Enantioselective dissipation of pyriproxyfen in soils and sand

Abstract

Under normal conditions, the environmental behaviors of pesticides are affected by complex environmental factors and the manner of administration together with constraints. In order to meet the actual needs, we imitated the experiment and found that the degradation rate of pyriproxyfen in soils rendered complex changes. Rac-pyriproxyfen was successfully chiral separated on an AZ-H column and the residue analysis method was in accord with the demand of pesticide analysis. The results indicated that pyriproxyfen dissipated at a faster rate in Heilongjiang soil and Hainan soil, while at a much slower speed in another three soils and sand. Obvious enantioselective degradation was observed in Hainan soil and Qingdao sand. The results suggested that pyriproxyfen alone had low persistence in soil, but the moisture, soil type, the use of mixture formulation, and second spraying treatment could play important roles in dissipation of pyriproxyfen. Too large and too small moisture content could both make pyriproxyfen persist for a longer period in soil than in soil with 25% moisture content. Residues dissipated much slower after using Ai Qiu, while Shi Dingkang did not have a big effect on degradation, with only a small acceleration effect. Pyriproxyfen also dissipated in Hainan soil with difficulty after the second treatment.

Soil presence reduces the control effectiveness of a slow‐release formulation of pyriproxyfen on Aedes aegypti (Diptera: Culicidae) larvae

“…A high KOC indicates a tendency to be adsorbed and, once in the soil, to have low mobility. Adsorbed pyriproxyfen persistence in soil is reduced by rapid degradation via biological catalysis under static conditions . With the NFSRD, the highest concentration was closer to the soil surface.…”

Past, present, and future developments in enantioselective analysis using capillary electromigration techniques

“…As an example, Ibrahim et al found that a combination of either of two CDs with MEKC based on SDS provided better separation of imidazole enantiomers than any PSP individually [153]. Furthermore, many studies have reported ligand-exchange MEKC, another variant to achieve chiral separation [155][156][157]. This technique is intriguing for its ability to enhance separation resolution as well as influence enantiomer migration order [158].…”

Fate of Pyriproxyfen in Soils and Plants

“…In this context, Liu et al [27] evaluated the aerobic biodegradation of the two pyriproxyfen enantiomers in five types of soils and one sand site. The different half-lives found are listed in Table 1 with the main characteristics of the media.…”

“…Half-life values (t 1/2 ) of pyriproxyfen enantiomers in different types of soils and sand under aerobic conditions and with various experimental conditions (adapted from[27]). …”