bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-Time Polymerase Chain Reaction Detection of Cauliflower mosaic virus to Complement the 35S Screening Assay for Genetically Modified Organisms
Authors: Cankar Katarina , Ravnikar Maja , Žel Jana , Gruden Kristina , Toplak Nataša 
Published: February 2020

Abstract
Labeling of genetically modified organisms (GMOs) is now in place in many countries, including the European Union, in order to guarantee the consumer's choice between GM and non-GM products. Screening of samples is performed by polymerase chain reaction (PCR) amplification of regulatory sequences frequently introduced into genetically modified plants. Primers for the 35S promoter from Cauliflower mosaic virus (CaMV) are those most frequently used. In virus-infected plants or in samples contaminated with plant material carrying the virus, false-positive results can consequently occur. A system for real-time PCR using a TaqMan minor groove binder probe was designed that allows recognition of virus coat protein in the sample, thus allowing differentiation between transgenic and virus-infected samples. We measured the efficiency of PCR amplification, limits of detection and quantification, range of linearity, and repeatability of the assay in order to assess the applicability of the assay for routine analysis. The specificity of the detection system was tested on various virus isolates and plant species. All 8 CaMV isolates were successfully amplified using the designed system. No cross-reactivity was detected with DNA from 3 isolates of the closely related Carnation etched ring virus. Primers do not amplify plant DNA from available genetically modified maize and soybean lines or from different species of Brassicaceae or Solanaceae that are natural hosts for CaMV. We evaluated the assay for different food matrixes by spiking CaMV DNA into DNA from food samples and have successfully amplified CaMV from all samples. The assay was tested on rapeseed samples from routine GMO testing that were positive in the 35S screening assay, and the presence of the virus was confirmed.
Experimental Evaluation of Different Precision Criteria Applicable to Microbiological Counting Methods
Authors: Lombard Bertrand , Cornu Marie , Lahellec Cecile , Feinberg Max H 
Published: February 2020

Abstract
The dispersion of microbiological counting measurements, when repeating the analysis on the same material both within a laboratory (repeatability) and between laboratories (reproducibility) can be characterized by the organization of interlaboratory studies, where several sets of identical test materials are sent to several laboratories. Using the example of data generated by an interlaboratory study on enumeration of Listeria monocytogenes in foods by the standardized reference method (colony-count technique), 2 types of robust estimators of reproducibility standard deviations, based on the median, were examined, in comparison with the classical estimators, based on the mean. Experimental evaluation indicated that the 3 approaches gave consistent results for most of the combinations. The usual log10 transformation of the enumeration results was also questioned before these calculations were conducted.
Sensitive Determination of Anionic Surfactants in Water with Trans-4-[4′-(N-methyl-N-hydroxylethylamino)-cinnamyl-N-9-(4′-(2,2′:6′,2″-terpyridine))-phenylmethylene]pyridine Bromide by the Light-Absorption Ratio Variation Approach
Authors: Yang Jia-Xiang , Gao Hong-Wen , Hu Zhang-Jun , Jiang Min-Hua 
Published: February 2020

Abstract
The light-absorption ratio variation approach was described and applied to the determination of anionic surfactants (AS) in water with a novel chromophore, Trans 4-[4′-(N-methyl-N-hydroxylethylamino)-cinnamyl-N-9-(4′-(2,2′:6′,2″-terpyridine))-phenylmethylene]pyridine bromide (BTMHCTPP). The complexations between BTMHCTPP and sodium dodecyl sulfate (SDS) and sodium dodecylbenzenesulfonate (SDBS) at pH 3.85 were characterized by the break point approach. Results have shown that both 1BTMHCTPP:1SDS and 1BTMHCTPP:1SDBS complexes were formed, and that ΔAr (ΔAr = light-absorption ratio variation) is linear for the range of AS between 0.05 and 1.00 mg/L. The limits of detection (3σ) are 0.045 mg/L for SDS and 0.040 mg/L for SDBS. The complexation is selective in the presence of EDTA, and it has been applied to the analysis of water samples with satisfactory results.
Bioactive Peptides Derived from Food
Authors: Rutherfurd-Markwick Kay J , Moughan Paul J 
Published: February 2020

Abstract
As interest in the ability of functional foods to impact on human health has grown over the past decade, so has the volume of knowledge detailing the beneficial roles of food-derived bioactive peptides. Bioactive peptides from both plant and animal proteins have been discovered, with to date, by far the most being isolated from milk-based products. A wide range of activities has been described, including antimicrobial and antifungal properties, blood pressure-lowering effects, cholesterol-lowering ability, antithrombotic effects, enhancement of mineral absorption, immunomodulatory effects, and localized effects on the gut. Although there is still considerable research to be performed in the area of food-derived bioactive peptides, it is clear that the generation of bioactive peptides from dietary proteins during the normal digestive process is of importance. Therefore, it will become necessary when determining dietary protein quality to consider the potential effects of latent bioactive peptides that are released during digestion of the protein.
Determination of Pantothenic Acid in Foods by Optical Biosensor Immunoassay
Authors: Haughey Simon A , O'Kane Anthony A , Baxter G Andrew , Kalman Andras , Trisconi Marie-José , Indyk Harvey E , Watene Gaylene A 
Published: February 2020

Abstract
An optical biosensor inhibition immunoassay was developed using a specific pantothenic acid-binding protein for the quantitation of free pantothenic acid (vitamin B5) in foodstuffs. Samples were prepared by a simple extraction procedure in buffer, and vitamin content was estimated against authentic calibrants in the same buffer. Performance parameters included a working range of 10–5000 ng/mL, a limit of detection of 4.4 ng/mL, precision relative standard deviation of 5.4–7.1% over a range of concentrations, and recoveries &gt;95% in the matrixes tested. A wide range of foodstuffs, including National Institute of Standards and Technology reference samples, were tested in 3 independent laboratories and the results were compared with microbiological assay and liquid chromatography/mass spectrometry (LC/MS) methods. The results indicate that the biosensor technique is appropriate for the estimation of pantothenic acid in a wide range of foodstuffs.
A Simple Determination of Mizoribine in Human Plasma by Liquid Chromatography with UV Detection
Authors: Kaji Hiroaki , Maiguma Takayoshi , Inukai Yoko , Ono Hiroshige , Taniguchi Ritsuko , Makino Kazutaka , Tagawa Yoshinobu , Teshima Daisuke 
Published: February 2020

Abstract
A simple liquid chromatography (LC) method was developed for determination of the therapeutic level of mizoribine in human plasma. After precipitation of plasma proteins with 6% perchloric acid, mizoribine was determined by LC with spectophotometric detection. The peak height for mizoribine was linearly related to its concentrations, which ranged from 0.09 to 3.13 μg/mL. Therefore, the limit of quantitation was considered to be 0.09 μg/mL. The accuracy was 104.96–107.37%. The intra- and interday relative standard deviation values were in the range of 1.10–3.25%. The detection limit was 0.025 μ g/mL, defined as a signal-to-noise ratio of 3. The plasma concentrations of mioribine were not related to the dosage. Because mizoribine was mainly excreted in the urine, the plasma concentrations of mizoribine might be affected by a change in renal function. Therefore, the mizoribine concentration in blood should be monitored and the dosage adjusted, depending on the condition of renal function. It was suggested that the present method may be applied well in the therapeutic drug monitoring for mizoribine.
Optimization of Two Flow-Injection Spectrophotometric Methods for the Determination of Indapamide in Pharmaceutical Dosage Forms
Authors: Rodríguez Juan C , Barciela Julia , García Sagrario , Herrero Carlos , Peña Rosa M 
Published: February 2020

Abstract
Multivariate experimental design has been used to optimize 2 flow-injection spectrophotometric methods for the determination of indapamide in pharmaceutical dosage forms, both pure and commercial tablets. The methods are based on the oxidation of this drug with iron (III) in acidic medium and the subsequent formation of an intensive orange-red complex between the liberated iron (II) and 2,2′-bipyridyl or 1,10-phenanthroline reagents. Plackett-Burman designs were applied as a screening method to evaluate the most significant factors with few experiments. Central composite 23+ star designs were performed to evaluate the response surfaces. The methods have been fully validated and were applied successfully to the determination of indapamide in pure and pharmaceutical forms with good accuracy and precision. Therefore, the 2 proposed procedures are simple, inexpensive, and rapid flow methods for the routine determination of indapamide in pharmaceutical preparations.
A New Process for Preparation of Soybean Protein Concentrate with Hexane-Aqueous Ethanol Mixed Solvents
Authors: Zhang Wei-Nong , Liu Da-Chuan 
Published: February 2020

Abstract
A new process for the preparation of soybean protein concentrate (SPC) by directly extracting full-fat soy flour with a mixture of hexane and aqueous ethanol was established. Compared with conventional methods, it has some advantages, such as saving energy and reducing protein denaturation caused by heat action during solvent recovery, because this process saves one step of solvent recovery. The effects of aqueous ethanol concentration and the mixure ratio (hexane to ethanol) on the degree of protein denaturation and product quality were investigated, on the basis of which the orthogonal tests were performed. The optimum technical parameters were obtained by analyzing the results of the orthogonal tests with statistical methods. We found that SPC can be obtained by extracting full-fat soy flour under the following conditions: mixture ratio hexane: 90% ethanol, 9:1, v/v; extraction temperature, 45°C; ratio of solid to solvents, (1:2 w/v); and 5 repeated extractions (15 min each time). The results of quality analysis showed that solubility of the product was improved significantly [nitrogen solubility index (NSI) 46.6%] compared with that for ethanol washing of protein concentrate (NSI 8.7%).
Sample Preparation Improvement in Polycyclic Aromatic Hydrocarbons Determination in Olive Oils by Gel Permeation Chromatography and Liquid Chromatography with Fluorescence Detection
Authors: Martinez-López Sandra , Morales-Noé Asuncion , Pastor-Garcia Agustin , Morales-Rubio Angel , Guardia Miguel de la 
Published: February 2020

Abstract
The determination of 15 polycyclic aromatic hydrocarbons (PAHs) in olive oil samples has been improved in order to obtain a fast methodology with a low limit of detection through the combination of liquid–liquid extraction with acetonitrile and preparative gel permeation chromatography (GPC) prior to the injection of purified extracts into a C18 column. Acetonitrile–water was used as the mobile phase with a gradient from 50 to 95%, w/w, acetonitrile in 30 min. The oven temperature was maintained at 15°C, and fluorometric detection was made at a fixed excitation wavelength of 264 nm and variable, optimal emission wavelength for each analyte ranging from 352 nm for 11-H-benzo(b)fluorene to 500 nm for indeno(1,2,3-cd)pyrene. Recovery for all the compounds studied varied from 75 to 111%, and limit of detection values from 0.05 ng/g for benzo(k)fluoranthene to 0.48 ng/g for indeno(1,2,3-cd)pyrene, corresponding to 0.09 ng/g benzo(a)pyrene. Results were compared with those obtained by liquid–liquid extraction followed by a cleanup on silica and a direct GPC treatment of oil samples diluted in dichloromethane, 2 other methodologies that are appropriate for quantifying PAHs in olive oils. However, the proposed method improves the determination limits, reduces the time of analysis, and provides a highly stable baseline for sample chromatograms.
Liquid Chromatography with Mass Spectrometry—Detection of Lipophilic Shellfish Toxins
Authors: Stobo Lesley A , Lacaze Jean-Pierre C L , Scott Alasdair C , Gallacher Susan , Smith Elizabeth A , Quilliam Michael A 
Published: February 2020

Abstract
A rapid multiple toxin method based on liquid chromatography with mass spectrometry (LC/MS) was developed for the detection of okadaic acid (OA), dinophysistoxin-1 (DTX-1), DTX-2, yessotoxin (YTX), homoYTX, 45-hydroxy-YTX, 45-hydroxyhomo-YTX, pectenotoxin-1 (PTX-1), PTX-2, azaspiracid-1 (AZA-1), AZA-2, and AZA-3. Toxins were extracted from shellfish using methanol–water (80%, v/v) and were analyzed using a C8 reversed-phase column with a 5 mM ammonium acetate–acetonitrile mobile phase under gradient conditions. The method was validated for the quantitative detection of OA, YTX, PTX-2, and AZA-1 in 4 species (mussels, Mytilus edulis; cockles, Cerastoderma edule; oysters, Crassostrea gigas; king scallop, Pecten maximus) of shellfish obtained from United Kingdom (UK) waters. Matrix interferences in the determination of the toxins in these species were investigated. The validated linear range of the method was 13–250 μg/kg for OA, PTX-2, and AZA-1 and 100–400 μg/kg for YTX. Recovery and precision ranged between 72–120 and 1–22%, respectively, over a fortification range of 40–160 μg/kg for OA, PTX-2, and AZA-1 and 100–400 μg/kg for YTX. The limit of detection, reproducibility, and repeatability of analysis showed acceptable performance characteristics. A further LC/MS method using an alkaline hydrolysis step was assessed for the detection of OA, DTX-1, and DTX-2 on their esterified forms. In combination with the LC/MS multiple toxin method, this allows detection of all toxin groups described in Commission Decision 2002/225/EC.
Quantitative Evaluation of 28 Mineral Elements by Inductively Coupled Plasma/Mass Spectrometry and Its Application in Source Identification of Indian Opium
Authors: Mudiam Mohanakrishna R , Kumar Sanjukta A , Mahadevan Sudhershanan , Ghosh Priyankar , Sarin Rajendra K , Beedu Sashidhar R 
Published: February 2020

Abstract
An analytical method based on inductively coupled plasma/mass spectrometry (ICP/MS) was developed for the determination of 28 mineral elements (Cr, Mn, Co, Ni, Cu, Zn, Ga, Sr, Cd, Ag, Ba, Pb, Bi Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) in Indian opium samples. The detection limits were found to be in the range of 0.0008–0.45 ng/mL. The recoveries of spiked samples for each element were found to be in the range of 83–106%, with a precision of less than 9%. A total of 124 opium samples from India were analyzed for the distribution pattern of the 28 mineral elements. Quantitative elemental data were subjected to chemometric analysis in order to determine an optimal classifier to evaluate the source of Indian opium. The study indicated that mineral elements might not be the suitable discriminators for the discrimination of licit opium-growing divisions of India. However, the methodology developed and the analytical data on elemental profile may find important forensic application in discriminating Indian opium with that of licit and illicit opium originating from different geographical regions of world.
Quantitative Determination of β-Asarone in Calamus by High-Performance Thin-Layer Chromatography
Authors: Widmer Valeria , Schibli Anne , Reich Eike 
Published: February 2020

Abstract
A quantitative high-performance thin-layer chromatographic method for determination of β-asarone in Calamus rhizome was developed and validated. The method is suitable for proper identification of Acorus calamus. Through the use of caffeine-modified silica gel as the stationary phase and toluene–ethyl acetate (93 + 7, v/v) as the mobile phase, β-asarone is baseline separated from its isomer α-asarone. Scanning densitometry with absorption measurement at 313 nm allows specific, accurate, and precise quantification of β-asarone. The working range of 40 to 200 ng absolute of the target substance is sufficient to establish whether a given sample passes the limit test of 0.5% maximum as required by the Swiss Pharmacopoeia.
Analysis of Phenothiazines in Human Body Fluids Using Disk Solid-Phase Extraction and Liquid Chromatography
Authors: Marumo Akemi , Kumazawa Takeshi , Lee Xiao-Pen , Fujimaki Koichiro , Kuriki Ayako , Hasegawa Chika , Sato Keizo , Seno Hiroshi , Suzuki Osamu 
Published: February 2020

Abstract
Seven phenothiazine derivatives, perazine, perphenazine, prochlorperazine, propericiazine, thioproperazine, trifluoperazine, and flupentixol, have been found to be extractable from human plasma and urine samples using disk solid-phase extraction (SPE) with an Empore C18 cartridge. Human plasma and urine (1 mL each) containing the 7 phenothiazine derivatives were mixed with 2 mL of 0.1M NaOH and 7 mL distilled water and then poured into the disk SPE cartridges. The drugs were eluted with 1 mL chloroform– acetonitrile (8 + 2) and determined by liquid chromatography with ammonium formate/formic acid–acetonitrile gradient elution. The detection was performed by ultraviolet absorption at 250 nm. The separation of the 7 phenothiazine derivatives from each other and from impurities was generally satisfactory using a SymmetryShield RP8 column (150 × 2.1 mm id, 3.5 μm particle size). The recoveries of the 7 phenothiazine derivatives spiked into plasma and urine samples were 64.0–89.9% and 65.1–92.1%, respectively. Regression equations for the 7 phenothiazine derivatives showed excellent linearity, with detection limits of 0.021–0.30 mg/mL for plasma and 0.017–0.30 μg/mL for urine. The within-day and day-to-day coefficients of variation for both samples were commonly below 9.0 and 14.9%, respectively.
Determination of Cefdinir by a Stability-Indicating Liquid Chromatographic Method
Authors: Mehta Tushar N , Subbaiah Gunta , Pundarikakshudu Kilambi 
Published: February 2020

Abstract
A simple, fast, specific, stability-indicating, and precise reversed-phase liquid chromatographic method was developed for the determination of Cefdinir in its different dosage forms, i.e., capsules and suspensions. The method was developed and optimized by analyzing the placebo preparation, formulations, and degraded samples of the drug substance according to the International Conference on Harmonization. The proposed method can successfully separate the drug from degradation products formed under stress conditions along with pharmaceutical ingredients such as preservatives. The developed method was used successfully to determine Cefdinir in capsules and Insta-use suspensions. The developed method was found to be linear for a concentration range of 6–14 μg/mL. Average recoveries obtained with the method were 99.3 ± 0.4 and 99.6 ± 0.4% for Insta-use suspensions and capsules, respectively. The method was shown to be specific, precise, and robust.
Determination of Chlormequat and Mepiquat in Foods by Liquid Chromatography/Mass Spectrometry or Liquid Chromatography/Tandem Mass Spectrometry: Interlaboratory Study
Authors: Alder Lutz , Startin James R ,   Collaborators:, Alonso S , Anspach T , Brewin S , Broekaert C , Christiansen A , DeKok A , Frase U , Fresvig M , Hemmerling Ch , Hermansson E , Hiemstra M , Hogendoorn E , Kolb J , Kombal R , Melk Ch , Polonji B , Quirijns J K , Ross L , Saint-Joly Ch , Scherbaum E , van Damme D , Welter A , Wüst B 
Published: February 2020

Abstract
Interlaboratory validation studies have been performed on 2 methods for the determination of chlormequat (CLQ) and mepiquat (MPQ). Both methods used identical extraction procedures and stable isotope internal standardization but differed in the use of liquid chromatography/mass spectrometry (LC/MS) or LC/tandem mass spectrometry (LC/MS/MS) for the determination, the amount of internal standard used, and the expected limit of detection. After addition of deuterated internal standards, CLQ and MPQ were extracted with methanol–water and determined by LC/MS or LC/MS/MS with positive electrospray ionization. Eight European laboratories participated in the LC/MS method study, analyzing mushroom, pear, wheat flour, and fruit puree with residues of CLQ in the range 0.040–1.19 mg/kg and of MPQ in the range 0.041–0.39 mg/kg. For CLQ, the Horwitz ratio (HoRat) values for individual test materials/levels were in the range 0.85–1.13 with amean of 1.00, showing good method performance. For MPQ, the Ho values for mushroom, pear (both levels), and wheat flour were in the range 0.83–0.94, again indicating good method performance. For the determination of MPQ in infant food (fruit puree) at 0.041 mg/kg, the Ho was 1.7 when a value of 0 reported by one participant was excluded. In the LC/MS/MS study, in which 11 laboratories participated, a separate sample set was analyzed with residues of CLQ in the range 0.007–1.03 mg/kg and of MPQ in the range 0.008–0.72 mg/kg. Ho values for CLQ were in the range 0.27–1.36 and for MPQ in the range 0.51–2.10, all corresponding to acceptable method performance.
Development of EPA Method 535 for the Determination of Chloroacetanilide and Other Acetamide Herbicide Degradates in DrinkingWater by Solid-Phase Extraction and Liquid Chromatography/TandemMass Spectrometry
Authors: Shoemaker Jody A , Bassett Margarita V 
Published: February 2020

Abstract
U.S. Environmental Protection Agency (EPA) Method 535 has been developed in order to provide a method for the analysis of Alachlor ESA and other acetanilide degradation products, which are listed on EPA's 1998 Drinking Water Contaminant Candidate List. Method 535 uses solid-phase extraction with a nonporous graphitized carbon sorbent to extract the ethane sulfonic acid (ESA) and oxanilic acid degradates of propachlor, flufenacet, dimethenamid, alachlor, acetochlor, and metolachlor from finished drinking water matrixes. Separation and quantitation of the target analytes are achieved with liquid chromatography/tandem mass spectrometry. Dimethachlor ESA and butachlor ESA were chosen during the method development as the surrogate and internal standard. Drinking water samples were dechlorinated with ammonium chloride without adversely affecting the analyte recoveries. Typical mean recoveries of 92116% in deionized water and 89116% in ground water were observed with relative standard deviations of &lt;5%.
Determination of Organophosphorus Pesticide Residues in the Roots of Platycodon grandiflorum by Solid-Phase Extraction and Gas Chromatography with Flame Photometric Detection
Authors: Yi Xionghai , Hua Qing , Lu Yitong 
Published: February 2020

Abstract
Asimple and rapid sample preparation method using accelerated solvent extraction and solid-phase extraction (SPE) cleanup for determining organophosphorus (OP) pesticides in the roots of Platycodon grandiflorum was developed. The OP pesticides were concentrated by use of an SPE cartridge (ENVI-Carb) and quantitatively analyzed and confirmed by capillary gas chromatographywith flame photometric detection. The pesticides were eluted from the cartridges with 20mL acetonitriletoluene (3 1, v/v). The averag recovery from 10 g P. grandiflorum roots, fortified at 3 levels ranging from 0.04 to 1.00 mg/kg, was 91.9 with a relative standard deviation of 4.3. The limits of detection ranged from 1.16 103 mg/kg (dimethoate) to 4.64 103 mg/kg (dichlorvos). The proposed method showed acceptable accuracy and precision while minimizing environmental concerns, time, and labor.