bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Throughput Determination of Seven Trace Elements in Food Samples by Inductively Coupled PlasmaMass Spectrometry
Authors: Chan Kwok Chu , Yip Yiu Chung , Chu Hei Shing , Sham Wing Cheong
Published: February 2020

A method was developed for high-throughput determinations of 7 elements in food samples, namely antimony (Sb), arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and tin (Sn). The samples were digested by closed-vessel microwave-assisted digestion using concentrated nitric acid (HNO3) as the medium, followed by microwave- assisted evaporation to concentrate the sample solutions before dilution to the desired volume. The microwave-assisted evaporation procedure effectively reduced the final acid concentration to around 8 before analysis by inductively coupled plasmamass spectrometry (ICPMS). This reduction allows determination by ICPMS to proceed without further sample dilution, which would affect the detection limit. The method was validated, and method recoveries for As, Cd, Cr, Pb, and Hg were within the certified ranges of the chosen certified reference materials. Recoveries of the 7 elements from spiked samples ranged from 93.1 to 103.6. The standard uncertainties of precision for the 7 elements were between 3.1 and 4.3. Interlaboratory comparison studies for As, Cd, and Pb gave z-scores ranging from 0.2 to 0.3.
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

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 <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

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

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 <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

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

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

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

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 > 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

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 >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

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

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

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 >85%, and the relative standard deviations were <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

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

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

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

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 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

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%.
Ultrasound-Assisted Pseudodigestion for Toxic Metals Determination in Fish Muscles Followed by Electrothermal Atomic Absorption Spectrophotometry: Multivariate Strategy
Authors: Arain Mohammad B , Kazi Tasneem G , Jamali Mohammad K , Afridi Hassan I , Jalbani Nusrat , Memon Attique R
Published: February 2020

A simple and efficient procedure for the determination of arsenic (As), cadmium (Cd), and lead (Pb) in the edible parts of freshwater fish by ultrasonic-assisted acid pseudodigestion (USD) was developed. A Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of several variables at once. Five variablessonication time, sample mass of muscle tissue, temperature of the ultrasonic bath, mL of nitric acid, and mL of a mixture of acid and oxidantwere regarded as factors. From these studies, certain variables showed up as significant, and they were optimized by a 23+star central composite design, which involved 16 experiments. Optimum values of the variables were selected for the development of USD to determine the contents of As, Cd, and Pb in fish muscles used as pollution bioindicators from Lake Manchar (Sindh, Pakistan). The determination of the 3 toxic metals under study was performed by electrothermal atomic absorption spectrometry. The accuracy of the optimized procedure was evaluated by analysis of certified reference materials BCR 185R bovine liver and by comparison with conventional wet acid digestion methodology. The result obtained by the optimized method showed good agreement with the certified values and sufficiently high recovery. No significant differences were observed for P = 0.05. Relative standard deviation values (average of 10 separate determinations) were 1.21, 5.52, and 5.32% for As, Cd, and Pb, respectively.
Accelerated Solvent Extraction of Fluometuron from Selected Soils
Authors: Lancaster Sarah , Senseman Scott , Carson Katherine
Published: February 2020

Accelerated solvent extraction (ASE) is a recently developed extraction technique that is more rapid and produces less waste than do conventional liquid/liquid extraction methods. Optimal conditions were determined for ASE of fluometuron from 2 Weswood clay loam soils. Two solvents (acetonitrile and methanol), 2 temperatures (50 and 100C), and the number of static cycles (1, 2, and 3) were evaluated. The most efficient and reproducible extractions were obtained when methanol was combined with a 50C extraction temperature and the static cycle was repeated 3 times. These experiments indicated that existing extraction methods for fluometuron can easily be adapted for ASE.
Use of a Novel Medium, the Ionic Liquid 1-Butyl-3-Trimethylsilylimidazolium Hexafluorophosphate, for LiquidLiquid Extraction of Lead in Water and Its Determination by Graphite Furnace Atomic Absorption Spectrometry
Authors: Zaijun Li , Qiping Peng , Haixia Shan
Published: February 2020

The ionic liquid 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate, abbreviated as [C4tmsim][PF6], was developed as a novel medium for liquidliquid extraction of lead(II) in water, in which dithizone was used as a metal chelator to form a neutral leaddithizone complex. Under optimal conditions, the complex was extracted into the [C4tmsim][PF6] phase from aqueous solution and back-extracted with nitric acid solution into the aqueous phase that was used directly for the subsequent determination of Pb. The system using the ionic liquid demonstrated good extraction performance; the extraction and back-extraction efficiencies were 99.8 and 99.7%, respectively, for Pb(II) at 20 g/L. The above procedure, including the extraction and back-extraction, was used to enrich trace levels of Pb(II) in a relatively large volume of water samples (1000 mL water), and an enrichment factor of 400 was obtained. The enrichment coupled with graphite furnace atomic absorption spectrometry was successfully applied to the determination of Pb in water. The calibration graph was linear at levels near the detection limits up to 100 ng/L Pb(II). The limits of quantitation and detection for lead in real water samples were 2.5 and 1.0 ng/L, respectively. Lead recoveries of 96.2103.8% from spiked samples demonstrate the accuracy of the proposed method.
New Liquid Chromatography Method with Ultraviolet Detection for Analysis of Anthocyanins and Anthocyanidins in Vaccinium myrtillus Fruit Dry Extracts and Commercial Preparations
Authors: Cassinese Ciro , Combarieu Eric De , Falzoni Mario , Fuzzati Nicola , Pace Roberto , Sardone Nicola
Published: February 2020

The Vaccinium myrtillus fruits (bilberry) are a well-known anthocyanins source, and their extracts are widely used in dietary botanicals and pharmaceutical products for the treatment of vascular and vision disorders. Different analytical methods used for standardization of the bilberry extracts and their preparations are available from pharmacopeias and from the literature. However, the methods reported in the literature do not allow the detection of free anthocyanidins, which are markers of poor product quality. A new liquid chromatography method was developed and validated for the identification and quantification of both anthocyanins and anthocyanidins present in bilberry extracts and products. The method shows a good reproducibility and, due to its high specificity, is suitable to identify unequivocally the botanical raw materials used for manufacturing and to evaluate the extract composition, thus ensuring a high degree of product consistency and quality. Forty typical bilberry preparations belonging to 24 different brands were purchased in the marketplace and evaluated for their quality by using the developed method. Results revealed marked differences among the brands despite a common origin and labeling.
Development and Validation of Liquid Chromatographic and Ultraviolet Derivative Spectrophotometric Methods for Determination of Epinastine Hydrochloride in Coated Tablets
Authors: Ghisleni Daniela Dal Molim , Steppe Martin , Schapoval Elfrides E S
Published: February 2020

High-performance liquid chromatographic (LC) and ultraviolet derivative spectrophotometric (UVD) methods were developed and validated for the quantitative determination of epinastine hydrochloride in coated tablets. LC was performed on a reversed-phase RP-18 column with a mobile phase composed of 0.3 triethylamine (pH adjusted to 4.0 with 10 orthophosphoric acid)methanol (60 + 40, v/v). The first-order derivative method was performed at 243.8 nm using HCl and methanol as the solvent. The methods were validated according to U.S. Pharmacopoeia and International Conference on Harmonization guidelines. The statistical analysis by Student's t-test showed no significant difference between the results obtained by the 2 methods. The proposed methods were found to be simple, rapid, precise, accurate, robust, and sensitive, allowing perfect interchange. The LC and UVD methods can be used in the routine quantitative determination of the epinastine hydrochloride in coated tablets.
Intralaboratory Validation of Cell-Free Translation Assay for Detecting Ricin Toxin Biological Activity
Authors: Lindsey Changhong Y , Richardson Jenny D , Brown J Edward , Hale Martha L
Published: February 2020

A cell-free translation (CFT) assay for determining ricin biological activity was validated. The statistical data from the validation study showed a high level of precision within and between runs of the assay. The assay was specific for determining ricin biological activity in food-based matrixes and discriminated ricin from other ribosomeinactivating proteins. The mean bias (relative error) between measured ricin concentrations of 3 validation samples and their nominal concentrations was 1.1, 6.6, and 20.3, while the coefficient of variation (CV) was 14.1, 7.7, and 13.5, respectively, demonstrating good precision, accuracy, and linearity. The CVs of ricin concentrations in 2 ricin-containing samples calculated from a dilution series were <5 and <12, respectively, demonstrating very good parallelism. The analyte stability of ricin-containing samples stored for 1 month either at 4 or 20C, the stability of ricin stock solutions, and the results of assays executed by different analysts and using different luminometers were evaluated. The statistical validation data confirmed that the 4-parameter logistic equation, y = (a d)/[1 + (x/c)b] + d, provided an accurate representation of a sigmoidal relationship between the measured response and the observed ricin concentration for the CFT assay.
Impact of Foods Nutritionally Enhanced Through Biotechnology in Alleviating Malnutrition in Developing Countries
Authors: Gilani G Sarwar , Nasim Anwar
Published: February 2020

According to United Nations (UN) projections, the world's population will grow from 6.1 billion in 2000 to 8 billion in 2025 and 9.4 billion in 2050. Most (93) of the increase will take place in developing countries. The rapid population growth in developing countries creates major challenges for governments regarding food and nutrition security. According to current World Health Organization estimates, more than 3 billion people worldwide, especially in developing countries, are malnourished in essential nutrients. Malnutrition imposes severe costs on a country's population due to impaired physical and cognitive abilities and reduced ability to work. Little progress has been made in improving malnutrition over the past few decades. The Food and Agriculture Organization of the UN would like to see more nutrient-rich foods introduced into these countries, because supplements are expensive and difficult to distribute widely. Biofortification of staple crops through modern biotechnology can potentially help in alleviating malnutrition in developing countries. Several genetically modified crops, including rice, potatoes, oilseeds, and cassava, with elevated levels of essential nutrients (such as vitamin A, iron, zinc, protein and essential amino acids, and essential fatty acids); reduced levels of antinutritional factors (such as cyanogens, phytates, and glycoalkaloid); and increased levels of factors that influence bioavailability and utilization of essential nutrients (such as cysteine residues) are advancing through field trial stage and regulatory processes towards commercialization. The ready availability and consumption of the biofortified crops would have a significant impact in reducing malnutrition and the risk of chronic disease in developing countries.
Nutritional and Safety Assessments of Foods and Feeds Nutritionally Improved Through Biotechnology: Lysine Maize as a Case Study
Authors: Glenn Kevin C
Published: February 2020

During the last decade, the area of biotech crops modified for agronomic input traits (e.g., herbicide tolerance and insect protection) has increased to 90 million ha/year, grown by over 8 million farmers in a total of 17 countries. As adoption of these improved agronomic trait biotech crops has grown, so has interest in biotech crops that have improved nutritional characteristics for use as feed and food. A previous publication by the International Life Sciences Institute (ILSI) reported on the principles and concepts proposed for the nutritional and safety assessments of foods and feeds nutritionally improved through biotechnology. In this paper, the guidelines and principles recommended in the earlier publication are discussed relative to a specific case study, Lysine maize. Lysine maize is a feed ingredient with enhanced nutritional characteristics for poultry and swine and provides an alternative to the need for addition of supplemental lysine to some diets for these animals. The 2004 Task Force of the ILSI has also applied the concepts from that report to 4 other case studies: sweet potato enriched in provitamin A (2 examples, one using biotechnology and one using conventional breeding); Golden Rice 2; double-embryo maize; and ASP-1 enhanced protein sweet potato.
Application of Matrix Solid-Phase Dispersion and High-Performance Liquid Chromatography for Determination of Sulfonamides in Honey
Authors: Zou Qiong-Hui , Wang Jin , Wang Xiang-Feng , Liu Yuan , Han Jie , Hou Feier , Xie Meng-Xia
Published: February 2020

A novel method for simultaneous determination of 8 sulfonamide residues (sulfathiazole, sulfapyridine, sulfadiazine, sulfamerazine, sulfamonome-thoxine, sulfachloropyridazine, sulfamethoxazole, and sulfadimethoxine) in honey samples by high-performance liquid chromatography (HPLC) has been developed on the basis of precolumn derivatization with 9-fluorenylmethyl-chloroformate (FMOC-Cl). Sulfonamide residues in honey samples were extracted and purified by matrix solid-phase dispersion with C18 as the solid support. The residues were derivatized by FMOC-Cl, and the FMOC-sulfonamide derivatives were further purified by solid-phase extraction with silica gel as the solid support prior to HPLC analysis. The average recoveries for most sulfonamide compounds at different spiking levels (from 10 to 250 g/kg) were >70 with relative standard deviations <16, and their limits of detection were 4.0 g/kg. The established analytical method has high sensitivity and repeatability and can be applicable for determining the sulfonamide residues in various honey matrixes.
New High-Performance Liquid Chromatographic Method for Determination of Clopidogrel in Coated Tablets
Authors: Sippel Juliana , Sfair Letcia L , Schapoval Elfrides E S , Steppe Martin
Published: February 2020

A new high-performance liquid chromatographic method was developed and validated for clopidogrel determination in pharmaceutical formulations. The system consisted of an ACE 5 octadecylsilane (C18; 150 4.6 mm id), 5.0 m particle size column; methanol0.1 triethylamine (75 + 25, v/v), pH 5.3, mobile phase at a flow rate of 1.2 mL/min; and a diode array detector set at 220 nm. Specificity, linearity, precision, accuracy, and robustness were the parameters evaluated. The retention time for clopidogrel was 6.8 min. To estimate specificity, an aqueous sample solution was subjected to degradation by ultraviolet light and by acid, alkaline, and oxidation media. The peaks of degradation products did not interfere with the compound signal, and there was no interference when a placebo solution was analyzed. Linearity over a concentration range of 10.0 to 90.0 g/mL was shown (correlation coefficient = 0.9998). Low values of relative standard deviation indicated the adequate intraday and interday precision. The average recovery was found as 99.16. In the robustness test, small modifications to the mobile phase composition did not affect the determination of clopidogrel. The proposed method proved to be simple, fast, and cost efficient for the intended use.
The Effect of Preenrichment and Selective Enrichment Media on Recovery of Salmonella Typhi from the Tropical Fruit Mamey
Authors: Hammack Thomas S , Jacobson Andrew P , Andrews Wallace H
Published: February 2020

The Bacteriological Analytical Manual (BAM) Salmonella culture method did not detect Salmonella Typhi in mamey, the tropical fruit that was implicated in a 1999 typhoid outbreak. The relative effectiveness of BAM's nonselective preenrichment and selective media for the recovery of S. Typhi from mamey was examined to determine if the BAM's preenrichment/selective enrichment strategy was the cause of the method's failure with this food. The preenrichment media were lactose broth, buffered peptone water (BPW), and universal preenrichment (UP) broth. The selective enrichment media were selenite cystine (SC) broth, tetrathionate (TT) broth, and Rappaport-Vassiliadis (RV) medium. UP broth was significantly more effective (P < 0.05) than either lactose broth or BPW for the recovery of 2 different S. Typhi strains from mamey. Of 120 test portions tested, 105 S. Typhi-positive test portions were recovered using UP broth, whereas only 1 S. Typhi-positive test portion was recovered using BPW, and no S. Typhi-positive test portions were recovered using lactose broth. SC and TT broths were both significantly more effective (P < 0.05) than RV medium. Of 105 S. Typhi-positive test portions, SC broth recovered 80, TT broth recovered 67, and RV medium recovered 9. After the above comparison, an incomplete UP (UPI) broth formulation was found to be significantly more effective (P < 0.05) than the complete formulation (UPC). Of 80 total positive test portions, UPI recovered 71, whereas UPC recovered only 48. The following UP broth formulations were compared to determine if any of the components of the UP broth formulation were inhibitory to S. Typhi: UPC, UP broth without sodium pyruvate (UPS), UP broth without ferric ammonium citrate (UPF), UP broth without MgSO4 (UPM), and UPI. It was found that none of the ingredients were inhibitory to S. Typhi and that, out of 140 total test portions, UPI and UPF, with 108 and 103 positive test portions, respectively, were significantly more effective (P < 0.05) than the other UP broth formulations (82 for UPC, 74 for UPS, and 60 for UPM). Rather than being inhibitory to the growth of S. Typhi, it appears that ferric ammonium citrate enhanced the growth of competitors which suppressed the growth of S. Typhi. These results demonstrate that UPI and UPF are effective for the recovery of S. Typhi from mamey.
Determination of Phytase Activity in Feed: Interlaboratory Study
Authors: Gizzi Gisele , Thyregod Peter , von Holst Christoph , Bertin Gerard , Vogel Kurt , Faurschou-Isaksen Mai , Betz Roland , Murphy Richard , Andersen Betina Brandt
Published: February 2020

An interlaboratory study was conducted to determine the performance characteristics of a new method for the determination of phytase activity in feed samples. The method is based on the principle that inorganic phosphate is released from the substrate phytate under defined assay conditions and has been validated for its suitability to measure the enzyme activity of various phytase products. Two different experimental designs of the study were applied, allowing for the estimation of the precision of the method under repeatability, intermediate precision and reproducibility conditions, respectively. The relative standard deviation for repeatability (RSDr) ranged from 2.2 to 10.6 and the RSD for reproducibility (RSDR) ranged from 5.4 to 15. The suitability of the validated method for the intended purpose was demonstrated. The obtained performance profile of the method validated in this study was comparable to that of similar methods that were exclusively validated for one phytase product.
Single-Laboratory Validated Method for Determination of Nordihydroguaiaretic Acid in Chaparral-Containing Dietary Supplements
Authors: Gay Martha L , Musser Steven M
Published: February 2020

Nordihydroguaiaretic acid (NDGA) occurs naturally in chaparral (Larrea tridentate Coville), a plant which commonly grows in the Southwest United States and has been used for medicinal purposes by Native Americans indigenous to that region. In addition to its traditional use as a tea, manufacturers of dietary supplements have marketed chaparral-containing products in a variety of formulations. Because of the hepatotoxicity of NDGA, and its occurrence in regulated products, we have developed a method for the determination of NDGA in dietary supplements and have tested this method in several dietary supplement formulations. Products were extracted with 80 methanol, filtered, and analyzed by high-performance liquid chromatography. NDGA was detected and determined with both a diode array detector and negative-ion electrospray. Fragmentation in the triple-quadrupole mass spectrometer was obtained by collisional activation of the [M-H] ion. Collisional activation produced sufficient fragmentation to provide unambiguous identification. Lack of a stable isotope labeled internal standard has led us to compare quantitations based on UV detection with quantitations based on tandem mass spectrometry (MS/MS). Presence of NDGA was confirmed in several dietary supplement products. Quantitative results from the 2 detection methods were comparable for most products. The limit of quantitation using MS/MS was lower and fewer interferences were observed, although UV detection provided better linearity.
Determination of Aflatoxins B1, B2, G1, and G2 and Ochratoxin A in Ginseng and Ginger by Multitoxin Immunoaffinity Column Cleanup and Liquid Chromatographic Quantitation: Collaborative Study
Authors: Trucksess Mary W , Weaver Carol M , Oles Carolyn J , Fry Frederick S , Noonan Gregory O , Betz Joseph M , Rader Jeanne I
Published: February 2020

The accuracy, repeatability, and reproducibility characteristics of a method using multitoxin immunoaffinity column cleanup with liquid chromatography (LC) for determination of aflatoxins (AF; sum of aflatoxins B1, B2, G1, and G2) and ochratoxin A (OTA) in powdered ginseng and ginger have been established in a collaborative study involving 13 laboratories from 7 countries. Blind duplicate samples of blank, spiked (AF and OTA added) at levels ranging from 0.25 to 16.0 g/kg for AF and 0.25 to 8.0 g/kg for OTA were analyzed. A naturally contaminated powdered ginger sample was also included. Test samples were extracted with methanol and 0.5 aqueous sodium hydrogen carbonate solution (700 + 300, v/v). The extract was centrifuged, diluted with phosphate buffer (PB), filtered, and applied to an immunoaffinity column containing antibodies specific for AF and OTA. After washing the column withwater, the toxins were eluted from the column with methanol, and quantified by high-performance LC with fluorescence detection. Average recoveries of AF from ginseng and ginger ranged from 70 to 87 (at spiking levels ranging from 2 to 16 g/kg), and of OTA, from 86 to 113 (at spiking levels ranging from 1 to 8 g/kg). Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 2.6 to 8.3 for AF, and from 2.5 to 10.7 for OTA. Relative standard deviations for between-laboratory reproducibility (RSDR) ranged from 5.7 to 28.6 for AF, and from 5.5 to 10.7 for OTA. HorRat values were 2 for the multi-analytes in the 2 matrixes.
Simultaneous Determination of Potassium Clavulanate and Cefixime in Synthetic Mixtures by High-Performance Liquid Chromatography
Authors: Khan Islam Ullah , Sharif Shahzad , Ashfaq Muhammad , Asghar Muhammad Nadeem
Published: February 2020

A simple, precise, and sensitive high-performance liquid chromatographic method was developed and validated for the simultaneous determination of potassium clavulanate and cefixime in synthetic mixture form. The analytes were separated on a C18 column by using 0.03 M disodium hydrogen phosphate buffer (pH 6.5)methanol (84 + 16, v/v) as the mobile phase with detection at 220 nm. The method exhibited high sensitivity and good linearity in the concentration ranges of 12.562.5 and 20100 g/mL for potassium clavulanate and cefixime, respectively. The total run time for the 2 components was <8 min, and the average recovery was >101.5 with a relative standard deviation of <1.0. The proposed method was validated according to guidelines of the International Conference on Harmonization by evaluation of linearity, recovery, selectivity, robustness, limits of detection and quantitation, and within- and between-day precision. The results obtained for the synthetic mixture show that the method is highly precise and accurate for the simultaneous determination of potassium clavulanate and cefixime.