Cleaning out the old lab!
The old lab did research on metals present in water samples. They used a lot of spectroscopy and electrochemistry to do this.
These are ‘Ion Standards’ of different transition metals. Each has a standard concentration of 1000 µL/ml. You can use these standards to calibrate your instruments; that way your instruments will be able to determine the concentration of one of these metals accurately (within a small error range).
From left to right: Mercury, Chromium, Cerium, Cobalt, Rhodium*, Mercury, Manganese, Magnesium.
(again, you can see the difficulty with disposing of these chemicals easily =P)
*not Rhenium, thanks prussianpurple =]