bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Microwave-Assisted Extraction for the Analysis of Polychlorinated Biphenyls and Organochlorine Pesticides in Fish
Authors: Otake Takamitsu , Aoyagi Yoshie , Numata Masahiko , Yarita Takashi 
Published: February 2020

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

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

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

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

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

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

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

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

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

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

Abstract
Qualitative microbiological measurement methods in which the measurement results are either 0 (microorganism not detected) or 1 (microorganism detected) are discussed. The performance of such a measurement method is described by its probability of detection as a function of the contamination (CFU/g or CFU/mL) of the test material, or by the LODp, i.e., the contamination that is detected (measurement result 1) with a specified probability p. A complementary loglog model was used to statistically estimate these performance characteristics. An intralaboratory experiment for the detection of Listeria monocytogenes in various food matrixes illustrates the method. The estimate of LOD50 is compared with the Spearman-Kaerber method.
Simultaneous Screening and Target Analytical Approach by Gas Chromatography-Quadrupole-Mass Spectrometry for Pesticide Residues in Fruits and Vegetables
Authors: Mezcua Milagros , Martínez-uroz Maria A , Wylie Philip L , fernández-alba Amadeo R 
Published: February 2020

Abstract
A full-scan GC/quadrupole/MS method has been developed to perform large-scale screenings of pesticides and simultaneous quantification of 95 target compounds in a single run of 21 min. The screening method was performed by using a deconvolution of the spectrum of the full-scan data files acquired under a retention time locked method. The identification performance of the screening method was evaluated in eight different food matrixes at three different concentrations. The system was equipped with a programmable temperature vaporizing inlet, allowing 10 L injections. The LOQ in the full-scan mode and linearity were studied for four different matrixes. Correlation coefficients &gt;0.99 were achieved in all cases, and the LOD was &lt;20 g/kg for 80 of the studied pesticides. Maintenance of the system was reduced by the use of a QuickSwap device that provided backflush capabilities by reversing column flow immediately after elution of the last compound of interest. The combined screening and target method was used in the analysis of more than 100 food samples, including a carrot sample from the European Proficiency Test FV 10, with good results.
Stability-Indicating RP-HPLC Method Development and Validation for Duloxetine Hydrochloride in Tablets
Authors: Patel Sejal K , Patel Natavarlal J , Prajapati Arun M , Patel Dipti B , Patel Satish A 
Published: February 2020

Abstract
This paper describes the development of a stability-indicating RP-HPLC method for duloxetine hydrochloride (DLX) in the presence of its degradation products generated from forced decomposition studies. The drug substance was found to be susceptible to stress conditions of acid, base, oxidation, wet heat, dry heat, and photodegradation. The drug was found to be stable to the dry heat condition attempted. Successful separation of the drug from the degradation products formed under stress conditions was achieved on a Phenomenex C18 column (250 4.6 mm id, 5 µm particle size) using acetonitrilemethanol0.032 M ammonium acetate buffer (55 + 05 + 40, v/v/v) as the mobile phase at a flow rate of 1.0 mL/min at 40°C temperature. Quantification was achieved with photodiode array detection at 290 nm over the concentration range 0.25 µg/mL with mean recovery of 101.048 ± 0.53 for DLX by the RP-HPLC method. Statistical analysis proved the method is repeatable, specific, and accurate for estimation of DLX. Because the method could effectively separate the drug from its degradation products, it can be used as a stability-indicating method.
Membrane Sensors for the Selective Determination of Donepezil Hydrochloride
Authors: Mostafa Gamal Abdel Hafiz , Hefnawy Mohamed , Al-Majed Abdulrahman 
Published: February 2020

Abstract
The construction and electrochemical response characteristics of polyvinylchloride (PVC) membrane sensors for donepezil HCl (DP) are described. The sensing membranes incorporated ion-association complexes of DP cation and sodium tetraphenyl borate (sensor 1), phosphomolybdic acid (sensor 2), or phosphotungstic acid (sensor 3) as electroactive materials. The sensors displayed a fast, stable, and near-Nernstian response over a relatively wide DP concentration range (1 102 to 1 106 M), with cationic slopes of 53.0, 54.0, and 51.0 mV/ concentration decade over a pH range of 4.0 to 8.0. The sensors showed good discrimination of DP from several inorganic and organic compounds. The direct determination of 2.54000.0 g/mL DP showed average recoveries of 99.0, 99.5, and 98.5, and mean RSDs of 1.6, 1.5, and 1.7 at 100.0 g/mL for sensors 1, 2, and 3, respectively. The proposed sensors have been applied for direct determination of DP in two pharmaceutical preparations. The results obtained for determination of DP in tablets using the proposed sensors compared favorably with those obtained using an HPLC method. The sensors have been used as indicator electrodes for potentiometric titration of DP.
Detection of Methamphetamine, Methylenedioxymethamphetamine, and 3,4-Methylenedioxy-N-ethylamphetamine in Spiked Plasma by HPLC and TLC
Authors: Öztunç Aysel , Önal Armağan , Toker Sidika Ertürk 
Published: February 2020

Abstract
HPLC and TLC methods were developed for separation and detection of some amphetamine analogs: methamphetamine (MA); 3,4-methylenedioxymethamphetamine (MDMA, ecstasy); and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) in spiked plasma samples. The methods are based on purple chromogens formed by displacement reaction of these secondary aliphatic amine-bearing drugs with 7,7,8,8-tetracyanoquinodimethane at 80C for 25 min. For HPLC, both normal phase (silica gel) and RP (C18) columns were used. With the former, good detection limits in plasma were obtained with a 6 min run: 70, 100, and 500 ng/mL for MDMA, MA, and MDEA, respectively. For TLC, hexanechloroform (1 + 9) and benzene-diethyl ether-petroleum ether (4060)acetonitrileethyl methyl ketone (2 + 3.5 + 3.5 + 0.5 + 0.5) were used as mobile phases for silica gel 60 TLC and cyano-bonded silica gel HPTLC plates, respectively. The former offered more sensitive results than the latter. Influence of evaporation steps on recovery and interferences for the HPLC and TLC methods were investigated. The developed methods are selective, simple, and easily applicable.
Validation Study of a Rapid ELISA for Detection of Aflatoxin in Corn
Authors: Lupo Anthony , Roebuck Chris , Dutcher Monica , Kennedy Justina , Abouzied Mohamed 
Published: February 2020

Abstract
Neogen Corp. developed the Veratox aflatoxin test kit for the detection of total aflatoxin. 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 total aflatoxin detection in corn (994.08, 990.33, 979.18, 993.17, 990.32, 993.16, 991.31, and 990.74), varying between rapid and analytical-based methods and one rapid method that has been performance tested by the AOAC Research Institute (PTM 030701). However, the widely used reference method is AOAC Official MethodSM994.08, which is an HPLC method and is referred to as the reference method in this paper. Although considered the reference method, the HPLC procedure is complicated and requires the investment of both expensive equipment and a highly skilled technician. A rapid (e.g., ELISA) test kit to be validated by the AOAC Research Institute is needed.