Determination of non-extractable residues in soils: Towards a standardised approach.

After exposure of soils to anthropogenic organic chemicals non-extractable residues (NER) can be formed. The quantitative proportion of a compound which remains non-extractable is operationally defined by the extraction procedure employed and can be quantified only when using isotope labelled compounds (e.g.

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

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.