Biotic and Abiotic Transformation Pathways of a Short-Chain Chlorinated Paraffin Congener, 1,2,5,6,9,10-C₁₀H₁₆Cl₆, in a Rice Seedling Hydroponic Exposure System

Abstract

In this work, a typical congener of short-chain chlorinated paraffins (SCCPs) with six chlorine atoms (CP-4, 1,2,5,6,9,10-C10H16Cl6, 250 ng/mL) was selected to elaborate the comprehensive environmental transformation of SCCPs in rice seedling exposure system. CP-4 was quickly absorbed, translocated, and phytovolatilized by seedlings with a small quality of CP-4 (5.81–36.5 ng) being detected in the gas phase. Only 21.4 ± 1.6% of an initial amount (10,000 ng) of CP-4 remained in the exposure system at the end of exposure. Among the transformed CP-4, some were attributed to the degradation of the rhizosphere microorganism (9.1 ± 5.8%), root exudates (2.2 ± 4.2%), and abiotic transformation (3.0 ± 2.8%) that were proved by several transformation products found in the root exudate exposure groups and unplanted controls, and a majority was phytotransformed by rice seedlings. Here, 61 products were determined through complex transformation pathways, including multihydroxylation, −HCl elimination, dechlorination, acetylation, sulfation, glycosylation, and amide acid conjugation. The acetylated and amide acid conjugates of CPs were first observed. Phase I and Phase II phytometabolic reactions of CPs were found intertwining. These findings demonstrate that multiactive transformation reactions contribute to the overlook of CPs accumulated in plants and are helpful for the environmental and health risk assessments of SCCPs in agricultural plants.

Chlorinated Paraffin Pollution in the Marine Environment

“…This section discusses CPs in marine organisms, revealing their widespread occurrence, bioaccumulation, and biomagnification in the food webs of various marine environments, and potential risk to human health (Figure , Figure , and Table S5). Generally, markedly higher detection frequency occurred in SCCPs and MCCPs than in vSCCPs and LCCPs in marine organisms, which could be owing to a combination of the current production, use, emission of CPs, and their partitioning and transformation behaviors worldwide. , …”

In Vivo Profiling and Quantification of Chlorinated Paraffin Homologues in Living Fish

“…The metabolism of CPs has been indicated in previous studies by following radioactively labeled CPs or untargeted screening by high-resolution MS techniques. − The natural isotopic pattern of chlorine atoms is a characteristic distinguishing the chlorine-containing metabolites from the endogenous metabolites, which provides excellent evidence to elucidate the formula of the potential CP metabolites . Nevertheless, the in vivo study of CP metabolism has not yet been reported.…”

Phloem Redistribution of Pesticide Phenamacril in Plants Followed by Extensive Biotransformation

“…In addition, root exudates and/or rhizosphere microorganisms might also facilitate the transformation of phenamacril in hydroponic solution. 38 During 7− 28 days of exposure, M-232-2 was the major metabolite in the hydroponic solution, which accounted for 64%−86% of the total peak areas of all metabolites. More kinds of hydrolyzed metabolites (M-232-1/2/3/4) were extensively formed in plant tissues, and they contributed 37%−84% of the total measured peak areas in both plant tissues.…”