Effect of sodium chloride on herbicide-fluorinated stationary phase association-Evidence of a dual mechanism

Abstract

KeyWordsColumn liquid chromatography Fluorinated stationary phase PhenoxypropionTc adds Herbicides Thermodyna mTc pro pertTes SummaryThe effect oFsodium chloride (NaCI) or,, the mechanTsm oF retention oF a series oF phenoxypropionTc acids has been investigated For the fTrst tTme by hTgh-performance ITquTd chromatography (HPLC) wth a novel fluorTnated stationary phase (FSP).ThermodynamTc data relating to retention were determined for a wide range of NaCI concentrations (x). For all the herbicides, the mechanism of retention on the FSP can be divided into ~o regions of NaCI concentration, depending on whether CI (region I) or Na--(region II) has the predominant effect on herbi cide FSP association. This change in the herbicide interaction process was confirmed byan en thalpy entropyinvestigation. This dual mechanism was also used to enable better understand ing of the process of separation of halogenated molecules on this FSR

Anti-coagulant rodenticide binding properties of human serum albumin: a biochromatographic approach

“…According to this last equation, when enthalpy-entropy compensation is observed with a group of compounds in a particular chemical interaction, all the compounds have the same free energy G • iβ at the temperature β [23][24][25][26][27]. Combining Eqs.…”

“…Investigation of the enthalpy-entropy compensation temperature is a useful thermodynamic approach to the analysis of physicochemical data [23][24][25][26][27]. Mathematically, the enthalpy-entropy compensation can be expressed by the following equation [23][24][25][26][27]:…”

Immobilization of arginase and its application in an enzymatic chromatographic column: Thermodynamic studies of nor-NOHA/arginase binding and role of the reactive histidine residue

“…In order to confirm the binding properties of the immobilized enzyme on the chromatographic support, the study of the NOHA (N -hydroxy-l-arginine, an other well-known arginase inhibitor which is known to bind on the same active site than nor-NOHA) displacement of its arginase binding site by nor-NOHA was investigated using the Langmuir approach [47][48][49][50][51]. For this, single and multi-component isotherms were determined using the perturbation technique [47].…”

Development and Evaluation of a New Fluorinated Double-Wall Carbon Nanotube HPLC Stationary Phase

“…On the pentafluorophenyl phases the π-π interactions played a great role for the separation of aromatic solutes [12]. The great interest of these polar interactions for the chromatographic separation was also visualized for the separation of phenoxypropionic acid herbicides [9,10]. The specific properties of nanoparticles (large surface-to-volume ratio, etc.)…”

“…The fluorinated phases showed some size and shape selectivity, particularly for aromatic molecules [7][8][9][10][11]. On the pentafluorophenyl phases the π-π interactions played a great role for the separation of aromatic solutes [12].…”