Ultra fast separations of acetaminophen, caffeine, propofol and parabens are achieved in 30 s using the Thermo Scientific Accela UHPLC system with the 80 Hz PDA detector. The performance of the Accela PDA detector is highlighted by its low noise level, low drift, four orders of magnitude linear working range and high sensitivity.
This article describes some of the latest developments for the analysis of polymers and nanoparticles.
This is the fourth in a series of articles exploring current topics in separation science that will be addressed at the HPLC 2019 conference in Milan, Italy, from 16–20 June.
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.
In January 2004, LCGC Europe published an article on methods for selecting pure gases for analytical applications. 1 Here, the authors expand on this topic by addressing questions regarding gas mixtures - defined simply as more than one gas in a cylinder.
Pesticides are widely used in agriculture to protect crops and to improve efficiency of production. Consequently, governments, food producers and food retailers have a duty to ensure that any residues occurring in foods for human consumption are at or below statutory maximum residue levels (MRLs). Regulation EC 396/2005 adopted in the European Union sets MRLs for more than 500 different pesticides in over 300 different food commodities.
Exploring the use of GCxGC-FID as a technique for qualitative and quantitative analysis of perfumes
Using a bonded polymeric zwitterionic stationary phase, in HILIC mode, polar quaternary herbicides like Diquat can easily be retained, with good peak symmetry. The impact of ionic strength and organic content in the mobile phase is discussed.
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.