The authors look at the use of QuEChERS in the ongoing testing program in the gulf.
In this study we report on the use of a field-portable GC-MS with rapid sampling techniques such as solid-phase micro extraction, purge-and-trap, thermal desorption, and heated headspace to provide a fast response for in-field-SVOCs analyses for a wide variety of environmental-type samples including potable waters, tea, plants and road gravel. We will show that this field-portable approach can provide the required sensitivity, selectivity for the effective analysis of SVOCs with very high boiling points such as polycyclic aromatic hydrocarbon (PAHs), pesticides, phenolic compounds and phthalate esters in a number of different field-based samples, in less than 10 minutes.
For anyone who makes his or her living in the field of analytical chemistry, and more specifically, in the fields of chromatography or spectroscopy, the debate concerning the state of the conference industry is well known to say the least.
Since the discovery of gullies on Mars in 2000, NASA has endeavored to re-image areas known to have them. Now for the first time, using before and after images taken of the same region on Mars, a dune gully flow is shown to have happened very recently.
A single calibration curve run with staggered calibrants bracketing the unknowns is compared to running complete duplicate calibration curves, one at the beginning and one at the end of unknown sample analysis in an effort to accelerate discovery bioanalysis.
Surface-enhanced Raman spectroscopy (SERS) has been studied extensively over the last few decades with many advances in preparation of SERS substrates and coatings. While the bulk of the research in SERS substrate preparation has been devoted to pushing detection limits to higher sensitivity for measurement of single samples, the application of SERS to high-throughput analysis has been largely ignored. In this article, we present the use of commercially available SERS-coated microtiter plates in a dedicated Raman microtiter plate reader, enabling high-throughput trace analysis measurements. This article also describes the SERS substrate, the high-throughput plate reader, and preliminary results from samples representing trace analysis of explosives, nerve agents, pharmaceuticals, and biological compounds.
The authors discuss improvements in sample preparation for ADME/pharmacokinetic studies of therapeutic oligonucleotides.
The development of a phosphorylation probability scoring tool in an automated data search engine resolves ambiguity in site localization when compared to manual methods.
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.
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.
The authors discuss a noninvasive method for determining early indications of the rejection of a kidney transplant.
Polymer laminates typically make complex samples for infrared analysis, comprising multiple layers with defined thicknesses, in some cases less than 10 µm. When measuring extremely narrow laminate layers, the use of attenuated total reflectance (ATR) may provide improved spectra of the laminate cross-section, because ATR microscope objectives offer a greater spatial resolution than transmission due to additional magnification. This paper details the preparation of polymer laminate sample cross-sections and the collection of transmission and ATR spectra of various layers. Further analysis of the laminate spectra will also be explored utilizing a multivariate curve resolution (MCR) algorithm. An example laminate sample is examined utilizing all the tools available on a standard FT-IR microscope.
The authors discuss a noninvasive method for determining early indications of the rejection of a kidney transplant.
This paper describes the analysis of edible oils radial view ICP-OES. Information is provided regarding the most suitable wavelengths, background correction, and integration times. Results of a detection limit study are presented. The accuracy of the analytical method is validated using soybean, olive, and corn oil matrices.
Infrared spectroscopy is a powerful analysis technique used in the semiconductor industry to ensure the quality of silicon and silicon wafers. The authors discuss the use of an inexpensive, lab-based system to measure carbon and oxygen concentrations in silicon to the level of precision required by the solar silicon industry.
This article reviews the principles and major applications of step-scan Fourier transformyy}infrared spectroscopy, an important means for solving challenging problems in many areas of science and technology.
For the optimization of photodynamic therapy the spectroscopic detection of photosensitizer molecules, which are selectively enriched in tumour cells, can be useful.
This article discusses direct real-time monitoring of chemical reactions, an important tool in industrial processes in industries such as chemical, biotechnology, food, and pharmaceutical.
Since it was first described in 1974, surface-enhanced Raman spectrometry (SERS) has been thought to offer significant potential for a range of different applications. The theoretical sensitivity and specificity envisaged for this powerful technique has engaged scientists for many years, but practical challenges have hindered its routine adoption. Now, a new approach combines a robust and reliable substrate with expertise in surface chemistry and molecular biology on a platform that can be adapted for a wide variety of Raman instrumentation and customized routine applications.
Handheld Raman spectrometers are now designed and built for practical everyday use in a vast array of applications. The new BRAVO by Bruker takes handheld Raman Spectroscopy to a new level, overcoming the limitations of previously available systems such as limited wavelength accuracy, non-safe laser usage and fluorescence interference. Now with BRAVO wavelength accuracy is significantly better than competitive devices resulting in the highest data consistency and the BRAVO incorporates new technology called Sequentially Shifted Excitation (SSE™) to mitigate fluorescence.
The authors discuss the use of high-resolution LC-MS to analyze complex samples in regulated environments such as food and animal-feed analysis.
The authors discuss the use of electron-capture dissociation coupled with a linear ion trap time-of-flight mass spectrometer to investigate the structure of human transferrin.
The authors investigated the analytical capabilities of three types of mass analyzers for liquid chromatography-mass spectrometry (LC-MS) applications, studying the effects of instrument parameters and issues related to sample preparation on the performance of LC-MS analytical methods.
This article provides an overview of the instrument platforms, tools, and workflow for analyzing pesticides.
Raman imaging has moved on. It is now possible to capitalize on the wealth of information available from a Raman spectrum by imaging materials over large areas, with the spatial resolution, spectral resolution, and laser excitation parameters tailored to suit each application. Raman experiments and images from a diverse range of samples are presented.
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 authors discuss the use of electron-capture dissociation coupled with a linear ion trap time-of-flight mass spectrometer to investigate the structure of human transferrin.
A new high-throughput LC–MS/MS method meets the challenge of eliminating matrix effects for monitoring, with high specificity, polar organic pesticides such as glyphosate in food and water, while meeting targeted limits of detection.
Although not currently used in U.S. or European aquaculture, malachite green (MG) is still an effective and inexpensive fungicide that is used in other countries, particularly in Asia. During metabolism, MG reduces to leucomalachite green (LMG) (Figure 1), which has been shown to accumulate in fatty fish tissues. Trace levels of MG and LMG residues continue to be found in fish products. In a 2005 report, MG was found in 18 out of 27 live eel or eel products imported from China to Hong Kong local market and food outlets, resulting in a government recall and destruction of all remaining products (1).