used to establish a correlation between the uric acid in the flour and the number of insect fragments and excreta pellets present. A 42-data point least squares straight line having a slope of 1.62 and a correlation coefficient of 0.750 (99.9-100% valid) is used to establish the relationship of uric acid to insect defilement.
Ion-Pair High Performance Liquid Chromatographic Determination of Inosinic Acid in Meat
Authors: Kitada Yoshimi , Inoue Masashige , Tamase Kikuo , Imou Masako , Hasuike Akikazu , Sasaki Michiko , Tanigawa Kaoru
Published: February 2020

An ion-pair high performance liquid chromatographic (HPLC) technique is described for the determination of inosinic acid (IMP) in meat. The compound was extracted with perchloric acid and analyzed without cleanup. IMP is effectively separated, identified, and quantitated by using a reverse phase column, with ultraviolet detection. A C8 stationary phase and tetrabutyl ammonium as counter ion are used. Recovery of IMP added to meat at 500 or 2500 ppm levels was more than 95%; the limit of detection for IMP is 50 ppm.
Capillary Gas Chromatographic-Mass Spectrometric Determination of Individual Chlorobiphenyls in Technical Aroclors
Authors: Tuinstra Louis G M T H , Traag Wim A
Published: February 2020

Six technical Aroclors were separated into individual chlorobiphenyls on fused silica capillary columns. Fifty-three chlorobiphenyl standards were used to ascertain structures of a number of compounds in the technical mixtures by mass spectrometry. Results are compared with reports in the literature. Percentages of identified compounds are given, and the presence of unidentified chlorobiphenyls is indicated by the number of chlorine atoms, in order of compound elution from the column.
Reverse Phase Radial Compression High Performance Liquid Chromatographic Determination of Rotenone in Formulations
Authors: Bushway Rodney J
Published: February 2020

This paper describes a reverse phase radial compression high performance liquid chromatographic (HPLC) method to determine rotenone in pesticide formulations. Formulations are extracted in dioxane by gentle swirling while sonicating for 5 min. A 10 μL aliquot is injected into the HPLC system equipped with a radial compression unit (Z module) containing a μBondapak C18 Radial-Pak column. The mobile phase is acetonitrile-methanol-tetrahydrofuranwater (34 + 30 + 1 + 35). Rotenone is monitored at 280 nm. Retention time for rotenone is approximately 7 min with total analysis time of 20 min. For 5 different products analyzed 11 times each, the percent coefficients of variation were all below 1.65. No interferences from 11 other rotenoids and 8 pesticides which are sometimes formulated with rotenone were observed.
High Pressure Liquid Chromatographic Determination of Impurity Phenols in Technical 2,4-D Acid and 2,4-Dichlorophenol
Authors: Cochrane William P , Lanouette Monique , Singh Joginder
Published: February 2020

Thirteen technical 2,4-dichlorophenoxyacetic (2,4-D) acid and five 2,4-dichlorophenol (2,4-DCP) samples were obtained from several manufacturers and analyzed for the presence of various chlorinated phenolic impurities. Reverse phase high pressure liquid chromatography with a UV detector in series with an electrochemical detector was used for qualitative and quantitative determinations. Three solvent systems were investigated in the present study. The retention times obtained for various mono-, di-, and tri-chlorophenols with each solvent system are presented. The presence of ortho- and para-monochlorophenol (averages 1.23 and 0.41%, respectively), 2,6-dichlorophenol (average 4.5%), 2,4,6-trichlorophenol, and a dichloro-methyl phenol isomer were detected as contaminants in technical 2,4-DCP samples. Technical 2,4-D acid contained the same type of chlorophenol impurities but in much smaller amounts. A comparison of the sensitivity of a UV detector at 280 nm with an electrochemical detector showed the latter to be 5 to 15 times more sensitive, depending on the chlorophenol.
Direct Testing of Gelatin Hydrolysis in Rapid Perfringens Medium
Authors: Smith Marilyn , Mood Thomas J
Published: February 2020

Rapid perfringens medium (RPM) was previously shown to be effective for detection of low numbers of Clostridium perfringens in foods. The detection system of RPM is based on a stormy fermentation of litmus milk. RPM also contains 6% gelatin, and the present work was performed to determine if gelatin hydrolysis can be tested directly in this medium. Twenty-three strains of C. perfringens and related species were inoculated into tubes of RPM and lactose gelatin. All strains were positive for stormy fermentation on RPM after 24 h incubation at 46°C. Seventeen exhibited gelatin hydrolysis on both RPM and lactose gelatin. Tubes of RPM inoculated with slurries of food samples spiked with each of 11 strains of C perfringens were positive for stormy fermentation and gelatin liquefaction. Most C. perfringens hydrolyze gelatin, so this test augments stormy fermentation in RPM as an additional indicator for the presence of this pathogen.
High Pressure Liquid Chromatographic Determination of Putrefactive Amines in Foods
Authors: Hui Julia Y , Taylor Steve L
Published: February 2020

A high pressure liquid chromatographic (HPLC) procedure is described for determining the following putrefactive amines: histamine, tyramine, putrescine, cadaverine, tryptamine, and β-phenylethylamine. The amines were extracted from tuna or cheese with methanol. Futher cleanup was performed by sequential extractions with butanol and HC1. The acid extract was dried, and residues were derivatized with dansyl chloride. HPLC separations were performed on an Ultrasphere-ODS column at 33°C. A gradient elution program was used; the total elution time was less than 17 min. Linear standard curves with high correlation coefficients were obtained. The procedure allowed good recoveries of histamine, tyramine, putrescine, and cadaverine; recoveries of tryptamine and β-phenylethylamine were lower but constant. With this method, some swiss cheese samples were found to contain considerable amounts of histamine, tyramine, putrescine, cadaverine, and β-phenylethylamine. Canned tuna samples had very low levels of these amines. Since the presence of amines at high levels has been associated with tuna decomposition, this method may be useful in identifying decomposed fish.