Application Notes: General

Methods: Vials and closures were exposed to acetonitrile for 2 h and subsequently analysed by LC-UV, LC–MS, and GC–MS to characterize the interferences.

P-hydroxybenzoic acid esters, also called parabens, are widely used as antimicrobial preservatives in cosmetic products.

For many years, the use of guard columns has been advocated by column manufacturers and other experts to protect and extend column lifetime and performance of analytical columns from potential damage caused by the presence of chemical contaminants and microparticulates in the sample and mobile phase.

Phenol formaldehyde resins are formed by a step-growth polymerization. GPC/SEC with RI and UV detection is often used to characterize resins and to quantify the amount of different oligomeric species.

The analysis of tea tree oil requires a severe quality control due to its potential to induce and elicit skin allergies. Tea tree oil is an essential oil and consists of a large number of constituents. Heart-cut Multidimensional GC–MS is very well suited to analysis of samples of such high complexity.

The release of certain chemicals from building products is of increasing concern due to their potentially detrimental effect on human health and the environment; therefore, new regulations requiring the production of low emission materials are currently being implemented. Novel sampling technology has been developed to help building product manufacturers obtain informative emissions data to develop compliant products and maintain product quality on a routine basis.

This application note deals with the development of a fast method for the determination of 13 aldehyde and ketone derivates with the Agilent 1290 Infinity LC-system. The method, which used acetone as organic co-solvent, separates the analytes within 3.5 minutes.

Transferring LC methods between instruments and/or laboratory sites is a common practice that allows analytical scientists to maximize equipment usage.

For many years, the use of guard columns has been advocated by column manufacturers and other experts to protect and extend column lifetime and performance of analytical columns from potential damage caused by the presence of chemical contaminants and microparticulates in the sample and mobile phase.

Quantification of substances, such as drug impurities or library compounds when pure standards are not available is difficult yet often necessary.

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.

Methacholine chloride is a synthetic analogue of the neurotransmitter acetylcholine used to assess bronchial asthma of subjects in respiratory function labs and epidemiological field studies.

Use of UV filters in cosmetic formulations is regulated by international authorities. The concentration of these compounds in cosmetic products is controlled constantly. The following methods describe a simple, fast and ultra fast LC method for determination of UV absorbers. HALO C18* was used as column.

Conclusively determine the make and manufacturer of gunpowders by characterizing their distinguishing ingredients.

Following the recent surge in popularity of flash chromatography as a rapid purification technique, two options now exist for small-to-large-scale purifications of crude samples.

The resolution of time of flight (TOF) mass spectrometers continues to improve and attributes of the instrument that once were considered inconsequential have risen in importance as the push to higher and higher resolution continues.

The amaZon series is the next step in Bruker Daltonics' family of ion trap mass spectrometers. Incorporating a number of new innovations to Bruker's highly successful ion trap technology platforms, the amaZon series is a true leap forward in performance and reliability.

Fused silica capillary tubing is increasingly finding use in wave guiding applications. This application note discusses wave guiding optics in light guiding capillary.

LEAP has developed a new instrument for collecting the entire mobile phase stream during metabolic profiling HPLC–MS analyses into a sealed, 96-well, LTuma plate.

Quantification of substances, such as drug impurities or library compounds when pure standards are not available is difficult yet often necessary.

Explosive compounds are widely used in warfare, mining industries, terrorist attacks, and civil constructions. Explosive contaminated soils are mostly found on firing points, impact areas, and training ranges. The explosive contaminates in soil are possible sources for surface and ground water contaminations, posing environmental and public health risks due to the compounds' toxicity, carcinogenicity, and mutagenicity.

For many years, the use of guard columns has been advocated by column manufacturers and other experts to protect and extend column lifetime and performance of analytical columns from potential damage caused by the presence of chemical contaminants and microparticulates in the sample and mobile phase.

Since 2001 when they became available in North America, monolithic silica HPLC columns have become valuable analytical tools in the R&D and methods development laboratories.

One of the most important attributes of flexible fused silica capillary tubing is its outstanding strength. When made properly with a protective abrasion resistant coating and handled appropriately this material has proven to maintain its strength remarkably well.

In ion chromatography, the presence of a large amount of matrix ions makes quantification of the target ions difficult.

Separation of polar compounds by conventional reverse phase chromatography can be challenging due to their poor retention. Other HPLC approaches include normal phase chromatography (NPC) and its variation, hydrophilic interaction chromatography (HILIC).

Over the past several years column manufacturers have been introducing columns packed with smaller particle sizes – sub-2 µm and 3 µm – to take advantage of the improvements that such small particle size columns offer.

Since the gas flow required for the separation step in gas chromatography is frequently lower that that required to optimize the detection, nitrogen is used as a make-up gas to increase the gas flow for detection.