bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the Appetite Suppressant P57 in Hoodia gordonii Plant Extracts and Dietary Supplements by Liquid Chromatography/Electrospray Ionization Mass Spectrometry (LC-MSD-TOF) and LC-UV Methods
Authors: Avula Bharathi , Wang Yan-Hong , Pawar Rahul S , Shukla Yatin J , Schaneberg Brian , Khan Ikhlas A 
Published: February 2020

Abstract
Hoodia gordonii is traditionally used in South Africa for its appetite suppressant properties. P57AS3 (P57), an oxypregnane steroidal glycoside, is the only reported active constituent from this plant as an appetite suppressant. Effective quality control of these extracts or products requires rapid methods to determine P57 content. New methods of liquid chromatography/mass spectrometry (LC/MS) and LC-UV for analysis of P57 from H. gordonii have been developed. The quantitative determination of P57 was achieved with a Phenomenex Gemini (Torrance, CA) reversed-phase column using gradient mobile phase of water and acetonitrile, both containing 0.1% acetic acid. The method was validated for linearity, repeatability, and limits of detection and quantification. Good results were obtained in terms of repeatability (relative standard deviation &lt;5.0%) and recovery (98.5103.5%). The developed methods were applied to the determination of P57 for H. gordonii plant samples, one related genus (Opuntia ficus-indica), and dietary supplements that claim to contain H. gordonii.
Development and Validation of a High-Throughput Based on Liquid Chromatography with Ultraviolet Absorption and Mass Spectrometry Detection Method for Quantitation of Cichoric Acid in Echinacea purpurea Aerial-Based Dietary Supplements
Authors: Chen Pei 
Published: February 2020

Abstract
A new, rapid, and reproducible reversed-phased liquid chromatography (LC) method with ultraviolet (UV) absorption and/or mass spectrometry (MS) detection has been developed and validated for quantitation of cichoric acid, a major constituent of Echinacea spp. The method involves the use of a short Phenomenex Hydro-RP C18 column (4 μm, 50 × mm 3.0 mm id) and a simple isocratic mobile phase profile. Both UV (diode array detector) and selective-ion monitoring (SIM) at m/z 472.8 were used for quantitation of cichoric acid. The limit of detection was 0.75 ng for UV and 0.15 ng for MSSIM, and the limit of quantitation was is 2.5 ng for UV and 0.5 ng for MSSIM. Watermethanol (1 + 1) soluble extracts of 6 commercially available Echinacea purpurea aerial parts-based dietary supplements (EPADS). EPADS were first profiled using a traditional HPLC-UV method. Their UV chromatograms were compared, and cichoric acid was identified to be a key biomarker for EPADS. Then the samples were analyzed by the fast LC-UV/MS method. The turnaround time for a single analysiswas 3 min, compared to 15 to 60 min needed for traditional reported LC methods. The high-throughput method was able to separate the cichoric acid peak from peaks of other components in extracts of complex matrixes of EPADS.
Determination of Deltamethrin Residues in Plant Materials by Liquid Chromatography/Tandem Mass Spectrometry with Electrospray Ionization
Authors: Zimmer Dieter , Philipowski Christiane , Posner Birgit , Gnielka Agnes , Dirr Edgar , Dorff Mario 
Published: February 2020

Abstract
This paper describes a selective and sensitive method that uses liquid chromatography/tandem mass spectrometry with positive electrospray ionization (ESI+) for the determination of deltamethrin in a variety of crops. Samples were extracted by conventional high-speed blending. Some samples required no further cleanup; others were cleaned up by gel permeation chromatography, strong cation-exchange cartridges, or partitioning with n-hexane. In the determinative step, the buffered neutral mobile phase, consisting of 10 mM ammonium acetate (pH 6.8) and methanol, and ESI+ provided strong ammonium adduct formation to [M+NH4]+ at m/z 523, and the multiple-reaction monitoring (MRM) transition at m/z 523/281 was used for the quantitation of deltamethrin. A second MRM transition at m/z 525/283 was used for confirmation. The limit of quantitation (LOQ) values were 0.01 mg/kg for edible materials and 0.05 mg/kg for nonedible materials. Mean overall recoveries at the LOQ and the 10-fold LOQ ranged from 73 to 96%, and the relative standard deviations were &lt;10% for all samples materials analyzed.
Liquid Chromatographic Analysis of Cinchona Alkaloids in Beverages
Authors: Horie Masao , Oishi Mitsuo , Ishikawa Fusako , Shindo Tetsuya , Yasui Akiko , Ogino Shuzo , Ito Koichi 
Published: February 2020

Abstract
A method for the determination of Cinchona extract (whose main components are the alkaloids cinchonine, cinchonidine, quinidine, and quinine) in beverages by liquid chromatography was developed. A beverage with an alcohol content of more than 10% was loaded onto an OASIS HLB solid-phase extraction cartridge, after it was adjusted to pH 10 with 28% ammonium hydroxide. Other beverages were centrifuged at 4000 rpm for 5 min, and the supernatant was loaded onto the cartridge. The cartridge was washed with water followed by 15% methanol, and the Cinchona alkaloids were eluted with methanol. The Cinchona alkaloids in the eluate were chromatographed on an L-column ODS (4.6 mm id × 150 mm) with methanol and 20 mmol/L potassium dihydrogen phosphate (3 + 7) as the mobile phase. Cinchona alkaloids were monitored with an ultraviolet (UV) detector at 230 nm, and with a fluorescence detector at 405 nm for cinchonine and cinchonidine and 450 nm for quinidine and quinine (excitation at 235 nm). The calibration curves for Cinchona alkaloids with the UV detector showed good linearity in the range of 2400 μg/mL. The detection limit of each Cinchona alkaloid, taken to be the concentration at which the absorption spectrum could be identified, was 2 μg/mL. The recovery of Cinchona alkaloids added at a level of 100 μg/g to various kinds of beverages was 87.6-96.5%, and the coefficients of variation were less than 3.3%. A number of beverage samples, some labeled to contain bitter substances, were analyzed by the proposed method. Quinine was detected in 2 samples of carbonated beverage.
Analysis of Isoflavones in Foods and Dietary Supplements
Authors: Delmonte Pierluigi , Rader Jeanne I 
Published: February 2020

Abstract
Isoflavones are phytochemicals found in many plants. Because of their structural similarity to -estradiol, health benefits of isoflavones have been evaluated in age-related and hormone-dependent diseases. Daidzein, genistein, and glycitein are present as free forms or derivatives in foods containing soy or soy protein extracts. The analysis of isoflavones has become more complex, because preparations contain isoflavones from multiple sources (e.g., red clover, kudzu). Red clover contains primarily formononetin and biochanin A, while kudzu extracts, which are becoming increasingly common in dietary supplements, contain puerarin and daidzein, among other components. Isoflavones are present in foods and dietary supplements as free compounds, glucoside derivatives, 6-O-malonyl-7-O--d-glucoside derivatives, and 6-O-acetyl-7-O--d-glucoside derivatives. High-performance liquid chromatography (HPLC)/tandem mass spectrometry has been applied to the identification of isoflavone derivatives based on the fragmentation pattern of the parent ion, providing high selectivity and sensitivity in the quantitation of isoflavones in complex mixtures. HPLC with ultraviolet detection is often chosen for routine analysis, but a preliminary acid or basic hydrolysis of isoflavone derivatives is often required for the investigation of samples containing extracts from multiple sources. Several internal standards have been used in the analysis of isoflavones from a single botanical source (e.g., soy, red clover), but the identification of a general internal standard remains a challenging process.
Immunoassay as an Analytical Tool in Agricultural Biotechnology
Authors: Grothaus G David , Bandla Murali , Currier Thomas , Giroux Randal , Jenkins G Ronald , Lipp Markus , Shan Guomin , Stave James W , Pantella Virginia 
Published: February 2020

Abstract
Immunoassays for biotechnology engineered proteins are used by AgBiotech companies at numerous points in product development and by feed and food suppliers for compliance and contractual purposes. Although AgBiotech companies use the technology during product development and seed production, other stakeholders from the food and feed supply chains, such as commodity, food, and feed companies, as well as third-party diagnostic testing companies, also rely on immunoassays for a number of purposes. The primary use of immunoassays is to verify the presence or absence of genetically modified (GM) material in a product or to quantify the amount of GM material present in a product. This article describes the fundamental elements of GM analysis using immunoassays and especially its application to the testing of grains. The 2 most commonly used formats are lateral flow devices (LFD) and plate-based enzyme-linked immunosorbent assays (ELISA). The main applications of both formats are discussed in general, and the benefits and drawbacks are discussed in detail. The document highlights the many areas to which attention must be paid in order to produce reliable test results. These include sample preparation, method validation, choice of appropriate reference materials, and biological and instrumental sources of error. The article also discusses issues related to the analysis of different matrixes and the effects they may have on the accuracy of the immunoassays.
Quantitative Analysis of Phenobarbital in Dosage Form by Thin-Layer Chromatography Combined with Densitometry
Authors: Wójciak-Kosior Magdalena , Skalska Agnieszka , Matysik Grażyna , Kryska Magdalena 
Published: February 2020

Abstract
In this paper, a high-performance thin-layer chromatography (HPTLC) method combined with densitometry has been described. Chromatography was performed on silica gel Si 60F254 plates using dichloromethaneethyl acetateformic acid (9.5 + 0.5 + 0.1, v/v) mobile phase. This method has been successfully applied for the determination of phenobarbital in pharmaceuticals. Obtained results were comparable with traditionally used column high-performance liquid chromatography (HPLC) methods. For the proposed procedure, linearity (r &gt; 0.999), sensitivity (limit of detection 0.4 g/spot), recovery (97.8102.1%), and repeatability were found to be satisfactory. The HPTLC-densitometry method has many advantages, such as simplicity, reasonable sensitivity, rapidity, and low cost, and it can be successfully used in routine quality control of multidrug preparations containing barbiturates.
Interlaboratory Transfer of a Real-Time Polymerase Chain Reaction Assay for Quantitative Detection of Genetically Modified Maize Event TC-1507
Authors: La Paz José-Luís , Garca-Muniz Nora , Nadal Anna , Esteve Teresa , PuigdomÉnech Pere , Pla Maria 
Published: February 2020

Abstract
A real-time polymerase chain reaction (QPCR) assay was developed for quantitative detection of a genetically modified (GM) maize event TC-1507 and modification to conventional PCR for qualitative purposes. Sequences 5-flanking TC-1507 full-length insert were characterized and showed multiple rearrangements involving insert and maize chloroplast fragments. The event specificity of the TC-1507 assays was based on the detection of transgene and plant rearranged sequences found to 5 flank the insertion site. They were fully specific and exhibited a limit of detection below 10 target copies, allowing consistent detection of 0.1% GM levels. The QPCR was highly linear and efficient and proved adequate for quantification of GM contents, aiming at the fulfillment of legal requirements established in the European Union (i.e., compulsory labeling of TC-1507 levels &gt;0.9%). It satisfactorily determined TC-1507 contents on different matrixes and was successfully transferred to a different laboratory.
Effect of Ultrasound Agitation on the Release of Heavy Elements in Certified Reference Material of Human Hair (CRM BCR 397)
Authors: Kazi Tasneem G , Afridi Hassan I , Jamall Mohammad K , Kazi Gul H , Arain Mohammad B , Jalbani Nussrat , Sarfraz Raja A , Shar Ghulam Q 
Published: February 2020

Abstract
An ultrasonic-assisted leaching procedure was developed for the determination of heavy elements (As, Cu, Cd, Pb, and Zn) in Certified Reference Material of human hair (CRM 397) provided from the Community Bureau of Reference (BCR) of the Commission of the European Community. Concentrated nitric acid30% hydrogen peroxide (2 + 1) was used for the leaching method. The effects of different factors on acid leaching of elements, such as presonication time (without ultrasonic stirring), sonication or exposure time to ultrasound, and temperature of the ultrasonic bath have been investigated. Optimum values of these parameters were selected for the maximum extraction of heavy metals from CRM BCR 397 and human scalp hair samples of normal healthy males. To check the validity of the proposed method, a wet acid digestion method was used to obtain the total elemental concentration in CRM BCR 397 and scalp hair samples. Cu and Zn in leachate and digests were measured by flame atomic absorption spectrometry using a conventional air/acetylene flame, while As, Cd, and Pd were determined by electrothermal atomic absorption spectrometry. Under optimized conditions, the recovery for Zn, Cd, Pd, As, and Cu was 98, 98.5, 97.5, 98.2, and 95%, respectively, of those obtained with the wet acid digestion method.
Simultaneous Determination of Florfenicol and Florfenicol Amine in Fish, Shrimp, and Swine Muscle by Gas Chromatography with a Microcell Electron Capture Detector
Authors: Zhang Suxia , Sun Fengyun , Li Jiancheng , Cheng Linli , Shen Jianzhong 
Published: February 2020

Abstract
A rapid and sensitive gas chromatography method was developed for the simultaneous determination of florfenicol (FF) and its metabolite florfenicol amine (FFA) in fish, shrimp, and swine muscle. The extracted samples were defatted with hexane and cleaned up by solid-phase extraction using Oasis MCX cartridges. The eluate was evaporated to dryness, and residues were derivatized and determined by gas chromatography with a microcell electron capture detector. Overall average recoveries ranged from 81.7 to 109.7% for fish, 94.1 to 103.4% for shrimp, and 71.5 to 91.4% for swine muscle. The detection limit was 0.5 ng/g for FF and 1 ng/g for FFA, respectively. The method was validated for the determination of incurred swine muscle samples in an actual residue study.
Determination of Spinosad in Vegetables and Fruits by High-Performance Liquid Chromatography with UV and Mass Spectrometric Detection After Gel Permeation Chromatography and Solid-Phase Extraction Cleanup on a 2-Layered Column
Authors: Ueno Eiji , Oshima Harumi , Matsumoto Hiroshi , Saito Isao , Tamura Hiroto 
Published: February 2020

Abstract
A simple and reliable method was developed for the determination of spinosyns A and D, the active ingredients of spinosad, in vegetables and fruits, by high-performance liquid chromatography with UV detection (HPLC-UV) and confirmation by mass spectrometry (MS); the method uses selected gel permeation chromatography (GPC) and a 2-layered column for solid-phase extraction system. An aliquot of the crude sample extract obtained by acetonitrile extraction is loaded into the GPC system. The fraction containing spinosyns A and D is selectively collected and loaded directly onto a 2-layered column consisting of graphitized carbon (upper layer) and cyclohexyl-bonded silica gel (lower layer). After the column is washed with the GPC mobile phase acetonecyclohexane (3 7), the column is eluted with acetonitrile containing 2% triethylamine. The eluate is used for HPLC-UV/MS analysis. Average recoveries from fortified cabbage, green perilla, fig, and strawberry at analyte concentrations of 0.05 and 0.25 μg/g were &gt;85%, and the relative standard deviations were &lt;9%. The detection limits for spinosyns A and D in green perilla were 0.005 g/g by UV detection and 0.001 g/g by MS detection.
Phosphorated Calix[6]arene Derivatives as an Ionophore for Atropine-Selective Membrane Electrodes
Authors: Zareh Mohsen M , Malinowska Elizabeita 
Published: February 2020

Abstract
37,40-bis-(diethoxy-thiophosphoryl)oxy-5,11,17, 23,29,35-hexakis(1,1-dimethyl-ethyl)-calix[6]arene-8,39,41,42-tetrol; 37,38,39,40,41-pentakis-(diethoxythiophosphoryl)-oxy-5,11,17,23,29,35-hexakis (1,1-dimethylethyl)-calix[6]-arene-42-ol; and 37-(diethoxythiophosphoryl)oxy-5,11,17,23,29,35-hexakis-(1,1dimethylethyl)-calix[6]arene-38,39,40, 41,42-pentol were introduced as neutral ionophores for atropine-selective electrodes. Practical Nernstian responses were found (54.3, 49.1, and 50.8 mV/decade) for polyvinyl chloride membrane electrodes incorporating these compounds. They exhibited practical linear ranges of 1.9 10-6-7.9 10-3,7.9 10-6-7.9 10-3, and 6.3 10-6-7.9 10-3 M, respectively. The optimum pH range was 2.58.5. The selectivity coefficient values were estimated and interpreted. The electrode performance was correlated to the calixarene structure. Then, the electrode was applied to an actual analysis of pharmaceutical atropine preparations. The recovery values of 18.7 g/mL-5.5193 mg/mL atropine sulfate were 97.599.1%. The corresponding relative standard deviation values ranged between 0.39-0.72% for 5 determinations. The first electrode was applied successfully for analyzing atropine sulfate in injection solution and eye drops.
Determination of Cadmium and Lead in Biological Samples by Three Ultrasonic-Based Samples Treatment Procedures Followed by Electrothermal Atomic Absorption Spectrometry
Authors: Afridi Hassan I , Kazi Tasneem G , Arain Mohammad B , Jamali Mohammad K , Kazi Gul H , Jalbani Nusrat 
Published: February 2020

Abstract
The development of 3 different ultrasonic-based sample treatment methods, ultrasonic probe-assisted acid extraction, ultrasonic-assisted acid slurry, and ultrasonic-assisted acid pseudodigestion is presented. These methods were compared for the determination of Cd and Pb by electrothermal atomic absorption spectrometry in biological samples (blood and scalp hair) and validated by using certified materials BCR 397 human hair and BCR 185R bovine liver. The sample amounts chosen to perform the analysis were 100 mg and 0.5 mL for solids (human hair and bovine liver) and blood samples, respectively. An acid digestion induced by microwave energy was used to obtain the total metal concentrations and for comparative purposes. The best results were obtained with the ultrasonic-assisted acid pseudodigestion, with which it was possible to perform accurate and precise determination of the Cd and Pb contents in 2 certified reference materials and biological samples of 50 normal males of ages 2540 years. The precision of the methods, together with their efficiency, rapidity, low cost, and environmental acceptability, make them good alternatives for the determination of trace metals from biological samples. The precision of the methods for accuracy evaluation, resulting in good agreement according to the t-test for a 95% confidence level, and the relative standard deviations were lower than 10% (n = 10) for all determinations.
Multiresidue Determination of Quinolone and Fluoroquinolone Antibiotics in Fish and Shrimp by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Dufresne Guy , Fouquet Andre , Forsyth Don , Tittlemier Sheryl A 
Published: February 2020

Abstract
A multiresidue method was developed to measure low levels of 8 fluoroquinolones (norfloxacin, ofloxacin, danofloxacin, ciprofloxacin, desethylene ciprofloxacin, enrofloxacin, sarafloxacin, and difloxacin) and 4 quinolones (oxolinic acid, flumequine, nalidixic acid, and piromidic acid). Method detection limits range from 0.1 ng/g for quinolones to 0.4 ng/g for fluoroquinolones. Average recoveries range from 57 to 96%, depending on analyte and commodity; relative standard deviations are all less than 18%. The drugs are extracted from tissues using a mixture of ethanol and 1% acetic acid, diluted in aqueous HCl, and defatted by extraction with hexane. The compounds are further isolated using cation-exchange solid-phase extraction and measured using liquid chromatography with electrospray tandem mass spectrometry detection. The method has been evaluated and applied to the analysis of salmon, trout, and shrimp. Detectable residues were observed in 10 out of 73 samples, at concentrations ranging from 0.28 to 16 ng/g.
Quantitative Determination and Sampling of Lamivudine and Zidovudine Residues for Cleaning Validation in a Production Area
Authors: Santoro Maria InÊs Rocha Miritello , Fazio Tatiana Tatit , Singh Anil Kumar , Kedor-Hackmann Erica Rosa Maria 
Published: February 2020

Abstract
Lamivudine (3TC) and zidovudine (AZT) are systemic antiviral substances extensively used in human immunodeficiency virus (HIV) infected patients. Nowadays, 3TC, AZT, and several other pharmacologically potent pharmaceuticals are manufactured in the same production area. To assure quality of drug products and patient safety, properly validated cleaning methodology is necessary. A carefully designed cleaning validation and its evaluation can ensure that residues of 3TC and AZT will not carry over and cross contaminate the subsequent product. The aim of this study was to validate a simple analytical method for verification of residual 3TC and AZT in equipment used in the production area and to confirm the efficiency of the cleaning procedure. The liquid chromatography method was validated using a Nova-Pak&lt;sup/&gt; C18 column (3.9 150 mm, 4 m particle size) and methanolwater (20 + 80, v/v) as the mobile phase at a flow rate of 1.0 mL/min. Ultraviolet detection was made at 266 nm. The calibration curve was linear over a concentration range of 2.022.0 g/mL with a correlation coefficient of 0.9998. The detection and quantitation limits were 0.36 and 1.21 g/mL, respectively. The intra-day and interday precision expressed as relative standard deviation were below 2.0%. The mean recovery of the method was 99.19%. The mean extraction recovery from manufacturing equipment was 83.5%.
Determination of Niacin in Food Materials by Liquid Chromatography Using Isotope Dilution Mass Spectrometry
Authors: Goldschmidt Robert J , Wolf Wayne R 
Published: February 2020

Abstract
The availability of deuterium-labeled nicotinic acid makes stable isotope dilution mass spectromerty (MS) coupled with liquid chromatography (LC) an attractive option for the determination of the water-soluble B-vitamin niacin in food samples. A method was developed based on acid digestion, solid-phase extraction with a strong cation exchange column, and reversed-phase chromatography with a C18 column. Detection is by positive ion electrospray MS. Analysis in selected ion recording mode is subject to interference problems similar to those found with other LC determinations of niacin, but the additional selectivity of multiple reaction monitoring mode largely eliminates interference problems. The method was applied to 6 different food matrixes and to appropriate reference materials, including milk samples with niacin levels near 1 ppm. The method exhibited good accuracy, based on levels obtained for the reference materials, and relative standard deviations in the range of 0.55%.