bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simplex and Duplex Polymerase Chain Reaction Analysis of Herculex® RW (59122) Maize Based on One Reference Molecule Including Separated Fragments of 5 Integration Site and Endogenous Gene
Authors: Li Xiang , Yang Litao , Zhang Jianzhong , Wang Shu , Shen Kailin , Pan Liangwen , Zhang Dabing 
Published: February 2020

Abstract
Reference molecules, as positive controls and calibrators, have been recently developed in genetically modified organism analysis as a potential substitute for reference materials derived from plant raw materials. In this study, a novel reference molecule p59122, including the revealed 5 integration sequence of maize Herculex® RW (59122), was constructed that was suitable for simplex and duplex event-specific qualitative and quantitative PCR detections. The LOD values were 10 copies both for simplex and duplex qualitative PCR when p59122 was used as the calibrator. These values were comparable to those of using genomic DNA samples with 0.01 and 0.05, approximately 5 and 25 hyploid genomic DNA copies, respectively. The absolute LOD and LOQ values were confirmed to be as low as 10 and 25 copies of p59122 DNA both in simplex and duplex quantitative systems. Furthermore, ideal quantification data with low bias, SD and RSD values were obtained from the practical samples analyses in simplex and duplex real-time PCR systems using the reference molecule p59122 as a calibrator. All these results suggested that the developed reference molecule p59122 and the qualitative and quantitative PCR detection methods are suitable for identification and quantification of GM maize 59122 and its derived products.
Determination of the Insecticide Imidacloprid in Fruit Juices Using Micellar High-Performance Liquid Chromatography
Authors: Chin-Chen Mei-Liang , Esteve-Romero Josep , Carda-Broch Samuel 
Published: February 2020

Abstract
A simple and reliable HPLC method was developed to determine imidacloprid, a chloronicotinyl insecticide that has a highly specific affinity to the nicotinic acetylcholine receptor of insects, above its permissible limit of consumption in fruit juices (orange, apple, and a mixture of pineapple and pear). Samples were injected directly into a Kromasil C18 column, without any pretreatment step, using the micellar mobile phase 0.10 M sodium dodecyl sulfate and 2.5 (v/v) propanol buffered at pH 7 and UV detection at 210 nm. Under these conditions, imidacloprid was eluted in &lt;4 min with no interference by the endogenous compounds of the juice fruits. The analytical parameters linearity (r &gt; 0.9998) and intraday and interday precision (RSD 0.1 2.8 and 0.077, respectively) were obtained in the method validation. LOD and LOQ were calculated to be 0.4 and 1.5 ng/mL, respectively. Recoveries were in the 98103 range. The simplicity of the method makes it a good candidate for application in routine analysis in the area of food control and quality evaluation.
13C Nuclear Magnetic Resonance Spectroscopic Detection of the Adulteration of Extra Virgin Olive Oils Extracted from Different Cultivars with Cold-Pressed Hazelnut Oil
Authors: Vlahov Giovanna 
Published: February 2020

Abstract
13C NMR spectroscopy was applied to detect the adulteration of olive oils with hazelnut oil. Considering that the linolenate chain and the squalene hydrocarbon were absent in hazelnut oil, unlike olive oil, a 13C NMR spectroscopy method was developed to measure in addition to the triglyceride normal chains (i.e., saturated, oleate, and linoleate chains), the resonances of the linolenate chain and of squalene hydrocarbon. Acyl chain and squalene resonances highly discriminated olive oil samples by cultivars. Nevertheless, the hazelnut oil percentage factor prevailed over the cultivar factor, thus correctly classifying 86 of the authentic and adulterated olive oil samples according to the hazelnut oil percentages. In particular, 85.7, 73.7, and 100.0 of the authentic olive oil samples, and the samples adulterated with 5 and 20 of hazelnut oil, were correctly classified through cross-validation.
Toward a Quality Guide to Facilitate the Transference of Analytical Methods from Research to Testing Laboratories: A Case Study
Authors: Bisetty Krisnha , Gumede Njabulo Joyfull , Escuder-Gilabert Laura , Sagrado Salvador 
Published: February 2020

Abstract
At present, there is no single viewpoint that defines QA strategies in analytical chemistry. On the other hand, there are no unique protocols defining a set of analytical tasks and decision criteria to be performed during the method development phase (e.g., by a single research laboratory) in order to facilitate the transference to the testing laboratories intending to adapt, validate, and routinely use this method. This study proposes general criteria, a priori valid for any developed method, recommended as a provisional quality guide containing the minimum internal tasks necessary to publish new analytical method results. As an application, the selection of some basic internal quality tasks and the corresponding accepted criteria are adapted to a concrete case study: indirect differential pulse polarographic determination of nitrate in water samples according to European Commission requisites. Extra tasks to be performed by testing laboratories are also outlined.
Optimization and Validation of an RP-HPLC Method for Analysis of Hydrocortisone Acetate and Lidocaine in Suppositories
Authors: Jancic-Stojanović Biljana , Malenović Andjelija , Marković Slavko , Ivanović Darko , Medenica Mirjana 
Published: February 2020

Abstract
An RP-HPLC method has been optimized and validated for the simultaneous determination of hydrocortisone acetate and of lidocaine in suppositories. For the method optimization, response surface methodology was applied, and the obtained model was tested using analysis of variance. The optimal separations were conducted on a Beckman-Coulter 150 4.6 mm, 5 µm particle-size column at 20C. The mobile phase was methanolwater (65 + 35, v/v), pH adjusted to 2.5 with 85% orthophosphoric acid, with a flow rate of 1.0 mL/min. UV detection was performed at 250 nm. Phenobarbital was used as an internal standard. The method was validated for selectivity, linearity, precision, and robustness.
Development and Validation of a Stability-Indicating Assay Method for Simultaneous Determination of Perindopril and Indapamide in Combined Dosage Form by Reversed-Phase High-Performance Liquid Chromatography
Authors: Jogia Hitesh , Khandelwal Umesh , Gandhi Tripti , Singh Sukhdev , Modi Darshana 
Published: February 2020

Abstract
An approach of forced degradation study was successfully applied for the development of a stability-indicating assay method for simultaneous determination of perindopril and indapamide in a formulation in the presence of its degradation products. The method showed adequate separation of perindopril and indapamide from their associated main impurities and degradation products. Separation was achieved on an XTerra&lt;sup/&gt; RP18, 5 µm, 150 4.6 mm id column at 55°C by using the mobile phase NaH2PO4 buffer (pH 2.0; 0.005 M)acetonitrile (75 + 25, v/v ) at a flow rate of 1 mL/min and UV detection at 215 nm. Comprehensive stress testing of perindopril and indapamide was carried out according to the International Conference on Harmonization (ICH) guideline Q1A (R2). The specificity of the method was determined by assessing interference from the placebo and by stress testing of the drug (forced degradation). The drug was subjected to acid hydrolysis, base hydrolysis, oxidation, dry heat, and photolysis to apply stress conditions. There were no other coeluting, interfering peaks from excipients, impurities, or degradation products due to variable stress conditions, and the method was specific for determination of perindopril and indapamide in the presence of degradation products. The method was validated in terms of linearity, precision, accuracy, specificity, robustness, and solution stability. The linearity of the proposed method was investigated in the range of 2456 µg/mL (r2 = 0.9993) for perindopril and 7.517.5 µg/mL (r2 = 0.9992) for indapamide. Degradation products produced as a result of stress studies did not interfere with the detection of perindopril and indapamide, and the assay can thus be considered stability indicating.
Determination of Aflatoxins in Botanical Roots by a Modification of AOAC Official MethodSM 991.31: Single-Laboratory Validation
Authors: Weaver Carol M , Trucksess Mary W 
Published: February 2020

Abstract
AOAC Official MethodSM 991.31 for the determination of aflatoxins (AFs; sum of aflatoxins B1, B2, G1, and G2) in corn, raw peanuts, and peanut butter by using immunoaffinity column cleanup with LC has been modified and applied to the determination of AFs in botanical roots. The modifications were necessary to improve the performance of the method for matrixes beyond corn and peanuts. The extraction solvent was changed from a mixture of methanol and water to acetonitrile and water. The accuracy, repeatability, and reproducibility characteristics of this method were determined. Replicates of 10 test portions of each powdered root (black cohosh, echinacea, ginger, ginseng, kava kava, and valerian) at each spiking level (AFs at 0, 2, 4, 8, and 16 ng/g) were analyzed on 3 separate days. Test portions were extracted with acetonitrilewater (84 + 16, v/v), and the extracts were centrifuged, diluted with phosphate-buffered saline, filtered, and applied to an immunoaffinity column containing antibodies specific for AFs. After the column was washed with water, the toxins were eluted from the column with methanol and quantified by HPLC with fluorescence detection. All test materials except kava kava were found to contain AF at &lt;0.1 ng/g. Kava kava was naturally contaminated with AFs at 0.5 ng/g. Average within-day and between-days recoveries of AFs from botanical roots ranged from 88 to 112 and from 86 to 118, respectively. Total RSD values for within-day and between-days repeatability ranged from 1.4 to 15.9. HorRat values were &lt;0.4 for all of the matrixes examined. The modified AOAC Official Method 991.31 was found to be applicable to an analysis of the six botanical roots.
Determination of Total Dietary Fiber (CODEX Definition) by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study
Authors: McCleary Barry V , De Vries Jonathan W , Rader Jeanne I , Cohen Gerald , Prosky Leon , Mugford David C , Champ Martine , Okuma Kazuhiro ,   Collaborators:, Abercrombie L , Ames N , Bajoras T , Bhandari S , Burkhardt G , Camire M , Cohen G , Cui S , Dougherty M P , Erhardt S , Evans A , Grutters M , Hutton-Okpalaeke M , Illaens S , Kanaya K , Kohn A , Konings E , Lai G , Lee T , Marshak M , Neese U , Nishibata T , Santi A , Saylor D , Steegmans M , Themeier H , Thomsen A , Tervila-Wilo A , Walker R , Wang C 
Published: February 2020

Abstract
A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official MethodsSM 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 11.57 to 47.83. Digestion of samples under the conditions of AOAC Method 2002.02 followed by the isolation and gravimetric procedures of AOAC Methods 985.29 and 991.43 results in quantitation of HMWDF. The filtrate from the quantitation of HMWDF is concentrated, deionized, concentrated again, and analyzed by LC to determine the LMWSDF, i.e., all nondigestible oligosaccharides of degree of polymerization 3. TDF is calculated as the sum of HMWDF and LMWSDF. Repeatability standard deviations (sr) ranged from 0.41 to 1.43, and reproducibility standard deviations (sR) ranged from 1.18 to 5.44. These results are comparable to other official dietary fiber methods, and the method is recommended for adoption as Official First Action.
Enzyme-Linked Immunosorbent Assay Kit for the Determination of Soybean Protein in Processed Foods: Interlaboratory Evaluation
Authors: Sakai Shinobu , Adachi Reiko , Akiyama Hiroshi , Teshima Reiko , Morishita Naoki , Matsumoto Takashi , Urisu Atsuo ,   Collaborators:, Arakawa F , Endo Y , Haraguchi H , Hirose Y , Hirota M , Iidzuka T , Kojima K , Minegishi Y , Mishima T , Nishihara R , Seki T , Yamakawa H , Yano T , Yasuda K 
Published: February 2020

Abstract
The labeling of foods containing ingredients derived from soybean is recommended in Japan because of an increasing number of patients who are allergic to soybeans. To ensure proper labeling, a novel sandwich ELISA kit for the determination of soybean protein in processed foods (FASTKIT Ver. II, Soybean, Nippon Meat Packers, Inc.; soy kit) has been developed. Five types of incurred samples (model processed foods: rice gruel, sausage, sweet adzuki bean soup, sweet potato cake, and tomato sauce) containing 10 g soybean soluble protein/g food were prepared for use in interlaboratory evaluations of the soy kit. The soy kit displayed a sufficient RSDR value (interlaboratory precision: 9.313.4 RSDR) and a high level of recovery (97114) for all the incurred samples. The RSDr value for the incurred samples was mostly &lt;4.8. The results of this interlaboratory evaluation suggest that the soy kit can be used as a precise and reliable tool for the determination of soybean proteins in processed foods.
A Practical and Nontarnishing Method for the Analysis of Trace Nickel in Hydrogenated Cottonseed Oil by Inductively Coupled Plasma/Mass Spectrometry with Pressurized PTFE Vessel Acid Digestion
Authors: Zhang Ni , Ding Zhiying , Li Hao , Wang Xin , Shao Xiaodong 
Published: February 2020

Abstract
A practical and nontarnishing method for the determination of trace nickel (Ni) in hydrogenated cottonseed oil by inductively coupled plasma/mass spectrometry (ICP/MS) was developed. In order to avoid tarnishing in the pretreatment of samples, the technology of pressurized PTFE vessel acid digestion was applied. The temperature and acid content in the digestion were optimized. The results showed that hydrogenated cottonseed oil could be digested completely by the proposed method. Compared with the U.S. Pharmacopeia 28 and British Pharmacopoeia 2003 methods, the developed method avoided the risk of using platinum and the tarnish from silica crucibles. In addition, the analytical cycle of the test solution was shortened by the use of ICP/MS instead of graphite furnace atomic absorption spectrophotometry.
An Expression System for the E. coli Fermentation of Recombinant Antibody Fab Fragments from Mice and Rabbits
Authors: Wiebe Julia C , Schüller Carolin , Reiche Jana A , Kramer Karl , Skerra Arne , Hock Bertold 
Published: February 2020

Abstract
A mutually compatible vector system was developed for the bench-top fermenter production of mouse and rabbit Fab fragments comprising pASK85-pro-K411B and pASK85Rab-pro-WR13. These vectors provide a mouse- and rabbit-specific cloning site, respectively, the tetA promoter/operator and the proBA operon that complements the Pro biosynthetic deficiency of the Escherichia coli strain JM83 and can serve as an additional selection marker. Fermentation at elevated cell density (OD600 = 2040) of the atrazine-specific mouse Fab fragment K411B using JM83 harboring pASK85-pro-K411B in a 2 L bench-top vessel resulted in a yield of 240 g/L OD600 affinity-purified protein (13.8 mg). In contrast, expression of leporid Fab fragments using pASK85Rab-pro-WR13 was unsuccessful due to the aggregation of rabbit light chains, which probably relates to a general problem of this specific class of immunoglobulins with their additional Cys residues. Coexpression of rabbit Fab fragments together with four periplasmic folding-helper proteins encoded on pTUM4 led to a significantly improved folding efficiency, resulting in a yield of 50 µg/L OD600 affinity-purified rabbit Fab fragment (3.3 mg) from the 2 L bench-top fermenter.
High-Performance Liquid Chromatographic Determination of Dihydroergocristine in a Pharmaceutical Formulation with Fluorescence Detection
Authors: Douša Michal , Dubovská Michaela 
Published: February 2020

Abstract
A rapid procedure based on a direct extraction and HPLC determination of dihydroergocristine in a pharmaceutical preparation with fluorescence detection has been developed and validated. The optimized chromatographic conditions included a Purospher RP18e column, 5 µm particle size, 250 4.0 mm, and 25 mM potassium dihydrogen phosphate buffer (pH 2.8)acetonitrile (60 + 40, v/v) mobile phase at a flow rate of 1 mL/min. The separation was carried out at 50C, and the injection volume was 5 L. Fluorescence detection was performed at an excitation and emission wavelength of 224 and 344 nm, respectively. The mobile phase parameters such as organic solvent composition, temperature, and pH were studied. The proposed method has the advantages of a very simple sample pretreatment and fast HPLC determination.
Multi-Analyst, Multi-Matrix Performance of the QuEChERS Approach for Pesticide Residues in Foods and Feeds Using HPLC/MS/MS Analysis with Different Calibration Techniques
Authors: Lehotay Steven J , Mastovska Katerina , Lightfield Alan R , Gates Robert A 
Published: February 2020

Abstract
Three different calibration approaches were applied in HPLC/MS/MS using electrospray ionization for the determination of 14 diverse pesticide residues at different levels in a variety of food matrixes. This study was conducted as part of a 4 day training course for 17 chemists to learn the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach to pesticide residue analysis in foods. The analysts were divided into four different teams for the analysis of 12 different matrixes (strawberries, plums, carrots, green peppers, milk, molasses, alfalfa oats, corn silage, dry pet food, soybean, almonds, and foliage). The acetate-buffered QuEChERS protocol gave excellent results in the spiked samples for all matrixes tested. The HPLC/MS/MS calibration techniques consisted of external standardization in solvent solutions, matrix-matching, and the echo-peak technique. Peak areas were normalized to an internal standard in all three approaches. Matrix effects were observed with the corn silage, carrot, and foliage extracts, but they were minimal or nonexistent in the other matrixes. Matrix-matching best compensated for matrix effects, but has logistical difficulties in real-world application and required extra sample preparation compared to the other approaches. The echo-peak technique reduced matrix effects but did not eliminate them.
Multiresidue Analysis of Synthetic Pyrethroid Pesticides in Grapes by Gas Chromatography with Programmed Temperature VaporizingLarge Volume Injection Coupled with Ion Trap Mass Spectrometry
Authors: Banerjee Kaushik , Savant Rahul H , Dasgupta Soma , Patil Sangram H , Oulkar Dasharath P , Adsule Pandurang G 
Published: February 2020

Abstract
A multiresidue analysis method was optimized and validated for simultaneous estimation of 21 synthetic pyrethroid pesticides and their isomers in grape matrix at 10 ng/g and higher levels. The method involves extraction of a 10 g sample with 10 mL ethyl acetate, cleanup by dispersive SPE with primary-secondary amine (25 mg) sorbent, and estimation by GC/MS/MS large volume injection (LVI) through a programmed temperature vaporizer (PTV) injector. The PTV-LVI parameters of the gas chromatograph and the multiple reaction monitoring (MRM) parameters of the ion trap mass spectrometer were optimized for each compound to achieve the highest S/N. For each analyte, the unique and most abundant MRM transition was used for quantification, along with the next most abundant MRM transition for confirmatory identification. The abundance ratio of the confirmatory to quantifier MRMs was used to ensure unambiguous residue monitoring in unknown samples within a 20 tolerance range at the 10 ng/g level. The analytes were separated on a TR-5MS capillary column within a 22 min run time. The method was selective and sensitive and ensured separation of the synthetic pyrethroids from high-boiling matrix components. The LOD and LOQ of the analytes ranged between 0.5 to 3.1 and 2.5 to 10 ng/g, respectively. Linearity of solvent and matrix-matched calibrations between 2.0 and 250 ng/g was established for each compound with r2 &gt; 0.99. Recovery at 10, 25, and 50 ng/g levels of fortification in grapes ranged within 77115 with associated RSD values (n 8) up to 20.
Analytical Testing as a Tool for the Enforcement of Future Regulatory Thresholds for Food Allergens
Authors: Diaz-Amigo Carmen , Popping Bert 
Published: February 2020

Abstract
Food allergen labeling regulations have been implemented in several countries since 2006. Currently, experts are still discussing the introduction of thresholds or action levels, which should lead to the reduction of the widespread use of advisory statements (e.g., may contain) for the benefit of the allergic consumer. However, the establishment of threshold requires supporting analytical methodologies to enforce and comply with the regulations. This article discusses the possibilities and limitations of existing and emerging methodologies for the purpose of enabling compliance with and enforcement of allergen action levels.
Voltammetric Determination of Candesartan Cilexetil in Its Cu(II) Complex and Application to Pharmaceutical Formulations
Authors: Süslü İncilay , Özaltin Nuran , Altinöz Sacide 
Published: February 2020

Abstract
The aim of this study was to develop a new, simple, rapid, and sensitive square-wave adsorptive stripping voltammetric method for the determination of candesartan cilexetil in bulk form and pharmaceutical formulations by complex formation with Cu(II). The experimental and instrumental parameters affecting the response of the candesartan cilexetilCu(II) complex were investigated and optimized. This method was based on electrochemical reduction of candesartan cilexetilCu(II) complex at a hanging mercury drop electrode in phosphate buffer at pH 3.0 containing CuCl22H2O. A well-defined reduction peak was observed at 325 mV with 30 s accumulation time and 150 mV accumulation potential versus an Ag/AgCl reference electrode in the proposed method. The developed voltammetric method was validated in terms of linearity, sensitivity, precision, accuracy, recovery, selectivity, robustness, and ruggedness. The linear calibration range was 0.501.77 g/mL (r 0.9972). The LOD and LOQ of this method were 0.10 and 0.50 g/mL (n 7), respectively. The developed method was fully validated and applied to the pharmaceutical formulations, including candesartan cilexetil.