bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-Time PCR for Quantitative Detection of Chamois (Rupicapra rupicapra) and Pyrenean Ibex (Capra pyrenaica) in MeatMixtures
Authors: Fajardo Violeta , Gonzlez Isabel , Martn Irene , Rojas Mara , Hernndez Pablo E , Garca Teresa , Martn Rosario
Published: February 2020

A real-time quantitative polymerase chain reaction (PCR) technique was developed for the quantification of chamois and pyrenean ibex DNAs in meat mixtures by using a SYBR green detection platform. Two species-specific systems and a eukaryotic endogenous system were combined in the real-time PCR approach to quantify the target species. In the specific systems, a 133 base pair (bp) fragment of the 12S rRNA gene was amplified from chamois DNA, and an 88 bp fragment from the D-loop region was amplified from pyrenean ibex DNA. In the endogenous system, universal primers amplified a 141 bp fragment on the nuclear 18S rRNA gene from eukaryotic DNA. The threshold cycle values obtained with the 18S rRNA primers were used to normalize those obtained from chamois- or pyrenean ibex-specific systems, serving as endogenous control for the total content of PCR-amplifiable DNA in the sample. Analysis of experimental raw and heat-treated binary mixtures of chamois and pyrenean ibex meat in a swine meat matrix demonstrated the suitability of the assay for the detection and quantification of the target DNAs in the range of 0.10.8, depending on the species and treatment of the meat samples.
Pressurized Liquid Extraction and Microwave-Assisted Extraction in the Determination of Organochlorine Pesticides in Fish Muscle Samples
Authors: Barriada-Pereira Mercedes , Iglesias-García Iván , Gonzlez-Castro María J , Muniategui-Lorenzo Soledad , López-Maha Purificación , Prada-Rodríguez Daro
Published: February 2020

This paper describes a comparative study of 2 extraction methods, pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE), for the determination of organochlorine pesticides (OCPs) in fish muscle samples. In both cases, samples were extracted with hexaneacetone (50 + 50), and the extracts were purified by solid-phase extraction using a carbon cartridge as the adsorbent. Pesticides were eluted with hexaneethyl acetate (80 + 20) and determined by gas chromatography with electron-capture detection. Both methods demonstrated good linearity over the range studied (0.0050.100 g/mL). Detection limits ranged from 0.029 to 0.295 mg/kg for PLE and from 0.003 to 0.054 mg/kg for MAE. For most of the pesticides, analytical recoveries with both methods were between 80 and 120, and the relative standard deviations were <10. The proposed methods were shown to be powerful techniques for the extraction of OCPs from fish muscle samples. Although good recovery rates were obtained with both extraction methods, MAE provided advantages with regard to sample handling, cost, analysis time, and solvent consumption. Acceptable validation parameters were obtained although MAE was shown to be more sensitive than PLE.
Proposed Modifications to AOAC 996.06, Optimizing the Determination of Trans Fatty Acids: Presentation of Data
Authors: Rozema Brent , Mitchell Barbara , Winters Doug , Kohn Andrew , Sullivan Darryl , Meinholz Erin
Published: February 2020

The increased focus on the accuracy of Trans fatty acid data generated using current methodologies has resulted in research initiatives to optimize the quality of these assays. In this study, scientists combined the established methodology from AOAC 996.06 and the American Oil Chemists Society method Ce 1h-05, as well as other independent research. As a result, method modifications are proposed that could allow for a more accurate determination of Trans fat than the current AOAC 996.06 method. Validation data from this study are presented. The authors encourage peer review and offer to facilitate a collaborative validation to update AOAC 996.06.
Stability of Chosen Beta-Adrenolytic Drugs of Different Polarity in Basic Environment
Authors: Kwiecień Anna , Krzek Jan , Ylewski Marek
Published: February 2020

The stability of atenolol, acebutolol, and propranolol was investigated in sodium hydroxide solutions at concentrations of 0.1, 0.3, 0.5, and 1 M at 3 temperatures ranging from 37 to 95C. The degradation processes that occurred in drugs under investigation were described with kinetic parameters (k, t0.1, and t0.5) and energy of activation (Ea). It was found that the stability of the drugs increased toward lipophilic propranolol in the assumed experimental model. The rate constants k decreased, contrary to t0.1, t0.5, and Ea, which varied comparably to log P (partition coefficient), thus increasing from the most hydrophilic atenolol, through acebutolol of lower polarity, to the most lipophilic propranolol. The identification of degradation products was performed with the application of proton nuclear magnetic resonance spectrometry and thin-layer chromatographydensitometry and data from the literature.
Comparative Validation Study to Demonstrate the Equivalence of a Minor Modification to AOAC Method 999.09 [Visual Immunoprecipitate (VIP®) for Salmonella] to the Reference Culture Methods
Authors: Feldsine Philip T , Kerr David E , Shen George S , Lienau Andrew H
Published: February 2020

The Visual Immunoprecipitate (VIP®) for the Detection of Salmonella in Foods, AOAC Official Method 999.09, has been modified to use a simplified housing for the device. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture method. Three foods were analyzed. In total, valid results were obtained from 125 samples and controls. Results showed that the modified VIP for Salmonella is equivalent to the reference culture methods for the detection of Salmonella.
Development of a Potential Reference Material for Evaluating Antioxidant Activity
Authors: Luthria Devanand L , Vinyard Bryan T
Published: February 2020

Phenolic phytochemical are known to perform several functions ranging from phytoprotectants, to protecting lipids in food products, to antioxidant activity in animals and humans. The need for a common standard mixture containing multiple phenolic phytochemicals is critical for the development of a robust validation assay for accurately quantifying antioxidant activity in various matrixes. Different research groups have used A wide array of single purified reference phenolic compounds in this regard. A 5 compound mixture (caffeic acid, morin hydrate, hesperetin, catechin hydrate, and epigallocatechin gallate) containing phenolic compounds from 4 subgroups (phenolic acid, flavone, flavanone, and flavan-3-ol) was prepared. The mixture was assayed for stability evaluation by high-performance liquid chromatography (HPLC) using a diode array detection procedure for a 3 month time interval. HPLC analysis confirmed that there was no significant interaction between different components of the mixture. The among-sample relative standard deviation (RSD) of all 5 phenolic compounds, as well as the total HPLC area, was <1. The RSD due to instrument variation was <2 and the total RSD among-days was <5. These results unambiguously suggest that the sample was stable for a 3 month time interval in an amber vial stored in a refrigerator below 5C. This mixture is currently being used for the single-laboratory validation study for the assay of total phenolic content by the Folin-Ciocalteu method and the antioxidant capacity by oxygen radical absorbing capacity procedure.
Improving Industrial Full-Scale Production of Baker's Yeast by Optimizing Aeration Control
Authors: Blanco Carlos A , Rayo Julia , Giralda José M
Published: February 2020

This work analyzes the control of optimum dissolved oxygen of an industrial fed-batch procedure in which baker's yeast (Saccharomyces cerevisiae) is grown under aerobic conditions. Sugar oxidative metabolism was controlled by monitoring aeration, molasses flows, and yeast concentration in the propagator along the later stage of the propagation, and keeping pH and temperature under controlled conditions. A large number of fed-batch growth experiments were performed in the tank for a period of 16 h, for each of the 3 manufactured commercial products. For optimization and control of cultivations, the growth and metabolite formation were quantified through measurement of specific growth and ethanol concentration. Data were adjusted to a model of multiple lineal regression, and correlations representing dissolved oxygen as a function of aeration, molasses, yeast concentration in the broth, temperature, and pH were obtained. The actual influence of each variable was consistent with the mathematical model, further justified by significant levels of each variable, and optimum aeration profile during the yeast propagation was found.
Determination of Total Dietary Fiber in Selected Foods Containing Resistant Maltodextrin by a Simplified Enzymatic-Gravimetric Method and Liquid Chromatography: Interlaboratory Study in China
Authors: Fu Boqiang , Wang Jing , Roturier Jean Michel , Tang Zhiyu , Li Huan , Wei Guangyan
Published: February 2020

An interlaboratory study was conducted in China to validate the modified AOAC Official Method 2001.03 for the determination of total dietary fiber (TDF) in foods containing resistant maltodextrin (RMD), which will be adopted as the National Standard Method of China. The kind of buffer solution, the volume of filtrate evaporation, the volume of eluent for desalting and residual solution after evaporation, etc. were modified, which had been proved to have acceptable accuracy and precision in the routine assay. TDF contents in 3 representative foods and 2 kinds of RMD ingredient (i.e., NUTRIOSE 06 and NUTRIOSE 10) were measured using the modified method in 6 eligible laboratories representing commercial, industrial, and governmental laboratories in China. The results of the interlaboratory study indicated that the intralaboratory repeatability, interlaboratory reproducibility, and precision of the modified method are adequate for reliable analysis of TDF in food containing RMD, as well as resistant dextrin. Compared to AOAC Official Method 2001.03, the modified method is time- and cost-saving.
Purification of Pediocin PA-1 by Immunoaffinity Chromatography
Authors: Naghmouchi Karim , Drider Djamel , Fliss Ismail
Published: February 2020

A one-step purification procedure for purifying pediocin PA-1, a class IIa bacteriocin produced by Pediococcus acidilactici UL5, was developed based on column immunoaffinity chromatography with specific antipediocin PA-1 polyclonal antibodies coupled to cyanogen bromide-activated Sepharose. About 13.3 g/mL purified pediocin PA-1 was obtained from 15 mL P. acidilactici UL5 culture supernatant, as measured by enzyme-linked immunosorbent assay. The specific activity and average recovery of the eluted pediocin PA-1 were about 6602 AU/mg and 53.3, respectively. This is the first report of successful purification of pediocin PA-1 by immunoaffinity using pediocin PA-1-specific polyclonal antibodies.
Need for Accurate and Standardized Determination of Amino Acids and Bioactive Peptides for Evaluating Protein Quality and Potential Health Effects of Foods and Dietary Supplements
Authors: Gilani G Sarwar , Xiao Chaowu , Lee Nora
Published: February 2020

Accurate standardized methods for the determination of amino acid in foods are required to assess the nutritional safety and compositional adequacy of sole source foods such as infant formulas and enteral nutritionals, and protein and amino acid supplements and their hydrolysates, and to assess protein claims of foods. Protein digestibility-corrected amino acid score (PDCAAS), which requires information on amino acid composition, is the official method for assessing protein claims of foods and supplements sold in the United States. PDCAAS has also been adopted internationally as the most suitable method for routine evaluation of protein quality of foods by the Food and Agriculture Organization/World Health Organization. Standardized methods for analysis of amino acids by ion-exchange chromatography have been developed. However, there is a need to develop validated methods of amino acid analysis in foods using liquid chromatographic techniques, which have replaced ion-exchange methods for quantifying amino acids in most laboratories. Bioactive peptides from animal and plant proteins have been found to potentially impact human health. A wide range of physiological effects, including blood pressure-lowering effects, cholesterol-lowering ability, antithrombotic effects, enhancement of mineral absorption, and immunomodulatory effects have been described for bioactive peptides. There is considerable commercial interest in developing functional foods containing bioactive peptides. There is also a need to develop accurate standardized methods for the characterization (amino acid sequencing) and quantification of bioactive peptides and to carry out dose-response studies in animal models and clinical trials to assess safety, potential allergenicity, potential intolerance, and efficacy of bioactive peptides. Information from these studies is needed for determining the upper safe levels of bioactive peptides and as the basis for developing potential health claims for bioactive peptides. This information is, in turn, needed by regulatory agencies for developing appropriate policy and regulations on adding these substances to foods and for determining if health claims are scientifically substantiated.
Analysis of Soybean Protein-Derived Peptides and the Effect of Cultivar, Environmental Conditions, and Processing on Lunasin Concentration in Soybean and Soy Products
Authors: Wang Wenyi , Dia Vermont P , Vasconez Miguel , de Mejia Elvira Gonzalez , Nelson Randall L
Published: February 2020

Soybean, an important source of food proteins, has received increasing interest from the public because of its reported health benefits. These health benefits are attributed to its components, including isoflavones, saponins, proteins, and peptides. Lunasin, Bowman-Birk inhibitor, lectin, and -conglycinin are some of the biologically active peptides and proteins found in soybean. This article provides a comprehensive review on the recently used techniques in the analysis and characterization of food bioactive peptides, with emphasis on soybean peptides. The methods used to isolate and purify lunasin from defatted soybean flour were ion-exchange chromatography, ultrafiltration, and gel filtration chromatography. The identity of lunasin was established by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blot, matrix-assisted laser desorption ionizationtime of flight, and liquid chromatography. The results on the effect of soybean cultivar and environmental factors on lunasin concentration are also reported. The highest lunasin concentration, 11.7 0.3 mg/g flour, was found in Loda soybean cultivar grown at 23C; the lowest concentration, 5.4 0.4 mg/g flour, was found in Imari soybean cultivar grown at 28C. Lunasin concentration was affected by cultivartemperature, cultivarsoil moisture, and cultivartemperaturesoil moisture interactions. The variation on lunasin concentration suggests that its content can be improved by breeding, and by optimization of growing conditions. In summary, bioactive peptides can be accurately identified and quantified by using different techniques and conditions. In addition, lunasin concentration in soybean depends mainly on cultivar and to some extent on environmental factors, particularly temperature. Lunasin concentration in soy products was also affected by processing conditions.
Determination of Nutritional and Bioactive Properties of Peptides in Enzymatic Pea, Chickpea, and Mung Bean Protein Hydrolysates
Authors: Aluko Rotimi E
Published: February 2020

Within the primary structure of many pea and mung bean proteins are peptide sequences that can potentially be used in the formulation of therapeutic products for the treatment and prevention of human diseases. However, these peptide sequences need protease treatments before they can be released free of the parent proteins. Unlike chemical hydrolysis, enzymatic treatment enables more efficient tailoring of peptide products without formation of toxic by-products or destruction of amino acids. This review provides information on current methods that have been used to convert inactive pea and mung bean proteins into bioactive peptides. It focuses on 3 main bioactive properties, such as inhibitions of (1) angiotensin converting enzyme (ACE) activity; (2) calmodulin (CaM)-dependent enzymes; and (3) copper-chelating activity. ACE is an established marker for hypertension, high levels of some CaM-dependent enzymes are risk factors for various human diseases including cancer and Alzheimer's disease, and high vascular copper concentrations may potentiate atherosclerosis. Also reviewed are the production and evaluation of activity of hypoallergenic peptides that may offer protection against anaphylactic reactions. The 3 main proteins discussed are chickpea, mung bean, and field pea.
Determination of Chloramphenicol Residues in Bee Pollen by Liquid Chromatography/TandemMass Spectrometry
Authors: Fujita Kazuhiro , Ito Hironobu , Nakamura Munetomo , Watai Masatoshi , Taniguchi Makoto
Published: February 2020

A novel liquid chromatographic/tandem mass spectrometric (LC/MS/MS) method was developed for the trace residue determination of chloramphenicol (CAP) in bee pollen. CAP was extracted from bee pollen with a mixture of methanol and 1 metaphosphoric acid solution, followed by a 2-stage solid-phase extraction enrichment and cleanup. The first stage involved a polymeric cartridge, and the second stage involved an alumina neutral cartridge. The LC separation was performed on a C18 column with 10 mM ammonium formateacetonitrile (7 + 3) as the mobile phase and MS detection with negative-ion electrospray ionization. CAP-d5 was used as the internal standard. The method was validated according to Commission Decision 2002/657/EC. The calibration curves were linear between 0.1 and 5.0 ng/mL, and overall recoveries ranged from 98 to 113. Decision limits (CC) ranged from 0.05 to 0.07 g/kg, and detection capabilities (CC) ranged from 0.08 to 0.12 g/kg. The developed method was applied to 11 samples.
Thin-Layer Chromatography-Densitometric Analysis of -Mangostin Content in Garcinia mangostana Fruit Rind Extracts
Authors: Pothitirat Werayut , Gritsanapan Wandee
Published: February 2020

The fruit rinds of mangosteen (Garcinia mangostana Linn.) have long been used as traditional medicines for treatment of skin infections, wounds, and diarrhea. A simple thin-layer chromatography (TLC)-densitometric method has been developed for the simultaneous quantification of -mangostin in the extracts from unripe and ripe fruit rinds of G. mangostana. It was found in the ranges of 10.48 0.83 and 16.65 0.38 (w/w) in the dried unripe and ripe fruit rinds, respectively. The method was validated for linearity, precision, accuracy, limit of detection (LOD), and limit of quantitation (LOQ). The linearity was found over the range of 100500 ng/spot with regression coefficient 0.999. Intraday and interday precision studies showed the relative standard deviation was <2. Accuracy of the method was determined by a recovery study conducted at 3 different levels, and the average recovery was 99.49. The LOD and LOQ were 40 and 100 ng, respectively. The proposed TLC-densitometric method was found to be simple, precise, specific, sensitive, and accurate. This method can be used for routine quality control of raw material of G. mangostana fruit rind, extract, and its products. It also can be applied in quantifying this marker compound in other drugs.
Thin-Layer Chromatography-Densitometric Measurements for Determination of N-(Hydroxymethyl)nicotinamide in Tablets and Stability Evaluation in Solutions
Authors: Hubicka Urszula , Krzek Jan , uka Justyna
Published: February 2020

A thin-layer chromatography (TLC)-densitometric method was developed to determine N-(hydroxymethyl)nicotinamide in tablets and basic solutions along with nicotinic acid. Analysis was performed on silica gel F254 plates using chloroformethanol (2 + 3, v/v) mobile phase. The densitometric observations were made at 260 nm. The results showed good precision and accuracy; relative standard deviation was 2.37, and recovery ranged from 97.60 to 100.82. The limit of detection was 0.1 g/spot, while the linearity range was from 0.2 to 1.75 g/spot. Applicability of the newly developed method was tested for determination of N-(hydroxymethyl)nicotinamide in the preparation Cholamid. Densitometric measurements were used to evaluate stability of N-(hydroxymethyl)nicotinamide in basic solutions. It was found that decomposition corresponded to first-order reaction kinetics. The computed kinetic and thermodynamic parameters at 30C were as follows: k 0.00675/min, t0,5 1.71 h, t0,1 0.26 h, and Ea 44.75 kJ/mol.
Method for the Determination of Lycopene in Supplements and Raw Material by Reversed-Phase Liquid Chromatography: Single-Laboratory Validation
Authors: Müller André , Pietsch Bernd , Faccin Nicole , Schierle Joseph , Waysek Edward H
Published: February 2020

A single-laboratory validation study was conducted for a liquid chromatographic (LC) method for the determination of total and all-trans-lycopene in a variety of dietary supplements and raw materials. Gelatin-based and other water-dispersible beadlets, or tablets, capsules, and softgels containing such product forms, were digested with protease. Alginate formulations and the respective applications were treated with an alkaline sodium EDTA acetate buffer to release lycopene from the matrix. Lycopene and other carotenoids were extracted from the resulting aqueous suspensions with dichloromethane and ethanol. Oily product forms were directly dissolved in dichloromethane and ethanol. The extracts were chromatographed on an isocratic high-performance LC system using a C16 alkylamide modified silica column that provided satisfactory resolution of all-trans-lycopene from its predominant cis-isomers and separated the lycopene isomers from other carotenoids such as - and -carotene, cryptoxanthin, lutein, and zeaxanthin. The within-day precision relative standard deviation (RSD) for the determination of total lycopene ranged from 0.9 to 5.7 over concentration ranges of 50200 g/kg for raw materials and 0.324 g/kg for dietary supplements. The intermediate precision RSD (total RSD) ranged from 0.8 to 8.9. Recoveries obtained for beadlet and tablet material for the different extraction variants ranged from 95.0 to 102.1 at levels of 0.0220 g/kg for tablets and from 95.0 to 101.1 at levels of 1200 g/kg for beadlet material.
Standard Reference Materials for Analysis of Dietary Supplements
Authors: Sharpless Katherine E , Duewer David L
Published: February 2020

National Institute of Standards and Technology (NIST), in collaboration with the National Institutes of HealthOffice of Dietary Supplements and the U.S. Food and Drug Administration, is producing Standard Reference Materials (SRMs) for dietary supplements. These and other natural-matrix SRMs should be used in method validation, characterization of in-house quality control materials, and to establish traceability.
Development of a Stability-Indicating High-Performance Liquid Chromatographic Method for the Simultaneous Determination of Alprazolam and Sertraline in Combined Dosage Forms
Authors: Pathak Ashutosh , Rajput Sadhana J
Published: February 2020

The objective of the current study was to develop a validated stability-indicating high-performance liquid chromatographic method for alprazolam and sertraline in combined dosage forms. The method was validated by subjecting the drugs to forced decomposition under hydrolysis, oxidation, photolysis, and thermal stress conditions prescribed by the International Conference on Harmonization. The drugs were successfully separated from major and minor degradation products on a reversed-phase C18 column by using 75 mM potassium dihydrogen phosphate buffer (pH 4.3)acetonitrilemethanol (50 45 5, v/v/v) as the mobile phase with determination at 227 nm. The flow rate was 0.9 mL/min. The method was validated with respect to linearity, precision, accuracy, system suitability, and robustness. The responses were linear over the ranges of 180 and 5200 g/mL for alprazolam and sertraline, respectively. The recoveries of both drugs from a mixture of degradation products were in the range of 97101. The utility of the procedure was verified by its application to marketed formulations that were subjected to accelerated stability studies. The method distinctly separated the drugs and degradation products, even in actual samples. The products formed in marketed tablets were similar to those formed during stress studies.
Estimation of Dietary Intake of Biotin and Its Measurement Uncertainty Using Total Diet Samples in Osaka, Japan
Authors: Murakami Taro , Yamano Tetsuo , Nakama Akihiko , Mori Yoshiaki
Published: February 2020

Single-laboratory method performance parameters were evaluated for analysis of biotin in total diet samples by hydrolyzed extraction and microbiological assay with Lactobacillus plantarum. The method was shown to be accurate, repeatable, rugged, and applicable for the determination of biotin in a broad range of matrixes and concentrations of total diet samples. The measurement uncertainty was evaluated with all food sample groups by combining the relative uncertainty of precision, recovery from each food group, and interday variation factors calculated from the ruggedness test results. The estimated daily intake of biotin in Osaka city and its expanded measurement uncertainty were 70.1 11.2 g/day. The value was 1.6 times higher than the current adequate intake of biotin in Japan.
Single-Laboratory Validation and Uncertainty Analysis of 82 Pesticides Determined in Pomegranate, Apple, and Orange by Ethyl Acetate Extraction and Liquid Chromatography/Tandem Mass Spectrometry
Authors: Banerjee Kaushik , Oulkar Dasharath P , Patil Shubhangi B , Patil Sangram H , Dasgupta Soma , Savant Rahul , Adsule Pandurang G
Published: February 2020

Single-laboratory validation results are reported for the multiresidue determination of 82 pesticides at 10 ng/g levels in pomegranate, apple, and orange. Samples were extracted with ethyl acetate, and the extracts were cleaned up by dispersive solid-phase extraction with primary secondary amine sorbent. The concentrations of the pesticides were estimated within 18 min of chromatographic run time by liquid chromatography/mass spectrometry with multiple-reaction monitoring. The method was reproducible (HorRat of <0.5 at 10 ng/g) with measurement uncertainties of <15 for all the compounds at 10 ng/g in all 3 matrixes. The limits of quantitation ranged from 2.5 to 5.0 ng/g with recoveries of 70120 for most pesticides. Matrix-induced signal suppressions were significantly higher in orange compared with those in pomegranate and apple. The method offers a less expensive and safer alternative to the existing multiresidue analysis methods for fruits and vegetables.
Detection of Parvalbumin, a Common Fish Allergen Gene in Food, by Real-Time Polymerase Chain Reaction
Authors: Sun Min , Liang Chengzhu , Gao Hongwei , Lin Chao , Deng Mingjun
Published: February 2020

Fish, as one of the most common causes of IgE-mediated food hypersensitivity, has recently received increasing attention from the food industry and legislative and regulatory agencies. A real-time polymerase chain reaction assay based on TaqMan-MGB probe technology was developed for the detection of parvalbumin, a major fish allergen gene. The assay had a sensitivity up to 5 pg purified fish DNA and had no cross-reaction with other species, such as cattle, sheep, swine, chicken, shrimp, lobster, crab, squid, clam, rice, soybean, maize, and potato. The coefficient of variation for both intra- and interexperimental variability demonstrated high reproducibility and accuracy. The assay proved to be a potential tool for the detection and label management of fish allergens in food.
Proficiency Test for Chemical Laboratories for the Analysis of a Pesticide in a Formulated Product: Interlaboratory Study
Authors: Sanyal Doyeli , Rani Anita
Published: February 2020

A multilaboratory proficiency testing program was conducted by the National Accreditation Board for Testing and Calibration Laboratories (India) and coordinated by the Institute of Pesticide Formulation Technology. This program was conducted to compare the performance of individual laboratories in the area of pesticide formulation (Chlorpyrifos 20 EC) analysis. A total of 24 laboratories in India participated. Analysis of 2 parameters (i.e., estimation of the active ingredient and the acidity) of 2 samples of Chlorpyrifos 20 EC was the objective of this program. Homogeneity tests were performed before sample distribution. Performance of the participating laboratories was evaluated by using new robust statistics given in the guidelines of the National Association of Testing Authorities, Australia. Results were collated and statistically computed to calculate the value of 2 types of Z-scores (Zwi and Zbi). In addition to the statistical analysis, a graphical representation such as the Youden plot was also generated to evaluate the performance of participating laboratories.
Determination of Starch, Including Maltooligosaccharides, in Animal Feeds: Comparison of Methods and a Method Recommended for AOAC Collaborative Study
Authors: Hall Mary B
Published: February 2020

Starch is a nutritionally important carbohydrate in feeds that is increasingly measured and used for formulation of animal diets. Discontinued production of the enzyme Rhozyme-S required for AOAC Method 920.40 invalidated this method for starch in animal feeds. The objective of this study was to compare methods for the determination of starch as potential candidates as a replacement method and for an AOAC collaborative study. Many starch methods are available, but they vary in accuracy, replicability, and ease of use. After assays were evaluated that differed in gelatinization method, number of reagents, and sample handling, and after assays with known methodological defects were excluded, 3 enzymaticcolorimetric assays were selected for comparison. The assays all used 2-stage, heat-stable, -amylase and amyloglucosidase hydrolyses, but they differed in the gelatinization solution (heating in water, 3-(N-morpholino) propanesulfonic acid buffer, or acetate buffer). The measured values included both starch and maltooligosaccharides. The acetate buffer-only method was performed in sealable vessels with dilution by weight; it gave greater starch values (26 percentage units of sample dry matter) in the analysis of feed/food substrates than did the other methods. This method is a viable candidate for a collaborative study.
Validation of a Modification to Performance-Tested MethodSM 070601: Reveal® Listeria Test for Detection of Listeria spp. in Selected Foods and Selected Environmental Samples
Authors: Alles Susan , Peng Linda X , Mozola Mark A
Published: February 2020

A modification to Performance-Tested MethodSM (PTM) 070601, Reveal® Listeria Test (Reveal), is described. The modified method uses a new media formulation, LESS enrichment broth, in single-step enrichment protocols for both foods and environmental sponge and swab samples. Food samples are enriched for 2730 h at 30C and environmental samples for 2448 h at 30C. Implementation of these abbreviated enrichment procedures allows test results to be obtained on a next-day basis. In testing of 14 food types in internal comparative studies with inoculated samples, there was a statistically significant difference in performance between the Reveal and reference culture U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA/BAM) or U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) methods for only a single food in one trial (pasteurized crab meat) at the 27 h enrichment time point, with more positive results obtained with the FDA/BAM reference method. No foods showed statistically significant differences in method performance at the 30 h time point. Independent laboratory testing of 3 foods again produced a statistically significant difference in results for crab meat at the 27 h time point; otherwise results of the Reveal and reference methods were statistically equivalent. Overall, considering both internal and independent laboratory trials, sensitivity of the Reveal method relative to the reference culture procedures in testing of foods was 85.9 at 27 h and 97.1 at 30 h. Results from 5 environmental surfaces inoculated with various strains of Listeria spp. showed that the Reveal method was more productive than the reference USDA-FSIS culture procedure for 3 surfaces (stainless steel, plastic, and cast iron), whereas results were statistically equivalent to the reference method for the other 2 surfaces (ceramic tile and sealed concrete). An independent laboratory trial with ceramic tile inoculated with L. monocytogenes confirmed the effectiveness of the Reveal method at the 24 h time point. Overall, sensitivity of the Reveal method at 24 h relative to that of the USDA-FSIS method was 153. The Reveal method exhibited extremely high specificity, with only a single false-positive result in all trials combined for overall specificity of 99.5.
Novel Method for Identification and Quantification of Methanol and Ethanol in Alcoholic Beverages by Gas Chromatography-Fourier Transform Infrared Spectroscopy and Horizontal Attenuated Total ReflectanceFourier Transform Infrared Spectroscopy
Authors: Sharma Kakali , Sharma Shiba Prasad , Lahiri SujitChandra
Published: February 2020

Numerous methods are being used to identify and quantify methanol and ethanol in alcoholic beverages, including country liquors. Some of the known methods are density and refractive index measurements, and spectrophotometric measurements using Schiff's reagent or chromatropic acid. Other advanced techniques involve head space gas chromatography (GC), GCflame ionization detection, high-performance liquid chromatography, enzymatic reactions, and biosensors. However, identification and quantification of methanol and ethanol in beverages can be accurately done using GC-Fourier transform infrared spectroscopy (FTIR) and horizontal attenuated total reflectance (HATR)-FTIR. Identification of alcohols is possible from library matching of the IR spectra obtained from GC-FTIR. In water, methanol and ethanol show a very strong peak for CO, stretching at 1015.3 and 1044.2 cm1, respectively. The strong absorption of vibrational stretching frequency of CO present in alcohols was used for quantification purposes. The absorptions of CO group frequency of alcohols in water mixtures were measured using HATR-FTIR with a zincselenide crystal. Samples were placed directly on the HATR crystal, with alcohol concentrations ranging from 0.2 to 50.0 (v/v). The plot of absorptions against concentrations of methanol and ethanol obeyed Beer's law (r2 0.9998 and 0.9987, respectively), from which alcohol in the mixtures was quantified. Propan-2-ol and n-butanol showed no interference. The method is validated from absorption measurements of known mixtures of standard ethanol in water. This is a simple, specific, rapid, accurate, and nondestructive method of identification and quantification of methanol and ethanol in mixtures. It can be used to ascertain methanol contamination in alcoholic beverages that can lead to death or methanol poisoning by alcohol consumption.
Column Liquid Chromatography/Electrospray Ionization-Time of Flight-Mass Spectrometry and Ultraperformance Column Liquid Chromatography/Mass Spectrometry Methods for the Determination of Ginkgolides and Bilobalide in the Leaves of Ginkgo biloba and Dietary Supplements
Authors: Avula Bharathi , Wang Yan-Hong , Smillie Troy J , Khan Ikhlas A
Published: February 2020

Column liquid chromatography/electrospray ionization-time of flight-mass spectrometry (LC/ESI-TOF-MS) and ultraperformance column liquid chromatographic/MS (UPLC/MS) methods were developed for the determination of 5 terpenelactones in the leaves of Ginkgo biloba. The separation was performed using a C18 column and a mobile phase composed of water and acetonitrile. The limit of detection (LOD) values for ginkgolide J, ginkgolide C, ginkgolide B, and ginkgolide A were found to be in the range of 110 ng/mL by both methods, and the bilobalide LOD was 200 ng/mL by LC/ESI-TOF and 35 ng/mL by UPLC/MS. Using the optimized method, 4 commercial products were analyzed. Concentrations of total marker compounds in these products were in the 0.0915.4 range, with individual ginkgo terpenelactones being detected at ppb levels. LC/MS with ESI is described for the identification and quantification of ginkgolides and bilobalide in plant samples and dietary supplements that claim to contain G. biloba. These methods involve the use of the M NH4 and M H ions of sesquiterpenoids in the positive ion mode with extractive ion monitoring by LC/ESI-TOF-MS and selected ion monitoring by UPLC/MS. The LC method coupled with MS analysis yielded well-separated peaks which resulted in a clear identification of the compounds.
Development of a Rapid Resolution Liquid Chromatographic Method for Simultaneous Analysis of Four Alkaloids in Rhizoma coptidis Under Different Cultivation Conditions
Authors: Qiao Yan-Ling , Sheng Yu-Xin , Wang Li-Qun , Zhang Jin-Lan
Published: February 2020

A sensitive and specific method using rapid resolution liquid chromatography coupled with UV-Vis detection was developed for fingerprint analysis of Rhizoma coptidis and simultaneous determination of 4 alkaloids: jatrorrhizine, coptisine, palmatine, and berberine. Samples of R. coptidis grown under different cultivation conditions and from different habitats were analyzed. The analysis was performed using a reversed-phase octylsilyl (C8) column and gradient elution. The mobile phase consisted of acetonitrile and 20 mmol/L KH2PO4. Each analysis was completed within 3.5 min. The method showed good linearity within test ranges of 4.7547.50 g/mL for jatrorrhizine, 20.60164.80 g/mL for coptisine, 18.07180.73 g/mL for palmatine, and 89.70717.57 g/mL for berberine. The method showed good precision, repeatability, and stability for quantification of the 4 alkaloids. The lower limit of detection was 0.19 ng for jatrorrhizine, 0.21 ng for coptisine, 0.15 ng for palmatine, and 0.14 ng for berberine. The lower limit of quantification was 0.57 ng for jatrorrhizine, 0.82 ng for coptisine, 0.55 ng for palmatine, and 0.27 ng for berberine. The overall recovery ranged from 96.30 to 104.10 for the 4 alkaloids. The method is accurate, rapid, and convenient, and it is suitable for routine quality control of R. coptidis.
New Approaches for Determination of Glyphosate and Aminomethylphosphonic Acid from Different Tea SamplesProspects and Limits of Cleanup with Molecularly Imprinted Polymer and Titanium Dioxide
Authors: Kittlaus Stefan , Lipinski Jrgen , Speer Karl
Published: February 2020

Glyphosate is the most commonly used herbicide worldwide. To identify glyphosate and its metabolite, aminomethylphosphonic acid (AMPA), in the difficult-to-analyze matrix of tea, new methods were developed. The main emphasis was placed on the cleanup procedure. Two different solid-phase extraction methods were tested and evaluated: one with molecularly imprinted polymers, and the other with immobilized titanium dioxide. The optimization was carried out on the basis of aqueous standard solutions and spiked tea extracts. Validated results were presented for pipet tips that contained immobilized titanium dioxide. After the extraction of glyphosate from tea samples using hydrochloric acid (0.1), glyphosate and AMPA were concentrated on the adsorbent by pipetting up and down several times without changing the tip. The elution was carried out subsequent to a washing step with 5 ammonia. The extract was derivatized with 2,2,2-trifluoroacetic acid and 2,2,2-trifluoroethanol and then analyzed by GC with MS detection in the negative chemical ionization mode. Quantification was carried out in the selected-ion monitoring mode based on the m/z ratio of characteristic ions due to the ionization process. For glyphosate m/z = 370 was applied, and m/z = 351 for AMPA. The detection limit was 0.03 mg/kg tea for glyphosate and 0.006 mg/kg tea for AMPA. The recoveries for the tested working range (0.1 to 2.8 mg/kg tea) were low but constant at 14 and 12, respectively. Altogether, the method presented here can be carried out easily and quickly, and it gives reliable information on the presence of the analytes in a sample. Quantification is also possible using standard addition.
Analytical Utility of Quadrupole Time-of-Flight Mass Spectrometry for the Determination of Pesticide Residues in Comparison with an Optimized Column High-Performance Liquid Chromatography/Tandem Mass Spectrometry Method
Authors: Picó Yolanda , Blasco Cristina , Farré Marinella , Barceló Damiá
Published: February 2020

A multiresidue method for the analysis of 30 pesticides with different physicochemical properties in fruits and vegetables was developed. The method involves a rapid and small-scale extraction procedure based on matrix solid-phase dispersion using octadecylsilyl (C18) as the dispersant and dichloromethane as the eluent. The target pesticides were determined using column high-performance liquid chromatography/triple quadrupole-tandem mass spectrometry (LC/QqQ-MS/MS). The method was validated for sensitivity, linearity, reproducibility, and accuracy. A recovery study was conducted at 3 different levels, and the average ranged from 74 to 99 for all of the studied compounds, with relative standard deviations lower than 19. The proposed method achieved limits of quantitation between 0.5 and 10 g/kg, well below the maximum residue limits. The capability of the extraction procedure to extract pesticide residues other than those selected as target analytes has been checked by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/QqTOF-MS). Four incurred pesticides, not covered in the method as target analytes, were identified and unequivocally confirmed. Both systems were demonstrated to be complementary. LC/QqQ-MS/MS has the advantage that its detection limits are somewhat lower, and UPLC/QqTOF-MS offers the possibility to identify pesticides and transformation products not included as targets of the study.
Detection of the Potential Adulterant Teucrium chamaedrys in Scutellaria baicalensis Raw Material and Extract by High-Performance Thin-Layer Chromatography
Authors: Hong Thao , Jeong Mijeong Lee , Zahn Michael , Fay Brooke A , Lee Kangwoo , Hwangbo Huunjung , Park Eunhye , Kim Minjung , Ma Wenwen
Published: February 2020

Teucrium chamaedrys (Gemander) has been reported as an adulterant of Scutellaria lateriflora (American skullcap) herbal preparations and is also known to be hepatotoxic. A quick and simple high-performance thin-layer chromatographic (HPTLC) method was developed for the detection of T. chamaedrys (Germander) in S. baicalensis (Chinese skullcap) extract, an ingredient of the proprietary blend product, Univestin. The HPTLC profile of T. chamaedrys was distinguished from that of S. baicalensis by its bright green fluorescence bands. This simple method can be completed in an hour for the quality control of Univestin and its raw material, S. baicalensis. The method is sensitive and can detect T. chamaedrys at levels as low as 0.5 (w/w).
Determination of the Anti-Osteoporosis Drug Ipriflavone in Pharmaceutical Formulation by Stripping Voltammetric and Chromatographic Methods
Authors: El-Desoky Hanaa S , Beltagi Amr M , Ghoneim Mohamed M
Published: February 2020

Ipriflavone is a nonhormonal isoflavone derivative currently used as a bone-building agent for prevention and treatment of postmenopausal osteoporosis. Ipriflavone was reduced at the hanging mercury drop electrode in buffers of pH 211 via the consumption of 2 electrons corresponding to the reduction of the C=O double bond in the C 4 position of the analyte molecule. A fully validated square-wave adsorptive cathodic stripping (SW-AdCS) voltammetric method was described for the trace quantification of bulk ipriflavone. A linear response, with concentrations of bulk ipriflavone over the range 5 1094 107 M with a limit of detection of 1.5 109 M bulk ipriflavone, was obtained. Moreover, an LC-UV detection method was also described for determining ipriflavone. The peak area was proportional to the concentration of bulk ipriflavone over the range 1 1071 104 M with a limit of detection of 3 108 M. The described SW-AdCS voltammetric and LC methods were successfully applied for the assay of ipriflavone in iprivone tablets without interference from excipients. Accuracy and precision of both methods for determination of ipriflavone in its tablets were studied and discussed.
Optimization of the Treatment of Wheat Samples for the Determination of Phytic Acid by HPLC with Refractive Index Detection
Authors: Amaro Rosa , Murillo Miguel , Gonzlez Zurima , Escalona András , Hernández Lus
Published: February 2020

The treatment of wheat samples was optimized before the determination of phytic acid by high-performance liquid chromatography with refractive index detection. Drying by lyophilization and oven drying were studied; drying by lyophilization gave better results, confirming that this step is critical in preventing significant loss of analyte. In the extraction step, washing of the residue and collection of this water before retention of the phytates in the NH2 Sep-Pak cartridge were important. The retention of phytates in the NH2 Sep-Pak cartridge and elimination of the HCl did not produce significant loss (P = 0.05) in the phytic acid content of the sample. Recoveries of phytic acid averaged 91, which is a substantial improvement with respect to values reported by others using this methodology.
Determination of Bromoxynil Octanoate in Soil and Corn by GC with Electron Capture and Mass Spectrometry Detection Under Field Conditions
Authors: Liu Xin-Gang , Dong Feng-Shou , Zheng Yong-Quan , Li Yuan-Bo
Published: February 2020

In this paper, a simple, and rapid analysis of bromoxynil octanoate is reported for soil, corn leaves, and corn seeds by utilizing one-step liquid-liquid extraction and partitioning, followed by GC with electron capture (ECD) and mass spectrometry (MS) detection. The method was validated by recovery experiments and assessment of matrix effects. Recoveries for GC-ECD and GC/MS were 82.3110.7 with a relative standard deviation of <14 using matrix-matched calibration solutions for quantification. The limit of quantitation (LOQ) values were 0.005 and 0.2 mg/kg for the ECD and MS detector, respectively, depending on the sensitivity of the target compound. The concentration levels for bromoxynil octanoate residue found in soil, corn leaves, and corn seeds from field experiments were clearly below the LOQ of the ECD detector. The half-life times of bromoxynil octanoate were 2.24.2 days in soil and corn leaves. These results indicated that the developed method was appropriate for analysis of bromoxynil octanoate in soil and corn samples.
LC Determination of Albiflorin and Paeoniflorin in Bai Shao (Paeonia lactiflora) as a Raw Herb and Dried Aqueous Extract
Authors: Lee Samiuela , Khoo Cheang S , Hennell James R , Pearson Jarryd L , Jarouche Mariam , Halstead Clynton W , Bensoussan Alan
Published: February 2020

A validated analytical method is reported for the analysis of paeoniflorin and albiflorin in Bai Shao (Paeonia lactiflora) as a dried raw herb and commercially prepared dried aqueous extract. The samples were extracted by sonication in methanol and the extract analyzed by LC-photodiode array with identity confirmation by electrospray ionization-tandem MS. A C18 column was used with an acetonitrilewater gradient mobile phase. Paeoniflorin and albiflorin were quantified at 230 nm. Ions with m/z 121 and 327 were produced with the MS detector, using the paeoniflorin precursor ion with m/z 479. For albiflorin, the precursor ion with m/z 479 produced the m/z 121 and 77 ions. The amounts of paeoniflorin and albiflorin found in the raw herb were 33.2 and 1.8 mg/g, respectively; and in the dried aqueous extract, the amounts were 34.8 and 15.7 mg/g, respectively. The LODs for paeoniflorin and albiflorin were 0.37 and 1.39 mg/g, respectively, for the raw herb and 0.25 and 0.06 mg/g, respectively, for the dried aqueous extract.