Nanoelectrospray versus electrospray in chiral analysis by the kinetic method

2009 ◽  
Vol 74 (2) ◽  
pp. 313-322 ◽  
Author(s):  
Václav Ranc ◽  
Vladimír Havlíček ◽  
Petr Bednář ◽  
Karel Lemr
Keyword(s):  
Kinetic Method ◽  
Ion Sources ◽  
Drug Formulation ◽  
Chiral Analysis ◽  
Central Metal ◽  
Real Samples ◽  
Hand Model ◽  
Reference Ligand ◽  
Ionization Processes ◽  
Successful Analysis

Electrospray ionization generates trimeric diastereoisomeric clusters as the first important step in chiral analysis by mass spectrometry using the Cooks′ kinetic method. Cu2+ and L-tryptophan were used as a central metal and as a chiral reference ligand, respectively. The comparison of electrospray and nanoelectrospray showed that although the electrospray system was generally more robust, the application of nanoelectrospray was essential for performing successful analysis in some cases, especially for real samples. Basically, no significant differences between the ion sources were observed for model samples of analytes (isoleucine, ephedrine, phenylalanine) without interfering matrix. On the other hand, model samples containing sodium chloride and a buffer containing a real sample (drug formulation Mucoseptonex E in which D-ephedrine is the active substance) could not be analyzed using ESI, whereas nano-ESI gave satisfactory results. An explanation is based on the differences of ionization processes occurring in the compared sources.

Chiral and Isomeric Analysis by Electrospray Ionization and Sonic Spray Ionization Using the Fixed-Ligand Kinetic Method

2005 ◽  
Vol 11 (2) ◽  
pp. 231-242 ◽  
Author(s):  
Lianming Wu ◽  
R. Graham Cooks
Keyword(s):  
Transition Metal ◽  
Electrospray Ionization ◽  
Chiral Recognition ◽  
Kinetic Method ◽  
Chiral Analysis ◽  
Cluster Ions ◽  
Dissociation Kinetics ◽  
Sonic Spray Ionization ◽  
Reference Ligand ◽  
Kinetics Of

The fixed-ligand version of the kinetic method has been used for chiral and for isomeric analysis by studying the dissociation kinetics of transition metal-bound trimeric cluster ions ([(MII + Lfixed – H)(ref*)(An)]+, where MII is a transition metal, Lfixed is a fixed (non-dissociating) ligand, ref* is a reference ligand and An is the analyte. The trimeric cluster ions are readily generated by electrospray ionization (ESI) or sonic spray ionization (SSI). The size of the fixed ligand, L-Phe–Gly–L-Phe–Gly, is chosen based on previous results but with the inclusion of aromatic functionality to increase chiral recognition. Improved chiral/isomeric differentiation results from enhanced chiral/isomeric interactions (metal–ligand and ligand–ligand) due to the fixed ligand. As shown in the cases of chiral dipeptides (D-Ala–D-Ala/L-Ala–L-Ala), sugars (D/L-glucose, D/L-mannose) and isomeric tetrapeptides (L-Ala–Gly–Gly–Gly/Gly–Gly–Gly–L-Ala), improved chiral/isomeric discrimination by factors from three to six were obtained by the fixed ligand procedure. Chiral recognition is independent of the concentrations of the analyte, the reference ligand, the fixed ligand and the transition metal salt, a great advantage for practical applications. In addition to increased chiral distinction, the simplified dissociation kinetics also contribute to improved accuracy in chiral quantification, in comparison with data obtained by investigating the dissociation kinetics of simple trimeric cluster ions [MII(ref*)2(An) – H]+. Accurate determination of enantiomeric excess ( ee) is demonstrated by enantiomeric quantification of D-Ala–D-Ala/L-Ala–L-Ala down to 2% ee. Both ESI and SSI allow chiral quantification with similar accuracies. The performance of chiral analysis experiments is not limited to ion trapping devices such as quadrupole ion trap mass spectrometers; a hybrid quadrupole-time of flight (Q-ToF) mass spectrometer is shown to provide an alternative choice. The fixed-ligand kinetic method is not restricted to any particular kinds of isomers and, hence, represents a general procedure for improving molecular recognition and chiral analysis in the gas phase.

Kinetic method for the simultaneous chiral analysis of different amino acids in mixtures

2003 ◽  
Vol 38 (4) ◽  
pp. 386-393 ◽  
Author(s):  
Lianming Wu ◽  
W. Andy Tao ◽  
R. G. Cooks
Keyword(s):  
Amino Acids ◽  
Kinetic Method ◽  
Chiral Analysis

On-line chiral analysis using the kinetic method

The Analyst ◽  
2016 ◽  
Vol 141 (8) ◽  
pp. 2441-2446 ◽  
Author(s):  
Ryan M. Bain ◽  
Xin Yan ◽  
Shannon A. Raab ◽  
Stephen T. Ayrton ◽  
Tawnya G. Flick ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Kinetic Method ◽  
Enantiomeric Excess ◽  
Solution Phase ◽  
Chiral Analysis ◽  
Tandem Mass ◽  
Phase Reaction ◽  
On Line

Chiral analysis of constituents in solution-phase reaction mixtures can be performed by tandem mass spectrometry using the kinetic method to determine the enantiomeric excess (ee).

Chiral analysis by mass spectrometry using the kinetic method in flow systems

2006 ◽  
Vol 41 (4) ◽  
pp. 499-506 ◽  
Author(s):  
Karel Lemr ◽  
Václav Ranc ◽  
Petr Fryčák ◽  
Petr Bednář ◽  
Juraj Ševčík
Keyword(s):  
Mass Spectrometry ◽  
Kinetic Method ◽  
Chiral Analysis ◽  
Flow Systems

A New Catalytic Kinetic Method for the Determination of Trace Amounts Vanadium with Resonance Rayleigh Scattering Detection

2013 ◽  
Vol 716 ◽  
pp. 66-69
Author(s):  
Xin Hui Zhang ◽  
Le Ning Hu ◽  
Ai Hui Liang
Keyword(s):  
Spectral Method ◽  
Rayleigh Scattering ◽  
Kinetic Method ◽  
Influence Factors ◽  
Resonance Scattering ◽  
Resonance Rayleigh Scattering ◽  
Scattering Intensity ◽  
Real Samples ◽  
Fluorescence Peak

A new catalytic kinetic method for the determination of vanadium (V) was proposed, based on the V (V) catalyze the slow reaction between KClO3and phenylgycollic acid (PA) in 0.6 mol/L H2SO4solution at 100 °C. The reduction product of ClO3-, Cl-, reacts with Ag+to form (AgCl)nnanoparticles. The nanoparticles exhibit a max resonance scattering spectral peak at 470 nm and a strongest fluorescence peak at 470 nm. The resonance scattering intensity at 470 nm is linear to the V concentration in the range of 2.0×10-9mol/L to 4.0×10-8mol/L. The influence factors on the catalytic resonance scattering determination of trace vanadium were examined. This catalytic resonance scattering spectral method has been applied to the analysis of vanadium in real samples, with satisfactory results.

On-line chiral analysis of benzylmercapturic acid and phenylmercapturic acid in human urine using UPLC-QToF mass spectrometry with the kinetic method

2012 ◽  
Vol 103 ◽  
pp. 170-176 ◽  
Author(s):  
Hua Jin ◽  
T. Daniel Thangadurai ◽  
Sung-Chan Jo ◽  
Dongri Jin ◽  
Shengyun Cui ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Human Urine ◽  
Kinetic Method ◽  
Chiral Analysis ◽  
On Line
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