The authors use headspace SIFT-MS to target and identify volatiles in various malt aldehydes. The specificity and speed are compared to current methodology.
ESA - a Dionex Company Application Note
There is more to using and interpreting certificates for chromatography standards than meets the eye
This article describes methods to quantitatively analyse genotoxic and potentially genotoxic impurities in pharmaceutical ingredients
Since the gas flow required for the separation step in gas chromatography is frequently lower than that required to optimize the detection, nitrogen is used as a make-up gas to increase the gas flow for detection.
A simultaneous headspace-GC–FID method was validated to establish methanol and ethanol assessment in blood, urine and saliva.
A simple rapid HPLC method for simultaneously determiing formononetin, biochanin A, daidzen and genistein in Red Clover
Investigating Solvent Purity Using Comprehensive Gas Chromatography: A Study of Acetones
Quantification of substances, such as drug impurities or library compounds when pure standards are not available is difficult yet often necessary.
Simulated Moving Bed technology (SMB) is a continuous chromatography technique widely used in the pharmaceutical/biotechnology industry. The continuous chromatographic separation of sodium sulphate (Na2 SO4) from a mixture of glucose and mannose was established by using the Orochem Zuccheroâ„¢ columns and the SMB technology. The main advantages of SMB over batch chromatography includes better yields, higher purity, and decreased solvent usage, which together make the SMB technology economically viable and ideal for desalting applications.
This article establishes the estimation of the uncertainty associated with the chromatographic determination of biogenic amines. The authors identify and estimate each source of uncertainty to establish the accuracy of results and to obtain a better understanding of the method. Thus, measurement uncertainty was split into two sections: uncertainty related to the working conditions, which considers the equipment used, and inherent uncertainty, which includes the chemical stages indicated in the procedure as well as calibration sources, taking into account the existence of the matrix effect. Recovery studies also were made to quantify the contribution of bias to the overall uncertainty. This parameter was calculated for the determination of biogenic amines in different types of samples.
Carbonyl compounds, in particular aldehydes, are reactive volatile substances. They are of concern to the public, because they are emitted as air pollutants by a large range of industrial processes and other combustion sources.
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.
An optimization strategy to obtain the best possible performance in the shortest analysis time for comprehensive off-line 2D-LC.
This article describes the operating principles of the direct-electron ionization (EI) interface, which is becoming more popular in many LC–MS applications. Matrix effects and the role of direct-EI as a universal detector for small molecule analysis are also discussed in detail. The advantages and drawbacks of this approach are described and a comparison with atmospheric pressure ionization (API) interfaces is made. The potential of direct-EI is illustrated with a selection of practical applications.
A modification of the popular PLE technique is discussed.
This article will shed some light on recent developments of micro-LC and the possibility of applying fast separations while reducing toxic and costly solvent waste.
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.
In this article, we review some key considerations for chromatographic technique selection and method development across the full drug process.
A simple and rapid HPLC method was established to simultaneously determine the active ingredients of red clover.
The presence of PFAS in the environment requires governmental agencies to establish regulatory limits for PFAS in human essentials, such as drinking water. LC–MS/MS can be used to analyze a wide range of sample types containing PFAS, but avoiding PFAS contamination is critical for this technique to work effectively.
Hypercrosslinked polystyrene-type (solid-phase extraction) SPE materials exhibit a unique ability to enter p-interactions with aromatic, heterocyclic and unsaturated compounds. This property permits selective extraction and pre-concentration of the above classes of species from non-polar media and fatty matrices. The principle has been exploited for developing analytical protocols to determine polar furan derivatives in mineral transformer oil, polyaromatic hydrocarbons (PAHs) in smoked fish and for the fractionation of polychlorinated aromatic compounds in environmental matrices.
A discussion on the analytical challenges that both liquid chromatography and mass spectrometry face as well as some potential solutions to these issues.
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.
A simple and rapid HPLC method was established to simultaneously determine the active ingredients of red clover.
The trend in residue analysis has changed from target-oriented procedures towards accurate mass full-scan MS techniques. This article describes these developments and addresses the implications of 2002/657/EC.
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.
This installment of Tips & Tricks deals with pressure monitoring for GPC/SEC systems and gives hints for efficient troubleshooting to solve issues that are identified in the laboratory.
Two-dimensional liquid chromatography (2D-LC) allows analysts to deal with complex samples that either cannot be adequately separated by one-dimensional liquid chromatography (1D-LC) or require excessively long analysis times. Peptide mixtures, whose characterization is relevant in many areas (e.g., proteomics, food analysis, pharmaceutical, life sciences), are a clear example of such complexity. An overview of the most used 2D-LC modes of operation is presented and several examples of their use for the separation of peptide mixtures are described.
This article describes the operating principles of the direct-electron ionization (EI) interface, which is becoming more popular in many LC–MS applications. Matrix effects and the role of direct-EI as a universal detector for small molecule analysis are also discussed in detail. The advantages and drawbacks of this approach are described and a comparison with atmospheric pressure ionization (API) interfaces is made. The potential of direct-EI is illustrated with a selection of practical applications.