Applicability of Passive Sampler Disks for Collection of Time-integrated River Water Samples for Toxicity Bioassay

Abstract

The applicability of Empore TM styrene-divinylbenzene reverse-phase sulfonated (SDB-RPS) passive sampler disks for integrative sampling of organic chemicals in river water was investigated to evaluate toxicity levels via bioassay using larval medaka (Oryzias latipes). Those disks were deployed for periods of 1, 2, 3, 7, and 10 days (PS different period), and at 2-day intervals over the 10-day sampling period (PS interval). Six 10-L grab samples were collected at the same time as PS interval sampling, and thereafter concentrated using Sep-Pak ® Plus PS-2 cartridges (GS). Adsorbed chemicals were subsequently eluted from Sep-Pak cartridges and SDB-RPS disks and prepared for toxicity tests and gas chromatography/mass spectrometry analysis. Compared with all PS samples, GS samples showed strong toxicity results. None of the PS interval samples showed toxicity, even though the amount of adsorbed chemicals in the 2nd interval sample was higher than in PS 7-and 10-day samples, which showed toxicity. Furthermore, the PS 10-day sample contents were not equivalent to the accumulated amounts of adsorbed chemicals in PS interval samples. On the basis of these results, it is assumed that during long-term sampling, chemicals adsorbed on disks might be affected by desorption or decomposition, and that some might be converted to more toxic compounds.