Authors
Latest:
Raman Confocal Analysis of an Inclusion in SapphireOne of the most powerful aspects of Raman microscopy is the capability to do confocal analysis of features inside of a sample without having to prepare or damage the sample to get the important spectral information.
Latest:
Forensic Application of Near-Infrared Spectroscopy: Aging of BloodstainsThe authors discuss the use of near-infrared spectroscopy to determine the age of a bloodstain, which can be critical in helping establish when a crime was committed.
Latest:
Native Measurement of a Biotherapeutic without Interference from Excipients Using Microfluidic Modulation SpectroscopyA new infrared spectroscopy technique, microfluidic modulation spectroscopy (MMS), delivers reproducible protein characterization over close to four orders of magnitude in protein concentration (from 0.1 to 200 mg/mL). This technique characterizes samples from the earliest stages of development through to manufacture.
Latest:
Rapid Chemical Threat Identification by SPME-GC–TMSA 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.
Latest:
New Approach for Optimizing a Monoclonal Antibody Biotherapeutic in Different FormulationsA prerequisite for a successful biotherapeutic formulation is one where the protein is stable and correctly folded. The new technique of dynamic multi-mode spectroscopy (DMS) was used to study the stability of a monoclonal antibody biotherapeutic formulated in acetate and lactate buffers. The samples were measured several times over a period of weeks and it became apparent that the antibody behaved differently as it aged in the two formulations, with the lactate formulation imparting greater robustness than the acetate.
Latest:
Analysis of Organic Compounds in Water Using Unique Concentration–Injection Techniques for Portable GC–MSA simple method for extraction and concentration of trace organic compounds found in water for gas chromatography-mass spectrometry (GC-MS) analysis was developed. The method used 25 and 45 mL glass vials with a 5-10 µm thick polymer coatings for extraction of analytes from 20 and 40 mL water samples, respectively. Analytes were subsequently transferred from the polymer coating into an organic solvent, which was reduced in volume to 200-400 µL for analysis. A 10-20 µL sample from the vial was transferred to a tiny coiled stainless steel wire filament using a micro-syringe, or by dipping the coil into the sample. After air evaporation of the solvent, the coil was inserted into the heated injection port of a portable GC-MS system where the analytes were desorbed. Injection using the coiled wire filament eliminated sample discrimination of high boiling point compounds, and minimized system contamination caused by sample matrix residues. The GC-MS contained a new resistively heated column bundle that allowed elution of low-volatility compounds in less than 4 min. Analyses of organochlorine pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyl congeners, pyrethroid insecticides, phthalate esters, and n-alkanes in water and wastewater samples were accomplished for low ppb concentrations in less than 10 min total analysis time.
Latest:
PittCon 2002 Review (PDF)Spectroscopy's annual overview of new instrumentation presented at the PittCon conference.
Latest:
Pesticide and Mycotoxin Analysis: Mastering the Complexity of the Cannabis MatrixThe method described here allows for the simultaneous analysis of 47 pesticides and five mycotoxins in cannabis in one simple QuEChERS procedure. This simple method is designed for implementation in start-up laboratories and in established laboratories that wish to streamline their sample preparation process, decrease solvent usage, and obtain accurate and fast results.
Latest:
Portable Transmission FTIR Analysis of Volatile Samples Using the DialPath Liquid CellTraditionally the analysis of volatile liquids by FTIR spectroscopy has always entailed a sealed fixed pathlength cell.
Latest:
Do We Qualify or Validate a Spectrometer?We critically review the qualification and validation approaches in the World Health Organization Technical Report Series (WHO TRS) 1019 Annex 3 and its applicability to spectrometer systems.
Latest:
The 2002 Spectroscopy Survey of Salaries and Employment Issues (PDF)A Look at Spectroscopists' Incomes and Attitudes about Their Jobs
Latest:
Recent Improvements in Benchtop GC–MSThe 30-year history of advances in gas chromatography–mass spectrometry technology continues today. Recent improvements in hardware, electronics, and data analysis software have resulted in new levels of productivity and sensitivity that have broadened the potential applications for this laboratory mainstay.
Latest:
Book Review: Atomic Spectroscopy in Elemental Analysis, MIchael Cullen, ed., (Blackwell Publishing, 2004) [PDF]This book covers most of the popular atomic spectroscopy methods used for the determination of the elemental composition of materials.
Latest:
Simple and Effective Control of Spectral Overlap Interferences in ICP-MSThe authors discuss a new approach to the control of spectral overlap interferences in inductively coupled plasma–mass spectrometry.
Latest:
Rapid Multielement Nanoparticle Analysis Using Single-Particle ICP-MS/MSComplex isobaric and polyatomic spectral interferences can be mitigated using triple quadrupole ICP-MS (ICP-MS/MS) with a collision–reaction cell (CRC). This configuration allows for the multielement characterization and detection of smaller nanoparticle sizes.
Latest:
Photovoltaic Device Characterization Using the UVISEL Spectroscopic EllipsometerHORIBA Jobin Yvon, Inc.
Latest:
Why Use Signal-To-Noise As a Measure of MS Performance When It Is Often Meaningless?Signal-to-noise of a chromatographic peak from a single measurement has been used determine the performance of two different MS systems, but this parameter can no longer be universally applied and often fails to provide meaningful estimates of the instrument detection limits (IDL).
Latest:
A New Tool for Mass Analysis of Unknown Molecules: High-Resolution Multistep Tandem MS with Wide Dynamic Range Quantitative AnalysisMass spectrometers are effective for identifying and quantifying unknown molecules, such as disease-related proteins and small molecules in pharmaceutical research and medical diagnosis. In addition, mass spectrometry (MS) can be particularly powerful when analyzing molecules with complex structures, such as posttranslationally modified proteins. Among various MS approaches, high-resolution multistep tandem MS (MS-MS) is an emerging methodology for accurate identification of complex molecules. In this article, we describe a new approach for mass analysis with enhanced quantitative capability combined with high-resolution multistep MS-MS, where the dynamic range of quantitation covers four orders of magnitude.
Latest:
Determination of Low Levels of Chromium in Biological Samples by ICP-MS Using Hydrogen as a Reaction GasChromium is a key ingredient in a number of metal alloys used for metal implants which, despite being coated with inert surface layer coatings, can break down over time as a result of biocorrosion. Leeching of metal ions from implants into surrounding bone, tissue, and body fluids can cause severe health problems. Although the toxicity of the metal is low, there is a potential health risk if chromium ions enter the body. In ICP-MS, the chromium (52Cr) signal can be affected by interference from the recombination of background plasma 40Ar and sample-specific matrix 12C. To eliminate this interference, hydrogen can be used in the iCRC as a reaction gas to allow accurate analysis of 52Cr. Results using certified clinical standards of chromium in blood, plasma, urine, and serum clearly demonstrate the benefit of using hydrogen as a collision gas to remove the argon-carbide polyatomic interference. This study shows that ICP-MS is an essential tool for clinical monitoring of metal ions in complex matrices and that hydrogen iCRC gas allowed for greater accuracy and a lower level of quantitation in clinical matrices.
Latest:
A New Tool for Mass Analysis of Unknown Molecules: High-Resolution Multistep Tandem MS with Wide Dynamic Range Quantitative AnalysisMass spectrometers are effective for identifying and quantifying unknown molecules, such as disease-related proteins and small molecules in pharmaceutical research and medical diagnosis. In addition, mass spectrometry (MS) can be particularly powerful when analyzing molecules with complex structures, such as posttranslationally modified proteins. Among various MS approaches, high-resolution multistep tandem MS (MS-MS) is an emerging methodology for accurate identification of complex molecules. In this article, we describe a new approach for mass analysis with enhanced quantitative capability combined with high-resolution multistep MS-MS, where the dynamic range of quantitation covers four orders of magnitude.
