bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization and Validation of an LC-FLD Method for Biotin in Infant Formula, Infant Cereals, Cocoa-Malt Beverages, and Clinical Nutrition Products
Authors: Gimnez Esther Campos , Trisconi Marie-Jose , Kilinc Tamara , Andrieux Pierre
Published: February 2020

A fast and simple chromatographic method to determine biotin in foods is presented. Biotin is extracted using papain (60°C, 1 h). After pH adjustment and filtration, biotin is determined by LC with fluorescence detection using postcolumn reagent avidin-FITC (avidin labeled with fluorescein isothiocyanate). The method has been validated in a large range of products: milk- and soy-based infant formulas, cereals, cocoa-malt beverages, and clinical nutrition products. The method showed recovery rates of 98.1 ± 5.7 (average ± SD) in a large range of concentrations. Biotin concentrations determined in infant formula standard reference materials 1846 and 1849 were in agreement with reference values. RSD of repeatability (RSDr) varied from 2.0 to 4.5%, and intermediate reproducibility (RSDiR) from 5.8 to 9.4%. LOD and LOQ were 3.0 and 5.0 µg/100 g, respectively. The proposed method is suitable for routine analysis of biotin in fortified foods (infant formulas, infant cereals, cocoa-malt beverages, and clinical nutrition products). It can be used as a faster, more selective, and precise alternative to the classical microbiological determination, and is easily transferable among laboratories.
Methodology for Determining Degree of Hydrolysis of Proteins in Hydrolysates: A Review
Authors: Rutherfurd Shane M
Published: February 2020

Degree of hydrolysis (DH) is defined as the proportion of cleaved peptide bonds in a protein hydrolysate. Several methods exist for determining DH; the most commonly used of these include the pH-stat, trinitrobenzenesulfonic acid (TNBS), o-phthaldialdehyde (OPA), trichloroacetic acid soluble nitrogen (SN-TCA), and formol titration methods. The pH-stat method is based on the number of protons released during hydrolysis; the TNBS, OPA, and formol titration methods are based on the measurement of amino groups generated from hydrolysis. The SN-TCA method measures the amount of TCA-soluble nitrogen, rather than DH. The pH-stat is the simplest and most commonly used method, but does not determine peptide bonds directly. In addition, the accuracy of the method depends on the type of hydrolytic enzymes used, the size of the hydrolyzed peptides, and the reaction temperature. Generally, the TNBS and OPA methods compare well and do directly determine DH. However, the assumption that the response factor for all derivatized N-terminal amino acids is similar may lead to inaccuracies. In conclusion, there is no consensus as to the best method for determining the DH of protein hydrolysates; consequently, there is a need for a standardized approach if interstudy comparisons are to be made.
Issues in Mass Spectrometry Between Bench Chemists and Regulatory Laboratory Managers: Summary of the Roundtable on Mass Spectrometry Held at the 123rd AOAC INTERNATIONAL Annual Meeting
Authors: Heller David N , Lehotay Steven J , Martos Perry A , Hammack Walter , Fernndez-Alba Amadeo R
Published: February 2020

At the 123rd AOAC INTERNATIONAL Annual Meeting in Philadelphia, PA, 45 residue chemists gathered for a roundtable discussion of mass spectrometry (MS) used for regulatory chemical residues analysis. The session was conceived to address current technical and communication issues about MS between bench chemists and their bosses. The topics covered a range of practical, routine, and recurring issues on capabilities and limitations of MS techniques, and suggestions on how chemists may better communicate their MS results with customers. The customers in this sense include laboratory managers, quality assurance officers, laboratory clients, regulatory officials, policy-makers, lawyers, and others who have interest in the data. The stated goals devised by the roundtable panelists were to provide independent advice, describe limitations, give practical tips, help set realistic expectations, and answer questions from the attendees. The panelists divided the topics into three main themes: practical aspects in routine analysis using MS, choice of MS technique depending on the purpose for analysis, and qualitative identification and confirmation concepts. This report was written to summarize and expand upon the discussion, frame the current issues, and provide advice on handling common situations in MS analysis and reporting of results. Topics included LODs, data quality objectives, quantification and reporting results, matrix effects, calibration, terminology, differences in performance across MS platforms, proficiency testing, qualitative analysis, and laboratory accreditation. Conclusions are presented as a set of questions for structuring a dialog between bench chemists and laboratory managers.
Multiresidue Analysis of 95 Pesticides at Low Nanogram/Liter Levels in Surface Waters Using Online Preconcentration and High Performance Liquid Chromatography/Tandem Mass Spectrometry
Authors: Jansson Christer , Kreuger Jenny
Published: February 2020

A new multiresidue method for the analysis of 95 pesticides and breakdown products with a wide range of physiochemical properties in surface and ground water using online solid-phase extraction coupled with HPLC/MS/MS is presented. Using an injection volume of only 500 L filtered water, an LOD in the 110 ng/L range was achieved for all but one substance, and recoveries were, with a few exceptions, in the 70120 range. Large differences were found in the adsorption of pesticides on nine filter materials tested for filtration of the water samples. Filters of regenerated cellulose were chosen due to good recoveries and easy handling. Results from the proposed method were compared with results from previously used methods for 31 pesticides in 99 surface water samples, collected in 2008, with good agreement.
Liquid Chromatography-Particle Beam Electron Ionization Mass Spectrometry Method for Analysis of Botanical Extracts: Evaluation of Ephedrine Alkaloids in Standard Reference Materials
Authors: Castro Joaudimir , Balarama Krishna M V , Marcus R Kenneth
Published: February 2020

The preliminary validation of a high-performance liquid chromatography particle beam mass spectrometry method (HPLC-PB/MS) with electron impact ionization source for analysis of botanical extracts is presented. The LC-PB/MS system was evaluated for the analysis of ephedrine alkaloids using ephedra-containing National Institute of Standards and Technology dietary supplement standard reference materials (SRMs) 3241 Ephedra Sinica Stapf Native Extract and 3242 Ephedra Sinica Stapf Commercial Extract. The ephedrine alkaloids were separated by reversed-phase chromatography using a phenyl column at room temperature. A linear gradient method with a mobile phase composition varying from 5:95 [MeOH:0.1 trifluoroacetic acid (TFA) in water] to 20:80 (MeOH:0.1 TFA in water) at a flow rate of 1.0 mL/min, with an analysis time of less than 20 min, was used. The source block temperature was evaluated to determine the optimal operating conditions by monitoring the intensities and fragmentation patterns of the ephedrine alkaloids. Ephedrine and N-methylephedrine were taken as a representative of the test alkaloids. The LODs on the sub-nanogram level were achieved, with ephedrine, pseudoephedrine, and methylephedrine in the SRMs quantified by a standard addition method with recoveries of 86 and RSDs of 14 (N = 3).
Fingerprint Analysis of Ginkgo biloba Leaves and Related Health Foods by High-Performance Liquid Chromatography/Electrospray Ionization-Mass Spectrometry
Authors: Song Jiajia , Fang Guozhen , Zhang Yan , Deng Qiliang , Wang Shuo
Published: February 2020

A fingerprint analysis method was developed for Ginkgo biloba leaves and was successfully used for quality evaluation of related health foods by HPLC with electrospray ionization MS. Fifteen samples of G. biloba leaves, which were collected from 15 different locations in China, were analyzed and identified in this study. By both peak analysis and similarity analysis of the fingerprint chromatograms, variation of constituents was easily observed in the leaves from different sources. By comparison with batches of authentic leaves, the authenticity, and quality consistency of related health foods in different matrixes were effectively estimated. It is important to mention that studying a wide range of authentic leaves from various habitats made the quality evaluation of commercial products more convincing and reasonable. The fingerprint-based strategy of the developed method should provide improved QC of G. biloba leaves and products.
Optimization and Validation of an RP-HPLC Method for Direct Determination of Metformin Hydrochloride in Human Urine and in a Dosage Form
Authors: El-Gindy Alaa , Nassar Mohammed Wafaa , El-Abasawy Nasr Mohammed , Attia Khalid Abdel-Salam , Al-Shabrawi Maisra
Published: February 2020

A simple, selective, sensitive, accurate, and precise method was developed for determination of metformin hydrochloride (MF) in human urine using RP-HPLC. The method depends upon using an octylsilyl (C8) 5 m particle size column at ambient temperature with mobile phase consisting of 33 mM sodium dihydrogen phosphate containing 6.38 mM hexanesulfonic acid sodium salt and adjusted to apparent pH 3.0 with phosphoric acidacetonitrile (93 7, v/v) at a flow rate of 1.5 mL/min. Quantitation was achieved with UV detection at 231 nm based on peak area with a linear calibration curve over the concentration range of 0.0150 g/mL. The proposed method was applied to the determination of the urinary excretion pattern of MF (the cumulative amounts excreted were calculated without pretreatment of the urine sample) and for determination of the dissolution pattern of MF tablets. The proposed method was completely validated according to the U.S. Food and Drug Administration guidelines.
Stress Degradation Studies and Kinetic Determinations of Duloxetine Enteric-Coated Pellets by HPLC
Authors: Gomes Patrícia , Wingert Nathalie R , Paim Clésio S , Schapoval Elfrides E S , Steppe Martin
Published: February 2020

A stability-indicating HPLC assay method was developed for the quantitative determination of duloxetine (DLX) in a pharmaceutical dosage form in the presence of its degradation products, and kinetic determinations were evaluated in acid conditions and UV-C radiation exposure. Chromatographic separation was achieved by use of an ACE C18 column (250 4.0 mm id, 5 m particle size). The mobile phase was prepared by mixing aqueous 50 mM potassium phosphate buffer (pH 6.0 containing 0.3 triethylamine) and acetonitrile (60 40, v/v). DLX was rapidly degraded in an acid medium and in the presence of hydrogen peroxide and UV-C radiation; it was more stable in alkaline medium. The described method was linear over a range of 4.014.0 g/mL for determination of DLX (r = 0.9998). The precision was demonstrated by the RSD of intraday (0.791.07) and interday (0.85) studies. The mean recovery was found to be 100.56. The acid degradation of DLX in 0.1 M HCl solution showed an apparent zero-order kinetics (k = 0.177 g/mL/min), and the photodegradation demonstrated an apparent first-order kinetics (k = 0.082 g/mL/min). The developed method was found to be simple, specific, robust, linear, precise, and accurate for the determination of DLX in enteric-coated pellets.
Quantitative Analysis of the Cholesterol-Lowering Drugs Ezetimibe and Simvastatin in Pure Powder, Binary Mixtures, and a Combined Dosage Form by Spectrophotometry, Chemometry, and High-Performance Column Liquid Chromatography
Authors: Lotfy Hayam Mahmoud , Alamein Amal Mahmoud Aboul , Hegazy Maha Abdel Monem
Published: February 2020

Simple, accurate, sensitive, and precise UV spectrophotometric, chemometric, and HPLC methods were developed for simultaneous determination of a two-component drug mixture of ezetimibe (EZ) and simvastatin (SM) in laboratory-prepared mixtures and a combined tablet dosage form. Four spectrophotometric methods were developed, namely, ratio spectra derivative, ratio subtraction, isosbestic point, and mean centering of ratio spectra. The developed chemometric-assisted spectrophotometric method was the concentration residual augmented classical least-squares method; its prediction ability was assessed and compared to the conventional partial least-squares method. The developed HPLC method used an RP ZORBAX C18 column (5 m particle size, 250 4.6 mm id) with isocratic elution. The mobile phase was acetonitrilepH 3.5 phosphate buffer (40 60, v/v) at a flow rate of 1.0 mL/min, with UV detection at 230 nm. The accuracy, precision, and linearity ranges of the developed methods were determined. The developed methods were successfully applied for determination of EZ and SM in bulk powder, laboratory-prepared mixtures, and a combined dosage form. The results obtained were compared statistically with each other and to those of a reported HPLC method; there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.
Effect of Gamma Irradiation on Caprolactam Migration from Multilayer Polyamide 6 Films into Food Simulants: Development and Validation of a Gas Chromatographic Method
Authors: Félix1 Juliana S , Monteiro Magali , Manzoli José E , Padula Marisa
Published: February 2020

A GC method to determine caprolactam in water, 15 ethanol, and olive oil food simulants was developed and validated. Linear ranges varied from 0.96 to 642.82 g/mL for water, 0.64 to 800.32 g/mL for 15 ethanol, and 1.06 to 1062.34 g/g for olive oil, with correlation coefficients higher than 0.999. Method precision studies showed RSD values lower than 5.45, while method accuracy studies showed recovery from 72 to 111 for all simulants. The effect of gamma irradiation on caprolactam migration from multilayer polyamide 6 (PA-6) films intended for cheese into water, 15 ethanol, olive oil, and 3 acetic acid simulants was also studied. For migration assay, non-irradiated and irradiated (12 kGy) films were placed in contact with the simulant and exposed at 40C for 10 days. The validated method was used to quantify caprolactam migration from multilayer PA-6 films into the simulants, which ranged from 1.03 to 7.59 mg/kg for non-irradiated films, and from 4.82 to 11.32 mg/kg for irradiated films. Irradiation caused almost no changes in caprolactam levels, with the exception of olive oil, which showed an increase in the caprolactam level. All multilayer PA-6 films were in accordance with the requirements of the legislation for caprolactam migration.
Determination of Aflatoxin in Processed Dried Cassava Root: Validation of a New Analytical Method for Cassava Flour
Authors: Gnonlonfin G J Benoit , Katerere David R , Adjovi Yann , Brimer Leon , Shephard Gordon S , Sanni Ambaliou
Published: February 2020

A new method that uses HPLC with a photochemical reactor for enhanced detection was developed and validated for the determination of aflatoxins in cassava flour. Samples were spiked with a mixture of four aflatoxins at 5, 10, and 20 g/kg mixed with either 1 or 5 g NaCl and extracted with methanolwater (80 20, v/v) by shaking for 10 or 30 min. An immunoaffinity column was used for cleanup. HPLC with postcolumn derivatization, for enhancement of aflatoxin fluorescence, and fluorescence determination were used for quantitation of the toxin concentration. The method was validated for recovery, linearity, and precision at the three concentrations tested. Recovery ranges were 5270, 6985, and 8089 for the spiking levels of 5.0, 10.0, and 20.0 g/kg, respectively. It appears that the amount of salt (NaCl) and the shaking time are critical factors in this method; optimal performance was obtained when 1 g salt was used and the shaking time was 10 min. The good linearity and precision of the method allowed baseline separation from interferences, e.g., coumarins.
Optical Determination of L-tyrosine Based on Eggshell Membrane Immobilized Tyrosinase
Authors: Li Yong Jin
Published: February 2020

An optical biosensor based on the eggshell membrane immobilized tyrosinase is described for the detection of L-tyrosine (L-Tyr). The detection scheme was based on the measurement of absorption value of color adduct resulting from the reaction of 3-methyl-2-benzothiazolinone hydrazone and dopa-quinone produced from the enzymatic oxidation of L-Tyr. The prepared biosensor demonstrated optimum activity at pH 7, optimum temperature range of 2040C and a linear response for the L-Tyr concentration in range of 5200 M. It also showed good operation stability for repeated measurements (over 300 times) and storage stability after it had been kept at 4C for 3 months.
Modification of the BAX® System PCR Assay for Detecting Salmonella in Beef, Produce, and Soy Protein Isolate
Authors: Peng Linda X , Wallace Morgan , Andaloro Bridget , Fallon Dawn , Fleck Lois , Delduco Dan , Tice George
Published: February 2020

The BAX® System PCR assay for Salmonella detection in foods was previously validated as AOAC Research Institute (RI) Performance Tested MethodSM (PTM) 100201. New studies were conducted on beef and produce using the same media and protocol currently approved for the BAX System PCR assay for E. coli O157:H7 multiplex (MP). Additionally, soy protein isolate was tested for matrix extension using the U.S. Food and Drug Administration-Bacteriological Analytical Manual (FDA-BAM) enrichment protocols. The studies compared the BAX System method to the U.S. Department of Agriculture culture method for detecting Salmonella in beef and the FDA-BAM culture method for detecting Salmonella in produce and soy protein isolate. Method comparison studies on low-level inoculates showed that the BAX System assay for Salmonella performed as well as or better than the reference method for detecting Salmonella in beef and produce in 8–24 h enrichment when the BAX System E. coli O157:H7 MP media was used, and soy protein isolate in 20 h enrichment with lactose broth followed by 3 h regrowth in brain heart infusion broth. An inclusivity panel of 104 Salmonella strains with diverse serotypes was tested by the BAX System using the proprietary BAX System media and returned all positive results. Ruggedness factors involved in the enrichment phase were also evaluated by testing outside the specified parameters, and none of the factors examined affected the performance of the assay.
Chemical Composition and Antibacterial Activity of Origanum saccatum P.H. Davis Essential Oil Obtained by Solvent-Free Microwave Extraction: Comparison with Hydrodistillation
Authors: Sozmen Fazli , Uysal Burcu , Oksal Birsen S , Kose Elif Odabas , Deniz I Gokhan
Published: February 2020

The components of the essential oils (EOs) obtained by solvent-free microwave extraction (SFME) and hydrodistillation (HD) from endemic Origanum saccatum P.H. Davis were identified by using GC/MS. The main constituents of both EOs obtained by SFME and HD, respectively, from O. saccatum were p-cymene (72.5 and 70.6%), thymol (9.32 and 8.11%), and carvacrol (7.18 and 6.36%). The EO obtained by SFME contained substantially higher amounts of oxygenated compounds and lower amounts of monoterpenes than did the EO obtained by HD. The antibacterial activities of the EOs obtained by SFME and HD were evaluated with the disc diffusion method by comparison with 10 different bacterial strains. The antibacterial activity of the EO extracted by SFME was found to be more effective than that of the EO extracted by HD against seven of the tested bacteria.
Optimization and Validation of a Multiclass Screening and Confirmation Method for Drug Residues in Milk Using High-Performance Liquid Chromatography/Tandem Mass Spectrometry
Authors: Clark Susan B , Storey Joseph M , Turnipseed Sherri B
Published: February 2020

The further optimization and validation of a multiresidue veterinary drug screening method for milk is described. The drug residues of regulatory interest in milk include -lactams, sulfonamides, tetracyclines, fluoroquinolones, and macrolides. A previously published procedure has been modified to incorporate new compounds and to collect both screening and confirmatory ion transitions in one acquisition method. Milk samples were extracted with an equal volume of acetonitrile. The samples were then subjected to cleanup with a bonded SPE cartridge and a MW cutoff filter. The SPE protocol was modified to effectively recover a metabolite of flunixin. Established tolerance levels are set for most of these drugs in milk; thus, the screening procedure was semiquantitative, using positive controls for comparison. The positive controls, consisting of extracts from milk fortified with the drugs at their tolerance or safe level, were used to set statistically valid minimum response criteria for unknown samples. This updated method was validated with fortified milk, as well as with milk samples from animals administered veterinary drugs.
Substitute Technology for Reference Substances in the Analysis of Impurities in Cefonicid for Injection with HPLC Using a Diode Array Detector
Authors: Li Wei
Published: February 2020

With HPLC using a diode array detector (DAD), a method of substitution for reference substances in impurity profiling control was developed that combined peak tracking by the correlation of spectra with application of correction factors for determination of each impurity. For qualitative analysis, two-dimensional (2D) standard spectrochromatographic data produced by HPLC-DAD were compared with sample data to develop 2D chromatographic spectral correlative maps so that the three target impurities were recognized without preparation and injection of reference solutions. For quantitative analysis, correction factors among cefonicid and the three impurities were established. The correction factors were 1.06 for 5-mercapto-1,2,3,4-tetrazole 1-methyl sulfonic acid detected at 255 nm, 0.77 for 7-aminocephalosporanic acid detected at 265 nm, and 0.97 for methoxycefonicid detected at 268 nm. The method could be used in analysis of related substances in cefonicid for injection without recourse to chemical reference standards of the three impurities.
Capillary Methods for Drug Analysis
Authors: Hendrickx Ans , Mangelings Debby , Heyden Yvan Vander
Published: February 2020

This review gives an overview of the applicability of capillary electrophoresis, capillary liquid chromatography, capillary electrochromatography, and their derived techniques to analyze drug impurity mixtures, formulations, biological samples, and chiral compounds. For each application type, a few examples are given to illustrate the potential of the capillary technique. Details are provided about the capillaries used, chiral selectors, and stationary and mobile phases.
Development and Validation of an HPLC Method for Determination of Ziprasidone and Its Impurities in Pharmaceutical Dosage Forms
Authors: Pavlovic Marija , Malesevic Marija , Nikolic Katarina , Agbaba Danica
Published: February 2020

Ziprasidone is known as a novel “atypical” or “second-generation” antipsychotic drug. A sensitive and reproducible method was developed and validated for determination of ziprasidone and its major impurities, which are significantly different in polarity. The separation is performed on a Waters Spherisorb® octadecylsilyl 1 column (5.0 μm particle size, 250 × 4.6 mm id) using a gradient with mobile phase A [buffer–acetonitrile (80 + 20, v/v)] and mobile phase B [buffer–acetonitrile (10 + 90, v/v)] at a working temperature of 25°C. The buffer was 0.05 M KH2PO4 solution with an addition of 10 mL triethylamine/L solution, adjusted to pH 2.5 with orthophosphoric acid. The flow rate was 1.5 mL/min, and the eluate was monitored at 250 nm using a diode array detector. Optimization of the experimental conditions was performed using partial least squares regression, for which four factors were selected for optimization: buffer concentration, buffer pH, triethylamine concentration, and temperature. The proposed validated method is convenient and reliable for the assay and purity control in both raw materials and dosage forms.
Chemometric Detection of Acetaminophen in Pharmaceuticals by Infrared Spectroscopy Combined with Pattern Recognition Techniques: Comparison of Attenuated Total Reflectance-FTIR and Raman Spectroscopy
Authors: Komsta Łukasz , Czarnik-Matusewicz Henryk , Szostak Roman , Gumieniczek Anna , Pietraš Rafał , Skibiński Robert , Inglot Tadeusz
Published: February 2020

This paper presents and discusses the building of discriminant models from attenuated total reflectance (ATR)–FTIR and Raman spectra that were constructed to detect the presence of acetaminophen in over-the-counter pharmaceutical formulations. The datasets, containing 11 spectra of pure substances and 21 spectra of various formulations, were processed by partial least squares (PLS) discriminant analysis. The models found in the present study coped greatly with the discrimination, and their quality parameters were acceptable. A root mean square error of cross-validation was in the 0.14–0.35 range, while a root mean square error of prediction was in the 0.20–0.56 range. It was found that standard normal variate preprocessing had a negligible influence on the quality of ATR-FTIR; in the Raman case, it lowered the prediction error by 2. The influence of variable selection with the uninformative variable elimination by PLS method was studied, and no further model improvement was found.
Monolithic Spin Column: A New Extraction Device for Analysis of Drugs in Urine and Serum by GC/MS and HPLC/MS
Authors: Namera Akira , Nagao Masakata , Nakamoto Akihiro , Miyazaki Shota , Saito Takeshi
Published: February 2020

A monolithic spin column was developed for the extraction of analytes from biological materials. This column was constructed by packing a monolithic silica disk into a spin column. Sample loading, washing, and elution of the target drugs were accomplished simply by centrifugation of the column. Opiates and benzodiazepines are abused throughout the world. Identification and quantification of these drugs is very important to solve crimes or the cause of death. Three opiates (morphine, codeine, and dihydrocodeine) were extracted from urine and serum by using the column. After conversion to trimethylsilyl derivatives of the opiates by vigorous mixing with the derivatizing reagent, the solution was subjected to GC/MS. A linear curve was observed for opiates from 10 to 2500 ng/mL in urine and 5 to 1200 ng/mL in serum, respectively (correlation coefficient > 0.996). For benzodiazepines, the hydroxyl metabolites of triazolam and etizolam were extracted from urine using the column, and the eluate was directly analyzed by HPLC/MS without evaporation. The LOD values were at the ppb level, with RSD values lower than 15%. The proposed methods were successfully applied to clinical and forensic cases, and good agreement of results was obtained compared to conventional methods.
Development and Validation of a UHPLC Method for the Determination of Flavonoids in Red Wine
Authors: Baranowska Irena , Magiera Sylwia
Published: February 2020

A simple and fast ultra-high-performance liquid chromatography (UHPLC) method was developed for the identification and quantification of the following flavonoids in red wine: (±)-catechin, (–)-epicatechin, rutin, quercitrin, hesperidin, neohesperidin, (±)-naringenin, hesperetin, and chrysin. Chromatographic separation of the flavonoids was performed on a Chromolith® Fast Gradient C18e column. A gradient elution was used with mobile phases consisting of 0.1% formic acid in water and acetonitrile. UV detection was performed at 280 nm. A complete separation of flavonoids was possible within 6 min. The calibration curves showed good linearity (R2 ≥ 0.9990) in the selected range of each analyte; the LOD ranged between 0.06 and 0.19 μg/mL. An optimized sample preparation method utilized SPE. The Oasis HLB column with the highest recoveries was selected for the preconcentration step. This method was successfully applied to the determination of these flavonoids in the red wine samples with excellent results.
Determination of Enantiomers of Atenolol and Propranolol in Pharmaceutical Formulations by HPLC
Authors: Torul Hilal , Tamer Uğur
Published: February 2020

A validated HPLC-UV method was developed for the determination of R(–), S(+)-atenolol and R(–), S(+)-propranolol in pharmaceutical formulations. The proposed method required no elaborate sample preparation and was found to be selective, linear, and repeatable within the established ranges. Atenolol and propranolol isomers were separated using a Chirex 3022 (S) column with the mobile phases hexane–dichloromethane–methanol–trifluoroacetic acid (35 + 35 + 5 + 0.25, v/v/v/v) and hexane–dichloromethane–ethanol–trifluoroacetic acid (55 + 40 + 5 + 0.25, v/v/v/v), respectively. The LOD values of R(–) and S(+)-atenolol were 12.3 and 9.86 μg/mL, respectively, and 0.61 and 0.89 μg/mL, respectively, for R(–) and S(+)-propranolol. Retention times of R(–)-propranolol and S(+)-propranolol were 12.4 and 14.3 min, respectively, and 29.06 and 32.71 min, respectively, for (R)-atenolol and (S)-atenolol. The proposed method was applied to the determination of enantiomers in pharmaceutical formulations, and no interference from any excipients was found.
Determination of Fumonisins B1 and B2 in Corn-Based Foods for Infants and Young Children by LC with Immunoaffinity Column Cleanup: Interlaboratory Validation Study
Authors: Solfrizzo Michele , De Girolamo Annalisa , Gambacorta Lucia , Visconti Angelo , Stroka Joerg , van Egmond Hans P ,   Collaborators:, Bouten K , Breidbach A , Burdaspal P , Çimen D , MacDonald S , Mujahid C , Nuotio K , Patel; S , Pereboom-de Faw D , Pietri A , Schnaufer R , Seefelder W , Senyuva H Z , Sizoo E , Thim A M
Published: February 2020

A liquid chromatographic method for the determination of fumonisins B1 (FB1) and B2 (FB2) in corn-based foods for infants and young children was subjected to an interlaboratory validation study involving 11 laboratories. Five blind duplicate sample pairs of each matrix were analyzed to establish the accuracy, repeatability, and reproducibility of the method. Mass fractions in the baby food samples ranged from 89.1 to 384.4 μg/kg FB1 and from 22.5 to 73.6 μg/kg FB2. The method involved a warm extraction with citrate phosphate buffer–methanol–acetonitrile (50 + 25 + 25, v/v/v), a cleanup through an immunoaffinity column, and an end-determination of fumonisins by LC after automated precolumn derivatization with-o-phthaldialdehyde reagent. RSDs for within- laboratory repeatability (RSDr) ranged from 6.8 to 23.5% for FB1 and 7.6 to 22.9% for FB2. RSDs for between-laboratory reproducibility (RSDR) ranged from 15.4 to 26.2% for FB1 and 21.6 to 36.3% for FB2. Mean FB1 recoveries from baby foods spiked at 100.0 and 250.0 μg/kg were 89 and 96%, respectively; for FB2 spiked foods at 25.0 and 62.5 μg/kg recoveries were 90 and 85%, respectively. HorRat values ranged from 0.8 to 1.2 for FB1, whereas for FB2 they ranged from 0.9 to 1.4 when calculated according to Horwitz, and from 1.0 to 1.7 when calculated according to Thompson, indicating an acceptable among- laboratory precision for all matrixes (HorRat values <2).
Multiresidue Analysis of Multiclass Plant Growth Regulators in Grapes by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Oulkar Dasharath P , Banerjee Kaushik , Ghaste Manoj S , Ramteke Sahadeo D , Naik Dattatraya G , Patil Shubhangi B , Jadhav Manjusha R , Adsule Pandurang G
Published: February 2020

A selective and rapid multiresidue analysis method is presented for simultaneous estimation of 12 plant growth regulators (PGRs), namely, auxins (indol-3-acetic acid, indol-3-butyric acid, and naphthyl acetic acid), cytokinins (kinetin, zeatin, and 6-benzyladenine), gibberellic acid (GA3), abscisic acid, and synthetic compounds, namely, forchlorfenuron, paclobutrazole, isoprothiolane, and 2,4-dichlorophenoxy acetic acid (2,4-D) in bud sprouts and grape berries at the development stages of 2–3 and 6–8 mm diameters, which are the critical phases when exogenous application of PGRs may be necessary to achieve desired grape quality and yield. The sample preparation method involved extraction of plant material with acidified methanol (50%) by homogenization for 2 min at 15 000 rpm. The pH of the extract was enhanced up to 6 by adding ammonium acetate, followed by homogenization and centrifugation. The supernatant extract was cleaned by SPE on an Oasis HLB cartridge (200 mg, 6 cc). The final extract was measured directly by LC/MS/MS with electrospray ionization in positive mode, except for 2,4-D, GA3, and abscisic acid extracts, which required analysis in negative mode. Quantification by multiple reaction monitoring (MRM) was supported with full-scan mass spectrometric confirmation using “information-dependent acquisition” triggered with MRM to “enhanced product ionization” mode of the hybrid quadrupole-ion trap mass analyzer. The LOQ of the test analytes varied between 1 and 10 ng/g with associated recoveries of 80–120% and precision RSD <25% (n = 8). Significant matrix-induced signal suppression was recorded when the responses for pre- and postextraction spikes of analytes were compared; this could be resolved by using matrix-matched calibration standards. The method could successfully be applied in analyzing incurred residue samples and would, therefore, be useful in precisely deciding the necessity and dose of exogenous applications of PGRs on the basis of measured endogenous levels.
Procedures for Antibiotic Residues in Bovine Muscle Tissues
Authors: Blasco Cristina , Masia Ana , Morillas Francisco Gabriel , Picó Yolanda
Published: February 2020

Acetonitrile extraction followed by primary-secondary amine dispersive SPE cleanup QuEChERS (quick, easy, cheap, effective, rugged, and safe), was compared to pressurized liquid extraction (PLE) using water at 70°C for 10 min at 1500 psi for the determination of 16 veterinary drugs in bovine muscle tissues by LC/MS/MS. PLE was significantly more effective for the extraction of veterinary drugs (ranging from 69 to 103% with RSD ≤ 18%) than QuEChERS (ranging from 19 to 89% with RSD ≤ 19%). Linearity of the calibration curves was obtained over the range considered (from 10 μg/kg or LOQ to 1000, μg/kg) with r2 ≥ 0.99 for all the analytes by both methods. Although an internal standard was used, matrix effects were corrected using matrix- matched standards. LODs were from 5 to 30 μg/kg for PLE and from 10 to 100 μg/kg for QuEChERS. To establish and assess the most efficient conditions for each extraction method, statistical parametric and nonparametric tests were used. PLE with water almost eliminates the use or generation of hazardous wastes. The two methods were applied successfully in a routine analysis during surveys in 2008.
Development and Validation of a Method for the Quantification of Milk Proteins in Food Products Based on Liquid Chromatography with Mass Spectrometric Detection
Authors: Lutter Petra , Parisod Véronique , Weymuth Hans
Published: February 2020

The protection of allergic consumers is crucial to the food industry. Therefore, accurate methods for the detection of food allergens are required. Targeted detection of selected molecules by MS combines high selectivity with accurate quantifcation. A confrmatory method based on LC/selected reaction monitoring (SRM)-MS/MS was established and validated for the quantifcation of milk traces in food. Tryptic peptides of the major milk proteins β-lactoglobulin, β-casein, αS2-casein, and κ-casein were selected as quantitative markers. Precise quantifcation was achieved using internal standard peptides containing isotopically labeled amino acids. For each peptide, qualifer and quantifer fragments were selected according to Commission Decision 2002/657/EC. A simple sample preparation method was established without immunoaffnity or SPE enrichment steps for food matrixes containing different amounts of protein, such as baby food, breakfast cereals, infant formula, and cereals. Intermediate reproducibility, repeatability, accuracy, and measurement uncertainty were determined for each matrix. LOD values of 0.2–0.5 mg/kg, e.g., for β-lactoglobulin, were comparable to those obtained with ELISA kits. An LOQ of approximately 5 mg/kg, expressed as mass fraction skim milk powder, was validated in protein-rich infant cereals. The obtained validation data show that the described LC/SRM-MS/MS approach can serve as a confrmatory method for the determination of milk traces in selected food matrixes.
High-Performance Liquid Chromatography/Tandem Mass Spectrometry Method for the Determination of Arbidol in Human Plasma
Authors: Xiong Xin , Zhai Suodi
Published: February 2020

An HPLC/MS/MS method for the determination of arbidol in human plasma was developed. Arbidol and internal standard (loratadine) were extracted from alkaline plasma with tert-butyl methyl ether and analyzed on a Zorbax SB C18 column (30 × 2.1 mm id, 3.5 µm particle size). The detection was by monitoring arbidol at m/z 479.1 → 434.1 and the internal standard at m/z 383.2 → 337.2. The method was validated according to U.S. Food and Drug Administration guidelines. The calibration curve was linear over the range of 0.5–500 ng/mL using a 100 µL sample volume. The intraday and interday precisions were less than 6.5%, and acceptable values were obtained for accuracy, recovery, and sensitivity. The developed method was selective, simple, sensitive, and easily applicable.
RapidChek SELECTTMSalmonella Enteritidis Test System for the Detection of Salmonella Enteritidis in Poultry House Drag Swabs, Shell Egg Pools, and Chicken Carcass Rinsates
Authors: Muldoon Mark T , Gonzalez Verapaz , Sutzko Meredith I , Allen Ann-Christine Olsson , Creamer Samantha , Onisk Dale V , Lindpaintner Klaus
Published: February 2020

The RapidChek SELECTTMSalmonella Enteritidis Test System was validated for the detection of Salmonella Enteritidis (SE) in poultry house drag swabs, shell egg pools, and chicken carcass rinsates. The method utilizes RapidChek SELECTTMSalmonella (AOAC PTM License No. 080601) proprietary primary and secondary enrichment media. Following enrichment, an immunochromatographic test strip is inserted into the tube containing the secondary enrichment broth, developed for 10 min, and interpreted. Salmonella Enteritidis-inoculated samples (1–5 CFU SE/analytical unit) were tested by the test method as well as the appropriate cultural reference method U.S. Food and Drug Administration-Bacteriological Analytical Manual (drag swabs and egg pools) or U.S. Department of Agriculture-Food Safety and Inspection Service (chicken carcass rinsates). A total of 80 samples were tested by both methods in the study. Fifty-two samples were positive by the RapidChek SELECT Salmonella Enteritidis method and 38 were found positive by the respective reference method. The sensitivity of the method was 100% and the specificity was 100%. The accuracy of the test method was 137%, indicating that the method was more sensitive than the reference method. The RapidChek SELECT Salmonella Enteritidis method was tested with 82 Salmonella Group D1 strains including 63 Salmonella Enteritidis strains as well as 32 non-Salmonella Group D1 strains representing 10 bacteria genera. The test method detected all 82 Group D1 strains (100% sensitivity). None of the non-Salmonella Group D1 or other genera of bacteria were detected, indicating a specificity of 100%. The method was shown to be highly robust and stable under control and accelerated stability conditions.
Comparison of Two Methods for Determination of Tomato Paste Solids: Vacuum Oven versus Microwave Oven
Authors: Jazaeri Sahar , Kakuda Yukio , Gismondi Stephen , Wigle Doug G
Published: February 2020

Two analytical procedures used to determine total, soluble, and insoluble solids in tomato paste were evaluated. The microwave oven (MO) method was compared to the vacuum oven (VO) method. The VO method is tedious and measured the three solids fractions in the paste directly, while the MO method measured the total solids directly but used an equation to calculate the water-soluble and-insoluble solids. The MO method was faster and less labor-intensive, and yielded small but statistically signifcant higher values for total and insoluble solids and lower statistically signifcant values for soluble solids.
Validation of a Carnation-Specific Gene, ANS, Used as an Endogenous Reference Gene in Qualitative and Real-Time Quantitative PCR for Carnations
Authors: Zhu Hong , Jiang Lingxi , Tao Shiru , Lin Heyan , Wang Jinbin , Tan Furong , Zhao Kai , Wu Xiao , Li Peng , Pan Aihu , Jia Junwei , Tang Xueming
Published: February 2020

The validation of the anthocyanin synthase (ANS) gene as a carnation endogenous reference gene applicable both in classical and real-time PCR methods is a prerequisite for the development of PCR assays for genetically modifed (GM) carnation detection. This is important due to the fact that GM carnation lines, developed by Florigene Pty Ltd, have been approved for commercialization. In this study, both methods were tested on 14 different carnation cultivars, and identical amplifcation products were obtained with all of them. No amplifcation products were observed with samples from 14 other plant species, which demonstrated that the system was specifc to carnation. The results of Southern blot analysis confrmed that the ANS gene had a low copy number in the 10 tested carnation varieties. In qualitative and real-time PCR assays, the LOD values of 0.05 and 0.005 ng carnation DNA, respectively, were validated. Moreover, the real-time PCR system was validated with high PCR effciency and linearity. Thus, the ANS gene had species specifcity, low heterogeneity, and low copy number among the tested cultivars. These results provide evidence that the gene can be used as an endogenous reference gene of carnation, as well as in qualitative and quantitative PCR systems.
Determination of Ginsenoside Content in Asian and North American Ginseng Raw Materials and Finished Products by High-Performance Liquid Chromatography: Single-Laboratory Validation
Authors: Brown Paula N
Published: February 2020

A single-laboratory validation study was conducted for the quantification of Rg1, Re, Rb1, Rc, Rb2, and Rd in Asian ginseng (Panax ginseng C.A. Meyer) and North American ginseng (Panax quinquefolius L.) raw materials and finished products by RP-HPLC. The extraction with aqueous methanol was optimized for whole root, powdered extract, and finished product (raw, tablet, and capsule matrixes) test articles. Root materials were treated with base to hydrolyze acidic malonyl ginsenosides to their neutral counterparts. Calibration curves for each ginsenoside were linear over the following ranges (μg/g): 5–394 for Rg1, 15–1188 for Re, 39–2981 for Rb1, 6–499 for Rc, 5–406 for Rb2, and 7–600 for Rd, all having a coefficient of determination (r2) of ≥99.5%. The LOD for Rg1, Re, Rb1, Rc, Rb2, and Rd was determined to be 1.06, 1.25, 2.19, 1.24, 1.27, and 1.70 μg/mL, respectively. Quantitative determinations performed with eight test materials by two analysts over 3 days (n = 12) resulted in RSDr values that ranged from 1.11 to 7.61%.
Subnanogram Determination of Aniracetam in Pharmaceutical Preparations and Biofluids by Flow Injection Analysis with Chemiluminescence Detection Based on Its Enhancement of the Myoglobin-Luminol Reaction
Authors: Xiaodong Shao , Ying Li , Fagen Li , Yangqin Liu , Zhenghua Song
Published: February 2020

A novel flow injection chemiluminescence method with a myoglobin-luminol system is described for determining aniracetam. Myoglobin-bound aniracetam produced a complex that catalyzed the chemiluminescence reaction between luminol and myoglobin, leading to fast chemiluminescence. The chemiluminescence intensity in the presence of aniracetam was remarkably enhanced compared with that in the absence of aniracetam. Under the optimum reaction conditions the chemiluminescence increment produced was proportional to the concentration of aniracetam in the range of 0.1–1000.0 ng/mL (R2 = 0.9992), with a detection limit of 0.03 ng/mL (3δ). At a flow rate of 2.0 mL/min, the whole process, including sampling and washing, could be completed in 0.5 min, offering a sampling efficiency of 120/h; the RSD was less than 3.0% (n = 5). The method was satisfactory for determination of aniracetam in pharmaceutical preparations and human urine and serum samples. A possible mechanism of the reaction is also discussed.
Reveal®Salmonella 2.0 Test for Detection of Salmonella spp. in Foods and Environmental Samples
Authors: Hoerner Rebecca , Feldpausch Jill , Gray R Lucas , Curry Stephanie , Islam Zahidul , Goldy Tim , Klein Frank , Tadese Theodros , Rice Jennifer , Mozola Mark
Published: February 2020

Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A–E in a variety of food and environmental samples. A Performance Tested MethodSM validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A–E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non-salmonellae representing 14 genera, 32 were negative when tested with Reveal following nonselective enrichment, and the remaining strain was found to be substantially inhibited by the enrichment media used with the Reveal method. Results of ruggedness testing showed that the Reveal test produces accurate results even with substantial deviation in sample volume or device development time.