Liquid chromatography of ionogenic substances with nonpolar stationary phases

1977 ◽  
Vol 49 (1) ◽  
pp. 142-154 ◽  
Author(s):  
Csaba. Horvath ◽  
Wayne. Melander ◽  
Imre. Molnar
Keyword(s):  
Liquid Chromatography ◽  
Stationary Phases ◽  
Nonpolar Stationary Phases

Enhancement of retention by ion-pair formation in liquid chromatography with nonpolar stationary phases

1977 ◽  
Vol 49 (14) ◽  
pp. 2295-2305 ◽  
Author(s):  
Csaba. Horvath ◽  
Wayne. Melander ◽  
Imre. Molnar ◽  
Petra. Molnar
Keyword(s):  
Liquid Chromatography ◽  
Stationary Phases ◽  
Ion Pair ◽  
Pair Formation ◽  
Ion Pair Formation ◽  
Nonpolar Stationary Phases

scholarly journals Development and Application of a Novel Pluri-Residue Method to Determine Polar Pesticides in Fruits and Vegetables through Liquid Chromatography High Resolution Mass Spectrometry

Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 553
Author(s):  
Lorena Manzano-Sánchez ◽  
José Antonio Martínez-Martínez ◽  
Irene Domínguez ◽  
José Luis Martínez Vidal ◽  
Antonia Garrido Frenich ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
High Resolution ◽  
High Performance ◽  
Fruits And Vegetables ◽  
High Resolution Mass Spectrometry ◽  
Stationary Phases ◽  
Mean Values ◽  
Polar Pesticides ◽  
Relative Standard ◽  
The Matrix

Nowadays, highly polar pesticides are not included in multiresidue methods due to their physico-chemical characteristics and therefore, specific analytical methodologies are required for their analysis. Laboratories are still looking for a pluri-residue method that encompasses the largest number of polar pesticides. The aim of this work was the simultaneous determination of ethephon, 2-hydroxyethylphosphonic acid (HEPA), fosetyl aluminum, glyphosate, aminomethylphosphonic acid (AMPA), N-acetyl-glyphosate and N-acetyl-AMPA in tomatoes, oranges, aubergines and grapes. For that purpose, an ultra high performance liquid chromatography (UHPLC) coupled to a high resolution single mass spectrometer Orbitrap-MS were used. Different stationary phases were evaluated for chromatographic separation, and among them, the stationary phase Torus DEA provided the best separation of the selected compounds. The QuPPe method was used for the extraction of the analytes, but slight modifications were needed depending on the matrix. The developed method was validated, observing matrix effect in all matrices. Intra- and inter-day precision were estimated, and relative standard deviation were lower than 19%. Recoveries were satisfactory, and mean values ranged from 70% to 110%. Limits of quantification were between 25 and 100 µg kg−1. Finally, the analytical method was applied to different fruits and vegetables (oranges, tomatoes, aubergines and grapes).

Carboxylated cyclofructan 6 as a hydrolytically stable high efficiency stationary phase for hydrophilic interaction liquid chromatography and mixed mode separations

2016 ◽  
Vol 8 (31) ◽  
pp. 6038-6045 ◽  
Author(s):  
Yadi Wang ◽  
M. Farooq Wahab ◽  
Zachary S. Breitbach ◽  
Daniel W. Armstrong
Keyword(s):  
Liquid Chromatography ◽  
Benzoic Acid ◽  
Stationary Phase ◽  
Mixed Mode ◽  
High Efficiency ◽  
Stationary Phases ◽  
Hydrophilic Interaction Liquid Chromatography ◽  
Hydrophilic Interaction

Stationary phases composed of native cyclofructan 6 (CF6) and benzoic acid modified CF6 were synthesized and evaluated for hydrophilic interaction liquid chromatography (HILIC).

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