Development of Solid Ceramic Dosimeters for the Time-lntegrative Passive Sampling of Volatile Organic Compounds in Waters

摘要

Time-integrative passive sampling of volatile organic compounds (VOCs) in water can now be accomplished using a solid ceramic dosimeter. A nonporous ceramic, which excludes the permeation of water, allowing only gas-phase diffusion of VOCs into the resin inside the dosimeter, effectively captured the VOCs. The mass accumulation of 11 VOCs linearly increased with time over a wide range of aqueous-phase concentrations (16.9 to 1100 μg L~(-1)), and the linearity was dependent upon the Henry's constant (H). The average diffusivity of the VOCs in the solid ceramic was 1.46 X 10~(-10) m~2 s~(-1) at 25 °C, which was 4 orders of magnitude lower than that in air (8.09 × 10~(-6) m~2 s~(-1)). This value was 60% greater than that in the water-permeable porous ceramic (0.92 × 10~(-10) m~2 s~(-1)), suggesting that its mass accumulation could be more effective than that of porous ceramic dosimeters. The mass accumulation of the VOCs in the solid ceramic dosimeter increased in the presence of salt (>0.1 M) and with increasing temperature (4 to 40 °C) but varied only slightly with dissolved organic matter concentration. The solid ceramic dosimeter was suitable for the field testing and measurement of time-weighted average concentrations of VOC-contaminated waters.