Author



Mark Sanders

Latest:

Nontargeted Screening and Accurate Mass Confirmation of Pesticides Using High-Resolution LC–Orbital Trap Mass Spectrometry

The increasing use of pesticide testing coupled with reductions in maximum permissible residue levels of pesticides in food have driven demand for fast, sensitive, and cost-effective analytical methods for high-throughput screening of multiclass pesticides in food. Detection of 510 pesticides at low parts-per-billion levels can be achieved within minutes using orbital trap technology. The high resolving power of these systems enables accurate mass confirmation of all compounds, including isobaric pesticides. This article will provide an overview of current legislation and illustrate how mass spectrometry instrumentation can enable fast and accurate pesticide screening.


Henk Lingeman

Latest:

Novel Analytical Methods for the Discovery and Trace Analysis of Biochemically Active Compounds

Novel analytical methods for the discovery and trace analysis of biochemically active compunds in three main area are described: protein analysis, screening technologies and multidimensional separations.


Christine Gu

Latest:

Nontargeted Screening and Accurate Mass Confirmation of Pesticides Using High-Resolution LC–Orbital Trap Mass Spectrometry

The increasing use of pesticide testing coupled with reductions in maximum permissible residue levels of pesticides in food have driven demand for fast, sensitive, and cost-effective analytical methods for high-throughput screening of multiclass pesticides in food. Detection of 510 pesticides at low parts-per-billion levels can be achieved within minutes using orbital trap technology. The high resolving power of these systems enables accurate mass confirmation of all compounds, including isobaric pesticides. This article will provide an overview of current legislation and illustrate how mass spectrometry instrumentation can enable fast and accurate pesticide screening.


Rashid N. Qureshi

Latest:

Optimization of Asymmetrical Flow Field-Flow Fractionation

This article illustrates how to choose the best experimental parameters for asymmetrical flow field-flow fractionation.


Henk van der Kamp

Latest:

Data Handling and Validation in Automated Detection of Food Toxicants Using Full Scan GC–MS and LC–MS

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


Lester Taylor

Latest:

Rapid Screening of Pesticides Using U-HPLC/MS

The screening of pesticides, mycotoxins, and veterinary drugs is of great importance in regulated environments such as food or feed analysis. Due to some of the limitations of traditional triple quadrupole approaches (for example, targeted analyte detection, limited number of compounds, and unidentified unknown compounds), there is currently a trend towards use of full-scan MS data for the analysis of residue samples. Current screening approaches mainly rely on the use of ToF instruments coupled to U-HPLC delivering mass accuracy (~5 ppm) at a maximum resolution of <15,000. This can produce inaccurate mass measurements due the presence of unresolved background matrix interferences. In this work we show a full-scan MS screening approach with the Thermo Scientific Exactive mass spectrometer, a novel single-stage Orbitrapâ„¢ MS capable of providing precise mass accuracies at resolutions of up to 100,000 without the need for internal mass calibration.


Mary F. Lopez

Latest:

Quantitative Proteomic Workflow for Discovery of Early Rejection Kidney Transplant Peptide Biomarkers and Subsequent Development of SRM Assays in Urine

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.


Caroline Widdowson

Latest:

Assessing Permeation of VOCs Through Polymeric Materials

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.


Conrad Coester

Latest:

Analysis of Polymers and Protein Nanoparticles using Asymmetrical Flow Field-Flow Fractionation (AF4)

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


Christian W. Huck

Latest:

Fast High-Throughput Chemical and Physical Characterization of Stationary Phases by NIRS

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


Jessalynn Wheaton

Latest:

Simplifying Peptide Bioanalysis

Streamlined sample prep, LC and MS method development.


Luc De Cooman

Latest:

Real-Time Profiling of Volatile Malt Aldehydes Using Selected Ion Flow Tube Mass Spectrometry

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


Martijn van der Lee

Latest:

Data Handling and Validation in Automated Detection of Food Toxicants Using Full Scan GC–MS and LC–MS

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


Rida Al-Horr

Latest:

Matrix Elimination — In-line Removal of Chloride using InGuard Ag and Na Cartridges

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.


Michael Woodman

Latest:

Analysis of Impurities in Fine Chemical Octyl-dimethyl-4-aminobenzoate Using the Agilent 1290 Infinity LC and ZORBAX RRHT and RRHD 1.8 μm Columns

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.


M. Zeller

Latest:

Enhancing Phosphotyrosine Proteome Coverage Using a Combined ETD and CID Approach on a LTQ Orbitrap XL ETD

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.


Wiebke Lohmann

Latest:

Electrochemistry and LC–MS for Metabolite Generation and Identification: Tools, Technologies and Trends

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.



Werner Engewald

Latest:

Marjorie Groothuis Horning: Biochemist, Pharmacologist, and GC Pioneer

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



Jon H. Wahl

Latest:

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

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


Yingqing Yu

Latest:

Branching Out: Mass Spectrometry and the Shape of Biotherapeutics

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..


David Sarracino

Latest:

Quantitative Proteomic Workflow for Discovery of Early Rejection Kidney Transplant Peptide Biomarkers and Subsequent Development of SRM Assays in Urine

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.


Fuchao Chen

Latest:

Simultaneous Determination of Formononentin, Biochanin A, Daidzen and Genistein in Trifolium pratense (Red Clover) by HPLC

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



Bernard G. Sheldon

Latest:

Matrix Elimination — In-line Removal of Chloride using InGuard Ag and Na Cartridges

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.


Stephan Schultes

Latest:

Analysis of Polymers and Protein Nanoparticles using Asymmetrical Flow Field-Flow Fractionation (AF4)

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


Keith Waddell

Latest:

Comprehensive Characterization of Monoclonal Antibodies Using a Microfluidic Chip-Q-TOF Platform

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.


A.F.M. Altelaar

Latest:

Enhancing Phosphotyrosine Proteome Coverage Using a Combined ETD and CID Approach on a LTQ Orbitrap XL ETD

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.