New sampling device for on-site measurement of SVOC gas-phase concentration at the emitting material surface

The gas-phase concentration at the material surface (y(0) ) is pointed out in the literature as a key parameter to describe semivolatile organic compound (SVOC) emissions from materials. This is an important input data in predictive models of SVOC behavior indoors and risk exposure assessment. However, most of the existing measurement methods consist of determining emission rates and not y(0) and none allow on-site sampling. Hence, a new passive sampler was developed. It consists of a glass cell that is simply placed on the material surface until reaching equilibrium between material and air; y(0) is then determined by solid-phase microextraction (SPME) sampling and GC-MS analysis. The limits of detection are at the mu g/m(3) level and relative standard deviations (RSD) below 10%. A variation of 11% between two sets of experiments involving different cell volumes confirmed the y(0) measurement. In addition, due to the ability of SVOCs to be sorbed on surfaces, the cell wall/air partition was assessed by determining the inner cell surface concentration of SVOCs, which is the concentration of SVOCs adsorbed on the glass, and the cell surface/air partition coefficient (K-glass ). The recovery yields of the SVOCs sorbed on the cell walls are strongly compound-dependent and comprise between 2 and 93%. The K-glass coefficients are found to be lower than the stainless steel/air partition coefficient (K-ss ), showing that glass is suitable for the SVOC sampling. This innovative tool opens up promising perspectives in terms of identification of SVOC sources and quantification of their emissions indoors, and would significantly contribute to human exposure assessment.