Quaternary (triphenyl-) phosphonium compounds: Environmental behavior and toxicity

Abstract

An analytical method based on high resolution mass spectrometry coupled with liquid chromatography (LC-HRMS) for 25 quaternary phosphonium compounds (QPCs) and derived phosphine oxides (POs) was developed and validated. To investigate the occurrence and fate of QPCs in the aquatic environment, water, suspended solids and sediments from the rivers Rhine and Elbe (upper and middle Elbe as well as tidal Elbe) were analyzed, as well as samples from tributaries bearing significant loads of QPCs. For the first time, the quaternary phosphonium compound tetrabutylphosphonium (BuP) was detected. In the river Elbe concentrations were determined of up to 4700 ng/L (surface water) and 1000 μg/kg (sediment), respectively. Analysis of a time series of suspended solids (2005-2015) showed that QPCs have been present in the Elbe and Rhine catchment for at least one decade, with partly rising tendency. A degradation experiment with Rhine sediment revealed that triphenylphosphonium compounds (R-PhP) and BuP are persistent in contact with sediment and suspended solids and tend to sorb onto sediment particles. Toxicological studies (reactive oxygen species (ROS) after substance exposure, Ames test, Micronucleus test, determination of cytotoxicity) with selected QPCs confirmed that all of them exhibit cytotoxicity and some even genotoxic potential at elevated concentrations, which emphasizes the need for an emission regulation of these compounds.

Soft QPCs: Biscationic Quaternary Phosphonium Compounds as Soft Antimicrobial Agents

“…Under basic conditions, both P3P-12A,12A and P6P-12A,12A completely decomposed within 1 h and 5 h, respectively (Figure 3, bottom right and S12). In support of these 31 P NMR data, LCMS analysis indicated that the soft QPCs underwent hydrolysis at the phosphonium center rather than at the amide; the amide side chain was in fact observed completely intact (Figures S13 and S14). The major phosphorus decomposition product was identified to be a phosphine oxide (Figure 3, bottom).…”

“…Pleasingly, no mitochondrial toxicity was observed for the compounds tested (see Figure S23 and Table S2). This is particularly gratifying since some indication of toxicity of certain phosphonium compounds to aquatic flora and fauna has been reported …”

“…We hypothesized that the soft QPCs would degrade rapidly under acidic conditions due to expected reactivity at the amide and similar to the fate of soft QACs 15 while displaying relative stability in neutral and basic conditions. However, instead of observing the decomposition of the QPCs at pH = 4, both P3P-9A,9A and P6P-9A,9A immediately precipitated out of solution leaving no observable 31 P NMR signals for product or decomposition products (for full details, see Supporting Information). 1 H NMR spectroscopy and LCMS analysis confirmed that the precipitate was the corresponding intact P3P-9A,9A and P6P-9A,9A products: no decomposition products were observed from amide hydrolysis.…”

How to Address Consumers’ Concerns and Information Needs about Emerging Chemical and Microbial Contaminants in Drinking Water; The Case of GenX in The Netherlands

“…In addition to well-known drinking water contaminants, several (often unregulated) emerging chemical compounds have been detected in drinking water and its resources over the past decades, posing a new or increased threat to public health [17][18][19][20][21][22][23]. These chemicals are referred to as emerging contaminants, emerging pollutants or contaminants of emerging concern [24].…”

“…These chemicals are referred to as emerging contaminants, emerging pollutants or contaminants of emerging concern [24]. Recent examples are perfluoroalkyl and polyfluoroalkyl substances (PFAS) [25], 1,4-dioxane [21] and quaternary phosphonium compounds [20]. In addition to emerging chemical contaminants, emerging contaminants of a microbial nature have also been identified in drinking water in recent years [26,27].…”