bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantification of Eugenol, Luteolin, Ursolic Acid, and Oleanolic Acid in Black (Krishna Tulasi) and Green (Sri Tulasi) Varieties of Ocimum sanctum Linn. Using High-Performance Thin-Layer Chromatography
Authors: Anandjiwala Sheetal , Kalola Jyoti , Rajani Mandapati
Published: February 2020

Ocimum sanctum (family Lamiaceae) is a reputed drug of Ayurveda, commonly known as Tulasi. Inthe present work, we quantified 4 marker compounds, viz., eugenol, luteolin, ursolic acid, and oleanolic acid, from the leaf of green and black varieties of O. sanctum using high-performance thin-layer chromatography (HPTLC) with densitometry. The methods were found to be precise, with relative standard deviation (RSD) values for intraday analyses in the range of 0.52 to 0.91%, 0.77 to 1.29%, 0.11 to 0.16%, and 0.34 to 0.42% and for interday analyses in the range of 0.73 to 0.96%, 1.02 to 2.08%, 0.11 to 0.12%, and 0.39 to 0.64% for different concentrations of eugenol, luteolin, ursolic acid, and oleanolic acid, respectively. Instrumental RSD values were 0.24, 0.39, 0.21, and 0.18% for eugenol, luteolin, ursolic acid, and oleanolic acid, respectively. Accuracy of the methods was checked by conducting a recovery study at 3 different levels for the 4 compounds, and the average recoveries were found to be 99.73, 99.3, 100.58, and 100.57%, respectively. Eugenol content ranged from 0.175 to 0.362% (w/w) and luteolin from 0.019 to 0.046% (w/w) in the samples analyzed. Green variety was found to contain higher amounts of ursolic acid [0.478 and 0.348% (w/w), from Sources 1 and 2, respectively] than the black variety [0.252 and 0.264% (w/w) from Sources 1 and 2, respectively]. Black variety had 0.174 and 0.218% (w/w) of oleanolic acid from Sources 1 and 2, respectively, while it was not detected in the green variety. Ursolic acid and oleanolic acid ran at the same Rf value and could not be resolved in several solvent systems tried. However, we observed that only ursolic acid gave yellow fluorescence under 366 nm ultraviolet light after derivatization with anisaldehydesulfuric acid reagent. The HPTLC-densitometry methods for the quantification of the 4 markers in O. sanctum leaf will have the applicability in quality control.
Preparation and Characterization of a Suite of Ephedra-Containing Standard Reference Materials
Authors: Sharpless Katherine E , Anderson David L , Betz Joseph M , Butler Therese A , Capar Stephen G , Cheng John , Fraser Catharine A , Gardner Graeme , Gay Martha L , Howell Daniel W , Ihara Toshihide , Khan Mansoor A , Lam Joseph W , Long Stephen E , McCooeye Margaret , Mackey Elizabeth A , Mindak William R , Mitvalsky Staci , Murphy Karen E , Nguyenpho Agnes , Phinney Karen W , Porter Barbara J , Roman Mark , Sander Lane C , Satterfield Mary B , Scriver Christine , Sturgeon Ralph , Thomas Jeanice Brown , Vocke Robert D , Wise Stephen A , Wood Laura J , Yang Lu , Yen James H , Ziobro George C
Published: February 2020

The National Institute of Standards and Technology, the U.S. Food and Drug Administration, Center for Drug Evaluation and Research and Center for Food Safety and Applied Nutrition, and the National Institutes of Health, Office of Dietary Supplements, are collaborating to produce a series of Standard Reference Materials (SRMs) for dietary supplements. A suite of ephedra materials is the first in the series, and this paper describes the acquisition, preparation, and value assignment of these materials: SRMs 3240 Ephedra sinica Stapf Aerial Parts, 3241 E. sinica Stapf Native Extract, 3242 E. sinica Stapf Commercial Extract, 3243 Ephedra-Containing Solid Oral Dosage Form, and 3244 Ephedra-Containing Protein Powder. Values are assigned for ephedrine alkaloids and toxic elements in all 5 materials. Values are assigned for other analytes (e.g., caffeine, nutrient elements, proximates, etc.) in some of the materials, as appropriate. Materials in this suite of SRMs are intended for use as primary control materials when values are assigned to in-house (secondary) control materials and for validation of analytical methods for the measurement of alkaloids, toxic elements, and, in the case of SRM 3244, nutrients in similar materials.
Determination of Biotin by High-Performance Liquid Chromatography in Infant Formula, Medical Nutritional Products, and Vitamin Premixes
Authors: Thompson Linda B , Schmitz Daniel J , Pan Shang-Jing
Published: February 2020

A solid-phase extraction sample preparation procedure was developed for use with a high-performance liquid chromatography (HPLC) method for biotin analysis. The HPLC method used a reversed-phase C18 column; chromatography run time was 8.5 min. After eluting from the column, biotin went through postcolumn reaction to form a conjugate with streptavidinfluorescein isothiocyanate, which was then detected by a fluorescence detector. This method was tested with infant formula, medical nutritional products, and vitamin premix samples.
UV Spectrophotometric Determination of Bioflavonoids from a Semisolid Pharmaceutical Dosage Form Containing Trichilia catigua Adr. Juss and Ptychopetalum olacoides Bentham Standardized Extract: Analytical Method Validation and Statistical Procedures
Authors: Baby AndrÉ Rolim , Maciel Carolina P M , Kaneko Telma M , Velasco Maria Valria R
Published: February 2020

A precise, accurate, and sensitive UV spectrophotometric method was developed and validated for routine quantification of total bioflavonoids, expressed as rutin, from a topical oil-in-water pharmaceutical emulsion containing the extract of Trichilia catigua Adr. Juss and Ptychopetalum olacoides Bentham. The method was validated experimentally, and the data were treated rigorously by statistical analysis. The following analytical parameters were assessed: linearity, specificity, intra- and interrun precision measured as relative standard deviation (RSD, %), intra- and interrun accuracy (E, %), recovery (Rec., %), limit of detection (LOD, μg/mL), and limit of quantification (LOQ, μg/mL). The UV spectrophotometric method was linear (r2 0.9995) for standard rutin over the concentration range of 5.015.0 g/mL with specificity for total bioflavonoids (expressed as rutin) at 361.0 nm with an absence of interferents from the complex matrix; RSD of ≤1.79%, intrarun (E 97.88 ±1.75 to 99.0 ± 0.33%) and interrun (E 98.38 ± 1.12 to 100.79 ± 1.30%) accuracy; Rec. 98.64 ± 0.42 to 100.74 ± 0.41%; LOD 0.20 μg/mL; and LOQ 0.30 μg/mL.
Optimized Determination Method for trans-10-Hydroxy-2-Decenoic Acid Content in Royal Jelly by High-Performance Liquid Chromatography with an Internal Standard
Authors: Zhou Jinhui , Xue Xiaofeng , Li Yi , Zhang Jinzhen , Zhao Jing
Published: February 2020

An optimized reversed-phase high-performance liquid chromatography method was developed to detect the trans-10-hydroxy-2-decenoic acid (10-HDA) content in royal jelly cream and lyophilized powder. The sample was extracted using absolute ethanol. Chromatographic separation of 10-HDA and methyl 4-hydroxybenzoate as the internal standard was performed on a Nova-pak C18 column. The average recoveries were 95.0-99.2% (n = 5) with relative standard deviation (RSD) values of 1.3-2.1% for royal jelly cream and 98.0-100.0% (n = 5) with RSD values of 1.6-3.0% for lyophilized powder, respectively. The limits of detection and quantitation were 0.5 and 1.5 mg/kg, respectively, for both royal jelly cream and lyophilized powder. The method was validated for the determination of practical royal jelly products. The concentration of 10-HDA ranged from 1.26 to 2.21% for pure royal jelly cream samples and 3.01 to 6.19% for royal jelly lyophilized powder samples. For 30 royal jelly products, the 10-HDA content varied from not detectable to 0.98%.
Evaluation of a Method to Determine Flavonol Aglycones in Ginkgo biloba Dietary Supplement Crude Materials and Finished Products by High-Performance Liquid Chromatography: Collaborative Study
Authors: Gray Dean , LeVanseler Kerri , Pan Meide , Waysek Edward H , Chandra A
Published: February 2020

An interlaboratory study was conducted for evaluation of a method to determine the flavonol aglycones quercetin, kaempferol, and isorhamnetin in Ginkgo biloba products. The method calculates total glycosides based on these aglycones formed after acid hydrolysis. Twelve matrixes were chosen for study by 12 collaborating laboratories in 2 countries. Test materials included crude leaf material, standardized dry powder extract, single and multiple entity finished products, ethanol and glycerol tinctures, and National Institute of Standards and Technology (NIST) standard reference materials (SRMs). Results from 11 laboratories were used for the final calculations. Eight of the 12 matrixes evaluated produced acceptable results for total flavonol glycosides, with HorRat scores ranging from 1.31 to 2.05; repeatability relative standard deviations (RSDr) from 1.46 to 4.14; and reproducibility relative standard deviations (RSDR) from 4.67 to 9.69. These 8 matrixes consisted primarily of simple dosage forms (e.g., dry powder extracts, crude leaf samples, liquid extracts, and SRMs) and a single tablet product (Ginkgo Awareness). Four additional matrixes, consisting of 3 tablets and 1 soft gel product (Ginkgold, Ginkoba, Ginkogen, and Ginkgo Phytosome, respectively), showed greater total flavonol glycoside HorRat scores in comparison, ranging from 2.39 to 5.13, with RSDr values from 2.83 to 8.16, and RSDR values from 8.53 to 20.4. Based on the results presented here, the method is recommended for Official First Action for determination of total flavonol glycosides calculated from quercetin, kaempferol, and isorhamnetin in dry powder extracts, crude leaf material, liquid extracts, and a select finished product, Ginkgo Awareness.
Direct Injection Liquid Chromatographic Technique for Simultaneous Determination of Two Antihistaminic Drugs and Their Main Metabolites in Serum
Authors: Emara Samy , El-Gindy Alaa , Mesbah Mostafa K , Hadad Ghada M
Published: February 2020

A very simple liquid chromatographic technique was developed and validated for the simultaneous determination of 2 antihistaminic drugs, loratadine (LT) and terfenadine (TR), and their major active metabolites, desloratadine (DL) and fexofenadine (FX), respectively, in human serum. LT, DL, TR, and FX from directly injected serum samples were enriched on a protein-coated RP8 silica precolumn (10 4.6 mm id) while serum constituents, such as proteins and salts, were eluted to waste. Using an online column-switching system, the drugs and their metabolites were quantitatively transferred and separated on a second analytical column (Shim-pack 5 μm particle size cyanopropyl, 250 × 4.6 mm id) followed by ultraviolet detection at 243 nm for LT and DL and 220 nm for TR and FX. Very good precision, accuracy, and linearity were obtained over the range of 101000 ng/mL for LT and DL, 10500 ng/mL for TR, and 103000 ng/mL for FX in human serum. High extraction recoveries from serum ranging from 96.03 to 98.19, 95.44 to 97.26, 95.61 to 98.17, and 95.60 to 97.89 for LT, DL, TR, and FX, respectively, were obtained.
Evaluating the Use of Fatty Acid Profiles to Identify Francisella tularensis
Authors: Whittaker Paul , Day James B , Curtis Sherill K , Fry Frederick S
Published: February 2020

Rapid capillary gas chromatography (GC) with flame-ionization detection was used to determine the cellular fatty acid profiles of Francisella tularensis. Two subspecies of F. tularensis, the live vaccine strain (LVS) derived from holarctica and a novicida strain Utah 112 (U112), were used to compare the extracted fatty acid methyl esters (FAMEs). A data set for the 2 subspecies was prepared using fatty acid profiles of bacteria grown on 2 types of media, Mueller-Hinton and cysteine heart agar supplemented with 5% rabbit blood (CHAB), and harvested at various time intervals (Day 1 through Day 4) with replicates prepared on different days. A total of 204 samples were analyzed. The results showed that these fatty acid quantitative profiles were unique for each of the subspecies and could be used as a fingerprint for the organism. It was determined by this rapid method that approximately 88% of the fatty acids in both the LVS and U112 strains included 6 saturated fatty acids: 10:0, 12:0, 14:0, 16:0, 18:0, and 20:0; and 4 hydroxy fatty acids 10:0 2OH, 16:0 3OH, 17:0 3OH, and 18:0 3OH. Data analysis and determination of clustering were performed by principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA). Both PCA and SIMCA showed clear separation of the LVS and U112 strain and would be useful for prediction of unknowns. It was determined that the incubation time can be reduced from 48 to 24 h, and results are highly predictive for the identification of F. tularensis. In summary, analysis of FAMEs from F. tularensis subspecies LVS and U112 grown on CHAB or Mueller-Hinton media, and using a rapid GC method can provide a sensitive procedure for identification of these organisms.
Determination of Mammalian Lignans in Biological Samples by Modified Gas Chromatography/Mass Spectrometry
Authors: Bommareddy Ajay , Arasada Bhanu L , Mathees Duane P , Dwivedi Chandradhar
Published: February 2020

Lignans in flaxseed have been part of the human diet for centuries. In 1955, the isolation and structure of the lignan derivative secoisolariciresinol diglucoside (SDG) was reported. The biological role of SDG and mammalian lignan metabolites enterodiol and enterolactone was initially reported 20 years later. Experimental evidences showed the beneficial effects of lignans on breast, colon, and thyroid cancer. A modified gas chromatography/mass spectrometry (GC/MS) assay was developed for lignans in serum and colon samples of rats fed flaxseed meal. The method developed for the analysis of metabolites involves extraction and derivatization of samples and quantitative analysis by selected ion monitoring using GC/MS. The levels of lignan metabolites enterodiol and enterolactone were determined to be 0.013 and 0.23 M in serum samples and 0.008 and 1.63 M in colon samples.
Application of a Validated Method in the Stability Study of Colistin Sulfate and Methylparaben in a Veterinary Suspension Formulation by High-Performance Liquid Chromatography with a Diode Array Detector
Authors: PÉrez-Lozano Pilar , GarcÍa-Montoya Encarna , Orriols Anna , MiÑarro Montse , TicÓ Josep Ramon , SuÑÉ-Negre Josep Maria
Published: February 2020

A methodology following International Cooperation on Harmonization for Veterinary Products (VICH) guidelines for the stability evaluation of colistin sulfate in a nonaqueous suspension pharmaceutical dosage form for veterinary use (via their drinking water) is described. This method monitors the percentage of colistin sulfate during the stability study of the preparation in drinking water and establishes the shelf life of the final product by a new high-performance liquid chromatography method which was developed and validated for the simultaneous determination of colistin sulfate [colistin A (Polymixin E1) and colistin B (Polymixin E2)] and methylparaben (Nipagin) using a diode array detector (DAD). The method uses a Kromasil C18 column and isocratic elution. The mobile phase consisted of an acetonitrilesodium sulfate anhydrous solution (25 + 75) pumped at a flow rate of 1.5 mL/min. The DAD was set at 215 nm. The validation study was carried out according to the VICH guidelines in order to prove that the new analytical method meets the reliability characteristics, which include the fundamental criteria for validation: selectivity, linearity, precision, accuracy, and sensitivity. The method was applied during the quality control or stability studies of the suspension dosage form in order to quantify the drug (colistin) and preservative, and proved to be suitable for rapid and reliable quality control.
Simultaneous Determination of Nitroimidazole Residues in Honey Samples by High-Performance Liquid Chromatography with Ultraviolet Detection
Authors: Zhou Jinhui , Shen Jianzhong , Xue Xiaofeng , Zhao Jing , Li Yi , Zhang Jinzhen , Zhang Suxia
Published: February 2020

A rapid and sensitive high-performance liquid chromatography (LC) method was developed for the simultaneous determination of metronidazole (MNZ), dimetridazole (DMZ), ronidazole (RNZ), tinidazole (TNZ), and 2-hydroxymethyl-1-methyl-5-nitroimidazole (HMMNI) in honey. After extraction with ethyl acetate and evaporation, the residue containing the nitroimidazoles was dissolved in ethyl acetatehexane and subjected to solid-phase extraction cleanup by amine extraction columns. The effluent was evaporated to dryness, and residues were dissolved and determined by LC with an ultraviolet detector set at 315 nm. The limits of detection were 1.02.0 ng/g for MNZ, DMZ, RNZ, TNZ, and HMMNI in honey. Average recoveries ranged from 71.5101.4% in honey fortified at 10, 20, 50, and 100 ng/g. The method was validated for the analysis of real honey samples.
Micellar Enhanced Spectrofluorometric Determination of Labetalol Through Complexation with Aluminium(III): Application to Dosage Forms and Biological Fluids
Authors: El-Enany Nahed
Published: February 2020

Two simple, sensitive, and specific spectrofluorometric procedures have been developed for the determination of labetalol (LBT) in pharmaceuticals and biological fluids. LBT was found to react with Al3+ , both in acetate buffer of pH 4.5 (Procedure I) and borate buffer of pH 8.0 (Procedure II), to produce highly fluorescent stable complexes. The fluorescence intensity could be enhanced by the addition of sodium dodecyl sulfate, resulting in 3.5- and 2.7-fold increases in the fluorescence intensity for Procedures I and II, respectively. In both procedures, the fluorescence intensity was measured at 408 nm after excitation at 320 nm. The different experimental parameters affecting the development and stability of the fluorescent products were carefully studied and optimized. The fluorescence intensity-concentration plots were rectilinear over the range of 0.020.1 and 0.010.05 g/mL with a detection limit of 0.003 and 0.001 g/mL for Procedures I and II, respectively. The proposed method was successfully applied to commercial tablets containing LBT. The results were in good agreement with those obtained using a reference spectrofluorometric method. Furthermore, the method was applied for the determination of LBT in spiked human plasma, and the recovery (n = 4) was 93.30 2.62%. A proposal of the reaction pathway was postulated for Procedures I and II, respectively.
Gas-Liquid Chromatographic Determination of Milk Fat and Cocoa Butter Equivalents in Milk Chocolate: Interlaboratory Study
Authors: Buchgraber Manuela , Androni Simona ,   Collaborators:, Berndt E-M , Kaufmann-Horlacher I , Lomnitz A , Matissek R , Maurer R , Neuberger G , Rodriguez-Estrada M T , Schreiner M , Schulokat S , Schut M , Wachter N
Published: February 2020

A collaborative trial was conducted to validate an analytical approach comprising method procedures for determination of milk fat and the detection and quantification of cocoa butter equivalents (CBEs) in milk chocolate. The whole approach is based on (1) comprehensive databases covering the triacylglycerol composition of a wide range of authentic milk fat, cocoa butter, and CBE samples and 947 gravimetrically prepared mixtures thereof; (2) the availability of a certified cocoa butter reference material for calibration; (3) an evaluation algorithm, which allows reliable quantitation of the milk fat content in chocolate; (4) a subsequent correction to take account of the triacylglycerols derived from milk fat; (5) mathematical expressions to detect the presence of CBEs in milk chocolate; and (6) a multivariate statistical formula to quantitate the amount of CBEs in milk chocolate. Twelve laboratories participated in the validation study. CBE admixtures were detected down to a level of 0.5 g CBE/100 g milk chocolate, without false-positive or -negative results. The applied quantitation model performed well at the statutory limit of 5 CBE addition to milk chocolate, with a prediction error of 0.7, and HorRat values ranging from 0.8 to 1.5. The relative standard deviation for reproducibility (RSDR) values for quantitation of CBEs in analyses of chocolate fat solutions ranged from 2.2 to 3.8 and for analyses of real chocolate samples, from 4.1 to 4.7, demonstrating that the whole approach, based solely on chocolate fat blends, is applicable to real milk chocolate samples.
Evaluation of Serum as a Potential Matrix for Multiresidue Determination of Fluoroquinolone Antibiotics in Chicken Using Liquid Chromatography-Fluorescence-Mass Spectrometryn
Authors: Schneider Marilyn J , Reyes-Herrera Ixchel , Donoghue Dan J
Published: February 2020

An efficient multiresidue method was successfully applied to the determination of fluoroquinolones (FQs) in chicken serum. In this method, FQs are extracted from matrix with ammoniacal acetonitrile, and the extracts are defatted and then evaporated. After addition of basic phosphate buffer and filtration, the samples are analyzed by liquid chromatography-fluorescence-mass spectrometryn (multiple mass spectrometry; MSn). This approach allows for simultaneous quantitation (fluorescence) and confirmation (MSn) of the FQs. Using this method, 8 FQs were determined in fortified chicken serum at levels of 10, 20, 50, and 100 ng/g. Recoveries ranged from 7199, with excellent relative standard deviations (<10). Limits of quantitation for the FQs ranged from 0.055 ng/g. Confirmation was achieved by comparison of MS2 or MS3 product ion ratios with those of standard FQ samples. These quantitative and confirmatory results were compared with those obtained for muscle using this approach. Serum and muscle samples from enrofloxacin-dosed chickens were also analyzed with this method. The results show that enrofloxacin can be determined in both serum and muscle of chickens dosed at a level formerly approved by the U.S. Food and Drug Administration, for up to at least 48 h after withdrawal from dosing, and suggest that serum can provide an efficient matrix for monitoring FQ levels in chicken.
Detection of Actaea racemosa Adulteration by Thin-Layer Chromatography and Combined Thin-Layer Chromatography-Bioluminescence
Authors: Verbitski Sheryl M , Gourdin Gerald T , Ikenouye Larissa M , McChesney James D , Hildreth Jana
Published: February 2020

Actaea racemosa L. (black cohosh; syn. Cimicifuga racemosa L. Nutt.) is a native North American perennial whose root and rhizome preparations are commercially available as phytomedicines and dietary supplements, primarily for management of menopausal symptoms. Despite its wide use, methods that accurately identify processed A. racemosa are not well established; product adulteration remains a concern. Because of its similar appearance and growing locales, A. racemosa has been unintentionally mixed with other species of the genus, such as Actaea pachypoda Ell. (white cohosh) and more commonly Actaea podocarpa DC. (yellow cohosh). The genus Actaea also has 23 temperate species with numerous common names, which can also contribute to the misidentification of plant material. Consequently, a variety of Actaea spp. are common adulterants of commercially available black cohosh preparations. Thin-layer chromatography (TLC) and combined TLC-bioluminescence (Bioluminex) are efficient, economical, and effective techniques which provide characteristic patterns and toxicity profiles for each plant species. These data indicate that common black cohosh adulterants, such as yellow cohosh, can be differentiated from black cohosh by TLC and TLC-bioluminescence. This study also showed that unknown contaminants that were not detected using standard A. racemosa identity techniques were readily detected by TLC and TLC-bioluminescence.
Comparison of Digestibility and Quality of Intact Proteins with Their Respective Hydrolysates
Authors: Potier Myléne , Tomé Daniel
Published: February 2020

Quality of proteins depends on their composition in essential amino acids and on the availability of amino acids. Great interest has been shown in the role played by hydrolysates of proteins in clinical diets for pathologies with reduced absorptive capacity and food allergies caused by intact protein epitopes. Milk proteins are the most important protein source used in the development of protein hydrolysates designed for nutritional support of patients. Several studies have shown that casein and whey hydrolysates have a composition in amino acids equivalent to that in native milk proteins and that digestibility is similar or better. Among plant proteins, soy is the major source of hydrolysates. Soy hydrolysates are also used in infant formulas. Plant hydrolysates have good functional properties and a nutritional quality similar to that of starting material. Some technical improvements in production of hydrolysates, particularly for plants, are nevertheless necessary to improve product palatability.
Simultaneous Estimation of Acetylsalicylic Acid and Clopidogrel Bisulfate in Pure Powder and Tablet Formulations by High-Performance Column Liquid Chromatography and High-Performance Thin-Layer Chromatography
Authors: Patel Rashmin B , Shankar Madhira B , Patel Mrunali R , Bhatt Kashyap K
Published: February 2020

This paper describes validated high-performance column liquid chromatographic (HPLC) and high-performance thin-layer chromatographic (HPTLC) methods for simultaneous estimation of acetylsalicylic acid (ASA) and clopidogrel bisulfate (CLP) in pure powder and formulations. The HPLC separation was achieved on a Nucleosil C8 column (150 mm length 4.6 mm id, 5m particle size) using acetonitrilephosphate buffer, pH 3.0 (55 + 45, v/v) mobile phase at a flow rate of 1.0 mL/min at ambient temperature. The HPTLC separation was achieved on an aluminum-backed layer of silica gel 60F254 using ethyl acetatemethanoltolueneglacial acetic acid (5.0 + 1.0 + 4.0 + 0.1, v/v/v/v) mobile phase. Quantitation was achieved with UV detection at 235 nm over the concentration range 424 g/mL for both drugs, with mean recoveries of 99.98 0.28 and 100.16 0.66 for ASA and CLP, respectively, using the HPLC method. Quantitation was achieved with UV detection at 235 nm over the concentration range of 4001400 ng/spot for both drugs, with mean recoveries of 99.93 0.55 and 100.21 0.83 for ASA and CLP, respectively, using the HPTLC method. These methods are simple, precise, and sensitive, and they are applicable for the simultaneous determination of ASA and CLP in pure powder and formulations.
Simultaneous Determination of Free Carnitine and Total Choline by Liquid Chromatography/Mass Spectrometry in Infant Formula and Health-Care Products: Single-Laboratory Validation
Authors: Andrieux Pierre , Kilinc Tamara , Perrin Christian , Campos-Giménez Esther
Published: February 2020

A single-laboratory validation study was conducted for a liquid chromatographic/mass spectrometric (LC/MS) method for the simultaneous determination of the free carnitine and total choline in milk-based infant formula and health-care products. The sample preparation used for both carnitine and choline was adapted from AOAC Official Method 999.14, with an acidic and enzymatic hydrolysis of esterified forms of choline. Carnitine and choline were quantified by ion-pair chromatography with single-quadrupole MS detection, using their respective deuterated internal standards. The repeatability relative standard deviation was 2.5 and 2.1, respectively, for carnitine and choline. The intermediate reproducibility relative standard deviation was <4.7 and 2.4, respectively, for carnitine and choline. The ranges of the average product-specific recoveries were 9298 and 94103, respectively, for carnitine and choline. Choline concentration determined in infant formula reference material SRM 1846 was in agreement with the reference value. The proposed method was compared with the enzymatic methods for a range of products; good correlation (r = 0.99) was obtained, although a significant bias was observed for both analytes. The method, with a short chromatographic run time (7 min), is convenient for routine analysis to enhance analytical throughput and is a good alternative to enzymatic assays.
Spectrophotometric and Column High-Performance Liquid Chromatographic Methods for Simultaneous Estimation of Metoprolol Tartrate and Hydrochlorothiazide in Tablets
Authors: Garg Gopal , Saraf Shailendra , Saraf Swarnlata
Published: February 2020

Simple, accurate, economical, and reproducible UV spectrophotometric and column high-performance liquid chromatographic (HPLC) methods were developed for simultaneous estimation of a 2-component drug mixture of metoprolol tartrate and hydrochlorothiazide in combined tablet dosage form. The first method used the simultaneous equation method with 7 mixed standards and the absorption maxima at 223 and 271 nm, respectively, for metoprolol tartrate and hydrochlorothiazide in methanol. Linearity was observed in the concentration ranges of 424 and 216 g/mL for metoprolol tartrate and hydrochlorothiazide, respectively. The developed HPLC method used a reversed-phase C18 column and methanolwater (95 + 5) mobile phase at an ambient temperature of 27 2C and UV detection at 225 nm; the run time was 10 min, and quantification was based on peak area. The injection repeatability and intraday and interday repeatability were calculated. Paracetamol was used as an internal standard for the HPLC method, and linearity was observed in the concentration range of 550 g/mL for metoprolol and 220 g/mL for hydrochlorothiazide. The proposed methods were successfully applied for the determination of metoprolol tartrate and hydrochlorothiazide in bulk powder and dosage form. The results obtained were analyzed statistically, and there was no significant difference between the 2 methods. The validation was performed according to International Conference on Harmonization guidelines.
Development of a Selective and Sensitive Spectrophotometric Method for the Trace Determination of Thallium(III) Using 3-Methyl-2-benzothiazolinone Hydrazone Hydrochloride and N-(1-naphthyl)-ethylenediamine Dihydrochloride
Authors: Nagaraja Padmarajaiah , Al-Tayar Naef Ghllab Saeed , Kumar Anantharaman Shiva
Published: February 2020

A simple, selective, sensitive, and rapid spectrophotometric method has been developed for the determination of thallium(III) using 3-methyl-2-benzothiazolinone hydrazone hydrochloride and N-(1-naphthyl)-ethylenediamine dihydrochloride. The obtained product had an absorption maximum of 590 nm. Beer's law was valid over the concentration range of 0.158 g/mL. The molar absorptivity and Sandell's sensitivity of the colored system were 2.93 104 L/molcm and 0.00723 g/mL, respectively. The effect of different acids on the sensitivity of the method, interference by foreign substances, the optimum reaction conditions, and other analytical parameters were evaluated. The proposed method has been successfully applied in the analysis of Tl(III) in standard reference materials, synthetic mixtures, and water and urine samples. The performance of the proposed method was evaluated in terms of Student's t-test and variance ratio F-test, which indicated the significance of the proposed method over reported methods.
Evaluation of Microwave-Assisted Extraction for the Analysis of Polychlorinated Biphenyls and Organochlorine Pesticides in Fish
Authors: Otake Takamitsu , Aoyagi Yoshie , Numata Masahiko , Yarita Takashi
Published: February 2020

The efficiency of microwave-assisted extraction (MAE) was evaluated for the analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in fish. An isotope dilution method was used for quantification via analysis of the samples by gas chromatography and mass spectrometry. MAE solvent, temperature, and time were optimized, and observed concentrations were compared. The MAE results were also compared to those of other extraction techniques (Soxhlet extraction, pressurized liquid extraction, saponification, and homogenization). Concentrations of PCBs and OCPs obtained by MAE at 120C for 10 min were comparable to those by the other techniques. The results suggest that MAE can be used for the analysis of PCBs and OCPs in fish.
Polymerase Chain Reaction-Restriction Fragment Length Polymorphism Authentication of Raw Meats from Game Birds
Authors: Rojas María , González Isabel , Fajardo Violeta , Martín Irene , Hernández Pablo E , garcía Teresa , Martín Rosario
Published: February 2020

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis has been applied to the identification of meats from quail (Coturnix coturnix), pheasant (Phasianus colchicus), red-legged partridge (Alectoris rufa), guinea fowl (Numida meleagris), capercaillie (Tetrao urogallus), Eurasian woodcock (Scolopax rusticola), woodpigeon (Columba palumbus), and song thrush (Turdus philomelos). PCR amplification was performed using a set of primers flanking a conserved region of approximately 720 base pairs (bp) from the mitochondrial 12S rRNA gene. Restriction site analysis based on sequence data from this DNA fragment permitted the selection of Alul and BfaI endonucleases for species identification. The restriction profiles obtained when amplicons were digested with the chosen enzymes allowed the unequivocal identification of all game bird species analyzed. However, the use of the PCR-RFLP technique described is limited to raw meat authentication. It is not suitable for cooked products because thermal treatment strongly accelerates DNA degradation leading to difficulties in amplifying the 720 bp fragment.
Interlaboratory Validation of the Mehlich 3 Method for Extraction of Plant-Available Phosphorus
Authors: Zhang Hailin , Kariuki Solomon , Schroder Jackie L , Payton Mark E , Focht Charlie
Published: February 2020

The Mehlich 3 (M3) method is widely used for extraction of plant-available phosphorus (P) from soil over a wide range of pH values. The method is also used by many laboratories to determine multiple plant-available nutrients simultaneously. However, this method has not been statistically validated within and among laboratories. The objective of this study was to determine the repeatability (within-laboratory performance) and reproducibility (among-laboratories performance) of the M3 method by using a wide variety of soils. An in-house homogeneity test was conducted for 10 soils. Three replicates of each of the 10 soils were sent to 26 domestic and international laboratories primarily for P analysis. Samples were scooped, weighed, or both scooped and weighed for extraction. The P in extracts was quantified by the participating laboratories by using inductively coupled plasma-atomic emission spectrometry (ICP-AES) or colorimetrically. For the scooped samples analyzed colorimetrically, the repeatability relative standard deviation (RSDr) ranged from 2.07 to 12.1; the RSDr ranged from 2.2 to 21.4 for the scooped samples analyzed by ICP-AES. For the weighed samples analyzed colormetrically, the RSDr values were 1.099.34, and for the weighed samples analyzed by ICP-AES, they were 1.705.76. For the reproducibility data, the RSDR values ranged from 6.85 to 50.8 for the scooped-colorimetry category, from 6.95 to 73.9 for the scooped-ICP-AES category, from 7.19 to 42.6 for the weighed-colorimetry category, and from 5.29 to 35.9 for the weighed-ICP-AES category. The greatest RSD values were associated with the Susitna soil, which had the smallest concentration of extractable P. Because of the relatively small concentration of P in this soil, the laboratories were attempting to measure solution concentrations that were close to the detection limits. The Horwitz ratios (HorRat) were also used to evaluate the repeatability, HorRat(r), and reproducibility, HorRat(R). Overall, the M3 P method appears to be both repeatable and reproducible across the 4 categories, and the vast majority of the HorRat values for both repeatability and reproducibility were within the acceptable range. The results of this study indicate that the M3 P method for the determination of plant-available P in soil is both accurate and precise when standardized procedures are used. The method has been shown to be suitable for use as a reference method for testing soil materials for extractable P.
Quantitation and Validation of Macrolide Endectocides in Raw Milk by Negative Ion Electrospray MS/MS
Authors: Durden David A , Wotske Janice
Published: February 2020

Macrolide endectocides (abamectin, doramectin, emamectin, eprinomectin, ivermectin, and moxidectin) are used to treat animals against a variety of parasites. They are approved for use with food animals, but require long withdrawal times. Two compounds, eprinomectin and moxidectin, are approved for use with lactating cattle and have established maximum residue limit values of 20 and 40 g/kg, respectively. The remaining compounds may appear in milk if there is off-label or accidental use. This method is capable of quantitating and confirming the presence of six of the macrolide endectocides over the concentration range 160 g/kg (parts per billion). Selamectin is used as the internal standard. The compounds are extracted with C18 solid-phase extraction under basic conditions and quantitated by negative ion LC-MS/MS using one selected reaction monitoring transition, with a second transition used for verification. The limits of detection were determined from between-day experiments as 0.14, 0.14, 0.18, 0.24, 0.25, and 0.25 g/kg for abamectin, doramectin, emamectin, eprinomectin, ivermectin, and moxidectin, respectively. The detection capability CC for eprinomectin was measured as 28.5 g/kg, and 50.0 g/kg for moxidectin using five milk matrices.
Determination of Sucralose in Soft Drinks by High-Performance Thin-Layer Chromatography: Interlaboratory Study
Authors: Stroka Joerg , Doncheva Ivanka , Spangenberg Bernd ,   Collaborators:, Bouten K , Braemer R , Caemmerer B , Dzido T , Grosse-Damhues J , Kemme J , Koch A , Kraus S , Morlock G , Schneider R , Schulz M , Vega M , Widmer V
Published: February 2020

An interlaboratory comparison was carried out to evaluate the effectiveness of a method based on HPTLC in which reagent-free derivatization is followed by UV/fluorescence detection. The method was tested for the determination of sucralose (C12H19Cl3O8; (2R,3R,4R,5S,6R)-2- [(2R,3S,4S,5S)-2,5-bis(chloromethyl)-3,4-dihydroxyoxolan- 2-yl]oxy-5-chloro-6-hydroxymethyl)oxane-3, 4-diol; CAS Registry No. 56038-13-2) in carbonated and still beverages at the proposed European regulatory limits. For still beverages, a portion of the sample was diluted with methanolwater. For carbonated beverages, a portion of the sample was degassed in an ultrasonic bath before dilution. Turbid beverages were filtered after dilution through an HPLC syringe filter. The separation of sucralose was performed by direct application on amino-bonded (NH2) silica gel HPTLC plates (no cleanup needed) with the mobile phase acetonitrilewater. Sucralose was determined after reagent-free derivatization at 190C; it was quantified by measurements of both UV absorption and fluorescence. The samples, both spiked and containing sucralose, were sent to 14 laboratories in five different countries. Test portions of a sample found to contain no sucralose were spiked at levels of 30.5, 100.7, and 299 mg/L. Recoveries ranged from 104.3 to 124.6 and averaged 112 for determination by UV detection; recoveries ranged from 98.4 to 101.3 and averaged 99.9 for determination by fluorescence detection. On the basis of the results for spiked samples (blind duplicates at three levels), as well as sucralosecontaining samples (blind duplicates at three levels and one split level), the values for the RSDr ranged from 10.3 to 31.4 for determinations by UV detection and from 8.9 to 15.9 for determinations by fluorescence detection. The values for the RSDR values ranged from 13.5 to 31.4 for determinations by UV detection and from 8.9 to 20.7 for determinations by fluorescence detection.
Importance of Tetrahydroiso -acids to the Microbiological Stability of Beer
Authors: Caballero Isabel , Agut Montserrat , Armentia Alicia , Blanco Carlos A
Published: February 2020

While beer provides a very stable microbiological environment, a few niche microorganisms are capable of growth in malt, wort, and beer. The production of off-flavors and development of turbidity in the packaged product are due to the growth and metabolic activity of wild yeast, certain lactic acid bacteria (LAB) and anaerobic Gram-negative bacteria. Beer also contains bitter hop compounds, which are toxic to Gram-positive and Gram-negative bacteria, and contribute to preventing the spoilage of this beverage. In the boiling process, the hop -acids (humulones) are isomerized into iso -acids. These products are responsible for the bitter taste of beer, but they also play an essential role in enhancing foam stability. Antibacterial activity of iso -acids and their hydrogenated derivates (rhoiso -acids and tetrahydroiso -acids) in MRS broth and beer have been evaluated against different LAB (Lactobacillus and Pediococcus) for the determination of their beer-stabilizing capabilities. Besides this, we have determined the minimum inhibitory concentration and the bacteriostatic effect of each compound against Pediococcus. We found that tetrahydroiso-acids (added directly to beer during production processes) are the compounds that present the greatest antibacterial activity against the main agents implicated in beer spoilage.
Extractable Trace Metals Content of Dust from Vehicle Air Filters as Determined by Sequential Extraction and Flame Atomic Absorption Spectrometry
Authors: Saracoglu Sibel , Soylak Mustafa , Elçi Latif
Published: February 2020

A modified four-step sequential extraction procedure developed within the Standards, Measurement, and Testing Program (formally the Community Bureau of Reference) of the European Commission was applied to determine the distribution of Cd, Cu, Fe, and Mn in air filter dust samples collected from vehicles. The four fractions were acid-soluble, reducible, oxidizable, and residual. These fractions have the advantage of providing better insight into the mechanism of association of metals in the dust. The determination of trace metals in dust samples was performed by flame atomic absorption spectrometry. The results obtained after applying the sequential extraction scheme indicated that Cu was the most abundant metal in the organic and residual fractions of the dust matrix. Fe was found mainly in the residual fraction, and the major amounts of Mn and Cd were present in the acid-soluble and bound-to-carbonate fraction. The mean values of Cd, Cu, Fe, and Mn were found to be 15.58, 33.54, 1625, and 180 g/g, respectively. The results obtained are in agreement with data reported in the literature.
Determination of Tricaine Residues in Fish by Liquid Chromatography
Authors: Nochetto Cristina B , Reimschuessel Renate , Gieseker Charles , Cheely Christie-Sue , Carson Mary C
Published: February 2020

Tricaine methanesulfonate (MS-222) is approved by the U.S. Food and Drug Administration, Center for Veterinary Medicine (CVM), as an anesthetic drug for select aquaculture species. It was approved for use as a handling aid with a 3 week withdrawal time. The drug is rapidly metabolized and excreted; therefore, CVM approved its use without requiring a regulatory method for drug residues in tissues. However, there are concerns that the drug may be used to sedate fish during transport to slaughter. A regulatory method will enable monitoring for unsafe residues of this drug resulting from extralabel use. We present a quantitative method, using LC at a target level of 0.1 mg/kg (ppm), for three different farmed species: salmon (Salmo salar); tilapia (Oreochromis spp.); and catfish (Ictalurus punctatus). The assay begins with an acetonitrile extraction, followed by filtration and mixed-mode cation-exchange solid-phase extraction cleanup. The extracts are analyzed by reversed-phase LC with UV detection at 320 nm. The method was validated by using fish fillets with incurred residues, control fish fillets, and fish fillets fortified at half the target level, the target level, and twice the target level (0.05, 0.1, and 0.2 ppm, respectively). For all species, accuracy is 80 and the RSD is 10. The method complies with CVM performance criteria for the determination of veterinary drug residues.
Measurement of Vitamin D in Foods and Nutritional Supplements by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Huang Min , LaLuzerne Paul , Winters Doug , Sullivan Darryl
Published: February 2020

Vitamin D is a fat-soluble vitamin with great nutritional interest. An HPLC/MS/MS method was developed to measure vitamin D with atmospheric pressure chemical ionization. Under the experimental parameters used, the LOQ was 0.018 IU/g or 0.45 ng/g, which greatly enhances the capability of measurement of vitamin D at low levels in foods and supplements. This method was validated with spike recovery of 100 15 and the RSD of less than 10 for most sample matrixes, including infant formula, cheese, cereal and cerealbased foods, multivitamin supplements, and pet foods. The results for vitamin D were compared with those obtained by other methods.
Direct Determination of Atrazine Residue on Chinese Cabbage Leaf Using Desorption Electrospray Ionization-Tandem Mass Spectrometry and Its Application for Diagnosing Atrazine Drift Phytotoxicity
Authors: Zhang Xin-Zhong , Li Chong-Jiu , Chen Shan-Shan , Li Xiao-Juan , Han Hao , Ma Xiao-Dong
Published: February 2020

A method was developed for the determination of atrazine residue and phytotoxicity on a nontargeted plant, the Chinese cabbage. The analysis was done by desorption electrospray ionization combined with ion trap MS/MS. Within the range of 63.13 to 2525 pg/mm2 of atrazine on the specimen, the linear relationship of the average peak area of extracted product ion m/z 174 (y) versus the surface concentration of atrazine (x) was estimated as y 5066.5x 85779; r was 0.9994, with RSD between 3.37 and 26.17. The LOQ of atrazine on the leaf surface was lower than 63.13 pg/mm2. The method is highly applicable to detect atrazine residue and evaluate atrazine phytotoxicity on Chinese cabbage leaf with good accuracy, selectivity, sensitivity, and specificity.
Estimation of the POD Function and the LOD of a Qualitative Microbiological Measurement Method
Authors: Wilrich Cordula , Wilrich Peter-Theodor
Published: February 2020

Qualitative microbiological measurement methods in which the measurement results are either 0 (microorganism not detected) or 1 (microorganism detected) are discussed. The performance of such a measurement method is described by its probability of detection as a function of the contamination (CFU/g or CFU/mL) of the test material, or by the LODp, i.e., the contamination that is detected (measurement result 1) with a specified probability p. A complementary loglog model was used to statistically estimate these performance characteristics. An intralaboratory experiment for the detection of Listeria monocytogenes in various food matrixes illustrates the method. The estimate of LOD50 is compared with the Spearman-Kaerber method.