The internal consistency of the 'analyst' diffusive sampler - A long-term field test

A recently developed diffusive sampler, intended for use in long-term ambie nt measurements of volatile aromatic hydrocarbons, has been tested to deter mine the upper limits of its Sampling capacity A test has been performed ov er 12-month period to evaluate these limits in terms of its 'internal consi stency (i.e. checking if the sum of the amounts of a given pollutant, deter mined over shorter consecutive periods, matches the amount determined from a single long-term exposure). Results demonstrate that the uptake rate of t he device, in a real (indoor) atmosphere, is constant for approximately 8 m onths for benzene and for approximately 10 months for toluene. The upper li mit for higher homologous species was not reached after exposure for a year to typical ambient concentrations. This means the device can be successful ly used for several months, thereby enabling low-cost determinations of amb ient BTX concentrations.