EarlyView Articles

Development and validation of a sensitive method for simultaneous determination of rosuvastatin and N ‐desmethyl rosuvastatin in human plasma using liquid chromatography/negative electrospray ionization/tandem mass spectrometry

Published: May 30, 2013

Author(s): H. K. Lee, C. S. Ho, M. Hu, B. Tomlinson, C. K. Wong

Journal: Biomedical Chromatography

ABSTRACT A sensitive and specific liquid chromatography tandem mass spectrometric method was developed and validated for the simultaneous determination of rosuvastatin (ROS) and N‐desmethyl rosuvastatin (NOR‐ROS) in human plasma using deuterium‐labeled internal standards. The plasma samples were prepared using liquid–liquid extraction with diethyl ether. Chromatographic separation was accomplished on an Xterra MS C18 column. The mobile phase...

Forensic analysis of arsenic poisoning in Japan by synchrotron radiation X‐ray fluorescence

Published: May 30, 2013

Author(s): Jun Kawai

Journal: X-Ray Spectrometry

Synchrotron radiation X‐ray fluorescence (SR‐XRF) analysis reports of a poisoning case by arsenic, 25 July 1998, Japan, for forensic investigation purposes are reviewed. In these forensic analyses, SPring‐8 and KEK‐PF beamlines were used for minor element (Sn, Sb, Mo, Bi, Ba) analysis in the arsenic pesticide specimens, sampled at the crime scene as well as the neighborhood of the suspect. For this case, two kinds of documents were...

Direct and efficient liquid chromatographic‐tandem mass spectrometric method for opiates in urine drug testing – importance of 6‐acetylmorphine and reduction of analytes

Published: May 29, 2013

Author(s): Maria Andersson, Nikolai Stephanson, Inger Öhman, Tommy Terzuoli, Jonatan D Lindh, Olof Beck

Journal: Drug Testing and Analysis

Opiates comprise a class of abused drugs that is of primary interest in clinical and forensic urine drug testing. Determination of heroin, codeine, or a multi‐drug ingestion is complicated since both heroin and codeine can lead to urinary excretion of free and conjugated morphine. Liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) offers advantage over gas chromatography‐mass spectrometry by simplifying sample preparation but...

Desialylation improves the detection of recombinant erythropoietins in urine samples analyzed by SDS‐PAGE

Published: May 29, 2013

Author(s): Philippe Desharnais, Jean‐François Naud, Christiane Ayotte

Journal: Drug Testing and Analysis

Recombinant erythropoietin (rhEPO) has been misused for over two decades by athletes, mainly but not only in endurance sports. A direct rhEPO detection method in urine by isoelectric focusing (IEF) was introduced in 2000, but the emergence of third‐generation erythropoiesis‐stimulating agents and so‐called biosimilar rhEPOs, together with the sensitivity of human endogenous EPO (huEPO) pattern to enzymatic activities and its modification...

Fast and sensitive analysis of dermorphin and HYP ⁶ ‐dermorphin in equine plasma using liquid chromatography tandem mass spectrometry

Published: May 29, 2013

Author(s): Caroline C. Wang, Petra Hartmann‐Fischbach, Tim R. Krueger, Terry L. Wells, Amy R. Feineman, Joanne C. Compton

Journal: Drug Testing and Analysis

Dermorphin and HYP6‐dermorphin are hepta‐ peptides and natural opioids originally isolated from the skin of South American frogs. They are more potent than morphine but less likely to produce drug tolerance and addiction. These properties make them ideal candidates for the doping of racehorses to enhance performance during competition. Dermorphin was recently classified as a Class I...

Rapid acquisition of multifrequency, multislice and multidirectional MR elastography data with a fractionally encoded gradient echo sequence

Published: May 28, 2013

Author(s): Philippe Garteiser, Ramin S. Sahebjavaher, Leon C. Ter Beek, Septimiu Salcudean, Valérie Vilgrain, Bernard E. Van Beers, Ralph Sinkus

Journal: NMR in Biomedicine

In MR elastography (MRE), periodic tissue motion is phase encoded using motion‐encoding gradients synchronized to an externally applied periodic mechanical excitation. Conventional methods result in extended scan time for quality phase images, thus limiting the broad application of MRE in the clinic. For practical scan times, researchers have been relying on one‐dimensional or two‐dimensional motion‐encoding, low‐phase sampling and a...

Diffusion‐weighted MRI and its role in prostate cancer

Published: May 27, 2013

Author(s): Tsutomu Tamada, Teruki Sone, Yoshimasa Jo, Akira Yamamoto, Katsuyoshi Ito

Journal: NMR in Biomedicine

In the last 5 years, the multiparametric approach has been investigated as the method for the MRI of prostate cancer. In multiparametric MRI of the prostate, at least two functional MRI techniques, such as diffusion‐weighted MRI (DW‐MRI) and dynamic contrast‐enhanced MRI, are combined with conventional MRI, such as T2‐weighted imaging. DW‐MRI has the ability to qualitatively and quantitatively represent the diffusion of water molecules by ...

¹ H NMR and hyperpolarized ¹³ C NMR assays of pyruvate–lactate exhange: a comparative study

Published: May 27, 2013

Author(s): Deborah K. Hill, Yann Jamin, Matthew R. Orton, Nicolas Tardif, Harold G. Parkes, Simon P. Robinson, Martin O. Leach, Yuen‐Li Chung, Thomas R. Eykyn

Journal: NMR in Biomedicine

Pyruvate–lactate exchange is mediated by the enzyme lactate dehydrogenase (LDH) and is central to the altered energy metabolism in cancer cells. The measurement of exchange kinetics using hyperpolarized 13C NMR has provided a biomarker of response to novel therapeutics. However, the observable signal is restricted to the exchanging hyperpolarized 13C pools and the endogenous pools of 12C‐labelled metabolites are invisible in these measurements. In...

Structure and chain polarization of long polyynes investigated with infrared and Raman spectroscopy

Published: May 27, 2013

Author(s): N. R. Agarwal, A. Lucotti, D. Fazzi, M. Tommasini, C. Castiglioni, W.A. Chalifoux, R. R. Tykwinski

Journal: Journal of Raman Spectroscopy

Symmetrically and unsymmetrically endcapped polyynes (triisopropylsilyl – TIPS – and super trityl endcapping groups) have been studied with density functional theory calculations and Raman and infrared spectroscopy. This spectroscopic investigation provides general guidelines for studying the vibrational and structural features of sp‐carbon‐based materials, which nowadays are at the center of growing interest for the potential...

Determination of cefdinir levels in rat plasma and urine by high‐performance liquid chromatography–tandem mass spectrometry: application to pharmacokinetics after oral and intravenous administration of cefdinir

Published: May 27, 2013

Author(s): Hyo‐Eon Jin, In‐Bong Kim, Chong‐Kook Kim, Han‐Joo Maeng

Journal: Biomedical Chromatography

ABSTRACT A selective and sensitive liquid chromatography tandem mass spectrometry method (LC‐MS/MS) was developed and validated for the determination of cefdinir in rat plasma and urine. Following a simple protein precipitation using methanol, chromatographic separation was achieved with a run time of 10 min using a Synergi 4 µ polar‐RP 80A column (150 × 2.0 mm, 4 µm) with a mobile phase consisting of 0.1% formic acid in water and...

Role of high‐field MR in studies of localized prostate cancer

Published: May 24, 2013

Author(s): Miriam W. Lagemaat, Tom W. J. Scheenen

Journal: NMR in Biomedicine

Magnetic resonance imaging is attracting increasing attention from the uroradiological community as a modality to guide the management of prostate cancer. With the high incidence of prostate cancer it might come as a surprise that for a very long time (and in many places even at present) treatment decisions were being made without the use of detailed anatomical and functional imaging of the prostate gland at hand. Although T2‐weighted MRI...

Determination of salbutamol by direct chiral reversed‐phase HPLC using teicoplanin as stationary phase and its application to natural water analysis

Published: May 24, 2013

Author(s): Noelia Rosales‐Conrado, Margherita Dell'Aica, María Eugenia León‐González, Luis Vicente Pérez‐Arribas, Luis María Polo‐Díez

Journal: Biomedical Chromatography

ABSTRACT A direct chiral LC‐UV method was optimized for the determination of salbutamol (SAL) β2‐agonist in environmental water. Two commercially available columns were evaluated: teicoplanin Chirobiotic‐T™ (150 × 2.1 mm i.d., 5 µm) and vancomycin Chirobiotic‐V™ (150 × 2.1 mm i.d., 5 µm). Finally, teicoplanin chiral stationary phase was selected for SAL enantiomer resolution. In order to preserve its integrity and maintain the column...

Desalkylflurazepam found in patients’ samples after high‐dose midazolam treatment

Published: May 24, 2013

Author(s): Susanne Vogt, Jürgen Kempf, Jürgen Buttler, Volker Auwärter, Wolfgang Weinmann

Journal: Drug Testing and Analysis

Effects of exercise‐induced intracellular acidosis on the phosphocreatine recovery kinetics: a ³¹ P MRS study in three muscle groups in humans

Published: May 23, 2013

Author(s): Gwenael Layec, Emil Malucelli, Y. Le Fur, David Manners, Kazuya Yashiro, Claudia Testa, Patrick J. Cozzone, Stefano Iotti, David Bendahan

Journal: NMR in Biomedicine

Little is known about the metabolic differences that exist among different muscle groups within the same subjects. Therefore, we used 31P‐magnetic resonance spectroscopy (31P‐MRS) to investigate muscle oxidative capacity and the potential effects of pH on PCr recovery kinetics between muscles of different phenotypes (quadriceps (Q), finger (FF) and plantar flexors (PF)) in the same cohort of 16 untrained adults. The estimated muscle...

Texture‐based and diffusion‐weighted discrimination of parotid gland lesions on MR images at 3.0 Tesla

Published: May 23, 2013

Author(s): Julia Fruehwald‐Pallamar, Christian Czerny, Laura Holzer‐Fruehwald, Stefan F. Nemec, Christina Mueller‐Mang, Michael Weber, Marius E. Mayerhoefer

Journal: NMR in Biomedicine

The purpose of this study was to evaluate whether texture‐based analysis of standard MRI sequences and diffusion‐weighted imaging can help in the discrimination of parotid gland masses. The MR images of 38 patients with a biopsy‐ or surgery‐proven parotid gland mass were retrospectively analyzed. All patients were examined on the same 3.0 Tesla MR unit, with one standard protocol. The ADC (apparent diffusion...

Concept and role off extreme objects in PCA/SIMCA

Published: May 23, 2013

Author(s): Alexey L. Pomerantsev, Oxana Ye Rodionova

Journal: Journal of Chemometrics

For the construction of a reliable decision area in the soft independent modeling by class analogy (SIMCA) method, it is necessary to analyze calibration data revealing the objects of special types such as extremes and outliers. For this purpose, a thorough statistical analysis of the scores and orthogonal distances is necessary. The distance values should be considered as any data acquired in the experiment, and their distributions are...

A 22‐channel receive array with Helmholtz transmit coil for anesthetized macaque MRI at 3 T

Published: May 23, 2013

Author(s): Thomas Janssens, Boris Keil, Peter Serano, Azma Mareyam, Jennifer A. McNab, Lawrence L. Wald, Wim Vanduffel

Journal: NMR in Biomedicine

The macaque monkey is an important model for cognitive and sensory neuroscience that has been used extensively in behavioral, electrophysiological, molecular and, more recently, neuroimaging studies. However, macaque MRI has unique technical differences relative to human MRI, such as the geometry of highly parallel receive arrays, which must be addressed to optimize imaging performance. A 22‐channel receive coil array was constructed...

Effect of mineralogical and microstructural properties on surface roughness and gloss of some ornamental marbles subjected to polishing process

Published: May 23, 2013

Author(s): S. Gürcan, R. M. Goktan, A. Yıldız

Journal: X-Ray Spectrometry

High surface finish quality of the produced slabs is generally desirable in the stone processing industry. This paper presents the results of an experimental investigation into the effects of mineralogical‐petrographical and chemical variables on the surface roughness and glossiness of some selected ornamental marbles subjected to grinding–polishing processes. For this purpose, a series of grinding–polishing procedures were performed on...

Theoretical and experimental study on the angular dependence of scattering processes in X‐ray fluorescence systems

Published: May 23, 2013

Author(s): M. Guerra, M. Manso, S. Pessanha, S. Longelin, M. L. Carvalho

Journal: X-Ray Spectrometry

The role of X‐ray reflectivity, coherent, and incoherent scattering has been studied in light samples. The angular dependence of these processes was evaluated, and the best geometrical settings for X‐ray fluorescence spectrometers was studied both for symmetrical and asymmetrical setups. Emphasis is given to biaxial planar geometry rather than triaxial orthogonal geometry, due to the use of low power X‐ray tubes and non‐cryogenic...

Nitrogen determination by SEM‐EDS and elemental analysis

Published: May 23, 2013

Author(s): M.F. Gazulla, M. Rodrigo, E. Blasco, M. Orduña

Journal: X-Ray Spectrometry

This paper describes a methodology for the analysis of nitrogen by scanning electron microscope with an energy dispersive X‐ray spectrometer (SEM‐EDS). The methodology was developed to have a rapid and accurate alternative method to the elemental analysis by combustion and thermoconductivity detection that does not imply the decomposition of the sample. Two methods by SEM‐EDS were established: a quantitative method...