bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substrate Supporting Disc Method for Confirmed Detection of Total Coliforms and E. coli in all Foods: Collaborative Study
Authors: Feldsine Philip T , Falbo-Nelson Maria T , Hustead David L ,   Collaborators:, Aaronson J , Arling V , Baker M , Bozzuffi J , Bremer N , Chlebowski E , Clarke J , Crane A , Daniell E , Daugherty N , David J , Davis T , Diaz R , Donnelly S , Elwood M , Forgey R , Freshley J , Glowka L , Gottshall R , Graham R , Gray M , Griffith M , Hansen M , Harmon T , Herman R , Hofstrand P , Huether K , Irbys S , Jackey B , Jackson J , Jones T , Khasmakhi A , Lifur L , Linger T , MaCeda J , Mackin M , Marone C , McClure A , McDonagh S , Milligan L , Nelson J , Pandit K , Poole S , Rizzo M , Robinson J , Sparano R , Schriver J , Seibert M , Stone J , Summers D , Sweger L , Tebay D , Vera G , Weaver A , Wempe J , Wilkinson C , Willett J , Willoughby S , Zook T 
Published: February 2020

Abstract
The Coli Complete® substrate supporting disc (SSD) method for simultaneous confirmed total coliform count and Escherichia coli determination in all foods was compared with AOAC most probable number (MPN) methods, 966.23 and 966.24. Twenty-nine laboratories participated in this collaborative study in which 6 food types were analyzed. Four food types, raw ground beef, pork sausage, raw liquid milk, and nut meats, were naturally contaminated with coliform bacteria. Two foods, dry egg and fresh frozen vegetables, were seeded with coliforms. Three food types, ground beef, raw liquid milk, and pork sausage, were naturally contaminated with E. coli. Although pork sausage was naturally contaminated, the level was very low (&lt;10/50 g); therefore, additional E. coli were inoculated into 1 lot of this food type. Three food types, nut meats, dry egg, and fresh frozen vegetables, were inoculated with E. coli. For naturally contaminated samples, duplicate determinations were made on 3 separate lots for each food type. For inoculated samples, low, medium, and high contamination levels plus uninoculated control samples were examined in duplicate. Data were analyzed separately for total coliform bacteria and for E. coli. Mean log MPN counts were determined by the SSD method and the appropriate AOAC MPN method. Results were then analyzed for repeatability, reproducibility, and mean log MPN statistical equivalence. Results were statistically equivalent for all total coliform levels in all food types except frozen vegetable and raw nut meat uninoculated control samples and 1 lot of pork sausage where the SSD method produced statistically significant greater numbers. For the E. coli determinations, results were statistically equivalent across all samples and all levels for each food type. The SSD method has been adopted first action by AOAC International for confirmed detection of total coliforms and E. coli in all foods.
Liquid Chromatographic Determination of Melengestrol Acetate in Feeds
Authors: Campbell Harold M , Sauvé François 
Published: February 2020

Abstract
A method for melengestrol acetate (MGA) was developed to accurately determine 0.08-220 ppm MGA in animal feeds. MGA is extracted from an aqueous slurry of feed sample with hexane and partitioned from hexane into aqueous methanol and then into dichloromethane. After evaporation of the dichloromethane, the dried extract is transferred with chloroform into a volumetric flask. An aliquot is pipetted into a mixed column of silica gel and acid aluminum oxide, and the MGA is eluted with hexane-acetone. The residue is dissolved in methanol, and the MGA is quantitated by reversed-phase liquid chromatography (LC). The method was validated by using commercial feeds and laboratory-fortified feeds. The method was also applied successfully to corn silages supplemented with MGA. Recoveries [and associated coefficients of variation (CVs)] for feeds fortified in the laboratory with MGA 100 at 0.2,0.8, and 5 ppm were 96.9 (6.28), 102 (3.59), and 109% (2.06%), respectively. CVs for a variety of commercial feeds varied from 0.88 to 3.84%. An inter laboratory study was also conducted to compare the LC method to the AOAC gas chromatographic method.
Survey of Total Tetrahydrophthalimide in Baby Foods Using Both Enzyme-Linked Immunosorbent Assay and Gas Chromatography/Mass Spectrometry: A Comparative Study
Authors: Yeung Jupiter M , Newsome W Harvey 
Published: February 2020

Abstract
An enzyme-linked immunosorbent assay (ELISA) method was compared with a gas chromatographic/ mass spectrometric (GC/MS) method for determining the concentration (in parts per million) of the combination of captan and its degradation product tetrahydrophthalimide (THPI) in 13 fruit samples and in a survey of baby foods. Ninety baby foods (49 fruits, 28 juices, and 13 vegetables) from 2 different suppliers were sampled. All captan in the samples was converted to THPI before each analysis. None of the samples contained a concentration of combined captan and THPI that violated the maximum residue limit of 5.0 ppm. Eight samples of baby food tested positive for THPI at levels ranging from 0.019-0.041 ppm by the GC/MS method, whereas 20 samples tested positive in the ELISA assay. All samples that tested positive with the GC/MS method also tested positive with the ELISA method. Thirteen percent of the baby food samples tested false positive with the ELISA method. The ELISA assay also gave higher values than the GC/MS method. The ELISA method can be effectively used as a primary screening tool to select samples testing positive for THPI. The concentration of THPI in these samples can then be verified using the GC/MS method.
Semiautomatic Determination of Furanic Aldehydes in Food and Pharmaceutical Samples by a Stopped-Flow Injection Analysis Method
Authors: Espinosa-Mansilla A , Peña A Muñoz Dela , Salinas F 
Published: February 2020

Abstract
A kinetic study of the reactions of 5-hydroxymethyl-2-furfuraldehyde and furfural with 2-thiobarbituric acid (TBA) by a stopped-flow flow injection analysis technique has been undertaken. A semiautomatic method for the analytical determination of these furanic aldehydes is proposed on the basis of reaction with TBA. The proposed stopped-flow method was successfully applied to several commercial pharmaceutical preparations and food samples. The procedure is faster than the earlier procedure for determination of these compounds in foods and pharmaceuticals.
Variability Associated with Sampling, Sample Preparation, and Chemical Testing for Aflatoxin in Farmers' Stock Peanuts
Authors: Whitaker Thomas B , Dowell Floyd E , Hagler Winston M , Giesbrecht Francis G , Wu Jeremy 
Published: February 2020

Abstract
Forty farmers’ stock lots of runner peanuts suspected of containing aflatoxin were identified by the Federal State Inspection Service by using the visual Aspergillus flavus inspection method. A 900 kg portion was removed from each lot and divided into 50 samples each of 2.27 kg (5 lb), 4.54 kg (10 lb), and 6.81 kg (15 lb) weights. For each sample, foreign material was removed, pods were shelled, and all kernels were comminuted for 7 min in a vertical cutter mixer. A100 g subsample was removed from each comminuted sample for aflatoxin analysis by liquid chromatography (LC). The total variance associated with each sample size was estimated. The total variance was also partitioned into sampling, sample preparation, and analytical variance components. Each variance component was shown to be a function of aflatoxin concentration. By using regression techniques, the relationship between variance and aflatoxin concentration was developed for each variance component. The total, sampling, sample preparation, and analytical variances associated with testing a lot at 100 ppb with a 2.27 kg sample, 100 g subsample, and using LC analytical techniques are 25 378,23 533,1830, and 15, respectively. Sampling, sample preparation, and analysis account for 92.7, 7.2, and 0.1% of the total variability, respectively.
Confirmation of Chloramphenicol Residues in Bovine Milk by Gas Chromatography/Mass Spectrometry
Authors: Kijak Philip James 
Published: February 2020

Abstract
A gas chromatographic/mass spectrometric method was developed to confirm the presence of chloramphenicol (CAP) at 0.5 ng/mL in bovine milk. meta-Nitrochloramphenicol (20 ng) is added to 10 mL milk as a surrogate standard. The milk is mixed with ethyl acetate and then loaded onto a diatomaceous earth-filled, solid-phase extraction (SPE) column; CAP is eluted with additional ethyl acetate. A solution of 4% NaCI in water is added to the eluant, and ethyl acetate is removed by evaporation under a flow of N2. The sample is defatted with hexane and then loaded onto a C18-SPE column. The column is washed with water, and CAP is eluted with methanol. The methanol is evaporated under a flow of N2, and the trimethylsilyl derivative is prepared with Sylon HTP (hexamethyldisilazane–trimethylchlorosilane–pyridine, 3 + 1 + 9). The excess reagent is evaporated under N2, and the residue is taken up in cyclohexane-hexane (60 + 40). CAP is separated on a 30 m × 0.25 mm id methylsilicone column having a film thickness of 0.25 pm and analyzed by methane negative chemical ionization with selected ion monitoring. The ions with m/z 304, 322, 358, 360, 466, and 468 are monitored. Confirmation is based on the presence of 5 ions with relative ion abundances within 10% of that obtained by using standards.
Optimization of a Liquid Chromatographic Method Based on Information Theory: Application of the Method to Dissolution Testing
Authors: Matsuda Rieko , Hayashi Yuzuru , Ishibashi Mumio , Takeda Yasushi 
Published: February 2020

Abstract
The simultaneous optimization of mobile phase composition, column length, detection wavelength, and flow rate was applied to the development of an assay method for dissolution testing of multi-ingredient formulations. This optimization procedure is called Total Chromatographic Optimization and is based on the information theory of chromatography. Optimal chromatographic conditions resulted in very rapid and precise measurements. The dissolution test procedures, including sampling, dilution, filtering, and assay, were performed automatically by a laboratory robotic system. The dissolution medium was sampled every 15 min and analyzed immediately for drug concentration.
Determination and Speciation of Arsenic in Human Urine by Ion-Exchange Chromatography/Flow Injection Analysis with Hydride Generation/Atomic Absorption Spectroscopy
Authors: de Blas O Jimenez , Gonzalez S Vicente , Rodriguez R Seisdedos , Mendez J Hernandez 
Published: February 2020

Abstract
A flow injection–hydride generation/atomic absorption spectroscopic method for the measurement of total urinary arsenic and for the selective determination of inorganic arsenic, monomethylarsonic acid (MMAA), and dimethylarsinic acid (DMAA) was developed. Destruction of the organic matrix is necessary to measure total arsenic content of urine samples. Digestion of this matrix with HNO3–H2SO4–H2O2 is described. The separation of inorganic, monomethylated, and dimethylated arsenic compounds in urine was performed with ion-exchange chromatography on AG 50 W-X8 resin. Detection limits of 2 ppb for each arsenic form and of 3 ppb for total arsenic in urine analyzed after mineralization were found. Recoveries in triplicate urine samples spiked with 10 ppb inorganic arsenic, 20 ppb MMAA, and 40 ppb DMAA were 93, 91, and 85%, respectively. The precision (relative standard deviation) of the method obtained in 10 replicate analyses of urine samples spiked with arsenic metabolites varied from 3.2 to 4.6%. This method is applicable to urine samples in studies relating to arsenic exposure and its monitoring.
Determination of Phenol Pollutants in Water at Trace Levels: Extraction by a Reversible Graphitized Carbon Black Cartridge
Authors: Di Corcia Antonio , Marchese Stefano , Samperi Roberto , Cecchini Giancarlo , Cirilli Luciano 
Published: February 2020

Abstract
A method for determining the 11 phenols designated as priority pollutants by the U.S. Environmental Protection Agency at the parts-per-trillion level in water sampled from the environment is described. Drinking (2 L), ground (1.5 L), and river (0.5 L) water samples are preconcentrated by passing them through a 1 g graphitized carbon black (GCB) reversible cartridge at a flow rate of approximately 70 mL/min. After the GCB cartridge is washed with 1.5 mL methanol to eliminate water, the cartridge is reversed and then back-flushed with an acidic CH2Cl2-CH3OH mixture for eluting phenols. After partial solvent removal, the sample is subjected to reversed-phase liquid chromatography with UV detection by either a conventional or a diode-array detector. Recoveries of phenols added to 2 L of drinking water at levels between 0.05 and 4 μg/L were higher than 90%. Compared with an oc-tadecyl bonded silica (C18) cartridge, the GCB cartridge had a far better extraction efficiency for the more highly water-soluble phenols. The extent to which the presence of fulvic acids in water affected the recovery of the phenols considered was investigated.
Determination of Malachite Green Residues in the Eggs, Fry, and Adult Muscle Tissue of Rainbow Trout (Oncorhynchus mykiss)
Authors: Allen John L , Gofus Jane E , Meinertz Jeffery R 
Published: February 2020

Abstract
Malachite green, an effective antifungal therapeutant used in fish culture, is a known teratogen. We developed a method to simultaneously detect both the chromatic and leuco forms of malachite green residues in the eggs, fry, and adult muscle tissue of rainbow trout (Oncorhynchus mykiss). Homogenates of these tissues were fortified with [14C] malachite green chloride and extracted with 1% (v/v) acetic acid in acetonitrile or in methanol. The extracts were partitioned with chloroform, dried, redissolved in mobile phase, and analyzed by liquid chromatography (LC) with postcolumn oxidation of leuco malachite green to the chromatic form. LC fractions were collected every 30 s for quantitation by scintillation counting. Recoveries of total [14C] malachite green chloride residue were 85 and 98% in eggs fortified with labeled malachite green at concentrations of 0.5 and 1.00 μg/g, respectively; 68% in fry similarly fortified at a concentration of 0.65 μg/g; and 66% in muscle homogenate similarly fortified at a level of 1.00 μg/g. The method was tested under operational conditions by exposing adult rainbow trout to 1.00 mg/L [14C] malachite green chloride bath for 1 h. Muscle samples analyzed by sample oxidation and scintillation counting contained 1.3 and 0.5 μg/g total malachite green chloride residues immediately after exposure and after a 5-day withdrawal period, respectively.
Gas Chromatographic Determination of p-Chloroaniline in a Chlorhexidine Digluconate-Containing Alcohol Foam Surgical Scrub Product
Authors: Gavlick Walter K , Davis Paula K 
Published: February 2020

Abstract
A gas chromatographic (GC) method with flame ionization detection was developed to separate and quantitate p-chloroaniline (PCA) from other components in a chlorhexidine digluconate (CHG)-containing alcohol foam surgical scrub product. A simple sample preparation method was developed in which 1-butanol was used to dissolve the foam and precipitate the CHG, which otherwise would interfere with the GC analysis. The method was validated with respect to linear dynamic range, precision, accuracy, selectivity, limit of detection, and limit of quantitation.
Determination of Honey Authenticity by Anion-Exchange Liquid Chromatography
Authors: Swallow Kevin W , Low Nicholas H 
Published: February 2020

Abstract
Methodology using anion-exchange liquid chromatography with pulsed amperometric detection was developed to determine the addition of invert syrups (beet or cane) and high-fructose corn syrup to honey. The invert syrups used were either chemically (commercially) or enzymatically prepared. Fingerprint oligosaccharides were shown to be present in these sweeteners, which were either not detectable or present at low concentrations in pure honey. Forty-four pure honey samples produced in continental North America, Hawaii, China, and Australia were used in this study.
Spectrophotometric Determination of Decamethrin and Its Residues in Insecticidal Formulations and in Water
Authors: Raju R V Prabhakara , Naidu R Raghava 
Published: February 2020

Abstract
Three spectrophotometric methods were developed for the microdetermination of decamethrin in insecticidal formulations and in water. The methods are based on the hydrolysis of decamethrin with methanolic KOH to 3-phenoxybenzaldehyde; condensation of the hydrolysis product with 2,4- dinitrophenylhydrazine (2,4-DNPH), 4-nitrophenylhydrazine (4-NPH), or 2,4,6-trinitrophenylhydrazine (2,4,6-TNPH) under alkaline conditions; and measurement of the condensates at the absorption maxima of 444,535, and 480 nm, respectively. The relationship between absorbance and concentration was linear in the ranges of 0.1–5.0 μg/mL, 0.5–7.0 μg/mL and 0.1–5.5 μg/mL for 2,4-DNPH, 4-NPH, and 2,4,6-TNPH, respectively. The methods are sufficiently sensitive and can be used to detect decamethrin at concentrations as low as 0.1 μg/mL.
Liquid Chromatographic Determination of Norflurazon and Its Initial Metabolite in Soil
Authors: Willian William T , Mueller Thomas C 
Published: February 2020

Abstract
A rapid, sensitive method for the determination of norflurazon in 4 soils is described. Data on the initial soil metabolite is also obtained in soils with low organic matter. The method consists of extraction of soil samples with methanol, filtration, liquid chromatographic separation of methanol-soluble components by using a C18 column, and fluorescence detection with excitation at 294 nm and emission measured at 398 nm. Recoveries from fortified soils were &gt;90% for norflurazon and &gt;80% for desmethylnorflurazon from the Shipps, Lexington, and Harkey soils. Average percent relative standard deviations over the soils examined was 5.5% for norflurazon and 8.7% for desmethylnorflurazon. The limit of detection for norflurazon was 10 ng/g soil, whereas the limit of detection for desmethylnorflurazon was 100 ng/g soil because of its smaller relative detector response.
Determination of Reserpine in Tablets by Liquid Chromatography with Fluorescence Detection: Revised Procedure
Authors: Cieri Ugo R 
Published: February 2020

Abstract
A procedure is presented for the determination of reserpine in tablets by liquid chromatography (LC) that is a slight modification of a method presented in a previous publication. The sample is extracted with methanol, and solutions are filtered through filter paper. For LC, a 7.5 cm column is used; the mobile phase is methanol containing a small volume of an aqueous solution of the sodium salt of 1-pentanesulfonic acid. Detection is by fluorescence with 280 nm excitation and 360 nm emission. Two commercial samples containing 0.1 and 0.25 mg reserpine were analyzed. For each sample, 2 determinations were made on a ground composite. Ten tablets were also analyzed individually. A linearity study was conducted, with solutions ranging in concentration from 80 to 120% of the amount present in the reference solution.
Determination of Trace Elements in Water by Inductively Coupled Plasma–Mass Spectrometry: Collaborative Study
Authors: Longbottom J E , Martin T D , Edgell K W , Long S E , Plantz M R , Warden B E 
Published: February 2020

Abstract
A joint U.S. Environmental Protection Agency (U.S. EPA)—AOAC interlaboratory method validation study was conducted on U.S. EPA method 200.8, Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma–Mass Spectrometry. The purpose of the study was to determine and compare the mean recovery and precision of the inductively coupled plasma–mass spectrometry (ICP–MS) analyses for 20 trace elements in reagent water, drinking water, and groundwater. The formal study was based on Youden’s nonreplicate plan for collaborative tests of analytical methods. The test waters were spiked with the 20 trace elements at 6 concentration levels in the 0.8–200 μg/L range, prepared as 3 Youden pairs. Thirteen collaborators spiked 100 mL aliquots of the test waters, acidified them with 1 mL concentrated HNO3 and 0.5 mL concentrated HCl, reduced the volume to 20 mL by heating in an open beaker at 85°C, refluxed them for 30 min at 95°C, and diluted them to 50 mL. After centrifuging or settling the samples, a 20 mL portion of the supernatant was diluted to 50 mL and analyzed by ICP–MS. Related experiments evaluated the method performance in wastewater and wastewater digestate at a single concentration pair, and an alternative nitric acid digestion procedure. Mean recoveries for reagent water, drinking water, and groundwater were generally 95–105% with between-laboratory relative standard deviations about 4–8%. The method also worked well with wastewaters and digestate, with between-laboratory relative standard deviations averaging 8% and recoveries averaging 100%. Recoveries of silver, however, were low in all matrixes at concentrations over 100 μg/L. The nitric acid digestion procedure was comparable in accuracy and precision to the mixed-acid digestion in U.S. EPA method 200.8. The method was adopted first action by AOAC INTERNATIONAL.
Simultaneous Determination of Organic Acids and Vitamin C in Green Beans by Liquid Chromatography
Authors: Vazquez Oderiz M L , Vazquez Blanco M E , Lopez Hernandez J , Simal Lozano J , Romero Rodriguez M A 
Published: February 2020

Abstract
A method is described for determining and quantitating organic acids (oxalic, malic, citric, and fumaric) and vitamin C by liquid chromatography with a UV–visible detector that allows simultaneous monitoring at 2 wavelengths. The method was applied to samples of green beans (Phaseolus vulgaris L.). Recoveries were 97.8% for oxalic acid, 98.9% for malic acid, 98.7% for citric acid, 99.2% for fumaric acid, and 98.5% for vitamin C. Method precisions (coefficients of variation) were 1.7% for oxalic acid, 0.8% for malic acid, 0.9% for citric acid, 1.5% for fumaric acid, and 1.2% for vitamin C. Measurement precisions (coefficients of variation) were 1.32% for oxalic acid, 0.33% for malic acid, 0.62% for citric acid, 1.01 % for fumaric acid, and 0.39% for vitamin C. Limits of detection were 0.025 mg/mL for oxalic acid, 0.022 mg/mL for malic acid, 0.024 mg/mL for citric acid, 1.0 × 10−4 mg/mL for fumaric acid, and 2.7 × 10−4 mg/mL for vitamin C.
Citrate-Insoluble P2O5: Problems with Ammoniated Fertilizers
Authors: Gliksman Joseph E 
Published: February 2020

Abstract
An AOAC collaborative study of a new direct method for available P2O5 in fertilizer was conducted in 1992. Results on a monoammonium phosphate sample showed more variability than other sample types and also showed the largest absolute difference among the 3 methods compared in the study. Additional study pointed to problems with AOAC method 963.03 for citrate-insoluble
Determination of Ractopamine Hydrochloride in Swine, Cattle, and Turkey Feeds by Liquid Chromatography with Coulometric Detection
Authors: Turberg Michael P , Macy Thomas D , Lewis Jerry J , Coleman Mark R 
Published: February 2020

Abstract
A liquid chromatographic method is described for the determination of ractopamine hydrochloride (LY31537) in swine, turkey, and cattle feeds in the 1.25–100 ppm range and in swine supplement at 100 ppm. Feed samples were extracted with acidified methanol. An aliquot of the feed extract was diluted with water and buffered to pH 10.5 ± 0.5 with sodium carbonate to convert ractopamine hydrochloride to a free base. The free base was extracted from the buffered sample with ethyl acetate. The extract was further purified on an acid-washed, silica solid-phase extraction cartridge. After conversion of the free base back to the salt form with pH 4.5 buffer, analytical separation and quantitation of ractopamine hydrochloride were accomplished on IBM phenyl and Whatman ODS reversed-phase columns with coulometric detection at +600 mV. Mean daily recovery levels ranged from 85 to 100% for feeds fortified at 1.25 to 100 ppm. The coefficients of variation ranged from 1 to 6% for feeds fortified at 2.5 to 100 ppm.