NMR spectroscopy has become a standard technique in studies both on carbon capture and storage. C NMR allows the detection of two peaks for carbonated aqueous samples: one for CO and another one for the species H CO , HCO , and CO -herein collectively named H CO . The chemical shift of this second peak depends on the molar fraction of the three species in equilibrium and has been used to assess the equilibrium between HCO and CO .
View Article and Find Full Text PDFThe migration process in capillary electrophoresis is obtained by using a high-voltage power supply, and the basic idea is to keep the control on the migration velocity of the analytes by controlling either the applied voltage or current. The effectiveness of this control has impact on the resulting electropherogram and, thus, in the identification and quantification of the analytes. Although the usual electropherogram is the record of the detector signal as a function of time, other two domains should be considered: charge and mobility.
View Article and Find Full Text PDFJ Chromatogr A
January 2019
A capillary electrophoresis with diode array and tandem mass spectrometry detection (CE-UV-MS/MS) method has been developed for the targeted assessment of cardiovascular biomarkers candidates, trimethylamine-N-Oxide (TMAO) and l-carnitine, and creatinine in human urine samples. The dual detection was applied due to the high concentration of creatinine (monitored by UV detection at 200 nm) in relation to TMAO and l-carnitine (quantified by selected reaction monitoring (SRM) mass spectrometry), in human urine. All instrumental parameters, sheath liquid (SHL) and background electrolyte (BGE) compositions were optimized with a pool of urine provided by adult healthy volunteers and evaluated by signal-to-noise ratio (SNR) and peak shape of TMAO.
View Article and Find Full Text PDF