A: Yes you can. The basic DGT equation can be used.
cDGT (nmol or ng mL-1) is the mean concentration of analyte measurable by DGT in the pore water adjacent to the surface of the DGT device, averaged over the total deployment time.
M (nmol or ng) is the mass of analyte accumulated in the binding layer.
Δg (also known as δmbl) (cm) is the total thickness of the materials that comprise the diffusion layer (gel and filter membrane).
Dmdl (cm2 s-1) is the diffusion coefficient of analyte in the material diffusion layer.
Ap (cm2) is the physical area of the exposed filter membrane or the area of sliced gel that is measured.
t (s) is the deployment time.
The key thing here is that because DGT continually removes analyte, its concentration at the surface of the DGT device may be lowered during the course of the deployment. In some soils and sediment the analyte may be continually resupplied to solution from the solid phase. When this effective buffering is substantial the measured cDGT is the same as the cDGT that would be measured directly on the porewaters. Comparison of cDGT with alternative measurements of concentrations in porewaters (or soil solution) can provide information on the dynamics of analyte exchange between porewater and solid phase.
A detailed appreciation with thorough referencing of the principles involved in deploying DGT in soils and sediments can be found in
- J, Lehto, Principles and applications in soils and sediments, Chapter 7, in: Diffusive Gradients in Thin-films (DGT) for Environmental Measurements, Editor: William Davison, Cambridge University Press, 2016