bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Method for the Detection of -Lactamases in Milk Samples
Authors: Cui Shenghui , Li Jingyun , Hu Changqin , Jin Shaohong , Ma Yue
Published: February 2020

With the rapid growth of the dairy industry and the establishment of strict antimicrobial residue limits in the People's Republic of China's (PRC) milk supply, a -lactamase product known as antimicrobial destroyer was introduced into dairy production without regulatory review. We developed a method for detecting this product in milk samples based on a modified cylinder plate method. The presence of -lactamase is defined as a difference between the inhibitory zones of the test samples (supplemented with 25 g/mL sulbactam plus 0.5 g/mL penicillin G) and control samples (supplemented only with 0.5 g/mL penicillin G) 3 mm. Using this method, 77 individually packaged milk samples were randomly collected from 5 retail stores in 3 cities over a 4-month period (May to August 2006). Of the 77 samples, 49 were found to be -lactamase-positive. In 2 undiluted milk samples showing extremely high -lactamase activity, 25 g/mL sulbactam could not inhibit penicillin G activity. Because there is a lack of safety data on -lactamases in milk products, these data indicated a potentially serious safety concern for the dairy industry in the PRC.
Stability-Indicating Method for Determination of Oxyphenonium Bromide and Its Degradation Product by High-Performance Liquid Chromatography
Authors: EL-Gindy Alaa , Emara Samy , Shaaban Heba
Published: February 2020

A high-performance liquid chromatographic (HPLC) method was developed for determination of oxyphenonium bromide (OX) and its degradation product. The method was based on the HPLC separation of OX from its degradation product, using a cyanopropyl column at ambient temperature with mobile phase of acetonitrile25 mM potassium dihydrogen phosphate, pH 3.4 (50 + 50, v/v). UV detection at 222 nm was used for quantitation based on peak area. The method was applied to the determination of OX and its degradation product in tablets. The proposed method was also used to investigate the kinetics of the acidic and alkaline degradation of OX at different temperatures, and the apparent pseudo first-order rate constant, half-life, and activation energy were calculated. The pH-rate profile of the degradation of OX in Britton-Robinson buffer solutions within the pH range 212 was studied.
Determination of Nucleotides and Nucleosides in Milks and Pediatric Formulas: A Review
Authors: Gill Brendon D , Indyk Harvey E
Published: February 2020

Nucleotides and nucleosides play important roles as structural units in nucleic acids, as coenzymes in biochemical pathways, and as sources of chemical energy. Milk contains a complex mixture of nucleotides, nucleosides, and nucleobases, and because of the reported differences in their relative levels in bovine and human milks, pediatric formulas are increasingly supplemented with nucleotides. Liquid chromatography is the dominant analytical technique used for the quantitation of nucleospecies and is commonly applied using either ion-exchange, reversed-phase, or ion-pair reversed-phase modes. Robust methods that incorporate minimal sample preparation and rapid chromatographic separations have been developed for routine product compliance analysis. This review summarizes the analytical techniques used to date in the analysis of nucleospecies in bovine and human milks and infant formulas.
Determination of Chlorinated Acid Herbicides in Vegetation and Soil by Liquid Chromatography/Electrospray-Tandem Mass Spectrometry
Authors: Schaner Angela , Konecny Jaclyn , Luckey Laura , Hickes Heidi
Published: February 2020

The method presented uses reversed-phase liquid chromatography with negative electrospray ionization and tandem mass spectrometry to analyze 9 chlorinated acid herbicides in soil and vegetation matrixes: clopyralid, dicamba, MCPP, MCPA, 2,4-DP, 2,4-D, triclopyr, 2,4-DB, and picloram. A 20 g portion is extracted with a basic solution and an aliquot acidified and micropartitioned with 3 mL chloroform. Vegetation samples are subjected to an additional cleanup with a mixed-mode anion exchange solid-phase extraction cartridge. Two precursor product ion transitions per analyte are measured and evaluated to provide the maximum degree of confidence in results. Average recoveries for 3 different soil types tested ranged from 72 to 107 for all compounds with the exception of 2,4-DB at 5699. Average recoveries for the 3 different vegetation types studied were lower and ranged from 53 to 80 for all compounds.
Simultaneous Identification and Quantification of Anthraquinones, Polydatin, and Resveratrol in Polygonum multiflorum, Various Polygonum Species, and Dietary Supplements by Liquid Chromatography and Microscopic Study of Polygonum Species
Authors: Avula Bharathi , Joshi Vaishali C , Wang Yan-Hong , Khan Ikhlas A
Published: February 2020

A high-performance liquid chromatographic (HPLC) method with ultraviolet absorption detection was developed to determine the presence of anthraquinones, polydatin, and resveratrol in Polygonum multiflorum Thunb. as well as other medicinal Polygonum species, viz., P. cuspidatum, P. oriental, P. aviculare, and P. vulgare, as well as commercial products that claim to contain P. multiflorum. The best results were obtained with a Phenomenex Gemini C18 column using gradient mobile phase composed of water (0.1 acetic acid) and acetonitrile (0.1 acetic acid). Elution was at a flow rate of 1.0 mL/min. The detection wavelength was 280 nm for anthraquinones and 320 nm for polydatin and resveratrol. The main anthraquinones identified were emodin and physcion. The HPLC pattern of P. multiflorum was also compared with 5 other species of Polygonum. The method was validated for precision, repeatability, and accuracy. The relative standard deviation was between 0.9 and 1.6. The method was sensitive, quick, and accurate for determination of anthraquinones, polydatin, and resveratrol in 6 different species of Polygonum and can be used for quality control of P. multiflorum. The commercial samples and the 6 Polygonum species were compared microscopically, and a detailed description is provided for P. multiflorum.
Stability-Indicating Methods for Determination of Tiapride in Pure Form, Pharmaceutical Preparation, and Human Plasma
Authors: Metwally Fadia H , Abdelkawy Mohammad , Abdelwahab Nada S
Published: February 2020

Four different stability-indicating procedures are described for determination of tiapride in pure form, dosage form, and human plasma. Second derivative (D2), first derivative of ratio spectra (1DD), spectrofluorimetric, and high-performance column liquid chromatographic (LC) methods are proposed for determination of tiapride in presence of its acid-induced degradation products, namely 2-methoxy-5-(methylsulfonyl) benzoic acid and 2-diethylaminoethylamine. These approaches were successfully applied to quantify tiapride using the information included in the absorption, excitation, and emission spectra of the appropriate solutions. In the D2 method, Beer's law was obeyed in the concentration range of 1.59 g/mL with a mean recovery of 99.94 1.38% at 253.4 nm using absolute ethanol as a solvent. In 1DD, which is based on the simultaneous use of the first derivative of ratio spectra and measurement at 245 nm in absolute ethanolic solution, Beer's law was obeyed over a concentration range of 1.59 g/mL with mean recovery 99.64 1.08%. The spectrofluorimetric method is based on the determination of tiapride native fluorescence at 339 nm emission wavelength and 230 nm excitation wavelength using watermethanol (8 + 2, v/v). The calibration curve was linear over the range of 0.23 g/mL with mean recovery of 99.66 1.46%. This method was also applied for determination of tiapride in human plasma. A reversed-phase LC method performed at ambient temperature was validated for determination of tiapride using methanoldeionized watertriethylamine (107 + 93 + 0.16, v/v/v) as the mobile phase. Sulpiride was used as an internal standard at a flow rate of 1 mL/min with ultraviolet detection at 214 nm. A linear relation was obtained over a concentration range of 230 g/mL with mean recovery of 99.66 0.9%. Results were statistically analyzed and compared with those obtained by applying the reference method. They proved both accuracy and precision.
Evaluation of Different Polymerase Chain Reaction Methods for the Identification of Vibrio Parahaemolyticus Strains Isolated by Cultural Methods
Authors: Croci Luciana , Suffredini Elisabetta , Cozzi Loredana , Paniconi Mara , Ciccaglioni Gianni , Colombo Mauro M
Published: February 2020

Control of contamination by Vibrio Parahaemolyticus in fishery products is often hampered by the lack of standardized methods and by the uncertainty associated with biochemical identification of the isolates. In this study, 5 polymerase chain reaction (PCR) methods for the identification of V. parahaemolyticus to the species level were evaluated by using 25 Vibrio reference strains and 163 isolates from fishery products, environmental sources, and clinical samples. Sequence targets of the methods were toxR, gyrB, and tlh genes (tested with 2 protocols), and the fragment pR72H. Isolate identification was confirmed by sequencing of the 16S rRNA gene and by PCR protocols for the identification of other Vibrio species. The PCR assay targeting the toxR gene achieved the highest performance (100 inclusivity and exclusivity). The 2 PCR protocols based on tlh gene detection, although showing the same inclusivity (100), differed in the exclusivity (50 and 91, respectively). Finally, the results provided by the PCR assays targeting the gyrB gene and pR72H fragment were less reliable and, in some cases, difficult to assess. According to the results of this study, the characteristics of accuracy expressed by the toxR identification method make it a suitable candidate as a reference method for the molecular identification of V. parahaemolyticus strains.
Liquid Chromatographic Method for the Quantification of Zearalenone in Baby Food and Animal Feed: Interlaboratory Study
Authors: Arranz Isabel , Mischke Carsten , Stroka Joerg , Sizoo Eric , van Egmond Hans , Neugebauer Michael ,   Collaborators:, Biselli S , Bonzaaijer G , Breyl I , Brodacz W , Bujara I , Burdaspal P , Cea J , Chan D , Danier J , Debreczeni L , De Girolamo A , De Rechter P , De Saeger S , Dittmar F , Esteves M E , Frohmuth G , González P , Griffin J , Hackenberg R , Hanschmann G , Iversen A , Jaus A , Just P , Lauber U , Legarda T , Li Feng-Qin , Meister U , Michelet J Y , Michels K , Mrkvilova M , Nordkvist E , Nuotio K , Özkaya Ş , Patel S , Petrová J , Pittet; A , Raditschnig A , Reutter M , Ritscher M , Schenerr H , Slezarova A , Sona T , van Osenbruggen T , Van Peteghem C , Vojsová Y , Wilson P , Wisniewska-Dmytrow H , Woese K
Published: February 2020

An interlaboratory trial for determination of zearalenone (ZON) in baby food and animal feed was conducted. The study involved 39 participants in 16 European Union member states, as well as Turkey, Uruguay, and China, representing a cross-section of industry, and official food control and research institutes. The method is based on immunoaffinity column cleanup followed by high-performance liquid chromatography using fluorimetry (HPLC-Fl). The test portion of the sample is extracted with methanolwater (75 + 25, v/v). The sample extract is filtered, diluted, and passed over an immunoaffinity column. ZON is eluted with methanol. The separation and determination of ZON is performed by reversed-phase HPLC-Fl with an excitation wavelength of 274 nm and an emission wavelength of 446 nm. Test portions of the samples were spiked at levels of 20 and 30 g/kg ZON in baby food and at levels of 100 and 150 g/kg ZON in animal feed. Mean recoveries from each participant ranged from 78 to 119 with an average value of 92 for baby food and from 51 to 122 with an average value of 74 for animal feed. Based on results for spiked samples (blind duplicates at 2 levels), as well as naturally contaminated samples (blind duplicates at 3 levels), the relative standard deviation for repeatability (RSDr) in baby food ranged from 2.8 to 9.0. For animal feed, this value ranged from 5.7 to 9.5. The relative standard deviation for reproducibility (RSDR) in baby food ranged from 8.2 to 13.3, and for animal feed this value ranged from 15.5 to 21.4. The Horwitz ratio (HorRat) in baby food ranged from 0.3 to 0.4, and for animal feed this value ranged from 0.6 to 0.9. The method showed acceptable within-and between-laboratory precision for each matrix, as required by European legislation.
Simultaneous Determination of Cu(II) and Ag(I) on SP Sephadex C25 as Complexes with 1-Phenyl-1,2-Propanedione-2-Oximethiosemicarbazone by Derivative Spectrophotometry
Authors: Morales Libby , Toral M Inés
Published: February 2020

The proposed method was based on retention and preconcentration of the complexes Cu(II)PPDOT and Ag(I)PPDOT on a solid phase in acid medium. The complexes were quantitatively retained in the cation exchanger SP Sephadex C25, and the analytical measurements were executed directly in the solid phase by derivative spectrophotometry. In this simultaneous determination, the second derivative and the zero crossing method were used. The determination of copper and silver was carried out to 321.0 and 427.0 nm, respectively. In order to obtain quantitative recoveries of the metal ions, various experimental analytical parameters, such as pH, stirring time, volume, and amount of solid phase, were optimized. The effect of interfering ions on the determination was described. The recovery values for Cu(II) and Ag(I) were found to be >98, and the relative standard deviation was 2. The detection limits (3 criterion) for Cu(II) and Ag(I) were found to be 0.9 108 and 13 108 M, respectively. The developed method was utilized for preconcentration and determination of Cu(II) and Ag(I) in industrial effluents and natural water samples. The results were consistent with those provided by inductively coupled plasma/mass spectrometry.
Modifications to the AOAC Use-Dilution Test for Quaternary Ammonium Compound-Based Disinfectants That Significantly Improve Method Reliability
Authors: Arlea Crystal , King Sharon , Bennie Barbara , Kemp Kere , Mertz Erin , Staub Richard
Published: February 2020

The AOAC use-dilution test (UDT) for bactericidal disinfectant efficacy (Method 964.02) has often been criticized for its extreme variability in test results, particularly for quaternary ammonium compound (QAC)-based disinfectants against Pseudomonas aeruginosa. While efforts are under way to develop a new and better test method for hospital disinfectant products that is globally acceptable, U.S. manufacturers and formulators of QAC products must continue in the interim to measure their product performance against the current UDT method. Therefore, continued variability in the UDT places an unnecessary and unfair burden on U.S. QAC product manufacturers to ensure that their products perform against an, at best, unreliable test method. This article reports on evaluations that were conducted to attempt to identify key sources of UDT method variability and to find ways to mitigate their impact on test outcomes for the method. The results of testing across 4 laboratories, involving over 6015 carriers, determined that operator error was a key factor in test variability. This variability was found to be significantly minimized by the inclusion of a simple culture dilution step. The findings from this study suggest possible refinements to the current AOAC UDT method that would serve to improve the overall ruggedness and reliability of the method and to optimize recovery of cells from the carrier surface, thereby further improving the accuracy and reproducibility of counts and test outcomes until such time as a replacement method is implemented.
Alkaloids and Saponins in Dietary Supplements of Blue Cohosh (Caulophyllum thalictroides)
Authors: Satchithanandam Subramaniam , Grundel Erich , Roach John , White Kevin D , Mazzola Eugene , Ganzera Markus , Rader Jeanne I
Published: February 2020

Preparations of blue cohosh (Caulophyllum thalictroides) have been used traditionally by Native Americans for medicinal purposes. Dietary supplements containing dried roots or extracts of blue cohosh rhizomes are available as dietary supplements. The safety and efficacy of these preparations have not been systematically evaluated. Recent studies indicate that ingestion of specific alkaloids in blue cohosh preparations can produce birth defects and neonatal heart failure. Blue cohosh also contains saponins, which may be responsible for uterine-stimulating effects. We determined the amounts of major alkaloids and saponins in preparations of blue cohosh by high-performance liquid chromatography (HPLC). Alkaloids and saponins were monitored with a photodiode array detector and an evaporative light-scattering detector, respectively. Profiles were compared with those of authenticated blue cohosh root extracts. Identities of the alkaloids and saponins were confirmed by HPLC/mass spectrometry and nuclear magnetic resonance spectrometry. Calculations based on the results of analyses of dietary supplements showed that maximum daily intake of alkaloids and saponins will vary with the form (e.g., root, liquid extract) and doses recommended in product labeling. Intakes may vary from <1 to 75 mg/day for alkaloids and from about 9 to 420 mg/day for saponins.
Determination of Hydrazine in Maleic Hydrazide Technical and Pesticide Formulations by Gas Chromatography: Collaborative Study
Authors: Riggs Anthony S , Borth David M , Tutty David G , Yu Wan S ,   Collaborators:, Barclay B , Bertrand N , Burns A , Cassidy P , Cobra J , Krol W , LaForge R , Phillips T , Podhorniak L , Rains D , Rose J , Simons C , Summer S
Published: February 2020

Twelve collaborating laboratories assayed hydrazine in technical maleic hydrazide (MH), 6-hydroxy-2H-pyridazin-3-one, and 2 formulated products, a liquid concentrate and a soluble granule, using gas chromatography (GC) with electron capture detection. The hydrazine content in the samples ranged from 0.03 ppm, in the liquid concentrate, to 0.26 ppm, in MH technical. Hydrazine and MH are dissolved in an aqueous solution. The MH is then precipitated out of solution by acidification. The solution containing hydrazine is treated with excess pentafluorobenzaldehyde (PFB) to form pentafluorobenzaldehyde azine (PFBA). The PFBA is extracted with hexane for analysis by GC using an electron capture detector. Peak area responses of PFBA are measured and quantified by external standardization. Hydrazine concentration is calculated from the PFBA determination. The laboratories weighed each test sample in duplicate with duplicate analysis for each weighing. Data from these laboratories were statistically analyzed. The average relative repeatability was determined to be 5.34 and the average relative reproducibility was 27.99.
Validated Stability-Indicating Methods for the Determination of Nizatidine in the Presence of Its Sulfoxide Derivative
Authors: Youssef Rasha M
Published: February 2020

Four new selective, precise, and accurate methods are described for the determination of nizatidine (NIZ) in the presence of its sulfoxide derivative in both the raw material and pharmaceutical preparations. Method A is based on zero-order (0D), first-derivative (1D), and second-derivative (2D) spectrophotometric measurement of NIZ in aqueous solution at the zero-crossing point of its sulfoxide derivative (at 314, 295334, and 318348 nm, respectively). Method B is a 1DD spectrophotometric method based on the simultaneous use of the first derivative of the ratio spectra and the measurement of peak amplitude at 297 nm. Method C uses a solvent-induced derivative-difference spectrophotometry with D1 measurement from peak to peak at 315345 nm. Method D involves quantitative densitometric evaluation of a mixture of the drug and its sulfoxide derivative after separation by high-performance thin-layer chromatography on silica gel plates with chloroformmethanol (9 + 1, v/v) as the mobile phase; Rf values for NIZ and its sulfoxide derivative were 0.4 and 0.2, respectively. The spot was scanned at 254 nm. The first-derivative spectrophotometric method was used to investigate the kinetics of the hydrogen peroxide degradation process at different temperatures. The apparent pseudo-first-order rate constant, half-life, and activation energy were calculated. The results obtained by the proposed methods were analyzed statistically and compared with those obtained by the official method. These methods are suitable as stability-indicating for the determination of NIZ in the presence of its oxidation-induced degradation product (sulfoxide derivative) either in the bulk powder or in pharmaceutical preparations.
Development and Validation of an HPLC Method to Quantify Camptothecin in Polymeric Nanocapsule Suspensions
Authors: Granada Andra , Murakami Fabio S , Sartori Tatiane , Lemos-Senna Elenara , Silva Marcos A S
Published: February 2020

A simple, rapid, and sensitive reversed-phase column high-performance liquid chromatographic method was developed and validated to quantify camptothecin (CPT) in polymeric nanocapsule suspensions. The chromatographic separation was performed on a Supelcosil LC-18 column (15 cm 4.6 mm id, 5 m) using a mobile phase consisting of methanol10 mM KH2PO4 (60 + 40, v/v; pH 2.8) at a flow rate of 1.0 mL/min and ultraviolet detection at 254 nm. The calibration graph was linear from 0.5 to 3.0 g/mL with a correlation coefficient of 0.9979, and the limit of quantitation was 0.35 g/mL. The assay recovery ranged from 97.3 to 105.0. The intraday and interday relative standard deviation values were <5.0. The validation results confirmed that the developed method is specific, linear, accurate, and precise for its intended use. The current method was successfully applied to the evaluation of CPT entrapment efficiency and drug content in polymeric nanocapsule suspensions during the early stage of formulation development.
Selective and Stability-Indicating Methods for the Simultaneous Determination of Mexiletine Hydrochloride and/or Its Related Substance: 2,6-Dimethylphenol
Authors: Belal Tarek S , Haggag Rim S , Shaalan Rasha A
Published: February 2020

Four simple, rapid, sensitive, and selective analytical procedures were developed for determination of mexiletine hydrochloride (MX) and/or its related substance: 2,6-dimethylphenol (DMP). The latter is a synthetic impurity for which a maximum pharmacopeial limit is defined. The first method depends on derivative-ratio spectrophotometry, for which the first-derivative signals of the ratio spectra at 259 nm ( = 3 nm) are selected for the determination of MX. The second method is based on the spectrofluorometric measurement of MX in alkaline solution in the presence of 15 mM sodium dodecyl sulfate micellar medium at 292 nm (Ex 260 nm). The third method is based on liquid chromatographic (LC) separation of MX and DMP on an RP-C8 column with a mobile phase consisting of 50 mM Na2HPO4acetonitrile (60 + 40, adjusted to pH 2.4), and quantification of the analytes is achieved with UV detection at 212 nm based on peak area. The fourth method uses the coupling reaction of DMP with 2,6-dibromoquinone-4-chlorimide (DBQC) in borate buffer to form an intensely colored product that was spectrophotometrically measured using first-derivative amplitudes at 670 nm ( = 6nm) for the determination of DMP. Different variables affecting each method were carefully investigated and optimized. The reliability and analytical performance of the proposed methods, including linearity, range, precision, accuracy, and detection and quantitation limits, were statistically validated. The first 3 methods were successfully applied for the stability-indicating determination of MX in laboratory-prepared mixtures with DMP, as well as for the determination of MX in capsules. Also, the LC and the DBQC spectrophotometric methods permitted the selective determination of DMP in the presence of a large excess of the parent drug at or near the pharmacopeial limit (0.11).
Bioactive Peptides
Authors: Shahidi Fereidoon , Zhong Ying
Published: February 2020

Peptides with biological activities, released during gastrointestinal digestion or food processing, play an important role in metabolic regulation and modulation, suggesting their potential use as nutraceuticals and functional food ingredients for health promotion and disease risk reduction. Many studies have reported that peptides from various food sources possess bioactivities, including antihypertensive, antioxidant, anticancer, antimicrobial, and opioid activities as well as immunomodulatory and cholesterol-lowering effects. More studies are being performed exploring the sources, bioavailabilities, and possible physiological/functional properties and the mechanisms of action of bioactive peptides. Technological approaches in terms of peptide preparation, purification, and characterization have also been investigated.
Gas Chromatographic Determination of High Molecular Weight Alcohols from Policosanol in Omega-3 Fish Oil by Acylation with Acetyl Chloride
Authors: Antolín Ernesto J Méndez , Canavaciolo Vctor L González , Pérez Roxana Sierra
Published: February 2020

A new validated gas chromatographic (GC) method using acetyl chloride as a derivatizing agent for determining policosanol's high molecular weight alcohols (policosanol's fatty alcohols; PFAs) in fish oil (FO) is described. Before derivatizing the alcohols, FO was subjected to a methylation reaction, and then the PFAs were isolated in a chloroform fraction by silica gel by column liquid chromatography. GC analysis was performed using a BPX-5 wide-bore column and 1-eicosanol as an internal standard. Validation assays applied to the method proved noninterference by a very complex mixture of the FO with PFAs, even for samples subjected to stress conditions. Good linearity [correlation coefficient >0.999, relative standard deviation (RSD) of the slope <1.3, and RSD of the response factors <1.9 with no bias] and accuracy (average recovery from 100.6 to 102.2) over a range of 28142 of the nominal concentration were obtained. Within-day and intermediate precisions at the nominal dose (100) were 1.7 and 2.9, respectively. The method was successfully used to identify and quantitate the PFAs in FO
Validated Reversed-Phase Column High-Performance Liquid Chromatographic Method for Separation and Quantification of Polyphenolics and Furocoumarins in Herbal Drugs
Authors: Govindarajan Raghavan , Singh Dhirendra Pratap , Rawat Ajay Kumar Singh
Published: February 2020

A rapid column high-performance liquid chromatographic-photodiode array method has been developed for the separation and identification of secondary metabolites, especially different types of phenols and furocoumarins, in a 35 min chromatographic run. The method has been optimized and validated for selectivity, precision, recovery, and robustness with the aim of application for standardization of selected herbal drugs. Almost all of the tested compounds had linearity of >98, with relative standard deviation <10 in terms of variation of retention time. Interday and intraday variability was <5. The developed method has been successfully applied in identification and quantification of phenols and furocoumarins present in different plants, viz., Artemisia pallens (whole plant), Hibiscus rosa-sinensis DC (flower), Heracleum candicans DC (fruit), and Ficus carica Linn (bark). The results indicate that the method is rapid, accurate, and robust for the analysis of different types of phenols and furocoumarins and, hence, can be successfully used in the quality control and standardization of plant extracts and herbal drugs.
Development and Validation of a High-Performance Thin-Layer Chromatographic Method, with Densitometry, for Quantitative Analysis of Ketorolac Tromethamine in Human Plasma
Authors: López-Bojórquez Ericka , Castañeda-Hernández Gilberto , Parra Mario González-de la , Namur Salvador
Published: February 2020

Ketorolac tromethamine is a potent nonsteroidal anti-inflammatory drug that is widely used in the treatment of moderate to severe pain. A new method was developed and validated for quantifying ketorolac (the free acid of the tromethamine salt) in human plasma by high-performance thin-layer chromatography. The stationary phase was silica gel 60, and the composition of the mobile phase was n-butanolchloroformacetic acidammonium hydroxidewater (9 3 5 1 2, v/v). The densitometric analysis of ketorolac was performed at 323 nm. The method was validated for precision (repeatability and reproducibility), accuracy, and sensitivity. Repeatability was 10.11% [coefficient of variation (CV)] and reproducibility was 12.18% (CV) as the maximum variation. Accuracy was determined at 3 different concentration levels, and results were within 15% of the predetermined range. Data were fitted by a linear mathematical function (linear regression). The calibration graph was linear in the range of 2002000 ng/mL. Average recovery was 73.67%. The method proved to be accurate, precise, and sensitive for the ketorolac tromethamine quantification.
Rapid High-Performance Thin-Layer Chromatographic Method for Detection of 5 Adulteration of Black Cohosh with Cimicifuga foetida, C. heracleifolia, C. dahurica, or C. americana
Authors: Ankli Anita , Reich Eike , Steiner Mario
Published: February 2020

Black cohosh (Cimicifuga racemosa) is used to treat discomfort during menopause and as a substitute for synthetic drugs in hormone replacement therapy. The mostly wildcrafted plant is ranked among the top-selling herbs in the United States. There is a risk for adulteration with the similar-looking C. americana, which grows in the same habitats of the eastern United States. Other adulterants found in today's global marketplace are the 3 Asian Cimicifuga species C. foetida, C. heracleifolia, and C. dahurica. A very practical, rapid, and reliable high-performance thin-layer chromatographic (HPTLC) method was developed for identification of C. racemosa and detection of its most common adulterants by fingerprint profiles. With specific derivatization reagents, mixtures of C. racemosa with a minimum of 5 of one of the adulterants can be detected. The proposed method was validated with respect to specificity, stability, precision, and robustness. It can be used for quality control of black cohosh raw material in a current Good Manufacturing Practices environment.
Comparative Evaluation of Methods Commonly Used to Determine Antimicrobial Susceptibility to Plant Extracts and Phenolic Compounds
Authors: King Thea , Dykes Gary , Kristianti Ruth
Published: February 2020

A comparison was made to evaluate the ability of the most commonly used qualitative agar diffusion methods and a quantitative broth dilution assay to determine the antimicrobial activity of a plant extract and a variety of phenolic compounds. A disc and well diffusion technique and a microtiter broth microdilution (MBM) assay were used as antimicrobial susceptibility tests of a plant extract and several phenolic compounds against 7 bacterial species. In both the well and disc diffusion assays, the level of reproducibility was poor and a linear or logarithmic relationship did not exist between inhibition zone size and the concentration of the agents. The MBM method produced the most consistent results and allowed the determination of the relative sensitivities of each species and the relative antimicrobial activities of each agent. This study demonstrated that when a diffusion method is used, multiple concentrations of the agent must be assayed to ensure that a relationship exists between the concentration of the agent and inhibition zone size. When a relationship does not exist, antimicrobial activity should be determined by a quantitative dilution technique.
Determination of Flumorph Residues in Vegetables, Soil, and Natural Water by Solid-Phase Extraction Cleanup and High-Performance Liquid Chromatography with UV Detection
Authors: Hu Ji-Ye , Zhang Yu-Chao , Yan Hai
Published: February 2020

A method for high-performance liquid chromatographic (HPLC) determination of flumorph residues in cucumber, tomato, soil, and natural water was developed and validated. Primary secondary amine or octadecylsilyl (C18) solid-phase extraction cartridges were used for sample preparation. Reversed-phase HPLC with UV detection was used for separation and quantification of the pesticide. The combined cleanup and chromatographic method steps were sensitive and reliable for simultaneous determination of residues of the 2 isomers of flumorph in the studied samples. This method is characterized by recovery >97.9, coefficient of variation <6.2, and limit of quantification of 0.01 mg/kg, in agreement with directives for method validation in residue analysis. Flumorph residues in the samples were further confirmed by HPLC/mass spectrometry. The proposed method is fast, easy to perform, and could be used for monitoring of pesticide residues.
Quantitative Determination of Quinocetone and Its Metabolites in Chicken Plasma by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Li Yong , Gao Zhi Xian , Dong FangTing , Cheng Yi Yong
Published: February 2020

A new method has been established for the simultaneous determination of the new veterinary drug quinocetone (3-methyl-2-cinnamoyl-N-1,4-dioxyquioxaline; QTN) and its 2 metabolites de-monoxy-quinocetone (3-methyl-2-cinnamoyl-N-1-monoxyquinoxaline; DMO-QTN) and de-dioxyquinocetone (3-methyl-2-cinnamoyl-N-quinoxaline; DDI-QTN) in chicken plasma by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The detection was performed using electrospray ionization in multiple reaction monitoring mode. The analysis of the linearity, accuracy, and precision of the method is described. The limits of detection and quantification of the LC/MS/MS method used for testing QTN, DMO-QTN, and DDI-QTN were 0.002 and 0.008 g/mL; 0.002 and 0.008 g/mL; and 0.003 and 0.010 g/mL, respectively. The method was validated and can be used in future pharmacokinetic studies.
Identification of Cervidae DNAin Feedstuff Using a Real-Time Polymerase Chain Reaction Method with the New Fluorescence Intercalating Dye EvaGreen
Authors: Chen Ying , Wu Yajun , Wang Jing , Xu Baoliang , Zhong Zhengyu , Xia Jingshi
Published: February 2020

A real-time qualitative and quantitative polymerase chain reaction method (cer-194) using the fluorescence dye EvaGreen and aimed at the cytochrome b sequence was established for detection of cervidae DNA in feedstuff. Eight meat meal samples derived from deer, bovine, ovine, camel, pig, rabbit, fish, and chicken and 17 cervidae hair samples covering 2 subfamilies, 4 genera, and 7 species were tested to prove the specificity of the cer-194 system and its universality within the cervidae family. Detection limit of 0.1 deer meat in fish meal, blood powder, and feather powder matrixes was confirmed.
Progress on the Development and Single-Laboratory Validation of a High-Performance Liquid Chromatographic Method for the Determination of Carbadox and Pyrantel Tartrate in Type B and C Medicated Feeds
Authors: Sabbatini Jane Z
Published: February 2020

Carbadox, an antimicrobial agent, and pyrantel tartrate, an anthelmintic, are feed additives that are often used in combination in the United States. The current AOAC methods for these analytes are spectrophotometric, using standard addition techniques. These methods are labor-intensive and prone to variability as well as matrix interferences. Published methods for both analytes that use high-performance liquid chromatography were evaluated and a test method was developed. The method uses a water prewetting step to enhance extraction of pyrantel followed by extraction with acetonitrileethanol (50 + 50). Sample extracts are filtered through a glass fiber filter and purified using alumina solid-phase extraction columns. Chromatography is performed on a C18 column with a gradient mobile phase of dibutylamine acetate and acetonitrile. The data show that both analytes exhibit acceptable peak shape when a C18 column that is both acid- and base-deactivated is used. Linearity has been established and initial recovery studies on medicated swine feeds are promising.
Determination of 142 Pesticides in Fruit- and Vegetable-Based Infant Foods by Liquid Chromatography/Electrospray Ionization-Tandem Mass Spectrometry and Estimation of Measurement Uncertainty
Authors: Wang Jian , Leung Daniel
Published: February 2020

A liquid chromatographic/electrospray ionization-tandem mass spectrometric method was developed and validated to determine 142 pesticides in fruit- and vegetable-based infant foods, including apples, apples and bananas, pears, bananas, apple juice, peas, sweet potatoes, creamed corn, squash, and carrots. Pesticides were extracted from infant foods by using the procedure known as the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Quantification was based on matrix-matched standard calibration curves with the use of an isotopically labeled standard or a chemical analogue as the internal standard to obtain method accuracy. The method performance parameters, including overall recovery, intermediate precision, and measurement uncertainty, were evaluated on the basis of a nested design. The performance results were calculated by using a compiled SAS program that provided a semiautomated procedure for handling a large number of calculations in a few seconds. In general, the overall recoveries, for spiking levels of 10, 50, and 80 g/kg, fell in a range of 81110, intermediate precisions were <20, and measurement uncertainties were <40. Chlorimuron-ethyl, ethofenprox, haloxyfop, naptalam, primisulfuron-methyl, pyridalyl, pyridate, quizalofop, and tebufenozide were the method problematic pesticides that had large measurement uncertainty (>40) due to low recovery and/or poor repeatability. The method provided an analytical range of 1100 g/kg with the lowest concentration level at 1 g/kg for all pesticides (signal-to-noise ratio of >10), except for aclonifen at 5 g/kg.
Determination of 7B3 Residues in Cotton Plants by Liquid Chromatography/Mass Spectrometry
Authors: Yan Xiao-Jing , Liang Xiao-Mei , Xu Yan-Jun , Jin Shu-Hui , Wang Dao-Quan
Published: February 2020

A method was developed for the determination of 7B3 (12-propyloxyimino-1,15-pentadecanlactam), a novel macrolactam fungicide, by liquid chromatography/mass spectrometry (LC/MS) with positive electrospray ionization (ESI+). The method used a reversed-phase C18 column and acetonitrilewater (60 + 40, v/v) mobile phase. The quick, easy, cheap, effective, rugged, and safe method was used for extraction of 7B3 from cotton plants, which involved the extraction of 10 g homogenized sample with 10 mL acetonitrile, followed by the addition of 4 g anhydrous MgSO4 and 1.0 g NaCl. After centrifugation, 1 mL of the buffered acetonitrile extract was transferred into a tube containing 50 mg primary secondary amine sorbent and 100 mg anhydrous MgSO4. After shaking and centrifugation, the final extract was transferred to an autosampler vial for concurrent analysis by LC/MS. The results of 7B3 determined by LC/MS in the selective ion monitoring mode were linear, and the matrix effect of the method was evaluated. The average recoveries of 7B3 fortified at different levels were within 84.1100.2, and the relative standard deviations were <7.5 for all samples analyzed. The method limit of detection and the limit of quantitation values were 0.03 and 0.1 mg/kg, respectively. The proposed method was successfully applied to determine 7B3 residues in practical samples. This method is sensitive, accurate, reliable, simple, and safe.
Analytical Determination of Virginiamycin Drug Residues in Edible Porcine Tissues by LC-MS with Confirmation by LC-MS/MS
Authors: Boison Joe , Lee Stephen , Gedir Ron
Published: February 2020

A liquid chromatographic-mass spectrometric (LC-MS) method was developed and validated for the determination and confirmation of virginiamycin (VMY) M1 residues in porcine liver, kidney, and muscle tissues at concentrations 2 ng/g. Porcine liver, kidney, or muscle tissue is homogenized with methanolacetonitrile. After centrifugation, the supernatant is diluted with phosphate buffer and cleaned up on a C18 solid-phase extraction cartridge. VMY in the eluate is partitioned into chloroform and the aqueous upper layer is removed by aspiration. After evaporating the chloroform in the residual mixture to dryness, the dried extract is reconstituted in mobile phase and VMY is quantified by LC-MS. Any samples eliciting quantifiable levels of VMY M1 (i.e., at concentrations 2 ng/g) are subjected to confirmatory analysis by LC-MS/MS. VMY S1, a minor component of the VMY complex, is monitored but not quantified or confirmed.
Single-Laboratory Validation for the Quantification of Neomycin B and Neomycin C in Animal Feeds by Liquid Chromatography Fluorescence Detection with Post-Column Derivatization
Authors: Driver Julee Lynn , Thiex Nancy , Raynie Douglas , Ofitserova Maria , Pickering Michael
Published: February 2020

Amethod using ion-exchange liquid chromatographic (LC) separation, post-column derivatization, and fluorescence detection to quantify neomycin B and neomycin C in animal feeds has been developed and validated. Improved methodology is required to achieve positive identification of antibiotics present and to more accurately determine the amount of antibiotics in feeds. The method sample range covers additive levels found in type A, B, and C medicated feed products (500.005 wt/wt neomycin base). The linear range for the method covers 50150 of expected sample concentrations. Average recovery from type A and B feeds, n = 9, was 100.4 neomycin with RSD = 2.28. Average recovery from type C feeds and milk replacers, n = 9, was 97.5 neomycin with RSD = 4.36. There were no interferences from soybean meal and milk replacer matrix components, oxytetracycline, or other aminoglycosides, with the exception of one gentamicin isomer, which co-elutes with neomycin B. However, neomycin and gentamicin are not a legal feed combination, and the presence of gentamicin can easily be discerned by the appearance of the 3 gentamicin homologs that do not interfere. Comparison of the proposed LC method to the microbiological method shows that the LC method provides comparable recoveries of neomycin from feed products throughout the range of concentrations found commercially.
Colorimetric Assay of Cimetidine in the Presence of Its Oxidative Degradates
Authors: Amin Alaa S , Dessouki Hassan A , Shama Sayed A , Gouda Eslam A
Published: February 2020

Three simple, accurate, and sensitive colorimetric methods for the determination of cimetidine (Cim) in pure form, in dosage forms, and in the presence of its oxidative degradates were developed. These methods are indirect, involve the addition of excess oxidant N-bromosuccinimide (NBS) for method A; cerric sulfate Ce(SO4)2 for methods B and C of known concentration in acid medium to Cim, and the determination of the unreacted oxidant by measurement of the decrease in absorbance of amaranth dye for method A, chromotrope 2R for method B, and rhodamine 6G, for method C at a suitable maximum wavelength, max: 520, 528, and 525 nm, for the 3 methods, respectively. Regression analysis of the Beer plots showed good correlation in the concentration ranges of 0.24.4 g/mL for method A, and 0.23.4 g/mL for methods B and C. The apparent molar absorptivity, Sandell sensitivity, and detection and quantitation limits were evaluated. The stoichiometric ratio between the drug (Cim) and the oxidant (NBS or Ce 4) was estimated. The validity of the proposed methods was tested by analyzing pure and dosage forms containing Cim with relative standard deviation 1.18. The proposed methods could successfully determine the studied drug with varying excess of its oxidative degradation products, with recovery between 99.2 and 101.8, 100.2 and 102.8, and 99.8 and 102.0 for methods AC, respectively.
Development and Validation of a Simple Method for Routine Analysis of Ractopamine Hydrochloride in Raw Material and Feed Additives by HPLC
Authors: Freire Ellen Figueiredo , Borges Keyller Bastos , Tanimoto Hélio , Nogueira Raquel Tassara , Bertolini Lucimara Cristiane Toso , de Gaitani Cristiane Masetto
Published: February 2020

A simple method was optimized and validated for determination of ractopamine hydrochloride (RAC) in raw material and feed additives by HPLC for use in quality control in veterinary industries. The best-optimized conditions were a C8 column (250 4.6 mm id, 5.0 m particle size) at room temperature with acetonitrile100 mM sodium acetate buffer (pH 5.0; 75 + 25, v/v) mobile phase at a flow rate of 1.0 mL/min and UV detection at 275 nm. With these conditions, the retention time of RAC was around 5.2 min, and standard curves were linear in the concentration range of 160240 g/mL (correlation coefficient 0.999). Validation parameters, such as selectivity, linearity, limit of detection (ranged from 1.60 to 2.05 g/mL), limit of quantification (ranged from 4.26 to 6.84 g/mL), precision (relative standard deviation 1.87), accuracy (ranged from 96.97 to 100.54), and robustness, gave results within acceptable ranges. Therefore, the developed method can be successfully applied for the routine quality control analysis of raw material and feed additives.
Estimation of Catechin in Ayurvedic Oil Formulations Containing Acacia catechu
Authors: Dubey Nidhi , Dubey Nitin , Mehta Rajendra , Saluja Ajay
Published: February 2020

A sensitive, simple, rapid, and efficient HPTLC method was developed and validated for the analysis of catechin in marketed Ayurvedic oil formulations containing Acacia catechu. Chromatography of methanolic0.1 formic acid (7:3, v/v) extracts of these formulations was performed on silica gel 60 F254 aluminum-backed TLC plates of 0.2 mm layer thickness. The plate was developed up to 85 mm with the ternarymobile phase chloroformacetone0.1 formic acid (7.7 + 1.5 + 0.8, v/v/v) at 22 2C with 20 min of chamber saturation. The system produced compact spots of catechin at an Rf value of 0.36. The marker, catechin, was quantified at its maximum absorbance of 296 nm. The limit of detection and quantitation values were 6 and 20 ng/spot, respectively. The linear regression analysis data for the calibration plot showed a good linear relationship with a correlation coefficient of 0.9993 in the concentration range of 2001200 ng/spot for catechin with respect to peak area. Repeatability of the method was 0.88 RSD. Recovery values from 97 to 102 indicate excellent accuracy of the method. The developed HPTLC method is accurate, precise, and cost-effective, and it can be successfully applied for the determination of catechin in marketed Ayurvedic oil formulations containing Acacia catechu.
Development of a Sensitive High-Performance Liquid Chromatographic Method with Simple Extraction for Simultaneous Determination of Huperzine A and Huperzine B in the Species Containing Lycopodium Alkaloids
Authors: Zhang Yanqing , Xie Junbo , Chen Wen-Qian , Zhou Tian-Yan , Lu Wei
Published: February 2020

A sensitive HPLC method with simple extraction was developed for simultaneous determination of huperzine A (HupA) and huperzine B (HupB) in Huperzia serrata, H. crispata, H. miyoshiana, and Lycopodiastrum casuarinoides. In order to avoid conventional multiple-step and time-consuming sample preparation methods, direct reflux extraction with alkaline chloroform was adopted. The quantitative determination was conducted by reversed-phase HPLC with a photodiode array detector set at 308 nm. Separation was performed on a Luna C18 column (250 4.6 mm id, 5 m) with methanol0.2 aqueous acetic acid (18 + 82, v/v) mobile phase. The method was validated for accuracy, reproducibility, precision, and limits of detection and quantification. Quantification of the two active compounds in the samples was performed by this newly developed method, and the content of HupA and HupB varied substantially among four different species. The satisfactory results indicated that the developed method can readily be utilized for quality control of the species of Huperziaceae and Lycopodiaceae containing the two compounds.