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The migration of chemicals through polymeric materials is difficult or impossible to model theoretically, placing an emphasis on experimental assessment to provide reliable empirical data. This article describes an investigation into the permeation of volatile chemicals through thin polymer membranes based on dynamic headspace, and how the information generated may be of value industrially - specifically in the fields of food packaging and personal protective equipment.

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This article describes some of the latest developments for the analysis of polymers and nanoparticles.

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A non-invasive near-infrared spectroscopy method to characterize a wide range of stationary phases.

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Streamlined sample prep, LC and MS method development.

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The authors use headspace SIFT-MS to target and identify volatiles in various malt aldehydes. The specificity and speed are compared to current methodology.

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An overview of current chromatography-based food toxicant screening is presented.

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In ion chromatography, the presence of a large amount of matrix ions makes quantification of the target ions difficult. Selective removal of matrix ions - matrix elimination - can be performed by treating a sample with a solid-phase extractant. Halides can be removed by precipitation with silver, which is present as a counterion in a cation-exchange resin. A subsequent treatment with a cation-trapping column removes residual dissolved silver ions.

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The Agilent 1290 Infinity LC has significant capabilities for a wide range of HPLC and UHPLC applications. It exhibits a broader power range (that is, the combination of pressure and flow capabilities) than any other commercially available system and has the flexibility to operate with a wide range of column dimensions and particle sizes. Additionally, advanced optical design in the diode array detector allows a wide dynamic range and high sensitivity, both of which are critical in the monitoring of small impurities in fine chemicals.

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Collision-induced dissociation (CID) and electron transfer dissociation (ETD) are complementary mass spectrometric fragmentation techniques. We have used CID and ETD in different approaches to analyse tyrosine phosphorylation using a Thermo Scientific LTQ Orbitrap XL equipped with ETD.

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This article provides an introduction to electrochemical liquid chromatography mass spectrometry. The instrumental set-up is presented and selected applications in drug development processes are discussed.

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A look back at this innovator’s career and her efforts to develop and popularize gas chromatography (GC), particularly for biomedical research.

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PALME almost eliminates consumption of hazardous solvents.

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Investigating Solvent Purity Using Comprehensive Gas Chromatography: A Study of Acetones

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Those fond of puns point out that mass spectrometry (MS) has become ever more focused in the last two decades, while at the same time offering ever more information. The dynamic market for biotherapeutics has driven a number of developments, particularly following the paradigm of well-characterized biopharmaceutical products (WCBP) (1,2). Partly as a result of automation and interfacing, those trained in biological or biochemical disciplines now use mass spectrometers routinely. This also means that the sorts of questions asked of MS have changed. Coping with biomolecule heterogeneity is a key challenge, not generally an issue for small molecule drugs. The data complexity means that mass information alone is insufficient. And at the submission stage, regulators are increasingly concerned about tertiary structure and conformation, something that was not previously an analytical requirement (2). Adding polyethylene glycol (PEG) to already heterogeneous molecules to prolong their half-lives in the body raises..

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The accurate diagnosis of renal allograft rejection currently depends upon a biopsy. Transplant medicine would benefit greatly from the availability of noninvasive tests for early detection of rejection and immunosuppressive drug therapeutic monitoring. Only a limited number of studies have been published to date on specific proteins associated with allograft rejection. Typically, renal dysfunction due to humoral transplant rejection or other pathologies results in the increase of protein excreted in urine (1–5). In blood, endogenous peptides (not generated by trypsin digestion ex vivo) are likely candidate biomarkers for many diseases and pathologies as they are secreted from tissues and enter the bloodstream (6,7). The analysis of endogenous protein and peptide fragments in urine can provide a noninvasive, early indication of kidney transplant rejection or disease.

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A simple and rapid HPLC method was established to simultaneously determine the active ingredients of red clover.

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PerkinElmer Application Note

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In ion chromatography, the presence of a large amount of matrix ions makes quantification of the target ions difficult. Selective removal of matrix ions - matrix elimination - can be performed by treating a sample with a solid-phase extractant. Halides can be removed by precipitation with silver, which is present as a counterion in a cation-exchange resin. A subsequent treatment with a cation-trapping column removes residual dissolved silver ions.

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This article describes some of the latest developments for the analysis of polymers and nanoparticles.

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Accurate, sensitive, and comprehensive characterization of monoclonal antibodies is an absolute necessity to the pharmaceutical and diagnostic industries to meet regulatory requirements and ensure the efficacy and safety of the final product. Microfluidic chip-based high performance liquid chromatography technology interfaced with the mass accuracy of quadrupole time-of-flight mass spectrometry provides the ability to rapidly and efficiently assess the quality of intact monoclonal antibodies, confirm their amino acid sequence, and determine their glycosylation state, while consuming very small amounts of these precious products.

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Collision-induced dissociation (CID) and electron transfer dissociation (ETD) are complementary mass spectrometric fragmentation techniques. We have used CID and ETD in different approaches to analyse tyrosine phosphorylation using a Thermo Scientific LTQ Orbitrap XL equipped with ETD.

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A miniature gas chromatograph incorporating a miniaturized chemical trap for enrichment, rapid thermal desorption of the trap, a resistively heated capillary column for programmed GC analysis and a micro-chip-based plasma emission detector (PED) is described. The sampling and chromatographic conditions for the analysis of volatile compounds in air are presented. The performance of the µCAD is illustrated in the universal (carbon) mode and for the selective detection of chlorinated and organo-mercury compounds. Detection limits (DLs) are at the sub-μg/L level in the carbon mode and 10 ng/L for organo-mercury compounds.

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The move from conventional particle sizes (5 μm or higher) to smaller diameter packing materials is one of the most attractive approaches to achieve higher separating efficiency. Recently developed 3 μm polysaccharide-derived chiral stationary phases demonstrate characteristics of favourable mass transfer kinetics, high column efficiency and good column permeability. This allows the fast analysis of enantiomers using conventional HPLC instruments.

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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.

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Despite the advantages of soft ionization ion-source technologies for improving confidence in the identification of a range of challenging analytes, soft ionization remains a niche technique for gas chromatography–mass spectrometry (GC–MS).

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Heating is a common and essential requirement in most biopharmaceutical production methods. Chitosan is an amino polysaccharide obtained by alkaline deacetylation of naturally abundant chitin.

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The addition of a light scattering detector dramatically increases the capabilities of gel permeation chromatography/size-exclusion chromatography (GPC/SEC) analysis. However, the complexity of the system also increases. This instalment of Tips & Tricks discusses column issues when working with light scattering detectors.

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What can chiral capillary GC do for you? The answer lies in what analysis one is attempting to accomplish. Here, we discuss the utility of chiral capillary GC and where the technique is most valuable, focusing on three application areas in particular.

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Advances in nano-ultrahigh-performance liquid chromatography–mass spectrometry (nUHPLC) and micro–UHPLC (?UHPLC) are described and evaluated, with reference to the analysis of veterinary drugs and steroids in porcine meat and urine, respectively.