bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation and Application of High-Performance Liquid Chromatographic and Spectrophotometric Methods for Simultaneous Estimation of Nebivolol and Hydrochlorothiazide: A Novel Approach to Multivariate Calibrations by R-Software Environment
Authors: Gowda Nagaraj , Panghal Surender , Vipul Kalamkar , Rajshree Mashru 
Published: February 2020

Abstract
A fast, simple reversed-phase HPLC method and two spectrophotometric methods based on principal component regression and partial least squares calibrations were developed for determination of nebivolol (NEB) and hydrochlorothiazide (HCTZ) in formulations without prior separation or masking. The HPLC assay utilized a Phenomenex-Luna RP-18(2) 250 4.6 mm, 5 m column with acetonitrile0.03 aqueous formic acid, pH 3.3 (65 + 35, v/v), mobile phase at a flow rate of 1.0 mL/min, and UV detection at 277 nm. The retention times of NEB and HCTZ were 2.133 and 2.877 min, respectively. The total run time was &lt;4 min. Chemometric calibrations were constructed by using an absorption data matrix corresponding to a concentration data matrix, with measurements in the range of 231310 nm ( 1 nm) in their zero-order spectra using 16 samples in a training set. The chemometric numerical computations were obtained by using R-Software Environment (Version 2.1.1). The proposed methods were validated for various International Conference on Harmonization regulatory parameters like linearity, range, accuracy, precision, robustness, LOD, LOQ, and HPLC system suitability. Laboratory-prepared mixtures and commercial tablet formulations were successfully analyzed using the developed methods. All results were acceptable and confirmed that the method is suitable for its intended use.
Determination of Furosine in Thermally Processed Foods by Hydrophilic Interaction Liquid Chromatography
Authors: Gökmen Vural , Serpen Arda , Morales Francisco J 
Published: February 2020

Abstract
Furosine, a marker of the impairment of lysine residues in protein, is formed during acid hydrolysis of the Amadori compound generated at the early stage of the Maillard reaction in thermally treated foods. An analytical method is described for the determination of furosine in thermally processed foods. The method entails acid hydrolysis of food, SPE cleanup with a hydrophilic-lipophilic sorbent, and hydrophilic interaction LC separation. The main advantage of the method is the separation of furosine by means of hydrophilic interaction LC analysis, which simply avoids ion-pairing agents during the chromatography for a complete baseline separation, or avoids the use of a metal-free chromatographic device. In addition, by combining microwave hydrolysis with hydrophilic interaction LC, the complete determination of furosine in a food sample takes approximately 2530 min. The LOD and the LOQ were 0.7 and 2.3 mg/kg, respectively, for furosine, based on S/Ns of 3 and 10, respectively. The recoveries ranged from 94.6 3.1 to 98.6 1.7 for spiking levels of 1001000 mg/kg sample. The method is easy to use and cost-effective, and gave reproducible results for both within-day and day-to-day tests.
Enzyme-Linked Immunosorbent Assay Kit for Beta-Lactoglobulin Determination: Interlaboratory Study
Authors: Štumr František , Gabrovská Dana , Rysová Jana , Hanák Petr , Plicka Jan , Tomková Kvta , Cuhra Petr , Kubk Martin , Barošvá Soňa , Karšulĺnová Lenka , Bulawová Hana , Brychta Josef 
Published: February 2020

Abstract
An interlaboratory study was performed in six laboratories to prove the validation of the ELISA method developed for quantitative determination of beta-lactoglobulin (BLG) in foods. The ELISA kit used for this study is based on rabbit polyclonal antibody. In-house validation of the kit did not produce false-positive results or cross-reactivity in a broad range of food matrixes containing no milk proteins. All participants obtained the BLG kit with a standard operational procedure, the list of the samples, samples, and a protocol for recording test results. The study included 14 food samples (extruded breakfast cereals, bread, two soy desserts, butter, chicken ham, chicken meat, wheat flour, long grain rice, jelly, two whey drinks, crackers, and bitter chocolate) and six spiked samples (two rice, two wheat flour, and two chicken meat). Nine samples of food matrixes containing no milk proteins showed BLG content lower than the first standard (0.15 mg/kg). Two samples of food matrixes with no milk proteins revealed BLG content higher than standard 3 (1.5 mg/100 g) and standard 4 (5.0 mg/100 g). Three food samples containing milk were tested as positive, and all spiked samples were evaluated as positive. The statistical tests (Cochran, Dixon, and Mandel) and analysis of variance were used to evaluate the interlaboratory study results. Repeatability and reproducibility limits, as well as LOQ (0.22 mg BLG/kg) and LOD (0.07 mg BLG/kg), for the kit were calculated.
Optimization of Ultrasonic-Assisted Acid Extraction of Mercury in Muscle Tissues of Fishes Using Multivariate Strategy
Authors: Shah Abdul Q , Kazi Tasneem G , Arain Mohammad B , Baig Jameel A , Afridi Hassan I , Jamali Mohammad K , Jalbani Nusrat , Kandhro Ghulam A 
Published: February 2020

Abstract
A simple and rapid ultrasound-assisted extraction procedure was developed for the determination of total mercury (Hg) in muscle tissues of freshwater fish species. A Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of variables, such as presonication time (without ultrasonic stirring), sonication time, ultrasonic bath temperature, nitric acid concentration, hydrochloric acid concentration, and sample mass of muscle tissues. Some variables showed a significant effect on recovery, and they were further optimized by a 23 + star central composite design that involved 16 experiments. The validation was carried out by analysis of certified reference material DORM-2 (dog fish muscles); for comparative purposes, an acid digestion induced by microwave energy was used. Cold vapor atomic absorption spectrometry was used for the determination of total Hg. No significant differences were established between the analytical results and the certified values (paired t-test at P &gt; 0.05). The LOD and LOQ of Hg were 0.133 and 0.445 g/kg, respectively, which demonstrated the high sensitivity of the proposed procedure for the determination of Hg at trace levels. The Hg concentrations in the muscle tissues of 10 freshwater fish species were found in the range of 35.367.8 g/kg on a dried basis, which were within the permissible limit of the World Health Organization.
Determination of a Two-Tailed 100(1-α)% Upper Limit on the Relative Error in the Laboratory-to-Laboratory Standard Deviation Obtained from an Interlaboratory Study
Authors: McClure Foster D , Lee Jung K 
Published: February 2020

Abstract
For some classes of analytical methods, it is assumed that the error in the laboratory-to-laboratory standard deviation (sL) is appreciable. To demonstrate the magnitude of this error in sL for such methods, formulas were derived to obtain a two-tailed 100(1-α)% upper limit on the relative error in sL obtained from an interlaboratory study, assuming that the laboratory-to-laboratory variance (sL2) obtained in the validation of an analytical method is approximately normal and/or Chi-square distributed. This 100(1-α)% upper limit is referred to as a margin of relative error in sL (MRE(sL)). Monte Carlo simulations were performed, and the results compared satisfactorily with the formula calculations. To aid in designing future interlaboratory studies in which concern is focused on the magnitude of the uncertainty in sL, expressed as a proportion of the true value (σL), a formula was derived to determine the number of laboratories needed to attain a given MRE in sL for a stated number of replicates per laboratory.
Structural and Immunogenic Effects of Multiple Hapten Loading on Carrier Protein
Authors: Singh K Vikas , Khanna Pooja , Suri C Raman , Garg Mohan L 
Published: February 2020

Abstract
Haptens are low-molecular-weight compounds that are usually nonimmunogenic in nature. These compounds are, in general, conjugated with carrier proteins to elicit an immune response for antibody production. In this work, we report the effect of multiple hapten loading on carrier protein after conjugation by monitoring the structural and immunogenic properties of the protein. Biochemical conjugation of carboxylated hapten (atrazine derivative) to bovine serum albumin via ε-amino groups of lysine residues was monitored by the intrinsic fluorescence intensity of tryptophan residues of protein. A significant blue shift of emission maxima confirmed the conformational changes with increasing molar ratio of hapten:protein. Circular dichroism spectroscopy suggested a decreasing trend for α-helical and increased formation of β-sheet structures in hapten-loaded protein. A further insight was sought by using molecular modeling methods for understanding of structural changes in the native protein post-hapten conjugation. A sequential approach for hapten loading on the carrier confirmed that initial binding could affect the possible binding sites for subsequent incorporation of hapten molecules. These changes play a major role in the immunogenic response of hapten-carrier conjugate. The approach taken to develop this model is promising, and can be generalized for studies with other protein-hapten combinations.
Extraction Efficiencies of Heavy Metals in Hydroethanolic Solvent from Herbs of Commerce
Authors: Sullivan James , Greenfield Jackie , Cumberford Greg , Grant Jim , Stewart Jeremy 
Published: February 2020

Abstract
Heavy metal contamination of herbal products is a major concern in the herbal and dietary supplement industry. Heavy metal exposure is well-documented to cause a variety of adverse human health effects and to negatively impact our environment. The Final Rule for Dietary Supplements for current good manufacturing practice regulation, 21 U.S. Food and Drug Administration Code of Federal Regulations 111, requires dietary supplement manufacturers to establish herbal purity limits for heavy metal contaminants considered safe for human consumption. Heavy metals may enter into the herbal manufacturing process via bioaccumulation from the harvest site or during postharvest processing phases, such as drying and/or liquid extraction. Traditionally, herbalists have used hydroethanolic solvents to extract herbal biomasses in pure food-grade ethanolwater combinations with solvent polarities capable of removing a wide range of hydrophilic and lipophilic constituents. The presented data demonstrate that hydroethanolic solvents are not completely efficient in the extraction of heavy metal accumulations from plant matrixes; and can act as an effective decontamination step in herbal product processing.
Kinetic Spectrophotometric Determination of Ciprofloxacin in a Pharmaceutical Preparation
Authors: Aslan Serap Saglik , Demir Betul 
Published: February 2020

Abstract
Two kinetic spectrophotometric methods were developed for determination of ciprofloxacin (CIP) in a pharmaceutical preparation. The methods are based on oxidation of CIP with potassium permanganate in alkaline media and measurement of the enhancement in the absorbance of manganate ion at 603 nm by spectrophotometry. The calibration graphs were constructed using the initial rate and fixed time methods. The linearity range for concentrations of CIP was found to be 4.020.0 g/mL. The RSD values for intraday and interday precision were 0.050.50 and 0.070.63, respectively. The procedures were applied successfully for determination of CIP in commercial tablets. The results compared well with those from a reference HPLC method. The proposed methods can be recommended for routine analysis of CIP in QC laboratories.
Comparison of Analytical Methods to Determine Sodium Content of Low-Sodium Foods
Authors: Ehling Stefan , Tefera Sebhat , Earl Robert , Cole Shannon 
Published: February 2020

Abstract
U.S. nutrition labeling regulations require the declaration of sodium content on food products. Accurate and reproducible determination of Na in foods with low Na content (&lt;140 mg/serving) is challenging because of laboratory contamination. Within-laboratory performance of inductively coupled plasma/MS (ICP/MS), flame atomic absorption spectrophotometry (FAAS), ion-selective electrode (ISE), and potentiometric titration of chloride ion were evaluated in 17 low-sodium foods. For 13 types of food, statistically significant differences (P &lt; 0.05) exist between the within-day and/or interday means obtained by ICP/MS, FAAS, and ISE. Median within-day and interday precent RSD values were 2.7 and 6.1, 3.5 and 3.2, and 5.6 and 6.2, respectively, by ICP/MS, FAAS, and ISE. The fewest matrix effects were found with ICP/MS, followed by FAAS, and ISE. FAAS gave higher results in a variety of matrixes when compared to ICP/MS and/or ISE. ISE did not perform well in fatty foods or at very low Na concentrations. Manufacturers' Nutrition Facts Panel sodium declarations exceeded levels found by analysis in &gt;70 of the foods. Analysis of chloride content does not produce reliable Na estimates in low-sodium foods, even when added sodium chloride is present. Methodological issues and contamination sources are discussed.
Single-Laboratory Validation of a Method for the Determination of Phenols and Phenates in Disinfectant Formulations by Liquid Chromatography with UV Detection
Authors: Phillips Tommy , Burns Adrian , Mcmanus Kenneth , Bontoyan Warren 
Published: February 2020

Abstract
A single-laboratory validation study was conducted for an LC method using UV detection for the simultaneous determination of the active ingredients o-phenylphenol (OPP), p-tert-amylphenol (PTAP), and o-benzyl-p-chlorophenol (OBPCP) in disinfectant formulations. Samples were extracted, the extracts diluted with acidified methanol, and the active ingredients separated by LC with a gradient mobile phase and quantified by using UV detection at 285 nm. For each active ingredient, the RSD was 3.7, and the intermediate reproducibility was 3.4. The active ingredient content of the spiked samples analyzed in this study ranged from 0.075 to 10.1 for the individual phenol active ingredients. The average recovery ranges were 86.7104.9, 82.8115.6, and 91.6114.7 for the active ingredients OPP, PTAP, and OBPCP, respectively, for the concentration range of 0.07510.1. This method, with a relatively short chromatographic run time (about 15 min), proved to be reliable and convenient for analyses of products or samples containing all or a combination of these phenol active ingredients.
Determination of Molecular Weight of Silk Fibroin by Non-Gel Sieving Capillary Electrophoresis
Authors: Wei Wei , Zhang Yaopeng , Shao Huili , Hu Xuechao 
Published: February 2020

Abstract
A simple non-gel sieving capillary electrophoresis (NGSCE) method was established to determine the MW of silk fibroin using CE. The background electrolyte with a pH of 8.8 was based on three components: polyethylene glycol, tris(hydroxymethyl)aminomethane, and sodium dodecyl sulfate (SDS). NGSCE showed a good linear relationship with satisfactory reproducibility between the migration time and the MW of standard proteins. It was found that the regenerated silk fibroin had an MW around 83 kDa with a wide MW distribution (MWD). This absolute value is lower than the result obtained from SDS-polyacrylamide gel electrophoresis due to the different principles of the methods, but their similar MWD shapes indicated that NGSCE could be a feasible, highly sensitive, rapid method for determination of the MW of silk fibroin.
Development and Validation of a Micellar High-Performance Liquid Chromatographic Method for Determination of Risedronate in Raw Material and in a Pharmaceutical Formulation: Application to Stability Studies
Authors: Walash Mohamed , Metwally Mohamed , Eid Manal , El-Shaheny Rania 
Published: February 2020

Abstract
A micellar HPLC method was developed for analysis of the antiosteoporosis drug risedronate. The analysis was carried out using a 250 4.6 mm id, 5 m particle size C18 Waters Symmetry column. The mobile phase consisted of 0.02 M sodium dodecyl sulfate + 0.3 triethylamine + 10 n-propanol, prepared in 0.02 M orthophosphoric acid. The pH of the mobile phase was adjusted to pH 6.0, and it was pumped at a flow rate of 0.7 mL/min with UV detection at 262 nm. The method showed good linearity in the range of 280 g/mL, with an LOD of 0.40 g/mL (1.31 106 M) and an LOQ of 1.21 g/mL. The suggested method was successfully applied for the analysis of risedronate in raw material and a tablet formulation, with average recoveries of 99.91 1.30 and 101.52 0.30, respectively. The stability-indicating capability of the proposed method was proved using forced degradation. By changing the pH of the mobile phase to 4.0, the oxidative degradation product could be separated from risedronate.
Separation and Preconcentration of Trace Amounts of Gold(III) Ions Using Modified Multiwalled Carbon Nanotube Sorbent Prior to Flame Atomic Absorption Spectrometry Determination
Authors: Afzali Daryoush , Ghaseminezhad Sima , Taher Mohammad Ali 
Published: February 2020

Abstract
Multiwalled carbon nanotubes are attractive as sorbents for SPE because they can be used for enrichment of organic compounds and metal ions at trace levels. In this study, multiwalled carbon nanotubes were oxidized with concentrated HNO3, and then the oxidized multiwalled carbon nanotubes were modified with 5-(4-dimethylaminobenzyliden)-rhodanine. The modified multiwalled carbon nanotubes were used as a solid sorbent for separation and preconcentration of trace amounts of Au(III) ions. The sorption of Au(III) ions was quantitative in the pH range of 2.05.0, whereas quantitative desorption occurred instantaneously with 5.0 mL 2.0 M Na2S2O3. The eluted solution was aspirated directly into the flame for atomic absorption spectrometry. The proposed method resulted in an enrichment factor of 94. The RSD of the method was 1.11 (n = 10, 2.0 g/mL) and the LOD was 0.15 ng/mL. The calibration curve for Au(III) was linear between 0.53 ng/mL and 36.0 g/mL in the initial solution, with an R2 value of 0.9999. The sorbent capacity of the modified multiwalled carbon nanotubes was 7.3 mg Au(III)/g sorbent. The influences of the experimental parameters, including sample pH, sample flow rate, eluent volume and flow rate, sample volume, and interference of some ions on the recoveries of the Au ions, were investigated. The proposed method was applied for preconcentration and determination of Au in different samples.
Analysis of Triclosan and Triclocarban in Soil and Biosolids Using Molecularly Imprinted Solid Phase Extraction Coupled with HPLC-UV
Authors: Verma Kusum S , Xia Kang 
Published: February 2020

Abstract
A molecularly imprinted polymer (MIP) able to selectively bind triclosan (TCS) and triclocarban (TCC), commonly used antibacterial agents in many consumer products, was prepared using noncovalent molecular imprinting methods. The prepared MIP was evaluated as a selective sorbent in SPE for sample cleanup before HPLC-UV analysis of TCS and TCC in soil and biosolid samples. The MIP was also compared with commercially available C18 SPE sorbent. The molecularly imprinted SPE (MISPE) developed in this study was more efficient than C18 SPE for the cleanup of extracts of soil and biosolid samples prior to the analysis of TCC and TCS using HPLC-UV. The LOQ values for both TCC and TCS in the soil samples were determined to be 40 g/kg; in the biosolid samples, the LOQ values were 100 and 300 g/kg for TCC and TCS, respectively. Compared to C18 SPE, using MISPE for sample cleanup may result in a significant reduction of analytical cost, because one MIP can be reused up to 35 times and HPLC-UV instead of HPLC/MS can be used for instrumental analysis following sample cleanup by MISPE.
Tradition- and Science-Based Quality Control of Chinese MedicinesIntroducing the Phyto-True System
Authors: Leung Albert Y 
Published: February 2020

Abstract
The current QC practice of quantifying presumed active chemicals or arbitrarily selected chemical markers is of doubtful value in assessing multicomponent complex traditional Chinese medicines (CMs) and often leads to an inconsistent or irreproducible research and clinical outcome. Consequently, the first and most important step in the QC of CMs (or other botanical medicines) whose exact active chemical components are unknown is to use analytical techniques that can comprehensively define the totality of the components/attributes making up their identity and quality. One of the most versatile techniques is HPTLC. Using HPTLC, along with other simple techniques such as FTIR spectroscopy and UV-Vis spectroscopy combined with complementary gene expression profiling, we have been able to correctly identify CM materials, detect adulterants, and differentiate closely related materials and botanical species. Our research has resulted in the introduction of the concept and specimens of Phyto-True Reference Material (PTRM™), aka Representative Botanical Reference/Research Material (RBRM™), now commercially available, and a novel patent-pending technology (Phyto-True™ system) that can serve as a starting point for the meaningful QC of traditional CMs so far not possible for these complex materials. Examples will be highlighted to demonstrate this new concept.
Study on Triterpenoic Acids Distribution in Ganoderma Mushrooms by Automatic Multiple Development High Performance Thin Layer Chromatographic Fingerprint Analysis
Authors: Yan Yu-Zhen , Xie Pei-Shan , Lam Wai-Kei , Chui Eddie , Yu Qiong-Xi 
Published: February 2020

Abstract
GanodermaLingzhi in Chineseis one of the superior Chinese tonic materia medicas in China, Japan, and Korea. Two species, Ganoderma lucidum (Red Lingzhi) and G. sinense (Purple Lingzhi), have been included in the Chinese Pharmacopoeia since its 2000 Edition. However, some other species of Ganoderma are also available in the market. For example, there are five species divided by color called Penta-colors Lingzhi that have been advocated as being the most invigorating among the Lingzhi species; but there is no scientific evidence for such a claim. Morphological identification can serve as an effective practice for differentiating the various species, but the inherent quality has to be delineated by chemical analysis. Among the diverse constituents in Lingzhi, triterpenoids are commonly recognized as the major active ingredients. An automatic triple development HPTLC fingerprint analysis was carried out for detecting the distribution consistency of the triterpenoic acids in various Lingzhi samples. The chromatographic conditions were optimized as follows: stationary phase, precoated HPTLC silica gel 60 plate; mobile phase, tolueneethyl acetatemethanolformic acid (15 + 15 + 1 + 0.1); and triple-development using automatic multiple development equipment. The chromatograms showed good resolution, and the color images provided more specific HPTLC fingerprints than have been previously published. It was observed that the abundance of triterpenoic acids and consistent fingerprint pattern in Red Lingzhi (fruiting body of G. lucidum) outweighs the other species of Lingzhi.