Acquisition and interpretation of a spectra database for ICP-AES analysis are described. The aim is the selection of nanometer-wide spectral windows containing several elements and several lines per element, so as to perform multiline analysis. An automatic line assignment procedure has been used. Information such as wavelength, sensitivity, line width, limit of detection, and level of detector saturation are stored. Filtering procedures are used for line selection, taking into account concentrations and possible spectral interferences.
An effective metabolite identification study should ideally include both qualitative and quantitative information that for both identifying metabolites, and determining the rate of clearance and the metabolic routes of the parent drug. Liquid chromatography–mass spectrometry (LC–MS) is considered the standard analytical technique for metabolite identification studies. To date, however, qualitative and quantitative information has always been obtained from two separation platforms: quadrupole time-of-flight (QTof) MS for the exact mass full-scan qualitative study, and tandem quadrupole MS for the multiple reaction monitoring (MRM) quantitative study. With advancements to QTof instrumentation, specifically, recent improvements in sensitivity and dynamic range, it is now possible to perform both qualitative and quantitative experiments on a single QTof mass spectrometer. This article describes a workflow that allows simultaneous qualitative and quantitative metabolite identification studies to be..
An effective metabolite identification study should ideally include both qualitative and quantitative information that for both identifying metabolites, and determining the rate of clearance and the metabolic routes of the parent drug. Liquid chromatography–mass spectrometry (LC–MS) is considered the standard analytical technique for metabolite identification studies. To date, however, qualitative and quantitative information has always been obtained from two separation platforms: quadrupole time-of-flight (QTof) MS for the exact mass full-scan qualitative study, and tandem quadrupole MS for the multiple reaction monitoring (MRM) quantitative study. With advancements to QTof instrumentation, specifically, recent improvements in sensitivity and dynamic range, it is now possible to perform both qualitative and quantitative experiments on a single QTof mass spectrometer. This article describes a workflow that allows simultaneous qualitative and quantitative metabolite identification studies to be..
Spectroscopy techniques are an important facet of the laboratory analytical and life science instrument industry, which continues to expand as its analytical requirements migrate across industries and geographic regions. Overall industry growth has been in the 6-8% range for the last few years, which is a sign of both its maturity and its stability. The demands of the life science marketplace, environmental concerns, and the search for new materials are important driving forces. Likewise, the shifting market focus from North America and Europe to Asia is changing the face of the industry. It is expected that 2008 will be a good year for the industry despite the likely economic slowdown in North America and Europe.
Bruker Daltonics, Inc.
Both Chinese ginseng and Korean ginseng are similar plant species and undergo similar handling procedures when harvested and processed for sale. Despite their similarities, Korean ginseng commands a higher price than Chinese ginseng on the open market and is believed to produce different clinical effects than Chinese ginseng. Chinese researchers are now employing new techniques on the two varieties of ginseng to understand their chemical differences. HPLC/UV-based strategies for distinguishing the two types of ginseng have proven to be mostly ineffective due to lack of resolution. Using UltraPerformance liquid chromatography/orthogonal acceleration (oa)–TOF mass spectrometry and exact mass measurement, the authors developed a high-resolution method using multivariate statistical analysis for separating and identifying differences between Chinese ginseng and Korean ginseng at the molecular level.
This study focuses on United States Environmental Protection Agency (US EPA) Method 524.3 for volatile organic compounds (VOCs) in water using gas chromatography–mass spectrometry (GC–MS).
The use of medicinal herbs as alternative treatment methods continues to grow. With this escalating use has come an increasing interest in determining the chemical compositions of these herbs in order to obtain a better understanding of their makeup and effects. In this study, Flos Chrysanthemi, a commonly used traditional Chinese medicine that has been cultivated for centuries, was analyzed to identify the main flavone compositions in one original breed of Flos Chrysanthemi (Hangbaiju) in China.
A person-portable gas chromatography–mass spectrometry (GC–MS) system employing a toroidal ion trap mass spectrometry (TMS) detector was used to analyze chemical threat related compounds. Introduction of analytes into the heated injector of the instrument was by solid-phase microextraction (SPME), and fast resistive heating of a low thermal mass (LTM) gas chromatography column assembly provided rapid analysis times. Methodology for positive identification of chemical threats can combine chromatographic retention time, comparison to traditional electron ionization mass spectral libraries, and observation of expected pseudomolecular ions produced through self-chemical ionization. Methods are discussed for sampling by SPME with GC–MS analysis in the field to measure airborne analyte concentrations.
Inductively coupled plasma–mass spectrometry (ICP-MS) is a mature method that offers reliable measurements across almost the entire periodic table. It has been established as the key methodology for investigating elemental concentrations, which play a central role in biological, environmental, chemical, and industrial processes. ICP-MS is capable of performing multielemental analyses in a single analytical run, achieving an overall productivity of more than 50 samples/h. The method also delivers lower detection limits compared to graphite furnace atomic absorption (GFAA) or inductively coupled plasma–optical emission spectrometry (ICP-OES).
The use of medicinal herbs as alternative treatment methods continues to grow. With this escalating use has come an increasing interest in determining the chemical compositions of these herbs in order to obtain a better understanding of their makeup and effects. In this study, Flos Chrysanthemi, a commonly used traditional Chinese medicine that has been cultivated for centuries, was analyzed to identify the main flavone compositions in one original breed of Flos Chrysanthemi (Hangbaiju) in China.
In preclinical development, the absolute quantification of peptides in biological matrices becomes a challenge due to the limited availability of stable label internal standards and affinity-based cleanup. This puts a renewed emphasis on matrix effects, especially for the bioanalysis of hydrophobic peptides. While the impact of matrix effects has been studied for extensively singly charged small molecules, their effect on multiply charged compounds has yet to be characterized fully. This article discusses initial results from matrix effect experiments in relation to the bioanalysis of hydrophobic peptides and techniques used to minimize matrix effects.
Illegal artisanal gold mining using mercury amalgamation is poisoning people and the ecosystem in the Amazon rain forest. By taking the technique of direct mercury analysis to a remote, field-based laboratory, the team of Professor Luis Fernandez is measuring the extent of the contamination in a wide variety of samples, including soil, fish, air and human hair.
The method presented here allows for the accurate, precise, and robust speciation, profiling, and quantification of cannabinoids in hemp oil extracts and commercial cannabinoid products for research and development laboratories.
A better understanding of the micro- and nanostructures of cellulose fiber composition before and after various chemical treatments, together with the distribution of bleaching additives to the final paper composition, is essential for further improvements of paper properties. Confocal Raman imaging is a valuable tool for such studies, as it reveals not only optical information but also information regarding the 3D distribution of the chemical compounds in the submicrometer range. In the paper surface finishing process, additional surface roughness parameters can be measured by combining confocal Raman microscopy with atomic force microscopy. Such combined analytical microscopes allow a direct linking between high-resolution imaging and chemical identification of various species on a surface.
An effective metabolite identification study should ideally include both qualitative and quantitative information that for both identifying metabolites, and determining the rate of clearance and the metabolic routes of the parent drug. Liquid chromatography–mass spectrometry (LC–MS) is considered the standard analytical technique for metabolite identification studies. To date, however, qualitative and quantitative information has always been obtained from two separation platforms: quadrupole time-of-flight (QTof) MS for the exact mass full-scan qualitative study, and tandem quadrupole MS for the multiple reaction monitoring (MRM) quantitative study. With advancements to QTof instrumentation, specifically, recent improvements in sensitivity and dynamic range, it is now possible to perform both qualitative and quantitative experiments on a single QTof mass spectrometer. This article describes a workflow that allows simultaneous qualitative and quantitative metabolite identification studies to be..
The authors discuss a noninvasive method for determining early indications of the rejection of a kidney transplant.
The authors discuss the use of vibrational spectroscopy to differentiate an authentic article from a counterfeit one throughout a product's lifecycle, from component receipt at the site of manufacture, to product receipt by the end user.
In this study, far-UV CD spectra of eight different mammalian serum albumins were measured repeatedly using automated CD spectroscopy. Two independent methods of normalizing the CD data were used to eliminate the need for accurate knowledge of protein concentration or extinction coefficient. The normalized far-UV data, representative of secondary structure, were compared to determine if there were statistically significant differences between samples. The two normalization methods agreed in every case, increasing confidence in the results.
In honor of Spectroscopy's celebration of 30 years covering the latest developments in materials analysis, we asked a panel of experts to assess the current state of the art of infrared (IR) spectroscopy and to try to predict how the technology will develop in the future.
Photonic Knowledge, Inc., a spin-off of Photon etc., introduces the Core Mapper?, a hyperspectral imager that produces instantaneous, precise in situ mineralogy, lithology, and alteration mapping. This unique patented technology answers the increasing demand of the mining industry for better exploration tools.
This article introduces the advantages of accurate mass high-resolution mass spectrometry LC–MS (HRMS) coupled to the dried blood spot (DBS) technique for fast PK applications in a discovery environment. Compared with the established norm of plasma bioanalysis using triple quadrupoles, HRMS coupled to DBS is a viable alternative. The benefit is access to critical new information (HRMS bioanalysis) and significantly less stress on the animal (DBS), both factors that potentially improve the quality of early PK data.
Mass spectrometry plays an increasingly significant role in the analysis of residues and contaminants in food. Here we will illustrate how the combination of ultrahigh-pressure liquid chromatography (UHPLC) and high-resolution time-of-flight-mass spectrometry (TOF-MS) is used to generate a screen of veterinary drug residues in products of animal origin. The use of UHPLC–TOF-MS and dedicated, workflow directed software allows rapid screening for large numbers of residues and automated quantification of positive samples. In addition, we illustrate how the data generated using MSE acquisition mode enable critical structural information to be collected, which offers additional selectivity and confirmatory data for compound identification and facilitates elucidation of the structure of newly discovered compounds.
Documents have been investigated to determine the feasibility of utilizing Raman and SERS Raman spectroscopy for the identification and characterization of inks on paper. Fluorescence reduction methods have been employed to facilitate the analysis by reducing the nascent fluorescence from paper and ink. Furthermore, ink crossings were investigated to demonstrate that ink applied after creation of a document could be differentiated from the originally applied ink.
The in situ combination of rheometry and Raman spectroscopy allows for real-time, synchronized measurement of both physical and chemical material properties.
In this study, apple juice samples are analyzed by IC–ICP–MS to determine the concentration of six arsenic species: the two inorganic, and highly toxic, species (As (V) and As [III]) and four organic species (arsenobetaine [AsB], arsenocholine [AsC], monomethylarsonic acid [MMA], and dimethylarsinic acid [DMA]).
The past decade has witnessed resurgent interest in coupling GC to atmospheric-pressure chemical ionization (APCI), which is suitable for the high column flows required for using flow modulation. This study assesses the use of GP-APCI with flow modulation for sensitive detection of selected trace organics.
Building on more than 10 years of Micro-XRF experience, the Orbis spectrometer yields a system with excellent Micro-XRF capability while setting a new standard in analytical flexibility. The Orbis incorporates a unique motorized turret integrating video and X-ray optics allowing coaxial sample view and X-ray analysis. The turret can accommodate two additional collimators along with the X-ray optic for a total of three X-ray beam sizes to expand the Orbis analytical capabilities beyond traditional Micro-XRF analysis.
Metabolite profiling in drug discovery can contribute significantly at the lead optimization stage in two main application areas. The first is the identification of major metabolites, which provides medicinal chemists with information on the metabolic "soft spots." These soft spots are locations on the molecule particularly susceptible to metabolic modification, which can contribute to high pharmacokinetic clearance. This information then can be used to optimize the structure of a lead compound or chemical series to slow the rate of metabolism and therefore reduce hepatic clearance. This improves the absorption, distribution, metabolism, and excretion (ADME) properties of the compound, such as bioavailability, exposure (as measured by area under the curve), and half-life. Through iterative optimization of the structure and timely generation of metabolism data following each structural modification, pharmacokinetic properties can be improved while maintaining activity against the therapeutic target.
Raman confocal spectroscopy is increasingly being applied for the analysis of embedded contaminants within materials. A non-contact, non-destructive analysis method, Raman spectroscopy requires very little sample preparation, has greater spatial resolution compared to FT-IR microscopy and the confocal analysis method allows visualization of materials within a clear sample matrix. This paper will investigate the analysis of an embedded contaminant within a polymer matrix on a glass substrate.