Description:
Many of the major time intensive steps in analytical chemistry procedures are very simple, routine steps that potentially could be automated. For example, when performing a series of chemical separation steps, often the matrix of the sample needs to be changed at the end of one separation before a sequential separation is performed. This matrix change typically involves evaporating the excess solution the sample is in to near dryness and then reconstituting the sample in a new solvent matrix. This evaporation is done under controlled conditions because of the need to carefully ensure the solvent is fully evaporated while the solute product of interest is not destroyed by overheating. An automated dry-down instrument would be very useful for this process to increase efficiency. Such a system would need to be compatible with various acid vapors (specifically to include HNO3, HCl, HF, and HClO4). Important features are the sample throughput and routing of off-gases so as to be able to process large numbers of samples (e.g., as many as 24, each of volume 0.1-10 milliliters) without cross contamination between them. Many of the principles needed for successful implementation of an automated evaporator are laid out in the patents referenced below. Altering these concepts for use with materials with high acid concentrations are needed. For example, to our knowledge no current commercial systems can use perchloric acid (HClO4).
