Enantiomeric separation of six chiral pesticides that contain chiral sulfur/phosphorus atoms by supercritical fluid chromatography

Abstract

Six chiral pesticides containing chiral sulfur/phosphorus atoms were separated by supercritical fluid chromatography with supercritical CO as the main mobile phase component. The effect of the chiral stationary phase, different type and concentration of modifiers, column temperature, and backpressure on the separation efficiency was investigated to obtain the appropriate separation condition. Five chiral pesticides (isofenphos-methyl, isocarbophos, flufiprole, fipronil, and ethiprole) were baseline separated under experimental conditions, while isofenphos only obtained partial separation. The Chiralpak AD-3 column showed a better chiral separation ability than others for chiral pesticides containing chiral sulfur/phosphorus atoms. When different modifiers at the same concentration were used, the retention factor of pesticides except flufiprole decreased in the order of isopropanol, ethanol, methanol; meanwhile, the retention factor of flufiprole increased in the order of isopropanol, ethanol, methanol. For a given modifier, the retention factor and resolution decreased on the whole with the increase of its concentration. The enantiomer separation of five chiral pesticides was an "enthalpy-driven" process, and the separation factor decreased as the temperature increased. The backpressure of the mobile phase had little effect on the separation factor and resolution.

A covalent organic framework for chiral capillary electrochromatography using a cyclodextrin mobile phase additive

“…CEC is often used as a separation technique and already showed its potential for chiral separation. 24 And several strategies have been reported to provide the chiral selectivity in CEC mode, such as synthesizing chiral solid phase, depositing chiral selector, using the chiral mobile phase additive. 25,26 An important advantage of adding the chiral additive to the running buffer is the flexibility, because there are a variety of chiral selectors, such as cyclodextrins, cyclodextrins derivatives, macrolides and some chiral small molecules, and convenient to combine with the high efficient solid phase resulting in synergistic benefits.…”

Preparation of a polydopamine/β‐cyclodextrin coated open tubular capillary electrochromatography column and application for enantioseparation of five proton pump inhibitors

“…Chirality is one of the fundamental properties of nature, which can be seen in various fields such as medicine, pesticides, environment, and food [1–4]. Most of the existing drugs have chiral enantiomers to date.…”

Asymmetric Synthesis of Stereogenic Phosphorus P(V) Centers Using Chiral Nucleophilic Catalysis

“…Organophosphorus compounds are common motifs in nucleotides, [1][2][3] pesticides, [4,5] herbicides, [6,7] and flame retardants [8]. Commonly, phosphate mimics with tri, tertra, or pentacoordinate geometries, with unique substitutions, create a chirality center on the phosphorus atom as shown in Figure 1.…”