bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of trans Vitamin K1 in Infant and Medical Nutritional Products Using AOAC Method 999.15 with Modified Preparation and Extraction Procedures and C30 Bonded Phase Chromatography: Single-Laboratory Validation
Authors: Schimpf Karen J , Thompson Linda B , Schmitz Daniel J 
Published: February 2020

Abstract
Modifications were made to AOAC Official MethodSM 999.15 to extend its applicability to specialty infant formulas containing hydrolyzed proteins and free amino acids, and to medical and adult nutritional products. Minor changes to the sample preparation procedure and chromatographic separation improved vitamin K1 recoveries and reduced chromatographic interferences in these types of matrixes. Currently AOAC Method 999.15 is applicable only to the determination of total vitamin K1 (phylloquione) in infant formula and milk (fluid, ready-to-feed, and powdered) containing &gt;1 g vitamin K1/100 g solids. AOAC Method 999.15 recoveries of vitamin K1 were improved by altering sample sizes, extraction solvents and amounts, and the reagent addition order and amount of water or aqueous solutions added. The chromatographic separation of vitamin K1 in medical nutritional products containing canola and marine oils was improved, and trans vitamin K1 was separated from the biologically inactive cis isomer in all products with a C30 3 m column and a 100 methanol mobile phase. With these modifications to the extraction procedure and chromatographic separation, AOAC Method 999.15 demonstrated acceptable precision and accuracy for the quantitation of trans vitamin K1 in specialty infant formulas containing hydrolyzed proteins and free amino acids, and medical and adult nutritional products. A single-laboratory validation of these minor modifications was completed. Fourteen different product matrixes were analyzed during validation. The intermediate precision averaged 4.15 RSD (range 2.525.81 RSD), and recovery data averaged 100.1 (range 92.2109).
Investigation of Matrix Effects for Some Pesticides in Waters by On-line Solid-Phase Extraction-Liquid Chromatography Coupled with Triple Quadrupole Linear Ion-Trap Mass Spectrometry and the Use of Postcolumn Introduction
Authors: Gru Yvan , Colin Ronan , Le Cloirec Pierre 
Published: February 2020

Abstract
The effect of analytical conditions on on-line SPE-LC/MS/MS was investigated. Real matrix-induced signal suppression or enhancement due to the ionization process was simulated by using postcolumn introduction experiments. Results were compared with global matrix effects that occur during a routine analysis. Four pesticides were studied: carbendazim, fenuron, thiabendazole, and vamidothion. These compounds have different behaviors in terms of matrix effects. Good correlations were shown, demonstrating that the main matrix effect is due to the ionization step. Good results were also obtained for the RSD values (&lt;5 for routine analysis and &lt;35 for postcolumn introduction).
Determination of Bioactive Compounds in Cortex Phellodendri by High-Performance Liquid Chromatography
Authors: Yang Qi , Zhang Feng , Gao Shou-Hong , Sun Lian-Na , Chen Wan-Sheng 
Published: February 2020

Abstract
An HPLC method combined with a photodiode array detector was developed for quantitative determination of five bioactive compounds that belong to two subclasses, including limonin, phellodendrine, jatrorrhizine, palmatine, and berberine in Cortex Phellodendri. The analysis was performed on an Agilent Diamonsil C18 column (4.6 250 mm, 5 m) using a gradient of acetonitrile and 0.3 aqueous diethylamine phosphate (v/v), a flow rate of 0.8 mL/min, and a detection wavelength of 220 nm. The calibration curve was linear over the range of 2.5100.0 g/mL for both phellodendrine and jatrorrhizine, 5.0200.0 g/mL for palmatine, and 7.5300.0 g/mL for both berberine and limonin. The average recoveries ranged from 97.56 to 102.53 with RSD 1.00. Samples from different geographical locations were analyzed to evaluate the applicability of the established method, and the results indicated that the method was efficient, sensitive, and reliable for determining limonin and four alkaloids in Cortex Phellodendri.
Development and Validation of an HPLC-DAD Analytical Procedure for Quality Control of Damiana (Turnera diffusa), Using an Antioxidant Marker Isolated from the Plant
Authors: PéRez-Meseguer Jonathan , Garza-JuáRez Aurora , Salazar-Aranda Ricardo , Salazar-Cavazos Ma Luz , dela Torre RodríGuez Yael C , Rivas-Galindo VeróNica , De Torres Noemí Waksman 
Published: February 2020

Abstract
Damiana is a shrub used as a dietary supplement and as an additive in several foods. This report presents the first validated analytical method for QC of products made from damiana. Through bioassay-guided fractionation, the compound showing the best antioxidant activity, determined using 2,2-diphenyl-1-picryl-hydrazyl assay in TLC, was purified and identified as 8-C--[6-deoxy-2-O-(-1-rhamnopyranosyl)-xylo- hexopyranos-3-uloside] (CI50 5.56 g/mL). This is the only natural source from which this compound has been reported, and has been found in all native damiana samples analyzed. Therefore, it was used as a biomarker to develop an HPLC-diode-array detection analytical procedure using the first-order derivative of the chromatograms. Separation was achieved using an AccQ Tag C18 150 3.9 mm (4 m) column, with a gradient of methanol and 0.1 trifluoroacetic acid in water. The method was shown to be accurate, sensitive, and reproducible, providing a useful quantitative means to apply QC to damiana products.
Validated HPLC Determination of the Two Fixed Dose Combinations (Chlordiazepoxide Hydrochloride and Mebeverine Hydrochloride; Carvedilol and Hydrochlorothiazide) in Their Tablets
Authors: Haggag Rim S , Shaalan Rasha A , Belal Tarek S 
Published: February 2020

Abstract
Simple, rapid, and selective RP-HPLC methods with UV detection were developed for simultaneous determination of chlordiazepoxide hydrochloride and mebeverine hydrochloride (Mixture I) and carvedilol and hydrochlorothiazide (Mixture II). The chromatographic separation in both mixtures was achieved by using an RP-C8 (octylsilyl) analytical column. For Mixture I, a mobile phase composed of acetonitrile0.05 M disodium hydrogen phosphatetriethylamine (50 + 50 + 0.2, v/v/v), pH 2.5, was used; the detector wavelength was 247 nm. For Mixture II, the mobile phase consisted of acetonitrile0.05 M disodium hydrogen phosphate (50 + 50, v/v), pH 4.0, and the detector was set at 220 nm. Quantification of the analytes was based on measuring their peak areas. Both mixtures were resolved in less than 6 min. The reliability and analytical performance of the proposed HPLC procedures were statistically validated with respect to linearity, range, precision, accuracy, selectivity, robustness, LOD, and LOQ. The linear dynamic ranges were 2.5150 and 2.5500 g/mL for chlordiazepoxide HCl and mebeverine HCl, respectively, and 0.25200 and 0.25150 g/mL for carvedilol and hydrochlorothiazide, respectively. The validated HPLC methods were successfully applied to the analysis of their commercial tablet dosage forms, for which no interfering peaks were encountered from common pharmaceutical adjuvants.
Preparation and Characterization of Standard Reference Material 1849 Infant/Adult Nutritional Formula
Authors: Sharpless Katherine E , Lindstrom Richard M , Nelson Bryant C , Phinney Karen W , Rimmer Catherine A , Sander Lane C , Schantz Michele M , Spatz Rabia O , Thomas Jeanice Brown , Turk Gregory C , Wise Stephen A , Wood Laura J , Yen James H 
Published: February 2020

Abstract
Standard Reference Material (SRM) 1849 Infant/Adult Nutritional Formula has been issued by the National Institute of Standards and Technology (NIST) as a replacement for SRM 1846 Infant Formula, issued in 1996. Extraction characteristics of SRM 1846 have changed over time, as have NIST's analytical capabilities. While certified mass fraction values were provided for five constituents in SRM 1846 (four vitamins plus iodine), certified mass fraction values for 43 constituents are provided in SRM 1849 (fatty acids, elements, and vitamins) and reference mass fraction values are provided for an additional 43 constituents including amino acids and nucleotides, making it the most extensively characterized food-matrix SRM available from NIST.
Quantitative Evaluation of Benzene, Toluene, and Xylene in the Larvae of Drosophila melanogaster by Solid-Phase Microextraction/Gas Chromatography/Mass Spectrometry for Potential Use in Toxicological Studies
Authors: Mudiam Mohana Krishna Reddy , Singh Mahendra Pratap , Chowdhuri Debapratim Kar , Murthy Ramesh Chandra 
Published: February 2020

Abstract
A simple, rapid, and solvent-free method for quantitative determination of benzene, toluene, and Xylene in exposed Drosophila larvae was developed using headspace solid-phase microextraction (HS-SPME) coupled to GC/MS. Larvae fed on standard Drosophila food mixed with benzene, toluene, and Xylene for 48 h were homogenized in Milli-Q water. Extraction of benzene, toluene, and Xylene was performed at 65C for 30 min on the SPME fiber (silica-fused). Subsequently, the fiber was desorbed in the GC injection port, followed by GC/MS analysis in the selected-ion monitoring mode. An external calibration curve was used for the quantification of benzene, toluene, and Xylene in the exposed organism. Recoveries were in the range of 78-82% (intraday) and 76-81% (interday) in larvae, and 9196 (intraday) and 87-92% (interday) in the diet. LOD with an S/N of 3:1 and LOQ with an S/N of 10:1 were in the range of 0.010.023 and 0.0340.077 µg/L, respectively. Percent RSD values for benzene, toluene, and Xylene were in the range of 0.500.81 (intraday) and 0.891.23 (interday) for retention time, and 2.163.85 (intraday) and 2.994.95 (interday) for peak concentration, showing good repeatability. This method was sensitive enough to quantitate benzene, toluene, and Xylene in small exposed organisms like Drosophila larvae. The SPME/GC/MS method developed may have wider applications in various in vivo toxicological studies.
Screening and Quantitative Confirmatory Method for the Analysis of Glucocorticoids in Bovine Milk Using Liquid Chromatography-Tandem Mass Spectrometry
Authors: Malone Edward M , Elliott Chris T , Kennedy David G , Regan Liam 
Published: February 2020

Abstract
An LC/MS/MS method was developed and validated for the simultaneous identification, confirmation, and quantification of 12 glucocorticoids in bovine milk. The method was validated in accordance with the criteria defined in Commission Decision 2002/657/EC. The developed method can detect and confirm the presence of dexamethasone, betamethasone, prednisolone, flumethasone, 6α-methylprednisolone, fluorometholone, triamcinolone acetonide, prednisone, cortisone, hydrocortisone, clobetasol propionate, and clobetasol butyrate in bovine milk. Milk samples are extracted with acetonitrile; sodium chloride is subsequently added to aid partition of the milk and acetonitrile mixture. The acetonitrile extract is then subjected to liquidliquid purification by the addition of hexane. The purified extract is evaporated to dryness and reconstituted in a wateracetonitrile mixture, and determination is carried out by LC/MS/MS. The method permits analysis of up to 30 samples in 1 day.
Determination of Pesticide Residues in Sewage Sludge: A Review
Authors: Tadeo José L , Sánchez-Brunete Consuelo , Albero Beatriz , Garcí-Valcárcel Ana I 
Published: February 2020

Abstract
Pesticides are widely applied to protect plants from diseases, weeds, and insect damage, and they usually come into contact with soil where they may undergo a variety of transformations and provide a complex pattern of metabolites. Spreading sewage sludge on agricultural lands has been actively promoted by national authorities as an economic way of recycling. However, as a byproduct of wastewater treatment, sewage sludge may contain pesticides and other toxic substances that could be incorporated into agricultural products or be distributed in the environment. This article reviews the determination of pesticides in sewage sludge samples. Sample preparation including pretreatment, extraction, and cleanup, as well as the subsequent instrumental determination of pesticide residues, are discussed. Extraction techniques such as Soxhlet extraction, ultrasound-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, and matrix solid-phase dispersion and their most recent applications to the determination of pesticides in sewage sludge samples are reviewed. Determination of pesticides, generally carried out by GC and HPLC coupled with different detectors, especially MS for the identification and quantification of residues, is summarized and discussed.
Use of Pressurized Liquid Extraction for the Simultaneous Analysis of 28 Polar and 94 Non-polar Pesticides in Agricultural Soils by GC/QqQ-MS/MS and UPLC/QqQ-MS/MS
Authors: Vidal José luis martínez , Sánchez Juan Antonio Padilla , Plaza-bolaños Patricia , Frenich Antonia Garrido , Romero-González Roberto 
Published: February 2020

Abstract
Due to the wide range of pesticides that can be used in agriculture, the development of fast multiresidue methods that simultaneously determine polar and non-polar pesticides is greatly demanded. This study shows the development and validation of a multiresidue method for the analysis of 98 non-polar pesticides and 28 polar pesticides in soil. A simultaneous extraction step by pressurized liquid extraction was utilized. The optimum results were obtained using ethyl acetatemethanol (3:1, v/v) with 2 min of preheat time and 85C as the extraction temperature. The final determination of non-polar pesticides was performed by GC, whereas polar pesticides were determined by ultra-performance liquid chromatography (UPLC). Both GC and UPLC were coupled to triple-quadrupole analyzers operating in tandem MS. The optimized extraction procedure was validated. The average extraction recoveries were in the range 72108 (10 g/kg) and 71106 (50 g/kg), with RSD values 26. The matrix effect was also evaluated, and matrix-matched standard calibration was finally applied for quantification. The suitability of the method was also checked by the analysis of a certified reference material. Furthermore, 26 real soil samples were analyzed by the proposed methods in order to assess their applicability. Several pesticides (e.g., bifenthrin, triadimefon, or endosulfan) were found in the samples.
Quantitative Analysis of Eugenol in Clove Extract by a Validated HPLC Method
Authors: Yun So-Mi , Lee Myoung-Heon , Lee Kwang-Jick , Ku Hyun-Ok , Son Seong-Wan , Joo Yi-Seok 
Published: February 2020

Abstract
Clove (Eugenia caryophyllata) is a well-known medicinal plant used for diarrhea, digestive disorders, or in antiseptics in Korea. Eugenol is the main active ingredient of clove and has been chosen as a marker compound for the chemical evaluation or QC of clove. This paper reports the development and validation of an HPLC-diode array detection (DAD) method for the determination of eugenol in clove. HPLC separation was accomplished on an XTerra RP18 column (250 4.6 mm id, 5m) with an isocratic mobile phase of 60 methanol and DAD at 280 nm. Calibration graphs were linear with very good correlation coefficients (r2 &gt; 0.9999) from 12.5 to 1000 ng/mL. The LOD was 0.81 and the LOQ was 2.47 ng/mL. The method showed good intraday precision (RSD 0.080.27) and interday precision (RSD 0.321.19). The method was applied to the analysis of eugenol from clove cultivated in various countries (Indonesia, Singapore, and China). Quantitative analysis of the 15 clove samples showed that the content of eugenol varied significantly, ranging from 163 to 1049 ppb. The method of determination of eugenol by HPLC is accurate to evaluate the quality and safety assurance of clove, based on the results of this study.
Development and Validation of a New HPLC-UV Method for the Simultaneous Determination of Triclabendazole and Ivermectin B1a in a Pharmaceutical Formulation
Authors: Shurbaji Maher , Al Rub Mohamad H Abu , Saket Munib M , Qaisi Ali M , Salim Maher L , Abu-Nameh Eyad S M 
Published: February 2020

Abstract
A rapid, simple, and sensitive RP-HPLC analytical method was developed for the simultaneous determination of triclabendazole and ivermectin in combination using a C18 RP column. The mobile phase was acetonitrilemethanolwateracetic acid (56 36 7.5 0.5, v/v/v/v) at a pH of 4.35 and flow rate of 1.0 mL/min. A 245 nm UV detection wavelength was used. Complete validation, including linearity, accuracy, recovery, LOD, LOQ, precision, robustness, stability, and peak purity, was performed. The calibration curve was linear over the range 50.09150.26 g/mL for triclabendazole with r = 0.9999 and 27.0181.02 g/mL for ivermectin with r = 0.9999. Calculated LOD and LOQ for triclabendazole were 0.03 and 0.08 g/mL, respectively, and for ivermectin 0.07 and 0.20 g/mL, respectively. The intraday precision obtained was 98.71 with RSD of 0.87 for triclabendazole and 100.79 with RSD 0.73 for ivermectin. The interday precision obtained was 99.51 with RSD of 0.35 for triclabendazole and 100.55 with RSD of 0.59 for ivermectin. Robustness was also studied, and there was no significant variation of the system suitability of the analytical method with small changes in experimental parameters.
Simultaneous Analysis of 70 Pesticides Using HPLC/MS/MS: A Comparison of the Multiresidue Method of Klein and Alder and the QuEChERS Method
Authors: Riedel Melanie , Speer Karl , Stuke Sven , Schmeer Karl 
Published: February 2020

Abstract
Since 2003, two new multipesticide residue methods for screening crops for a large number of pesticides, developed by Klein and Alder and Anastassiades et al. (Quick, Easy, Cheap, Effective, Rugged, and Safe; QuEChERS), have been published. Our intention was to compare these two important methods on the basis of their extraction efficiency, reproducibility, ruggedness, ease of use, and speed. In total, 70 pesticides belonging to numerous different substance classes were analyzed at two concentration levels by applying both methods, using five different representative matrixes. In the case of the QuEChERS method, the results of the three sample preparation steps (crude extract, extract after SPE, and extract after SPE and acidification) were compared with each other and with the results obtained with the Klein and Alder method. The extraction efficiencies of the QuEChERS method were far higher, and the sample preparation was much quicker when the last two steps were omitted. In most cases, the extraction efficiencies after the first step were approximately 100. With extraction efficiencies of mostly less than 70, the Klein and Alder method did not compare favorably. Some analytes caused problems during evaluation, mostly due to matrix influences.
Development and Validation of Stability-Indicating HPLC Method for the Simultaneous Determination of Paracetamol, Tizanidine, and Diclofenac in Pharmaceuticals and Human Serum
Authors: Siddiqui Farhan Ahmed , Arayne M Saeed , Sultana Najma , Qureshi Faiza 
Published: February 2020

Abstract
A method is described for the simultaneous determination of paracetamol, tizanidine, and diclofenac in mixtures. The method was based on HPLC separation of the three drugs followed by UV detection at 254 nm. The separation was carried out on a Hypersil ODS, C18 (250 × 4.6 mm id, 10 μm particle size) column using the mobile phase aqueous 0.2% ammonium carbonate–methanol (60 + 40, v/v) at a flow rate of 1 mL/min. The linear regression analysis data were used for the regression curve in the range of 170–10,000 ng/mL for paracetamol, 120–10,000 ng/mL for tizanidine, and 20–10,000 ng/mL for diclofenac. No chromatographic interference from tablet excipients was found. In order to check the selectivity of the proposed method, degradation studies were carried out using hydrolysis (acid, basic, and neutral), thermolysis, and oxidation. The developed method, after being validated in terms of precision, robustness, recovery, LOD, and LOQ, was successively applied to the analysis of pharmaceutical formulations and human serum.
Determination of Dodine in Fruit Samples by Liquid Chromatography Electrospray Ionization-Tandem Mass Spectrometry
Authors: Le Grand Rozenn , Saint-Marcoux Franck , Dulaurent Sylvain , Sauvage François-Ludovic , Moesch Christian , Lachâtre Gérard 
Published: February 2020

Abstract
A rapid and sensitive LC/electrospray ionization-MS/MS method has been developed for the determination of dodine in fruit samples. Based on a liquid–liquid extraction of 10 g solid fruit homogenate using an acetone–dichloromethane– hexane mixture and acetate ammonium buffer (pH 4.5), this LC/MS/MS procedure was characterized by recoveries above 50%, with good intra-assay precision (RSD &lt;13%) and interassay precision (RSD &lt;18%) for seven different matrixes (apple, apricot, cherry, peach, pear, plum, and quince). This method was validated from 5 to 500 μg/kg according to standard guidelines. Its LOD (1 μg/kg) and LOQ (5 μg/kg) were in accordance with recommendations of the European legislation defined for infant food [maximum residue level (MRL) = 10 μg/kg]. The whole procedure was finally tested on 1022 fruit samples intended for commercialization, both infant food samples and samples not intended in particular for babies. In this study, dodine was detected in 27 samples; none exhibited a concentration higher than the MRL.
Surface Plasmon Resonance Biosensor for Determination of Tetrodotoxin: Prevalidation Study
Authors: Vaisocherová Hana , Taylor Allen D , Jiang Shaoyi , Hegnerová Kateřina , Vala Milan , Homola Jiří , Yakes Betsy Jean , Deeds Jonathan , DeGrasse Stacey 
Published: February 2020

Abstract
A label-free surface plasmon resonance biosensor method was applied to determine tetrodotoxin (TTX) in pufferfish matrixes using an antibody inhibition assay format. A prevalidation study was conducted to demonstrate the assay performance characteristics, such as selectivity, LOD, LOQ, repeatability, reproducibility, and accuracy. Three participating laboratories reported standard curves in buffer and pufferfish matrix. A set of blind samples with TTX spiked into buffer as well as in 10 pufferfish extract were analyzed. Additionally, three blind naturally contaminated samples were analyzed, and the results were compared to those obtained using a reference method (HPLC/electrospray ionization-selected reaction monitoring-MS). The developed method was demonstrated to be capable of detecting TTX in pufferfish matrix standard samples in a broad concentration range (29000 ng/mL) with an LOD of 1.5 ng/mL. Between-laboratory recovery values were in the range of 51190 with a mean of 107, and 64180 with a mean of 103 for TTX-spiked samples in buffer and pufferfish matrix, respectively. Between-laboratory recoveries were in the satisfactory range of 101119 for naturally contaminated samples. This robust, rapid, and noninvasive method may serve as an attractive alternative to established methods for detection of TTX in pufferfish extracts.