The Application Notebook-12-01-2017

The Application Notebook

New separation techniques for the analysis of polar and ionic analytes have aroused great interest in the field of metabolomics and environmental investigation in the past two decades. Hydrophilic interaction liquid chromatography (HILIC) is a promising tool to address this challenge. HILIC separation is based on the polarity of analytes, which generally show stronger retention with increasing polarity according to the HILIC separation mechanism. Furthermore, the high content of organic solvent in the mobile phase leads to good ionization properties in the electrospray ionization (ESI), and consequently enhances the detection sensitivity by hyphenated mass spectrometry (MS) detector.

The Application Notebook

Microwave extraction becomes faster and easier with the new Milestone ETHOS X with its FastEX-24. This application note shows the use of Milestone technology for extraction of dioxins from environmental matrices, with emphasis on one of the most common challenge of this application: the carryover effect. The unique design of the FastEX-24 rotor with disposable glass vials allows easy and efficient dioxin extraction, and other organic pollutants, to be performed, avoiding any memory effect. The FastEX-24 simplifies the routine pollutants extraction process and provides superior productivity at lower costs.

A sensitive determination method with automated solid‑phase extraction (SPE) is presented and the recovery rates are compared with manual extraction. The automated extraction was developed with the SPE robot FREESTYLETM SPE module (LCTech GmbH). According to the European Regulation (EC) No 470/2009, CHROMABOND® HLB was applied for SPE (1). A high performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) method with the biphenyl phase NUCLEODUR® π2 was used for the subsequent analysis.

Ephedra alkaloids are phenethylamines that occur naturally in plants, including the herb Ma Huang used in traditional Chinese medicine. Ephedra alkaloids are potent CNS stimulants and also have a sympathomimetic effect on the peripheral nervous system. The aim of this study was to develop a multi-analyte procedure for the extraction, cleanup, and quantification of the ephedra alkaloids in functional foods and natural products. High capacity strong cation-exchange SPE cartridges were used for the isolation of ephedrine, pseudoephedrine, norephedrine, norpsuedoephedrine, methylephedrine, and synephrine from dietary supplements.

The Application Notebook

This study describes the monitoring of potentially harmful volatile organic compounds (VOCs) emitted from respiratory medical devices, by pumped sampling and thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS) analysis in accordance with ISO 18562 part 3. Emissions from two sets of face-mask supply tubing and three nasal cannulas were compared, and all were found to emit VOCs at levels that may give cause for concern.

Methods for monitoring alcohol consumption biomarkers EtG and EtS are generally limited by poor retention and coelution with matrix interferences, as well as by long analysis times and short column lifetimes. The dilute-and-shoot EtG/EtS LC–MS/MS analysis developed here using the novel Raptor EtG/EtS column easily resolves EtG and EtS from matrix interferences, providing consistent, accurate results for high-throughput labs testing human urine samples for alcohol consumption.