bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sequential-Injection Procedure for Determination of Iodide in Pharmaceutical and Drinking Water Samples by Catalytic Reaction with Spectrophotometric Detection
Authors: Erustes José Antonio , Forteza Rarel , Cerdà Victor 
Published: February 2020

Abstract
A novel sequential-injection system was developed for determination of iodide at very low concentrations by using a kinetic method. The method is based on the catalytic effect of iodide on the redox reaction between Ce4+ and As3+ first described by Sandell and Kolthoff. The calibration curve is constructed by measuring the decrease of Ce4+ absorbance versus iodide concentration with a delay time of 30 s. The detection limit is 1.5 μg/L, the working temperature is 45°C, and the working range is 0.002–0.5 mg/L. Reasonable agreement was obtained when the method was applied to pharmaceutical and drinking water samples. The method has a sample throughput of approximately 15/h.
Simultaneous Determination of all-trans-Retinoic Acid, β-Carotene, and Vitamin A in Galenic Preparations by Liquid Chromatography
Authors: Pucci Vincenzo , Bugamelli Francesca , Mandrioli Roberto , Raggi Maria A 
Published: February 2020

Abstract
The concentrations of vitamin A, β-carotene, and all-trans-retinoic acid in oral preparations were determined in a single analysis by a method based on isocratic, reversed-phase liquid chromatography (LC). The LC system consisted of a C18 column, a mobile phase of acetonitrile, dichloromethane, methanol, and water and a UV detector set at 330 nm. The linearity ranges were 25–250 ng/mL for trans-retinoic acid and vitamin A, and 100–1000 ng/mL for β-carotene. This LC method for the determination of retinoids is simple, precise, and accurate. No extraction procedure is required before the chromatographic analysis; only a suitable dilution is necessary. The method proved to be reliable, fast, and economical. Furthermore, this method is indicative of stability, because it allows for the determination of degradation products such as 13-cis-retinoic acid.
Comparison of Three Analytical Methods for Quality Control of Clozapine Tablets
Authors: Raggi Maria Augusta , Pucci Vincenzo , Bugamelli Francesca , Volterra Vittorio 
Published: February 2020

Abstract
Three different analytical methods for the quality control of clozapine in commercial formulations were developed and compared: a liquid chromatographic (LC) method with UV detection, a capillary zone electrophoretic (CZE) method, and a linear scan voltammetric (LSV) method. The isocratic LC procedure used a C18 reversed-phase column; the CZE method used an uncoated fused-silica capillary and phosphate buffer containing polyvinylpyrrolidone as the background electrolyte; the LSV method analyzed clozapine solutions with acidic phosphate buffer as the supporting electrolyte. The 3 methods gave similar and satisfactory results, in terms of precision and accuracy. Repeatability and intermediate precision were good (RSD% &lt; 2.2) and accuracy, resulting from recovery studies, was between 98 and 102%. The rapidity of analysis was high for all 3 methods, especially for the LSV.
Determination of 3-Trifluoromethyl-4-Nitrophenol and 3-Trifluoromethyl-4-Nitrophenol Glucuronide in Edible Fillet Tissue of Rainbow Trout and Channel Catfish by Solid-Phase Extraction and Liquid Chromatography
Authors: Hubert Terrance D , Vue Chue , Bernardy Jeff A , Horsen Daniel L Van , Rossulek Michelle I 
Published: February 2020

Abstract
3-Trifluoromethyl-4-nitrophenol (TFM) is a pesticide used for the selective control of sea lampreys (Petromyzon marinus) in stream and river tributaries of the Great Lakes. To determine concentrations of TFM and TFM glucuronide in the edible fillet tissue of fish during sea lamprey control treatments, an analytical method was developed to determine the concentrations of these residues in rainbow trout (Oncorhynchus mykiss; RBT) and channel catfish (Ictalurus punctatis; CCF). Homogenized fillets were extracted with methanol–water (80 + 20). TFM and TFM glucuronide were isolated from coextractives by C18 solid-phase extraction. TFM glucuronide was hydrolyzed to TFM by the addition of β-glucuronidase to the TFM glucuronide extract. The extracts were analyzed separately by liquid chromatography with UV–visible detection. Recoveries from TFM-fortified CCF and RBT tissues were 84.1 and 96.1%, respectively. The method detection limits (MDLs) are 2.4 ng/g for TFM-fortified tissues of CCF and 3 ng/g for those of RBT. Recoveries were 78.8 and 77%from TFM glucuronide-fortified CCF and RBT tissues, respectively. The MDLs for TFM glucuronide-fortified tissues are 3.5 and 6.9 ng/g for CCF and RBT, respectively.
Determination of 3-Chloro-1,2-Propanediol in Foods and Food Ingredients by Gas Chromatography with Mass Spectrometric Detection: Collaborative Study
Authors: Brereton Paul , Kelly Janet , Crews Colin , Honour Sarah , Wood Roger , Davies Ann ,   Collaborators:, Anklam E , Baigrie B , Diserens H , Drake P , Ebden C , Fukue N , Hageman L , Louter H , McBreen M , Perfetti G A , Sayer P , Slaiding I R 
Published: February 2020

Abstract
The results of a collaborative study are reported for the determination of 3-chloro-1,2-propanediol (3-monochloropropane-1,2-diol; 3-MCPD) in a wide range of foods and food ingredients, using gas chromatography with mass spectrometric detection and incorporating the use of a deuterated internal standard. After a pretrial study, 12 laboratories (6 United Kingdom, 1 Switzerland, 1 Japan, 2 United States, 1 The Netherlands, and 1 from the European Commission) were asked to analyze 12 test materials (as known duplicates or split-level samples) by using a prescribed procedure. The test materials consisted of duplicate samples of acid-hydrolyzed vegetable protein (containing 3-MCPD at 0.029 mg/kg), malt extract (0.055 mg/kg), wholemeal bread crumbs (0.030 mg/kg), salami (0.016 mg/kg), cheese alternative (0.043 mg/kg), and soup powder (split levels at 0.045 and 0.041 mg/kg). Repeatability ranged from 0.005 to 0.013 mg/kg and reproducibility, from 0.010 to 0.027 mg/kg, for the samples tested. Precision values were well within statistically predicted levels (HORRAT values of &lt;1 for 5 of the 6 matrixes tested) and within method criteria prepared by a joint working group composed of the United Kingdom Ministry of Agriculture, Fisheries and Food and industry representatives. The study demonstrated the satisfactory validation of the method for quantifying 3-MCPD at levels of ≥0.010 mg/kg. The limit of detection derived from separate in-house studies was estimated to be 0.005 mg/kg. The method was adopted First Action by AOAC INTERNATIONAL.
Identification of Hydrolyzed Inulin Syrup and High-Fructose Corn Syrup in Apple Juice by Capillary Gas Chromatography PVM 4:1999
Authors: Low Nicholas H , McLaughlin Michael A , Page Samuel W , Canas Benjamin J , Brause Allan R , Low Nicholas H 
Published: February 2020

Abstract
A peer-verified, gas chromatographic (GC) method is presented for the identification of hydrolyzed inulin syrup (HIS) and high-fructose corn syrup (HFCS) in apple juice. The procedure involves determining the Brix value of the apple juice or apple juice concentrate and preparing a dilution of the test sample to 5.5° Brix. A 100 μL aliquot of the 5.5° Brix test solution is then freeze-dried in a GC autosampler vial. The sugars in the freeze-dried residue are converted to trimethylsilyl derivatives, by the addition of an appropriate silylation reagent, and the vial is heated at 75°C for 30 min. After derivatization, the solution is introduced into a gas chromatograph where the analytes are separated on a 30 m, 0.25 mm id DB-5 column. The method can use hydrogen, helium, or nitrogen as the carrier gas. The analytes and marker compounds are measured by use of a flame ionization detector. Commercial apple juice concentrates were diluted with one of the 2 syrups at 2 levels. Dilution was ascertained by the presence of retrograde sugar markers found in the 2 sugar syrups. All 3 laboratories involved in the study were able to identify the correct diluent in the blind, randomly coded, apple juice test portions. The levels of dilution in the test portions were 0, 6.9% (HIS), 16.0% (HIS), 8.1% (HFCS), and 17.0% (HFCS). No false positive results were reported. Quantitative conclusions can be drawn when the same syrup is used for dilution and as a reference standard.
Moisture Variations in Brine-Salted Pasta Filata Cheese
Authors: Kindstedt Paul S 
Published: February 2020

Abstract
A study was made of the moisture distribution in brine-salted pasta filata cheese. Brine-salted cheeses usually develop reasonably smooth and predictable gradients of decreasing moisture from center to surface, resulting from outward diffusion of moisture in response to inward diffusion of salt. However, patterns of moisture variation within brine-salted pasta filata cheeses, notably pizza cheese, are more variable and less predictable because of the peculiar conditions that occur when warm cheese is immersed in cold brine. In this study, cold brining resulted in less moisture loss from the cheese surface to the brine. Also it created substantial temperature gradients within the cheese, which persisted after brining and influenced the movement of moisture within the cheese independently of that caused by the inward diffusion of salt. Depending on brining conditions and age, pizza cheese may contain decreasing, increasing, or irregular gradients of moisture from center to surface, which may vary considerably at different locations within a single block. This complicates efforts to obtain representative samples for moisture and composition testing. Dicing the entire block into small (e.g., 1.5 cm) cubes and collecting a composite sample after thorough mixing may serve as a practical sampling approach for manufacturers and users of pizza cheese that have ready access to dicing equipment.
Moisture Nonuniformity and Sampling Errors in Large Cheddar Cheese Blocks
Authors: Barbano David M 
Published: February 2020

Abstract
A study was made of the impact of nonuniform moisture distribution in 290 kg blocks of cheese on the accuracy of sampling the cheese for moisture content. The range of moisture from center to outside surfaces of the blocks was about 5%. The temperature gradient, developed in the first 24–48 h after cheese making, drove the moisture migration from warm to cold areas in the cheese blocks during initial cooling. The moisture gradient from center to outside of each block, the non-symmetrical nature of the gradient, and the actual length of the core sample all contributed to random and systemic error in sampling within a single cheese plant. It was concluded that average moisture differences from vat to vat in a factory were small, and large variations in moisture tests were due to sampling errors.
Movement of Moisture in Refrigerated Cheese Samples Transferred to Room Temperature
Authors: Emmons Douglas B , Bradley Robert L , Campbell Carol , Sauvé J Paul 
Published: February 2020

Abstract
When cheese samples refrigerated at 4°C in 120 mL plastic tubs were transferred to room temperature at 23°C, moisture began to move from the warmer surface to the cooler interior; the difference after 1 h was 0.2–0.4%. Others had observed that moisture moved from the interior of warmer blocks of cheese to the cooler surface during cooling at the end of cheese manufacture. In loosely packed cheese prepared for analysis, part of the moisture movement may have been due to evaporation from the warmer surface and condensation on the cooler cheese. It is recommended that cheese be prepared for analysis immediately before weighing. Cheese samples that have been refrigerated, as in interlaboratory trials, should also be remixed or prepared again.
Measuring Moisture in Cheese by Near Infrared Absorption Spectroscopy
Authors: McKenna David 
Published: February 2020

Abstract
Data in the literature indicate that the measurement of moisture in cheese by near infrared transmittance (NIT) is more accurate than by reflectance (NIR). The accuracy of the NIT measurement (SEP) was calculated for Edam, Gouda, Brie, Colby, and Cheddar. A range of SEP values (0.12–0.35) was obtained using different methods of calibration for different types of samples. There was close agreement between these results, as they related to the precision of the reference method. The calibration validation technique described as Standard Error of Cross Validation (SECV) generated results that compared very closely to the equivalent SEP values for independent sample sets.
Determination of DiazaCon in Quail Feed and Quail Serum by Ion Pair Reversed-Phase Chromatography
Authors: Johnston John J , Goodall Margaret J , Hurley Jerome C , Yoder Christi A , Miller Lowell A 
Published: February 2020

Abstract
Liquid chromatographic (LC) methods were developed for quantitating the potential avian contraceptive DiazaCon in quail feed and serum. DiazaCon was extracted from ground quail feed with basic n-butyl chloride. The n-butyl chloride extract was evaporated to dryness. The DiazaCon residues were dissolved in an aqueous methanolic ion pairing solution and quantitated by LC at 206 nm. Avian sera was combined with an equal volume of a pH 4 aqueous solution of ion pairing reagent and filtered to remove interfering proteins. DiazaCon was quantitated by LC. Mean recoveries for 500 and 2000 ppm fortified feed were 89.1 and 91.0%, respectively. The mean recovery for sera fortified at 5 levels ranging from 35 to 2000 ppm was 84.9%. Method limits of detection were approximately 14 and 13 ppm for feed and sera, respectively.
Separation and Quantitation of Hazardous Wastes from Abrasive Blast Media
Authors: Hwang Jiann-Yang , Jeong Mijeong Lee 
Published: February 2020

Abstract
A sample of glass bead abrasive blasting material (ABM) waste, received from Robins Air Force Base (Georgia), was examined to determine whether the waste could be rendered nonhazardous by separating paint contaminants from the ABM. The sample was analyzed with size distribution and toxicity characteristics leaching procedure. A Microtrac analyzer was used to measure the size of fine particles (−325 Tyler mesh), and scanning electron microscopy analysis was performed to identify the nature of the contaminants in the ABM waste. Tests using froth flotation, magnetic separation, desliming, and acid washing were conducted to develop a process for removing the contaminants. A pilot plant test using the developed process rendered 82.1% or the ABM waste material nonhazardous.
Determination of Trace Levels of Manganese in Various Biological and Environmental Samples by Atomic Absorption Spectrometry after Solid–Liquid Extraction and Preconcentration with the Ion Pair Formed by the Nitroso-S Anion and the Tetradecyldimethylbenzylammonium Cation
Authors: Taher Mohammad Ali , Dehzoei Ali Mostafavi 
Published: February 2020

Abstract
Manganese is quantitatively retained by 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S) and tetradecyldimethylbenzylammonium (TDBA) chloride on microcrystalline naphthalene in the pH range 9.5–10.6 from large volumes of aqueous solutions of various samples. After filtration, the solid mass consisting of the manganese complex and naphthalene is dissolved in 5 mL dimethylformamide and the metal is determined by flame atomic absorption spectrometry. Alternatively, the manganese complex can be quantitatively adsorbed on TDBA–naphthalene adsorbent packed in a column and determined similarly. About 0.2 μg manganese can be concentrated in a column from 400 mL aqueous sample with a concentration as low as 0.5 ng/mL. Eight replicate determinations of manganese at 0.8 μg/mL gave a mean absorbance of 0.156 for the final solution with a relative standard deviation of 1.4%. The sensitivity for 1% absorption was 23 ng/mL. The interference of a large number of anions and cations was studied, and the optimized conditions developed were used for trace determinations of manganese in various alloys, and in biological and environmental samples.
Solid-Phase Extraction, Separation, and Visible Spectrophotometric Determination of Trace Amounts of Iron in Water Samples
Authors: Yamini Yadollah , Amiri Nayyereh 
Published: February 2020

Abstract
A simple and reliable method is presented for the rapid extraction, separation, preconcentration, and determination of iron as its bathophenanthroline complex by the use of octadecylsilica membrane disks and spectrophotometry. We evaluted extraction efficiency, the influence of sample matrix, type and optimum amount of extractant, flow rates of sample solution and eluent, pH, amounts of bathophenanthroline and hydroxylamine hydrochloride, breakthrough volume, and limit of detection. We also studied the effects of various cationic interferences on percent recovery of iron. Complete elution of the complex from disks was obtained with a minimal amount of solvent. The limit of detection of the proposed method is 0.080 ppb. The method was applied to the recovery and determination of iron in natural waters.
Distribution among Sample Test Results when Testing Shelled Corn Lots for Fumonisin
Authors: Whitaker Thomas B , Hagler Winston M , Johansson Anders S , Giesbrecht Francis G , Trucksess Mary W 
Published: February 2020

Abstract
The statistical distribution known as the compound gamma function was studied for suitability in describing the distribution of sample test results associated with testing lots of shelled corn for fumonisin. Thirty-two 1.1 kg test samples were taken from each of 16 contaminated lots of shelled corn. An observed distribution consisted of 32 sample fumonisin test results for each lot. The mean fumonisin concentration, c, and the variance, s2, among the 32 sample fumonisin test results along with the parameters for the compound gamma function were determined for each of the 16 observed distributions. The 16 observed distributions of sample fumonisin test results were compared with the compound gamma function using the Power Divergence test. The null hypothesis that the observed distribution could have resulted from sampling a family of compound gamma distributions was not rejected at the 5% significance level for 15 of the 16 lots studied. Parameters of the compound gamma distribution were calculated from the 32-fumonisin sample test results using the method of moments. Using regression analysis, equations were developed that related the parameters of the compound gamma distribution to fumonisin concentration and the variance associated with a fumonisin test procedure. An operating characteristic curve was developed for a fumonisin sampling plan to demonstrate the use of the compound gamma function.
Identification of Allantoin, Uric Acid, and Indoxyl Sulfate as Biochemical Indicators of Filth in Food Packaging by LC
Authors: Carlson Marvin , Thompson Richard D 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was developed for the determination of allantoin, uric acid, and indoxyl sulfate in mammalian urine contaminated packaging material including paper bagging, corrugated cardboard, grayboard, and burlap bagging. The procedure involves solvent extraction and isolation of the 3 analytes by reversed-phase LC with ultraviolet detection at 225 nm for allantoin and 286 nm for uric acid and indoxyl sulfate. The composition of authentic mammalian urine such as mouse, rat, cat, dog, and human were also determined with regard to the 3 compounds of interest. A linear concentration range of 0.11–20.4, 0.02–10.0, and 0.04–30.0 μg/mL was obtained for allantoin, uric acid, and indoxyl sulfate, respectively. Limits of detection (LOD) and quantitation (LOQ) were 0.0104 and 0.0345 μg/mL for allantoin; 0.0018 and 0.0060 μg/mL for uric acid; and 0.0049 and 0.0165 μg/mL for indoxyl sulfate, respectively. Interday relative standard deviation values for a mixture of standard allantoin, uric acid, and indoxyl sulfate (n = 5) were 0.97, 0.80, and 0.94%, respectively. Analyte composition for 5 types of authentic mammalian urine varied from 0.19–6.88 mg/mL allantoin; 0.08–0.57 mg/mL uric acid; and 0.03–0.78 mg/mL indoxyl sulfate. Analyte content for 8 samples including 2 samples each for paper, cardboard, grayboard, and burlap bagging each contaminated with mouse or rat urine ranged from &lt;LOD to 4598 μg/gm allantoin; &lt;LOD to 202 μg/gm uric acid; and 17.5 to 616 μg/gm indoxyl sulfate. Recoveries of allantoin, uric acid, and indoxyl sulfate from 11 fortified samples (4 types) for both mouse and rat urine ranged from 28.2 to 114.1% for allantoin; 32.6 to 123.4% for uric acid; and 52.6 to 118.2% for indoxyl sulfate.
Determination of Lead and Cadmium in Ceramicware Leach Solutions by Graphite Furnace Atomic Absorption Spectroscopy: Method Development and Interlaboratory Trial
Authors: Hight Susan C 
Published: February 2020

Abstract
This method was developed to improve sensitivity and eliminate time consuming, evaporative pre-concentration in AOAC Method 973.82 and American Society for Testing and Materials method C738 for testing foodware. The method was developed using leach solutions obtained by leaching 9 differently decorated ceramic vessels with 4% acetic acid for 24 h at room temperature. Lead and cadmium concentrations in leach solutions were 0.005–17 600 and 0.0004–0.500 μg/mL, respectively. Concentrations were determined using peak area, phosphate chemical modifier (8.3 μg PO4−3), and a standard curve for quantitation. Optimized pre-atomization and atomization temperatures were 1300 and 1800°C, respectively, for Pb and 1100 and 1700°C, respectively, for Cd. Characteristic masses (mo) were 10 and 0.4 pg for Pb and Cd, respectively. Precision of repeated analyses of calibration solutions was ≤3% relative standard deviation. Precision of duplicate leach solution analyses on different days was 0–9% relative difference. Recovery from fortified leach solutions was 96–106%. Results obtained by this method agreed 92–110% with those of confirmatory analyses. Results of certified reference material solutions agreed 94–100% with certificate values. Pb and Cd limits of quantitation (LOQ) were 0.005 and 0.0005 μg/mL, respectively. Results from 3 trial laboratories for 4 leach solutions containing Pb and Cd concentrations of 0.017–1.47 and &lt;0.0005–0.0864 μg/mL, respectively, agreed 89–102% with results of the author. Two attributes of this method were noteworthy: (1) Background absorbance due to organic matter was entirely absent from atomization profiles, making the use of short pre-atomization hold times (2 s) possible. (2) Instrument precision was excellent and only one determination per solution was needed. Acceptance criteria for quality control measurements and a practical procedure for estimating the method LOQ during routine regulatory analyses are described.