bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Culture Media for Selective Enrichment and Isolation of Salmonella in Seafood
Authors: Kumar Rakesh , Surendran Poothuvallil K , Thampuran Nirmala
Published: February 2020

Seafood, including fish, shrimp, clam, crab, mussel, oyster, lobster, squid, octopus, and cuttlefish samples, was used to compare the recovery of Salmonella serovars by different selective enrichment and isolation media. The samples were selectively enriched in Rappaport-Vassiliadis (RV) broth and tetrathionate broth (TT), followed by selective isolation on Hektoen enteric (HE) agar, xylose lysine desoxycholate (XLD) agar, bismuth sulfite (BS) agar, and Brilliant Green (BG) agar media. Of 443 seafood samples analyzed, 108 were found to be contaminated with Salmonella. The role of selective enrichment in Salmonella spp. recovery with RV medium was distinctly high (70%) compared to TT broth (30%). The selective enrichment in RV broth followed by selective isolation on XLD, HE, BS, and BG agar recovered Salmonella at levels of 56, 41, 28, and 16%, respectively. Similarly, after enrichment in TT broth, XLD and HE agars recovered 27 and 23 respectively. The recovery of Salmonella with enrichment in TT followed by isolation on BS and BG was abysmally low at 4.6 and 5, respectively. There was no significant difference (P > 0.05) in the recovery of Salmonella using the combinations of XLD and HE media with selective enrichment in RV broth. However, performance difference (P <0.05) was observed in the recovery when BS and BG with RV, and XLD, HE, BS, and BG agars with TT broth were used. The present study showed that the combination of RV with XLD was the most efficient media for isolation of Salmonella from seafood when compared to other isolation media combinations.
Rapid Determination of Banned Sudan I in Foodstuffs Using a Mesoporous SiO2 Modified Electrode
Authors: Yang Xiaofeng , He Dihua
Published: February 2020

Rapid determination of Sudan I in foodstuffs is very important because it was found to be a carcinogen and its use in the food industry was banned. A rapid, sensitive, and convenient electrochemical method was developed for the determination of Sudan I based on the distinctive properties of mesoporous SiO2. The electrochemical responses of Sudan I were investigated. A sensitive oxidation peak was observed for Sudan I, and the peak currents greatly increased at the mesoporous SiO2-modified electrode, which can be attributed to its large surface area and high accumulation efficiency. The effects of pH, amount of mesoporous SiO2, scan rate, accumulation potential, and time were examined on the oxidation signals of Sudan I. The linear range was from 4.00 ⨯ 108 to 2.00 ⨯ 105 M, and the LOD was 7.50 ⨯ 109 M. The newly developed method was successfully used to detect and quantify Sudan I in hot chili powder and juice samples.
Bioanalytical Methods for Food Contaminant Analysis
Authors: Van Emon Jeanette M
Published: February 2020

Foods are complex mixtures of lipids, carbohydrates, proteins, vitamins, organic compounds, and other naturally occurring substances. Sometimes added to this mixture are residues of pesticides, veterinary and human drugs, microbial toxins, preservatives, contaminants from food processing and packaging, and other residues. This milieu of compounds can pose difficulties in the analysis of food contaminants. There is an expanding need for rapid and cost-effective residue methods for difficult food matrixes to safeguard our food supply. Bioanalytical methods are established for many food contaminants such as mycotoxins and are the method of choice for many food allergens. Bioanalytical methods are often more cost-effective and sensitive than instrumental procedures. Recent developments in bioanalytical methods may provide more applications for their use in food analysis.
Real-Time Polymerase Chain Reaction Detection of Fishmeal in Feedstuffs
Authors: Martí Irene , García Teresa , Rojas Maria , Pegels Nicolette , Pavón Miguel ángel , Hernández Pablo E , González Isabel , Martín Rosario
Published: February 2020

A SYBR Green PCR system was developed for detection of fishmeal in feedstuffs. The real-time PCR method combines the use of fish-specific primers that amplify an 87 base pair (bp) fragment of the mitochondrial 12S ribosomal RNA gene from fish species, and a positive control primer pair that amplifies a 99 bp fragment of the nuclear 18S ribosomal RNA gene in all eukaryotic organisms. The specificity of the primers was tested against 52 animal species and six plant species. Reference feedstuff samples were successfully tested for the presence of fishmeal, demonstrating the applicability of the assay to feedstuffs.
Quantitative Determination of Chemical Constituents from Seeds of Nigella sativa L. Using HPLC-UV and Identification by LC-ESI-TOF
Authors: Avula Bharathi , Wang Yan-Hong , Ali Zulfiqar , Khan Ikhlas A
Published: February 2020

An HPLC method was developed for the simultaneous determination of nine compounds of Nigella sativa L. The separation was achieved within 23 min by using C18 column material, a wateracetonitrile mobile phase, both containing 0.1 acetic acid gradient system and a temperature of 35C. The method was validated for linearity, repeatability, LOD, and LOQ. The LOD and LOQ of nine compounds were in the range of 0.0910 and 0.325 g/mL, respectively. The wavelength used for quantification with the diode array detector was 205 and 260 nm. LC/MS coupled with electrospray ionization interface method is described for the identification of compounds in N. sativa L. samples. This method involved the use of [MH] and [MNa] ions in the positive ion mode with extracted ion chromatogram.
Ultra-Fast Gradient LC Method for Omeprazole Analysis Using a Monolithic Column: Assay Development, Validation, and Application to the Quality Control of Omeprazole Enteric-Coated Pellets
Authors: Borges Keyller Bastos , Snchez Antonio Jos Macas , Pupo Mnica Tallarico , Bonato Pierina Sueli , Collado Isidro Gonzlez
Published: February 2020

A method was optimized for the analysis of omeprazole (OMZ) by ultra-high speed LC with diode array detection using a monolithic Chromolith Fast Gradient RP 18 endcapped column (50 2.0 mm id). The analyses were performed at 30C using a mobile phase consisting of 0.15 (v/v) trifluoroacetic acid (TFA) in water (solvent A) and 0.15 (v/v) TFA in acetonitrile (solvent B) under a linear gradient of 5 to 90 B in 1 min at a flow rate of 1.0 mL/min and detection at 220 nm. Under these conditions, OMZ retention time was approximately 0.74 min. Validation parameters, such as selectivity, linearity, precision, accuracy, and robustness, showed results within the acceptable criteria. The method developed was successfully applied to OMZ enteric-coated pellets, showing that this assay can be used in the pharmaceutical industry for routine QC analysis. Moreover, the analytical conditions established allow for the simultaneous analysis of OMZ metabolites, 5-hydroxyomeprazole and omeprazole sulfone, in the same run, showing that this method can be extended to other matrixes with adequate procedures for sample preparation.
An Interlaboratory Investigation on the Use of High-Performance Thin Layer Chromatography to Perform Assays of LamivudineZidovudine, Metronidazole, Nevirapine, and Quinine Composite Samples
Authors: Kaale Eliangiringa , Risha Peter , Reich Eike , Layloff Thomas P
Published: February 2020

Two laboratories extensively investigated the use of HPTLC to perform assays on lamivudinezidovudine, metronidazole, nevirapine, and quinine composite samples. To minimize the effects of differences in analysts' technique, the laboratories conducted the study with automatic sample application devices in conjunction with variable-wavelength scanning densitometers to evaluate the plates. The HPTLC procedures used relatively innocuous, inexpensive, and readily available chromatography solvents used in the Kenyon or the Global Pharma Health Fund Minilabs TLC methods. The use of automatic sample applications in conjunction with variable- wavelength scanning densitometry demonstrated an average repeatability or within-laboratory RSD of 1.90, with 73 less than 2 and 97 at 2.60 or less, and an average reproducibility or among-laboratory RSD of 2.74.
Method for the Direct Determination of Available Carbohydrates in Low-Carbohydrate Products Using High-Performance Anion Exchange Chromatography
Authors: Ellingson David , Potts Brian , Anderson Phillip , Burkhardt Greg , Ellefson Wayne , Sullivan Darryl , Jacobs Wesley , Ragan Robert
Published: February 2020

An improved method for direct determination of available carbohydrates in low-level products has been developed and validated for a low-carbohydrate soy infant formula. The method involves modification of an existing direct determination method to improve specificity, accuracy, detection levels, and run times through a more extensive enzymatic digestion to capture all available (or potentially available) carbohydrates. The digestion hydrolyzes all common sugars, starch, and starch derivatives down to their monosaccharide components, glucose, fructose, and galactose, which are then quantitated by high-performance anion-exchange chromatography with photodiode array detection. Method validation consisted of specificity testing and 10 days of analyzing various spike levels of mixed sugars, maltodextrin, and corn starch. The overall RSD was 4.0 across all sample types, which contained within-day and day-to-day components of 3.6 and 3.4, respectively. Overall average recovery was 99.4 (n = 10). Average recovery for individual spiked samples ranged from 94.1 to 106 (n = 10). It is expected that the method could be applied to a variety of low-carbohydrate foods and beverages.
Rapid Method for the Determination of Capsaicin and Dihydrocapsaicin in Gochujang Using Ultra-High-Performance Liquid Chromatography
Authors: Ha Jaeho , Seo Hye-Young , Shim You-Shin , Nam Hyun-Jin , Seog Homoon , Ito Masahito , Nakagawa Hiroaki
Published: February 2020

A sensitive and specific heating block method coupled with ultra-HPLC (u-HPLC) was developed for the analysis of capsaicin in Gochujang and validated by comparing with a conventional HPLC (AOAC Method 995.03). The method validation parameters yielded good results, including linearity, precision, accuracy, and recovery. The u-HPLC separation was performed on a reversed C18 column (50 2 mm id, particle size 2 m), followed by fluorescence detection (excitation 280 nm, emission 325 nm). Methanol was used as the extracting solvent, and the amount of sample taken was approximately 0.2 g; the optimum amount of extraction solvent and extraction time were 15 mL and 1 h, respectively. The recovery of capsaicin in Gochujang was more than 93, and the LOD and LOQ of the u-HPLC analysis were 0.05 and 0.16 g/g for capsaicin and 0.05 and 0.16 g/g for dihydrocapsaicin. The calibration graphs for capsaicin and dihydrocapsaicin were linear from 0.2 to 10.0 g/mL for u-HPLC. The interday and intraday precisions (RSD values) were <6.27.
ELISA Kit for Determination of Egg White Proteins: Interlaboratory Study
Authors: Tomková Kvìta , Cuhra Petr , Rysová Jana , Hanák Petr , Gabrovská Dana ,   Collaborators:, Baranda A , Baršová S , Brychta J , Bulawová H , „en…i… A , Del Barco J A G , Dvorská P , Iametti S , Jimenez E , Karšulínová L , Kubík M , Langerholc T , Laukkanen M-L , Martínez de Marañon I , Suñen Pardo E , Angel Pardo M , Piknová L , Plicka J , Martínez Quesada J , Postigo Resa I , Štumr F , Takkinen K
Published: February 2020

An interlaboratory study was conducted in 11 laboratories to validate an ELISA method developed for the quantitative determination of egg white proteins (EWPs) in foods. The ELISA kit used for this study is based on sheep polyclonal antibody. It does not produce any false-positive results or cross-reactivity in a broad food matrix range with zero EWP content. All participants obtained the Egg ELISA Kit-native with standard operational procedure and the list of samples, as well as the samples and a protocol for recording test results. The study included 10 food samples. Four samples of food matrix with zero EWP content showed EWP content lower than the first standard (EWP content 0.5 mg/kg). One sample of food matrix with zero EWP content revealed EWP content higher than standard 3 (1.5 mg EWP/kg). Five food samples containing EWP as an ingredient tested positive and one negative. The statistical tests (Cochran, Dixon, and Mandel) and analysis of variance were used to evaluate the interlaboratory study results. Repeatability and reproducibility limits, as well as LOQ (1.4 mg EWP/kg) and LOD (0.43 mg EWP/kg), were calculated for the kit.
A Simple HPLC Method for Quantitation of Quercetin in Herbal Extracts
Authors: D’Mello Priscilla M , Joshi Urmila J , Shetgiri Preetam P , Dasgupta Tarun K , Darji Kamil K
Published: February 2020

A reversed-phase HPLC method with UV detection was developed for the determination of quercetin. The method produced linear response over a wide concentration range, with an average accuracy of 95% and average intra- and interday variation of 0.75 and 0.3, respectively. The exactness of the method was proven by determining the recovery rates from 50 to 150% of standard concentration, which were found within the acceptable range of 95 to 105%. The method was used for quantitation of quercetin in the extracts of Psidium guajava, Vitis vinifera, and extracts rich in quercetin and other flavonols in the flavonoid family.
Reversed-Phase Ultra-Performance Liquid Chromatographic Method Development and Validation for Determination of Impurities Related to Torsemide Tablets
Authors: Patel Hitesh B , Mohan Arivozhi , Joshi Hitendra S
Published: February 2020

A simple RP-ultra-performance LC method was developed and validated for determination of impurities related to torsemide tablets. The rapid method provided adequate separation of all known related impurities and degradation products. Separation was achieved on a Zorbax SB-C18 column (50 × 4.6 mm id, 1.8 μm particle size) with binary gradient elution, and detection was performed at 288 nm. The drug product was subjected to oxidative, hydrolytic, photolytic, and thermal stress conditions to prove the specificity of the proposed method. The linearity and recovery were investigated for known impurities in the range of 0.025 to 1.0%, with respect to the drug concentration in the prepared sample. The linearity of the calibration curve for each of the impurities and torsemide was found to be very good (r2 > 0.999). Relative response factors for each of the known impurities were established by the slope ratio method from the linearity study.
Single Laboratory Validation of a Microsatellite Marker-Based Method in Tomato Variety Identification
Authors: Srivastava Deepak K , Shoemaker Lauren S , Franks Craig E , Sussman Michael D
Published: February 2020

The objective of this study was to develop a systematic and flexible method for assembling multiplex simple sequence repeat marker panels for high-throughput genome analysis in the tomato, Solanum lycopersicum, for varietal identification and to demonstrate the technical viability of these genetic markers for use in the enforcement of U.S. Department of Agriculture marketing order-based identity preservation programs. GeneMapper, a semiautomated software tool, was used for designing multiplex panels, allele identification, and polymorphism pattern evaluation of diverse tomato cultivars. Semiautomated genotyping was performed on a set of 12 microsatellite markers providing genome-wide coverage of the tomato chromosomes. Microsatellites were detected with fluorescently labeled primers grouped into five multiplex panels, and each primer pair was assessed in replicated trials for reliability of allele size estimates. Allele sizes for each locus were compared, and a database for 34 tomato varieties was developed. The microsatellite marker set identified distinct allelic peaks and unique genetic fingerprints for each of the studied tomato varieties. A "blind testing" exercise with UglyRipe™ and Vintage Ripe™ tomato varieties, using the above set of markers and database, further established the usefulness of these microsatellite markers for tomato commodity marketing order enforcement.
Ultra High Pressure Liquid Chromatography for Crude Plant Extract Profiling
Authors: Eugster Philippe J , Guillarme Davy , Rudaz Serge , Veuthey Jean-Luc , Carrupt Pierre-Alain , Wolfender Jean-Luc
Published: February 2020

Ultra high pressure liquid chromatography (UHPLC) systems operating at very high pressures and using sub-2 μm packing columns have allowed a remarkable decrease in analysis time and increase in peak capacity, sensitivity, and reproducibility compared to conventional HPLC. This technology has rapidly been widely accepted by the analytical community and is being gradually applied to various fields of plant analysis such as QC, profiling and fingerprinting, dereplication, and metabolomics. For many applications, an important improvement of the overall performances has been reported. In this review, the basic principles of UHPLC are summarized, and practical information on the type of columns used and phase chemistry available is provided. An overview of the latest applications to natural product analysis in complex mixtures is given, and the potential and limitations as well as some new trends in the development of UHPLC are discussed.
Binary HPLC-Diode Array Detector and HPLC-Evaporative Light-Scattering Detector Fingerprints of Methanol Extracts from the Selected Sage (Salvia) Species
Authors: Sajewicz Mieczysław , Staszek Dorota , Wojtal Łukasz , Kowalska Teresa , Hajnos Michał Ł , Waksmundzka-Hajnos Monika
Published: February 2020

This study is focused on an important family of the sage (Salvia) species, with Salvia officinalis L. having a long-established position in European traditional medicine. Binary fingerprints (chromatographic profiles) of six different sage species were compared using HPLC coupled with two different detectors: the diode-array detector and the evaporative light-scattering detector. Advantages of using binary fingerprinting over single-detector fingerprinting are demonstrated and discussed, with selected examples. Experimental data are provided for a comparison of the chemical composition of sage samples originating from two harvesting seasons (2007 and 2008). A number of phytochemical standards (i.e., certain phenolic acids, flavonoids, and coumarin) were used that allowed identification and semiquantitative estimation of these particular compounds in the analyzed methanol extracts.
Flow Injection Mass Spectroscopic Fingerprinting and Multivariate Analysis for Differentiation of Three Panax Species
Authors: Chen Pei , Harnly James M , Harrington Peter de B
Published: February 2020

This study describes the use of spectral fingerprints acquired by flow injection (FI)-MS and multivariate analysis to differentiate three Panax species: P. ginseng, P. quinquefolius, and P. notoginseng. Data were acquired using both high resolution and unit resolution MS, and were processed using principal component analysis (PCA), soft independent modeling of class analogy (SIMCA), partial least squares-discriminant analysis (PLS-DA), and a fuzzy rule-building expert system (FuRES). Both high and unit resolution MS allowed discrimination among the three Panax species. PLS-DA and FuRES provided classification with 100% accuracy while SIMCA provided classification accuracies of 77 and 88% by high- and low-resolution MS, respectively. The method does not quantify any of the sample components. With FI-MS, the analysis time was less than 2 min.
Validated Determination of Eight Antibiotic Substance Groups in Cattle and Pig Muscle by HPLC/MS/MS
Authors: Bohm Detlef A , Stachel Carolin S , Gowik Petra
Published: February 2020

The described multimethod is suited for the determination of 53 substances of eight antibiotic groupstetracyclines, quinolones, macrolides, sulfonamides, diphenylsulfones, diamino-pyrimidine derivatives, pleuromutilines, and lincosamidesin cattle and pig muscle. All substances were analyzed simultaneously with the same sample preparation and in one HPLC/MS/MS run. The validation of the multimethod was successfully accomplished with the help of an alternative in-house validation concept requiring only 48 experiments. The substances were validated at concentrations of 0.25, 0.5, 1.0, 1.5, and 2.0 MRL (maximum residue limit) or 5, 10, 20, 30, and 40 g/kg for substances without an MRL. The calculated relevant validation parameters were based on and comply with the requirements of Commission Decision 2002/657/EC, i.e., the decision limit, detection capability, repeatability, within-laboratory reproducibility, and recovery. The robustness of the method was demonstrated by varying seven factors of the analytical procedure. Several proficiency tests were carried out successfully to provide evidence for the applicability of the method.
Simultaneous Determination of 20 -Agonists in Pig Muscle and Liver by High-Performance Liquid Chromatography/Tandem Mass Spectrometry
Authors: Liu Chang , Ling Wenting , Xu Weidong , Chai Yifeng
Published: February 2020

A method was developed to determine 20 illegal residual -agonists in pork tissues, including muscle and liver simultaneously. The samples were hydrolyzed by -glucuronidase, purified by PCX SPE cartridges, and detected by HPLC coupled with electrospray ionization MS/MS operating in the positive ion mode. Matrix-fortified calibration was performed to compensate for the matrix effect and loss in sample preparation. Decision limit ranged from 0.05 to 0.23 g/kg in muscle and 0.05 to 0.57 g/kg in liver. Decision capacity ranged from 0.11 to 0.4 g/kg in muscle and 0.16 to 0.79 g/kg in liver. In Food Analysis Performance Assessment Scheme proficiency test 0287, a pig liver test material containing 13 -agonists was analyzed using the method developed, and clenbuterol and ractopaime were confirmed as being present. Z-scores for clenbuterol and ractopaime were 0.2 and 0.6, respectively.
Validated Stability-Indicating HPLC-UV Method for Simultaneous Determination of Glipizide and Four Impurities
Authors: Gupta Sakshi , Bansal Gulshan
Published: February 2020

A selective stability-indicating HPLC-UV method for simultaneous determination of glipizide and four impurities (DPs IIV) formed under hydrolytic conditions was developed and validated. The drug and impurities were resolved on an XTerra C18 column (250 4.5 mm id) in a single gradient run using buffer (0.005 M KH2PO4; pH 3.0)methanol (60 40, v/v; mobile phase A) and (20 80, v/v; mobile phase B) at a flow rate of 0.5 mL/min with 230 nm detection wavelength. The method was linear across concentration ranges of 0.2100, 0.1100, 0.5100, 0.2100, and 0.150 0000g/mL for glipizide and DPs IIV, respectively. The RSD for intraday and interday precision for the drug and impurities was <1 and <1.2, respectively. Satisfactory recoveries (96.5899.97) of each of the three concentrations selected across the linearity range of each analyte were obtained, proving the method was sufficiently accurate. The LOD was 0.07, 0.05, 0.16, 0.08, and 0.05 g/mL and the LOQ was 0.20, 0.14, 0.50, 0.23, and 0.14 g/mL for the drug and DPs IIV, respectively. Each peak was resolved with resolution of >2 from the nearest peak. Insignificant changes in retention time (<4) and calculated amount (<1.65) of drug and each impurity upon small but deliberate changes in various chromatographic parameters were observed, suggesting the method was robust. The method was applied successfully to stability testing of glipizide tablets.
High-Throughput Analysis of Amnesic Shellfish Poisoning Toxins in Shellfish by Ultra-Performance Rapid Resolution LC-MS/MS
Authors: Iglesia Pablo De La , Barber Esther , Giménez Gemma , Rodríguez-Velasco María Luisa , Villar-González Adriano , Diogéne Jorge
Published: February 2020

The application of ultra-performance rapid resolution LC on a 1.8 m particle-size column coupled with tandem MS (RRLC-MS/MS) is described for the analysis of amnesic shellfish poisoning (ASP) toxins in shellfish. Complete resolution among domoic acid (DA) and the isomers was achieved in less than 3 min. The method was intralaboratory validated for direct analysis of crude extracts without further cleanup. It showed LODs ranging from 0.05 to 0.09 mg/kg and a working range that complied with the current regulatory level for DA of 20 mg/kg, and with the level of 4.5 mg/kg recently proposed by the European Food Safety Authority. Confirmatory capabilities were demonstrated according to the Commission Decision 2002/657/EC criteria. The results obtained by RRLC-MS/MS agreed with those provided by the reference LC-UV method, both intralaboratory for the analysis of blind samples (R2 0.9751) and interlaboratory through participation in the proficiency test for ASP toxins during 2009 (z-score 0.962 and 0.177 for low- and high-contaminated samples, respectively). RRLC-MS/MS provided fast analysis and additional confirmatory capabilities for direct analysis of crude extracts while the performance and reliability of the results were maintained, even in very complex matrixes.
Validation Study of Immunoaffinity Column Chromatography Coupled with Solution Fluorometry or HPLC for the Detection of Aflatoxin in Peanuts and Corn
Authors: Lupo Anthony , Quain Anna , Fitzsimmons Alan , Allan Andrew , Popping Bert , Trucksess Mary , Shephard Gordon
Published: February 2020

Neogen Corp. has developed the Neocolumn for Aflatoxin DR for the detection of total aflatoxin by HPLC or solution fluorometry. The purpose of this study was to validate the method under the requirements of the AOAC Research Institute Performance Tested MethodsSM (PTM) program. There are several AOAC Official MethodsSM for detection of total aflatoxin in corn; they consist of rapid and analytical-based methods and two rapid methods (PTMs 030701 and 050901) that have been performance tested by the AOAC Research Institute. A widely used reference method, however, is AOAC Official MethodSM 991.31, which uses immumoaffinity cleanup followed by HPLC or solution fluorometry and is referred to as the reference method in this document. In internal studies, the Neocolumn method coupled with solution fluorometry demonstrated a relative recovery from peanuts of 101.6 of the reference value, with a CV of 3.9 across all levels analyzed; when coupled with HPLC, the Neocolumn method demonstrated a relative recovery from peanuts of 103.0 of the reference value with a CV of 3.5 across all levels analyzed. The Neocolumn method coupled with solution fluorometry demonstrated a relative recovery from corn of 116.9 of the reference value with a CV of 6.1 across all levels analyzed; when coupled with HPLC, the Neocolumn method demonstrated a relative recovery from corn of 91.2 of the reference value, with a CV of 5.4 across all levels analyzed. Calculations were made by comparison with the mean result obtained by the HPLC reference method, which showed respective CV values of 3.9 and 2.0 for recoveries from peanuts and corn, respectively.
Confirmatory Method for the Determination of Volatile Congeners and Methanol in Turkish Raki According to European Union Regulation (EEC) No. 2000R2870: Single-Laboratory Validation
Authors: Yilmaztekin Murat , Cabaroglu Turgut
Published: February 2020

A method described by European Union Regulation (EEC) No. 2000R2870 was validated and supported by GC/MS analysis for the determination of volatile congeners and methanol in Turkish raki. The method was validated in terms of specificity, accuracy, precision, LOD, LOQ, linearity, and robustness. The specificity of the method was demonstrated, and the method showed excellent accuracy (97.5100.1). Linearity was checked in the ranges of 0.20026.390 mg/100 mL for more volatile compounds and 1.15548.00 mg/100 mL for less volatile compounds, after concentrations found in Turkish raki were taken into account. The calibration curves of all analytes showed good linearity (R2 > 0.998). The within- and between-day precision (RSD) values of 11 analytes were in the range of 0.184.50. The LOD and LOQ values were in the range of 0.0140.362 and 0.0451.085 mg/100 mL, respectively. The method can be used as an absolute quantification method for the determination of volatile congeners and methanol in Turkish raki and for QC.
An Easy and Practical Method for Detection and Estimation of Microcrystalline Cellulose in Pasteurized Milk
Authors: Zhang Chi , Yang Jun , Qiao Ling
Published: February 2020

Microcrystalline cellulose (MCC) is suspected to be a new adulteration in pasteurized milk in China, yet an efficient method for MCC detection in dairy has not been established. This study presents a novel procedure to detect and estimate MCC in pasteurized milk using dialysis, cellulase hydrolysis, and a reducing sugar assay. The background value of reducing sugar was eliminated by dialysis, and cellulase activity toward MCC was stable in dialyzed milk. A criterion for MCC detection and an empirical formula for MCC estimation were summarized based on the reducing sugar variation after hydrolysis. The detection sensitivity was below 0.5 g/L. Reducing sugar distribution after cellulase-catalyzed hydrolysis was examined by HPLC, and revealed that most of the detected sugar was glucose. This paper describes a practical method for detection of MCC in pasteurized milk that might benefit dairy QC.
Rapid Determination of Fumagillin Residues in Honey by Liquid Chromatography–Tandem Mass Spectrometry Using the QuEChERS Method
Authors: Kanda Maki , Sasamoto Takeo , Takeba Kazue , Hayashi Hiroshi , Kusano Tomoko , Matsushima Yoko , Nakajima Takayuki , Kanai Setsuko , Takano Ichiro
Published: February 2020

A new, rapid, and efficient method for determining the fumagillin residues in honey was developed. The samples extracted were analyzed using LC/MS/MS. Chromatographic separation of fumagillin was performed in gradient mode on a C8 column (100 × 2.0 mm, 5 μm) at 40°C. The mobile phase consisted of a mixture of 2 mM ammonium formate–0.01% formic acid solution and methanol; the flow rate was set to 0.2 mL/min. Under these conditions, it was possible to measure fumagillin and its isomers as a single peak. The sample preparation procedure used is based on the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method, which is fast (approximately 30 min) and uses less organic solvent. The fumagillin was extracted with acetonitrile containing 0.1% formic acid, then purified using a solid-phase extraction method with an Oasis® mixed-mode weak anion-exchange cartridge. The overall recovery of fumagillin ranged from 88.1 to 99.4%; the intra- and interassay CVs were <4.5% and <4.9%, respectively. The LOQ was 0.1 μg/kg. LC/MS/MS coupled with the QuEChERS method showed strong potential as a method for determining fumagillin residues in honey.
Determination of Lipophilic Toxins by LC/MS/MS: Single-Laboratory Validation
Authors: Villar-González Adriano , Rodríguez-Velasco María Luisa , Gagoo-Martínez Ana
Published: February 2020

An LC/MS/MS method has been developed, assessed, and intralaboratory-validated for the analysis of the lipophilic toxins currently regulated by European Union legislation: okadaic acid (OA) and dinophysistoxins 1 and 2, including their ester forms; azaspiracids 1, 2, and 3; pectenotoxins 1 and 2; yessotoxin (YTX), and the analogs 45 OH-YTX, Homo YTX, and 45 OH-Homo YTX; as well as for the analysis of 13-desmetil-spirolide C. The method consists of duplicate sample extraction with methanol and direct analysis of the crude extract without further cleanup or concentration. Ester forms of OA and dinophysistoxins are detected as the parent ions after alkaline hydrolysis of the extract. The validation process of this method was performed using both fortified and naturally contaminated samples, and experiments were designed according to International Organization for Standardization, International Union of Pure and Applied Chemistry, and AOAC guidelines. With the exception of YTX in fortified samples, RSDr below 15% and RSDR were below 25%. Recovery values were between 77 and 95%, and LOQs were below 60 μg/kg. These data together with validation experiments for recovery, selectivity, robustness, traceability, and linearity, as well as uncertainty calculations, are presented in this paper.
Validation of a Digestion System Using a Digester Block/Cold Finger System for the Determination of Lead in Vegetable Foods by Electrothermal Atomic Absorption Spectrometry
Authors: De Jesus Robson M , Junior Mario M S , Matos Geraldo D , Santos Ana Dos M P , Ferreira Sérgio L C
Published: February 2020

This paper presents the validation of a system for sample digestion using a digester block/ cold finger to determine the lead content in vegetables by electrothermal atomic absorption spectrometry (ETAAS). After mineralization, lead contents were determined by ETAAS using a calibration curve based on aqueous standards prepared in 2.60 M nitric acid solutions containing 5 μg ammonium phosphate as chemical modifier. A pyrolysis temperature of 900°C and atomization temperature of 2000°C were used. This method allowed the determination of lead with a characteristic mass of 35 pg; LOD and LOQ of 0.6 and 2 ng/g, respectively, were found. The precision was investigated in terms of reproducibility and repeatability. Reproducibility was estimated by analysis of nine different portions of a certified reference material (CRM) of spinach leaves, and the repeatability was determined through the analysis of nine aliquots of the same solution. The reproducibility and repeatability were found to be 4.27 and 2.94% RSD, respectively. The accuracy was confirmed by analysis of whole meal flour, spinach leaves, and orchard leaves CRMs, all furnished by the National Institute of Standards and Technology. Lead contents were measured using the newly developed technique in 11 different potato samples. The lead contents ranged from 12.80 to 69.27 ng/g, with an average value of 28.59 ng/g. These values were in agreement with data reported in the literature.
Validation of a Method for Arsenic Speciation in Food by Ion Chromatography-Inductively Coupled Plasma/Mass Spectrometry After Ultrasonic-Assisted Enzymatic Extraction
Authors: Dufailly Vincent , Nicolas Marine , Janique-Payot Richoz , Poitevin Eric
Published: February 2020

A fully validated and rapid quantitative method is presented for determination of inorganic arsenic [arsenite, As(III) and arsenate, As(V)] and organic arsenic species (methylarsonic acid, dimethylarsinic acid, and arsenobetaine) by ion chromatography paired with inductively coupled plasma/MS after ultrasonic-assisted enzymatic extraction (UAEE) in rice- and seafood-based raw materials and finished products. This method gives toxicological meaning to arsenic analysis, since the sum of the toxic chemical forms As(III) and As(V) can be determined. In contrast to classical water–methanol extraction, UAEE enables drastic acceleration of sample extraction (5 min instead of several hours), while total arsenic extraction efficiency is improved without species conversion. Validation was performed to evaluate the method for selectivity, linearity, LOD/LOQ (0.007–0.020 mg/kg), trueness, precision (HorRat values, 0.2–0.6), recovery (93–122%), and uncertainty. The method was also satisfactorily tested using two proficiency tests. Performance characteristics are reported for four certified reference materials, standard reference material (SRM) 1568a (rice flour), Institute for Reference Materials and Measurements 804 (rice flour), SRM 2976 (mussel tissue), certified reference material-627 (tuna fish), and several commercial food samples populating five AOAC triangle food sectors. The results indicated that this speciation method is cost-efficient, time-saving, and accurate, as well as fit-for-purpose, according to International Organization for Standardization/International Electrotechnical Commission 17025:2005 standard, and could be used for routine analysis.
Determination of Some Heavy Metals by Flame Atomic Absorption Spectrometry Before Coprecipitation with Neodymium Hydroxide
Authors: Soylak Mustafa , Kizil Nebiye
Published: February 2020

A procedure is described for the determination of trace amounts of Cd(II), Ni(II), Cu(II), Pb(II), Fe(III), Co(II), and Mn(II) that combines flame atomic absorption spectrometry with neodymium hydroxide coprecipitation. The influences of analytical parameters (amount of neodymium, pH of the model solutions, etc.) that affect quantitative recoveries of the analyte ions were investigated. The effects of concomitant ions were also examined. The detection limits for analytes were found in the range of 0.2–3.3 μg/L. The validation of the presented procedure was controlled by analysis of certified reference materials (National Institute of Standards and Technology 1570a spinach leaves and TMDA 54.4 fortified lake water). The applications of the procedure were performed by the analysis of water, food, and herbal plants from Turkey.
Selective Determination of Arbutin in Cosmetic Products Through Online Derivatization Followed by Disposable Electrochemical Sensor
Authors: Zen Jyh-Myng , Yang Hsueh-Hui , Chiu Mei-Hsin , Yang Chao-Hsun , Shih Ying
Published: February 2020

An online derivatization followed by a disposable electrochemical sensor was used for the determination of arbutin (AR) in cosmetic products. The AR was chemically oxidized by MnO2 and subsequently reduced at inexpensive screen-printed carbon electrodes using a low detection potential which improved the selectivity of the method. The effects of various parameters, such as solution pH, detection potential, and flow rate of the mobile phase, were studied in detail. Under optimal conditions [pH 1.6 (0.1 M H3PO4), detection potential 0.0 V (versus Ag/AgCl), flow rate 0.6 mL/min], the linear range for AR was 0.1–1500 ppm (r2 = 0.999) with LOD of 30.06 ppb (S/N = 3). The practical application of the proposed method was demonstrated by the determination of arbutin concentration in commercial cosmetic products.
Reliable Detection of Milk Allergens in Food Using a High-Resolution, Stand-Alone Mass Spectrometer
Authors: Monaci Linda , Losito Ilario , Palmisano Francesco , Visconti Angelo
Published: February 2020

Reliable methods are needed for detection of allergenic milk proteins in complex food matrixes. The feasibility of an LC/high-resolution MS method for the analysis of milk proteins in a thermally processed model food (incurred cookies) and in white wine spiked, respectively, with milk powder and caseinate is described. Detection of milk proteins was based on the identification of unique peptides in the tryptic digests of cookie/wine extracts using an RP-HPLC separation coupled to an Exactive™ nonhybrid mass spectrometer using Orbitrap technology. The extremely high mass accuracy and resolution provided by the Orbitrap analyzer allowed a fast preliminary identification of four previously proposed peptide markers of caseins using only accurate values of the m/z of their ions. No interference was observed, despite the complexity of the analyzed matrixes. Moreover, the availability of a high- energy, collisionally activated dissociation cell integrated in the mass spectrometer enabled acquisition of peptide MS/MS-like spectra through post-source fragmentation. Confirmation of peptide marker identity could then be achieved by a comparison between experimental and predicted product ions. The described method shows the great potential of Orbitrap MS as a reliable technique in the field of protein allergen detection once the peptide markers are identified.
A Solid-Phase Microextraction GC/MS/MS Method for Rapid Quantitative Analysis of Food and Beverages for the Presence of Legally Restricted Biologically Active Flavorings
Authors: Bousova Katerina , Mittendorf Klaus , Senyuva Hamide
Published: February 2020

A method was developed using automated headspace solid-phase microextraction coupled with GC/MS/MS to simultaneously determine the presence of seven biologically active ﬂavoring substances whose levels of use in processed foods is controlled by statutory limits. The method can be applied to identify and quantify the presence of 1,2-benzopyrone (coumarin), β-asarone, 1-allyl-4-methoxybenzene (estragole), menthofuran, 4-allyl-1,2-dimethoxybenzene (methyl eugenol), pulegone, and thujone at levels ranging from 0.5 to 3000 mg/kg. The method has been optimized and validated for three different generic food types categorized on the basis of composition and anticipated use levels of ﬂavorings and food ingredients. The food categories are alcoholic and nonalcoholic beverages; semisolid processed foods (e.g., soups, sauces, confectionary, etc.); and solid foods (muesli, bakery products, etc.). The method is simple, inexpensive, and rapid, and eliminates the use of ﬂammable and toxic solvents. There is no sample preparation, and using MS/MS, unequivocal confrmation of identifcation is achieved even in highly complex matrixes containing many potential interfering volatiles. The method precision for spiked samples ranged from 2 to 21%, with the greatest variability associated with solid matrixes. The LOD and LOQ values were well below 0.1 and 0.5 mg/kg, respectively, in all cases for individual substances, fulflling requirements for enforcement purposes. The robustness of the method was demonstrated in a small survey of retail samples of four spirits, fve ﬂavored milks, three energy drinks, fve liqueurs, fve soups, 10 sauces, fve herbal teas, and three breakfast cereals.
Synthesis and Application of a New Thiazolylazo Reagent for Cloud Point Extraction and Determination of Cobalt in Pharmaceutical Preparations
Authors: Yamaki Regina Terumi , Nunes Luana Sena , De Oliveira Hygor Rodrigues , Araújo André S , Bezerra Marcos Almeida , Lemos Valfredo Azevedo
Published: February 2020

The synthesis and characterization of the reagent 2-(5-bromothiazolylazo)-4-chlorophenol and its application in the development of a preconcentration procedure for cobalt determination using ﬂame atomic absorption spectrometry after cloud point extraction is presented. This procedure is based on cobalt complexing and entrapment of the metal chelates into micelles of a surfactant-rich phase of Triton X-114. The preconcentration procedure was optimized by using a response surface methodology through the application of the Box-Behnken matrix. Under optimum conditions, the procedure determined the presence of cobalt with an LOD of 2.8 μg/L and LOQ of 9.3 μg/L. The enrichment factor obtained was 25. The precision was evaluated as the RSD, which was 5.5% for 10 μg/L cobalt and 6.9% for 30 μg/L. The accuracy of the procedure was assessed by comparing the results with those found using inductively coupled plasma-optical emission spectrometry. After validation, the procedure was applied to the determination of cobalt in pharmaceutical preparation samples containing cobalamin (vitamin B12).
Simultaneous Determination of Diloxanide Furoate and Metronidazole in Presence of Diloxanide Furoate Degradation Products
Authors: Abbas Samah S , Wagieh Nour E , Abdelkawy Mohamed , Abdelrahman Maha M
Published: February 2020

Three methods are presented for the simultaneous determination of diloxanide furoate (DLX) and metronidazole (MTR), used for their antiprotozoal and antiamoebic effect, in the presence of DLX alkaline degradates and in pharmaceutical formulations, without previous separation. The first method is chemometric-assisted spectrophotometry, in which principal component regression and partial least squares were applied. These two approaches were successfully applied to quantify each drug in the mixture using the information included in the absorption spectra in the range of 225–320 nm. The second method is TLC-densitometry, in which the binary mixture and degradates were separated on silica gel plates using a chloroform–acetone–glacial acetic acid (9.5 + 0.5 + 0.07, v/v/v) mobile phase and the bands were scanned at 254 nm. The last method is HPLC, in which DLX, MTR, and degradates were separated using the mobile phase acetonitrile–0.05 M dibasic potassium phosphate (25 + 75, v/v), adjusted to pH 4 with orthophosphoric acid, at a flow rate of 1 mL/min, on a C18 analytical column. Detection was at 254 nm. The proposed methods were successfully applied for the analysis of DLX and MTR in pharmaceutical formulations, and the results were statistically compared with a reported spectrophotometric method.
Corporate Liability for Toxic Torts Abroad: Vedanta v Lungowe in the Supreme Court
Authors: Bradshaw Carrie
Published: February 2020

Multinational corporate groups pose a challenge to traditional methods of legal control, particularly when corporations domiciled in wealthy western countries exploit, through foreign-domiciled subsidiaries, the resources and ‘weak governance’ of the developing world. In holding England as the proper place in which to bring a claim against both a UK-domiciled company and its Zambian subsidiary, for environmental damage abroad, the Supreme Court has allegedly ‘opened the door’ to similar future actions. However, in the absence of robust and mandatory due diligence requirements, parent companies may simply retreat from comprehensively reporting on group-wide systems of management and control. A desire to avoid future ‘voluntary assumptions of responsibility’ may be the undoing of post-Vedanta optimism.
Clinicopathological Features, Staging, and Current Approaches to Treatment in High-Risk Resectable Melanoma
Authors: Keung Emily Z , Gershenwald Jeffrey E
Published: February 2020

The incidence of melanoma in the United States has been increasing over the past several decades. Prognosis largely depends on disease stage, with 5-year melanoma-specific survival ranging from as high as 99% in patients with stage I disease to less than 10% for some patients with stage IV (distant metastatic) disease. Fortunately, in the last 5–10 years, there have been remarkable treatment advances for patients with high-risk resectable melanoma, including approval of targeted and immune checkpoint blockade therapies. In addition, results of recent clinical trials have confirmed the importance of sentinel lymph node biopsy and continue to refine the approach to regional lymph node basin management. Lastly, the melanoma staging system was revised in the eighth edition AJCC Cancer Staging Manual, which was implemented on January 1, 2018. Here we discuss these changes and the clinicopathological features that confer high risk for locoregional and distant disease relapse and poor survival. Implications regarding the management of melanoma in the metastatic and adjuvant settings are discussed, as are future directions for neoadjuvant therapies.
Primary mesenchymal chondrosarcoma of the orbit in a young female: imaging and histopathological features
Authors: D’Alì Lorenzo , Tulisso Angelica , Mariuzzi Laura
Published: February 2020

Mesenchymal chondrosarcoma (MCS) is a rare high-grade sarcoma of bone and soft tissue with highly aggressive behavior and a peak incidence in the second and third decades. We report a case of primary orbital MCS in a 30 year-old female, with radiological and clinicopathological features. Orbital MCS is an entity that should be considered in the differential diagnosis of calcified orbital lesions.