The oleum is then diluted with water to form concentrated sulfuric acid. The concentrated version should be diluted before use. If concentrated by evaporation, the drug may be diluted before administration. Concentrated analytes are often diluted to improve accuracy. Ammonia is so toxic that it must be diluted rapidly with large quantities of water. The sample may also be diluted or concentrated prior to analysis on an instrument. Conversely, coconut cream can be diluted into thinner coconut milk by simply adding water. They can be diluted in solvents like pure ethanol and polyethylene glycol. Coconut milk can be diluted to create coconut milk beverages. It is diluted with normal saline and injected directly into the corpora cavernosa. The flasks are then diluted to the mark and mixed well. The aged alcohol is then further diluted with demineralized water before bottling. Color used as a dye can be diluted. Similarly, noxious chemicals might be diluted considerably in an aquatic environment compared to terrestrial. As such, most vodka is diluted with water prior to bottling.