2005A&A...429..297M

We present a chemical abundance analysis on the basis of high signal-to-noise and high resolution spectra for 12 stars of our newly defined sample. The selection criterion for the stars of this sample was their position in the ``RV Tauri'' box in the [12]-[25], [25]-[60] two-colour diagram. An additional requisite was the presence of a near-IR excess. We found that the photospheres of nine stars are affected by the depletion process. Since the most likely origin of the near-IR excess is a disc, this strongly suggests that the phenomenon of depletion and the presence of a disc are linked. Among the depleted stars we find different depletion patterns. In seven stars elements with a condensation temperature below 1500K are not or only slightly affected. Large underabundances are measured only for most elements with a condensation temperature above 1500K.