bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Determination of Diethylene Glycol Contamination in Pharmaceutical Products
Authors: Baffi Patricia , Elneser Suria , Baffi Myrna , Melin Matilde De 
Published: February 2020

Abstract
A simple, rapid, and reliable method was developed for the quantitative determination of diethylene glycol (DEG) in pharmaceutical products using capillary gas chromatography with flame ionization detection. The method uses ethylene glycol as internal standard and allows for the separation of propylene glycol and DEG. The assay was linear in a DEG concentration range between 1.0 and 10.00 mg/mL, with coefficients of variation of 2.3–4.4% for the tested concentrations. Quantitation and detection limits, respectively, were 1.0 mg/mL and 0.15 mg/mL diethylene glycol. The method was used to analyze 3 pharmaceutical products possibly contaminated with diethylene glycol, of which one was suspected of causing intoxication and death in children. Infrared spectroscopy was used to confirm the identity of diethylene glycol. This analytical methodology is proposed for evaluation of pharmaceutical products containing glycols to prevent intoxication and for security level verification.
Equivalence of Visual Immunoprecipitate Assay (VIP®) for Salmonella for the Detection of Motile and Nonmotile Salmonella in All Foods to AOAC Culture Method: Collaborative Study
Authors: Feldsine Philip T , Mui Linda A , Forgey Robin L , Bargholz J , Kerr David E ,   Collaborators:, Al-Hasani S , Arling V , Beatty S , Bohannon J , Brannan J , Brown N , Bryant J , Burford M , Chavez C , Chinault K , Cooan N , Copeland F , Dixon L , Fitzgerald S , Franke W , Frissora R , Gailbreath K , Godon S , Good M , Ha T , Hagen H , Hanson S , Johnson K , Koch S , Leung S , Lienau A , Lin J , Lin S , Marolla B , Maycock L , McDonagh S , Miller L , Otten N , Post R , Resutek J , Rice B , Richter D , Ritger C , Schwantes D , Simon J , Smith J , Smith S , Stokes R , Thibideau J , Tuncan E , Uber D , Van Landingham V , Vrana D , West D 
Published: February 2020

Abstract
Six foods representative of a wide variety of processed, dried powder processed, and raw food types were analyzed by the Visual Immunoprecipitate Assay (VIP®) for Salmonella and AOAC INTERNATIONAL culture method. Paired samples of each food type were simultaneously analyzed; one sample by the VIP method and one by the AOAC culture method. A total of 24 laboratories representing federal government agencies and private industry, in the United States and Canada, participated in this collaborative study. Food types were inoculated with species of Salmonella with the exception of raw ground chicken, which was naturally contaminated. No statistical differences (p &lt; 0.05) were observed between VIP for Salmonella interpretation and the AOAC culture method for any inoculation level of any food type or naturally contaminated food. The method was adopted Official First Action status by AOAC INTERNATIONAL.
Isolation of Alicyclobacillus acidoterrestris from Fruit Juices
Authors: Walls Isabel , Chuyate Rolenda 
Published: February 2020

Abstract
K agar, a novel isolation medium developed for the food industry, was compared with other acidified media for isolation of Alicyclobacillus acidoterrestris spores. Spores were inoculated into apple juice, orange juice, and a fruit juice blend and then isolated on the following media: K agar, pH 3.7; semi-synthetic medium, pH 4.0; orange serum agar, pH 3.5; and minimal salts medium, pH 4.0. Media were incubated at 24, 35, 43, and 55°C. Highest recovery of spores was obtained with either K agar or semi-synthetic medium, incubated at 43°C. The effect of heat shocking spores at different times was also determined; heat shocking at 80°C for 10 min was considered appropriate. Peptone, previously shown to inhibit A. acidoterrestris, was not inhibitory when present in K agar. A collaborative trial with 9 laboratories was undertaken to determine the repeatability and reproducibility of counts on K agar. K agar prepared from individual components was compared with dehydrated K agar prepared by International BioProducts (Redmond, WA). There were no significant differences between log mean counts for the 2 media for each of the juices analyzed at both the high and the low inoculum levels. Repeatability and reproducibility values were not significantly different either within juices, within trials, or across all samples tested in both trials. K agar is suitable for isolation of A. acidoterrestris spores from fruit juices.
Revalidation and Long-Term Stability of National Institute of Standards and Technology Standard Reference Materials 1566, 1567, 1568, and 1570
Authors: Anderson David L , Cunningham William C 
Published: February 2020

Abstract
Multiple units of Standard Reference Materials (SRMs) 1566 Oyster Tissue, 1567 Wheat Flour, 1568 Rice Flour, and 1570 Trace Elements in Spinach, produced by the National Institute of Standards and Technology (NIST, then the National Bureau of Standards), were analyzed 17–20 years after the original certification dates and 12–15 years after the certificates became invalid. Instrumental neutron activation analysis and thermal neutron prompt (γ-ray activation analysis were used to measure mass fractions for 27 elements in these SRMs to revalidate them for use in quality assurance (QA) programs required for food analysis programs within the U.S. Food and Drug Administration. With the exception of Se in SRM 1567, all element mass fractions were in agreement with certified values and literature data. Some evidence of B loss from SRM 1568 was observed. These materials were judged to be suitable for continued use in QA programs. Findings showed that these matrixes exhibited stability of moisture, mass fraction, and weight basis for far longer (≥15 years) than was indicated by the 5-year validity statement on the NIST Certificates of Analysis.
Testing Shelled Corn for Aflatoxin, Part III: Evaluating the Performance of Aflatoxin Sampling Plans
Authors: Johansson Anders S , Whitaker Thomas B , Giesbrecht Francis G , Hagler Winston M , Young James H 
Published: February 2020

Abstract
The effects of changes in sample size and/or sample acceptance level on the performance of aflatoxin sampling plans for shelled corn were investigated. Six sampling plans were evaluated for a range of sample sizes and sample acceptance levels. For a given sample size, decreasing the sample acceptance level decreases the percentage of lots accepted while increasing the percentage of lots rejected at all aflatoxin concentrations, and decreases the average aflatoxin concentration in lots accepted and lots rejected. For a given sample size where the sample acceptance level decreases relative to a fixed regulatory guideline, the number of false positives increases and the number of false negatives decreases. For a given sample size where the sample acceptance level increases relative to a fixed regulatory guideline, the number of false positives decreases and the number of false negatives increases. For a given sample acceptance level, increasing the sample size increases the percentage of lots accepted at concentrations below the regulatory guideline while increasing the percentage of lots rejected at concentrations above the regulatory guideline, and decreases the average aflatoxin concentration in the lots accepted while increasing the average aflatoxin concentration in the rejected lots. For a given sample acceptance level that equals the regulatory guideline, increasing the sample size decreases misclassification of lots, both false positives and false negatives.
Determination of Sodium Azide in Beverages by Ion Chromatography
Authors: Oshima Harumi , Ueno Eiji , Saito Isao , Matsumoto Hiroshi 
Published: February 2020

Abstract
A convenient method for determination of sodium azide in beverages using ion chromatography is described. This method combines the specificity for azide with a simple sample preparation using a bubble and trap apparatus that removes any interferences. Sodium azide in a sample was acidified, and the azide was converted to the volatile hydrazoic acid, which was trapped in 2.5mM sodium hydroxide solution. Determination was performed by isocratic ion chromatography using suppressed conductivity detection. Calibration curves were linear for 0.5 to 20 μg/mL sodium azide and the detection limit was 0.05 μg/mL. Recoveries of sodium azide from spiked samples (10.0 μg/g) were more than 82.6%. The method was then used to analyze various beverages.
Determination of Oxycodone Hydrochloride in Oral Solutions by High-Performance Thin-Layer Chromatography/Densitometry
Authors: Salomies Hannele E M , Salo Piia K 
Published: February 2020

Abstract
A thin-layer chromatography/densitometry method was developed and validated for the determination of oxycodone hydrochloride in oral solutions by using silica gel plates. A horizontal technique was used for development of the plates. The optimum composition for the mobile phase, which provided a suitable Rf value of 0.6 for oxycodone, was propanol–acetic acid–water–25% ammonia–methanol (20 + 1 + 1 + 3 + 10). Detection was at 234 nm. Oxycodone hydrochloride was stable on the sorbent and was precisely and accurately measured in the range of 0.3–1.5 μg/band.
Voltammetric Determination of Benazepril and Ramipril in Dosage Forms and Biological Fluids through Nitrosation
Authors: Belal Fathalla , Al-Zaagi Ibrahim A , Abounassif Mohamed A 
Published: February 2020

Abstract
A simple and highly sensitive voltammetric method was developed for the determination of benazepril (I) and ramipril (II). The compounds were treated with nitrous acid, and the cathodic current produced by the resulting nitroso derivatives was measured. The voltammetric behavior was studied by adopting direct current (DCt), differential pulse (DPP), and alternating current (ACt) polarography. Both compounds produced well-defined, diffusion-controlled cathodic waves over the whole pH range in Britton-Robinson buffers (BRb). At pH 3 and 5, the values of diffusion-current constants (Id), were 5.90 ± 0.40 and 6.66 ± 0.61 for I and II, respectively. The current–concentration plots for I were rectilinear over the range of 1.5–40 and 0.1–30 μg/mL in the DCt and DPP modes, respectively; for II, the range was 2–30 and 0.1–20 μg/mL in the DCt and DPP modes, respectively. The minimum detectabilities (S/N = 2) were 0.015 μg/mL (about 3.25 × 10−8M) and 0.012 μg/mL (about 2.88 × 10−8M) for I and II, respectively, adopting the DPP mode. Results obtained for the proposed method when applied to the determination of both compounds in dosage forms were in good agreement with those obtained using reference methods. Hydrochlorthiazide, which is frequently co-formulated with these drugs, did not interfere with the assay. The method was also applied to the determination of benazepril in spiked human urine and plasma. The percentage recoveries adopting the DPP mode were 96.2 ± 1.21 and 95.7 ± 1.61, respectively.
Automated Microwave Digestion of Certifiable Color Additives for Determination of Mercury by Cold Vapor Atomic Absorption Spectrometry
Authors: Hepp Nancy M , Cargill Anne M , Shields Wendy B 
Published: February 2020

Abstract
A procedure using an automated microwave flow digestion technique was developed and validated for the digestion of samples of certifiable color additives before mercury determination by cold vapor atomic absorption spectrometry. Recovery studies were performed by spiking most of the color additives subject to batch certification by the U.S. Food and Drug Administration with inorganic mercury (HgNO3) and with organic mercury (CH3HgCl). Successful recoveries of 72–113% Hg added at the 1 μg/g level were obtained. A method detection limit of 0.2μg Hg/g was estimated from a Hg-spiked FD&C Yellow No. 6 sample. At the specification level of 1 ppm Hg (1 μg Hg/g), the 95% confidence interval was ± 0.2 ppm (0.2 μg Hg/g).
Preconcentration of Bismuth(III) and Copper(II) by Solid-Phase Extraction and Subsequent Determination by Differential Pulse Polarography
Authors: Bhalotra Anju , Prui Bal Krishan 
Published: February 2020

Abstract
A differential pulse polarographic method is proposed for the trace determination of bismuth and copper from large volumes of aqueous samples after adsorption of their 1-(2-thiazolylazo)-2-naphthol complexes onto microcrystalline naphthalene in the pH ranges of 7.2–9.0 and 4.0–7.8, respectively. Bismuth and copper are desorbed from microcrystalline naphthalene with 9 mL 1M HCl. Well-defined peaks are obtained at Ep = −0.09 and −0.20 V versus a saturated calomel electrode, in an HCl–isoquinoline medium as the supporting electrolyte, for bismuth and copper, respectively. Bismuth is reduced reversibly with a 3-electron change, whereas copper is reduced irreversibly under these conditions. The detection limits are 55 ng/mL for bismuth and 91 ng/mL for copper. Linearity is maintained in the concentration ranges of 0.18–13.5 and 0.30-17.3 μg/mL for bismuth and copper, respectively, with corresponding correlation coefficients of 0.9996 and 0.9885. The relative standard deviations are 1.0% for bismuth at 2.0 μg/mL and 1.4% for copper at 5.0 μg/mL. Various parameters were optimized to develop conditions for the determination of these metal ions in various samples.
Multiwavelength Spectral Correction for the Simultaneous Determination of Cu(II), Fe(II), and Zn(II) with 1-(5-Bromo-2-Pyridylazo)-2-Naphthol-6-Sulfonic Acid
Authors: Gao Hong-Wen 
Published: February 2020

Abstract
A new analytical method is described for the simultaneous determination of various components by multiwavelength spectrophotometry. Because of the influence of the free ligand and various complexes on spectrophotometric absorption, the spectral correction principle was used to establish the calculation matrix formula. The 3 sensitive reactions of Cu(II), Fe(II), and Zn(II), with 1-(5-bromo-2-pyridylazo)-2-naphthol-6-sulfonic acid were studied at pH 10.5. In analyses of fortified samples, the recoveries of Fe, Zn, and Cu were between 93.0 and 103%, 87.0 and 108%, and 92.5 and 108%, respectively; the relative standard deviations for 5 determinations of Fe, Zn, and Cu in unfortified ore were 3.6, 5.8, and 4.5%, respectively.
Determination of Sulfate in Natural and Residual Waters by Turbidimetric Flow-Injection Analysis
Authors: Morais Inês P A , Rangel António O S S , Souto M Renata S 
Published: February 2020

Abstract
A turbidimetric flow-injection system was developed for the determination of sulfate in natural and residual water samples, with no previous treatment, using spectrophotometric detection. The precipitating agent, 7.0% (w/v) barium chloride solution prepared in 0.10% (w/v) polyvinyl alcohol, was added by using the merging-zones approach. A 100 mg/L sulfate solution in 0.07M nitric acid was mixed with the sample before it entered the injection loop to improve the detection limit, provide in-line pH adjustment, and prevent the interference of some anionic species. The relative standard deviations of the results were between 1.4 and 3.0% and were in agreement with results obtained by the reference method. Samples within a linear concentration range of 10–120 mg SO42−/L can be analyzed at a rate of 40/h. The detection limit is 5 mg SO42−/L.
Rappaport-Vassiliadis Medium for Recovery of Salmonellaspp. from Low Microbial Load Foods: Collaborative Study
Authors: Hammack Thomas S , Amaguaña R Miguel , Andrews Wallace H ,   Collaborators:, Al-Hasani S M , Asmundson R , Battista K , Beatty S J , Berges-Soubies V A , Bozicevich T , Brooks D , Case J , Coles C , Copeland F , Davis-Debella P E , Entis P , Feldsine P , Fourcade L , Garcia G R , Goins D G , Jackson T , Koch S , Lafogiannis J A , Lee J , Lerner I , McIntyre D , McKee B , McNally S , Muchnik V , Mui L , Pfundheller R , Raghubeer E V , Rains D , Ruscica G , Schmieg J , Sellers R , Smoot M , Sobol R , Thunberg R , Torres S , Trinidad L F , Tuncan E , Watson J M 
Published: February 2020

Abstract
Twenty-three laboratories participated in a collaborative study to compare the relative effectiveness of Rappaport-Vassiliadis (RV) medium incubated at 42°C, selenite cystine (SC) broth (35°C), and tetrathionate (TT) broth (35 and 43°C) for recovery of Salmonella from the following foods with a low microbial load: dried egg yolk, dry active yeast, ground black pepper, guar gum, and instant nonfat dry milk. For dry active yeast, lauryl tryptose (LT) broth, incubated at 35°C, was used instead of SC broth. All of the foods were artificially inoculated with single Salmonella serovars, that had been lyophilized before inoculation, at high and low target levels of 0.4 and 0.04 colony forming units/g food, respectively. For analysis of 870 test portions, representing all of the foods except yeast, 249 Salmonella-positive test portions were detected by RV medium, 265 by TT broth (43°C), 268 by TT broth (35°C), and 269 by SC broth (35°C). For analysis of 225 test portions of yeast, 79 Salmonella-positive test portions were detected by RV medium, 79 by TT broth (43°C), 84 by TT broth (35°C), and 68 by LT broth (35°C). RV medium was comparable to, or even more effective than, the other selective enrichments for recovery of Salmonella from all of the foods except guar gum. It is recommended that RV (42°C) and TT (35°C) be used with foods that have a low microbial load, except for guar gum for which SC (35°C) and TT (35°C) are recommended.
New Method for Determination of Ten Pesticides in Human Blood
Authors: GarcÍa-Repetto Rosario , Giménez M Paz , Repetto Manuel 
Published: February 2020

Abstract
An analytical method was developed for precise identification and quantitation of 10 pesticides in human blood. The pesticides studied, which have appeared frequently in actual cases, were endosulfan, lindane, parathion, ethyl-azinphos, diazinon, malathion, alachlor, tetradifon, fenthion and dicofol (o-p′ and p-p′ isomers). The current method replaces an earlier method which involved liquid–liquid extraction with a mixture of n-hexane–benzene (1 + 1). The extraction is performed by solid-phase extraction, with C18 cartridges and 2 internal standards, perthane and triphenylphosphate. Eluates were analyzed by gas chromatography (GC) with nitrogen–phosphorus and electrochemical detectors. Results were confirmed by GC–mass spectrometry in the electron impact mode. Blood blank samples spiked with 2 standard mixtures and an internal standard were used for quantitation. Mean recoveries ranged from 71.83 to 97.10%. Detection and quantitation limits are reported for each pesticide. Examples are provided to show the application of the present method to actual samples.
Monitoring of Pesticide Residues in Egyptian Fruits and Vegetables During 1996
Authors: Dogheim Salwa M , Gad Alla Sohair A , El-Marsafy Ashraf M 
Published: February 2020

Abstract
Samples of the most common fruits and vegetables were collected from 8 local markets in 6 governorates. These 1579 samples were analyzed for residues of 53 pesticides, which included organophosphorus and organonitrogen compounds and some synthetic pyrethroids. Samples were also analyzed for residues of organochlorine pesticides, although they had been prohibited from use several years ago. Only 510 of the 1579 samples were analyzed for dithiocarbamate pesticide residues, which were determined as CS2. Overall, 76.1% of the total analyzed samples had no detectable residues, 23.9% contained detectable residues, and 2.59% contained residues that exceeded maximum residue limits. For individual crops, contaminated samples ranged from 0 to 96% of the number of samples analyzed. However, the highest violative percentage for samples of individual crops was 12.5. Chlorpyrifos, carbaryl, dimethoate, bromopropylate, and profenofos were the violative pesticides determined in fruit and vegetable samples. The results of the current study demonstrated that no restricted or banned pesticides such as DDT, HCH, and their isomers were found in any of the samples analyzed. Dithiocarbamate residues were detected in 9.4% of the 510 samples analyzed, with a violative percentage of 0.39, representing one grape sample and one peach sample.
Determination of Arsenic in Seafood by Focused Microwave Digestion and Hydride Generation–Atomic Fluorescence Detection
Authors: Vilanó Marc , Rubio Roser 
Published: February 2020

Abstract
A new method was developed for total arsenic determination in seafood products such as oysters, mussels, tuna fish, and algae. Matrix decomposition and oxidation to arsenate of all the arsenic compounds in the product were completed in 25 min by using a 3-step program of focused microwaves (40–120 W) with nitric and sulfuric acids. Quantitation was performed by hydride generation-atomic fluorescence detection (HG–AFS). Results of method optimization are presented and discussed. A detection limit &lt;125 μg/kg arsenic was obtained; the quantitation limit was close to 400 μg/kg, with repeatability and reproducibility &lt;5% relative standard deviation. Validation was performed by analyzing 4Reference Materials (arsenic concentration expressed as mg/kg): The National Institute of Standards and Technology SRM 1566a Oyster tissue (14.0 ± 1.2); the Bureau Community of Reference (now Standard Measurements & Testing Program) CRM 278 Mussel tissue (5.9 ± 0.2) and CRM 627 Tuna fish (4.8 ± 0.3); and the International Atomic Energy Agency RM 140 Fucus sample (44.3 ± 2.1).
Mixed-Mode Solid-Phase Extraction and Cleanup Procedures for the Liquid Chromatographic Determination of Thiabendazole and Carbendazim in Fruit Juices
Authors: Young Michael S , Phillips Dorothy J , Iraneta Pamela C , Krol Jim 
Published: February 2020

Abstract
Solid-phase extraction (SPE) procedures were developed for rapid cleanup and determination of thiabendazole and carbendazim in orange, apple, and grape juices. Samples were prepared by using an SPE cartridge containing a mixed-mode sorbent with both reversed-phase and strong cation-exchange chemistries. Analysis was by liquid chromatography with photodiode-array UV detection. Orange juice was analyzed by mixed-mode cation-exchange extraction with reversed-phase cleanup; the other juices were analyzed by reversed-phase extraction with cation-exchange cleanup. Recoveries &gt;80% for carbendazim and &gt;90% for thiabendazole. Quantitation limits were 20 μg/L for both analytes.
Simultaneous Determination of Residues of Emamectin and Its Metabolites, and Milbemectin, Ivermectin, and Abamectin in Crops by Liquid Chromatography with Fluorescence Detection
Authors: Yoshii Kimihiko , Kaihara Akiko , Tsumura Yukari , Ishimitsu Susumu , Tonogai Yasuhide 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was developed for the determination of emamectin and its metabolites (8,9-Z-isomer, N-demethylated, N-formylated, and N-methylformylated emamectin) in various crops. The analytes were extracted with acetone, cleaned up on cartridge columns (C18 and NH2), derivatized with trifluoroacetic anhydride and 1-methylimidazole, and determined by LC with fluorescence detection. Because radish inhibited the formation of the fluorescent derivatives, an additional Bond Elut PRS cartridge was used in the cleanup of Japanese radish samples. During sample preparation, N-formylated emamectin partially degraded to emamectin B1b and emamectin B1a, and the 8,9-Z-isomer partially degraded to N-demethylated emamectin. Therefore, emamectin and its metabolites were determined as total emamectin, i.e., their sum was estimated as emamectin benzoate. Their recoveries from most crops were approximately 80–110% with the developed method. The detection limits for the analytes in vegetables were 0.1–0.3 parts per trillion (ppt). The results for these compounds were confirmed by LC/mass spectrometry (LC/MS; electrospray ionization mode). Because the fluorescent derivative of emamectin was undetectable by LC/MS, the results for the analyte were confirmed by using a sample solution without derivatization. Limits of detection by LC/MS were similar to the fluorescence detection limits, 0.1–0.3 ppt in vegetables. In addition to the emamectins, milbemectin, ivermectin, and abamectin were also determined by the developed method.