With the threat of terrorism growing, the development of analytical techniques for the detection and identification of chemical warfare agent defradation products has increased. Capillary electrophoresis (CE) presents interesting features for this application.
Pesticide contamination of foodstuffs has become a worldwide concern, prompting various levels of regulation and monitoring. Traditionally, pesticides are quantified with gas chromatography (GC) combined with selective detectors (ECD, FID, etc.). Selective GC detectors are great tools to quantify one or two classes at a time. However, screening for a number of different classes of pesticides requires multiple runs utilizing various GC configurations to achieve sufficient chromatographic resolution for unambiguous quantification. Gas chromatography–mass spectrometry (GC–MS) provides positive confirmation of various pesticides in a single analytical run because its superior selectivity allows interference-free quantification even with peak coelution. GC–MS has become a preferred technique for pesticide analysis because of its single-run capability.
Negative chemical ionization GC-MS, used in conjunction with automated cold-on-column injection, provides efficient and sensitive quantification of explosive residues for environmental and forensic applications.
Potentiometry is a new detection method for liquid chromatography (LC) and capillary electrophoresis (CE). The principle behind this method is familiar to chromatographers because the signals depend on the partitioning tendency of analytes over the sensor coating and the eluent. This partitioning provokes a change in the surface potential and the detection of these changes can be classified as "potentiometric". A conversion algorithm is needed to convert the generated signals to concentration-related tracings (chromatograms).
Capillary extraction (CEx) is used to study the solventless in-tube extraction of naphthalene, acenaphthene, phenanthrene, fluoranthene, chrysene, benzo(a)pyrene and coronene in aqueous samples prepared by analyte spiking into clean waters or, as an alternative, by using the generator–column method of sample preparation. Analysis of laden extractors is conveniently performed by high-resolution gas chromatography (GC), with a flame-ionization detector (FID). Extraction set-ups and main extraction variables are investigated from a practical point of view. For 2- to 4-ring polycyclic aromatic hydrocarbons (PAHs), equilibrium times are within a few minutes, analytical sensitivity is in the parts-per-billion (ppb) range and reproducibility is better than 10% relative standard deviation (RSD) (n = 6). Coronene behaviour is unique and presumably determined by extreme hydrophobicity and thus very negligible aqueous solubility: in-tube extraction of coronene seems possible only if starting from..
The determination of inorganic elements in food substances is critical for assessing nutritional composition and identifying food contamination sources. The inorganic elements of interest can be divided into two classes: nutritional and toxic. It is important to determine the levels of both sets of elements accurately to assess both the nutritional and the harmful impacts of food substances. Nutritional elements such as Mg, P, and Fe are present at high levels (milligrams per kilogram), while toxic elements such as Pb, Hg, and Cd should be present only at trace levels (nanograms or micrograms per kilogram).
Biomimetic HPLC retention data can be used to measure how a compound will bind to proteins and phospholipids in vivo.
The determination of the carcinogenic food processing contaminant furan by headspace sampling of foods is challenging because it can easily escape from the sample during preparation. Furan can also be easily formed as a by-product when the sample is heated in the headspace apparatus. This article describes a number of approaches to overcome these difficulties and alternative methods to quantify furan in a variety of matrices.
Mass spectrometry has long been a preferred tool for protein identification and biomarker discovery, but preparation of biological samples remains a challenge. Hindrances include the wide range of protein concentrations, sample complexity, and loss or alteration of important proteins due to sample handling. This article describes recent developments in sample fractionation technologies that are overcoming these challenges in interesting ways and are enabling in-depth proteomic studies that were not possible in the past.
State-of-the-art mass spectrometry (MS) techniques of growing importance to life sciences research now include not just liquid chromatography (LC)–MSn (n = 2–11), but also LC–matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF), LC-MALDI-TOF-TOF, electrospray ionization (ESI)-TOF, and LC-Fourier transform (FT) MS.
Liquid chromatography–mass spectrometry (LC–MS) is a popular technique for the analysis of wine. This article gives an overview of wine analysis and new insights this technique has revealed regarding the composition of wine, possible health benefits, customer safety and the understanding of winemaking processes.
A detection method based upon aerosol charging was examined for its applicability and performance with high performance liquid chromatography.
Contamination of public buildings with PCBs used as softeners in the 1970's in sealants and wall and ceiling paints can still be detected. If certain threshold values in indoor air are exceeded the source has to be decontaminated. This requires an effective and fast determination of the PCB concentration in indoor air. Thermodesorption GC–MS is a method especially suitable for this purpose. Polychlorinated Biphenyls (PCBs) are highly toxic and carcinogenic chemical substances. Although first prepared in 1864, they have been industrially manufactured since 1929. The highest production amounts worldwide were recorded in the 1960s and the beginning of the 1970s. In the 1970s their use as additives for building materials was widespread because of their flame inhibiting and noise reduction properties.
Reproducing analysis conditions is crucial to achieving consistent, accurate results in gas chromatography–mass spectrometry (GC–MS). Valid reproduction demands appropriate application of technique, solid method design, reliable and accurate equipment, and a dedicated team of well-practiced technicians and researchers. But even when all these conditions are met, users can be held back by the more subtle elements in GC–MS operations, such as cutting or changing a column, or setting up the same experiment on different equipment. Even getting the parameters of a test organized so that it can be reproduced elsewhere - in a laboratory across the hall, the country, or the world - can be daunting. Consistent GC–MS results depend upon retention-time reproducibility.
AC Analytical Controls developed a new chromatographic solution that complies with all ASTM & EN chromatographic test methods listed in biodiesel specifications: the AC all-in-one Biodiesel analyser. Analysis results demonstrate that the AC analyser complies with EN 14103, EN 14105, EN 14106, EN 14110 & ASTM D6584 methods.
Through the years, Pittcon has provided a platform for leading researchers to present new breakthroughs in their scientific endeavors.
The biopharmaceutical industry continues to focus on the development of biotherapeutic monoclonal antibody (mAbs) drugs. In this article, the compatibility of SEC coupled with HRAM–MS for the analysis of mAbs is demonstrated.
The analysis of crude oil by means of different atmospheric pressure ionization (API) techniques is described. Crude oil is analysed without any separation prior to API-Fourier transform mass spectrometry. The use of a quadrupole/hexapole device to selectively enhance a certain mass range is demonstrated. Automated generation of molecular formulas from accurate mass measurements enables rapid compound identification.
Leslie Ettre is joined by Peter J.T. Morris as the duo discusses the work of James E. Lovelock, which eventually led to the invention of the electron-capture detector.
Potentiometry is a new detection method for liquid chromatography (LC) and capillary electrophoresis (CE). The principle behind this method is familiar to chromatographers because the signals depend on the partitioning tendency of analytes over the sensor coating and the eluent. This partitioning provokes a change in the surface potential and the detection of these changes can be classified as "potentiometric". A conversion algorithm is needed to convert the generated signals to concentration-related tracings (chromatograms).
Potentiometry is a new detection method for liquid chromatography (LC) and capillary electrophoresis (CE). The principle behind this method is familiar to chromatographers because the signals depend on the partitioning tendency of analytes over the sensor coating and the eluent. This partitioning provokes a change in the surface potential and the detection of these changes can be classified as "potentiometric". A conversion algorithm is needed to convert the generated signals to concentration-related tracings (chromatograms).
State-of-the-art mass spectrometry (MS) techniques of growing importance to life sciences research now include not just liquid chromatography (LC)–MSn (n = 2–11), but also LC–matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF), LC-MALDI-TOF-TOF, electrospray ionization (ESI)-TOF, and LC-Fourier transform (FT) MS.
Calibration refers to the process of determining the relation between the output (or response or signal) of a measuring instrument and the value of the input quantity or property. Depending on the univariate or multivariate character of the response (signal) used; either a univariate or a multivariate calibration is performed. The different calibration approaches are summarized in this article.
Liquid chromatography–mass spectrometry (LC–MS) is a popular technique for the analysis of wine. This article gives an overview of wine analysis and new insights this technique has revealed regarding the composition of wine, possible health benefits, customer safety and the understanding of winemaking processes.
You have purchased a new gas chromatograph. Your company's safety office has completed a review of your lab's supplies. Before setting up your gas chromatograph, you read the instructions and familiarize yourself with the instrument. You might even give some thought to the exposure risks for the various substances in your samples. Yet, what about the less visible risks inherent in the gas delivery system that makes this a gas chromatograph?
Serum protein profiling using mass spectrometry (MS) is one of the most promising approaches for biomarker identification.
This installment of "Sample Prep Perspectives" discusses techniques for the reduction/depletion of high-abundance proteins.
Potentiometry is a new detection method for liquid chromatography (LC) and capillary electrophoresis (CE). The principle behind this method is familiar to chromatographers because the signals depend on the partitioning tendency of analytes over the sensor coating and the eluent. This partitioning provokes a change in the surface potential and the detection of these changes can be classified as "potentiometric". A conversion algorithm is needed to convert the generated signals to concentration-related tracings (chromatograms).