To use the Ehrlichs and Hoffman reagent test kit, put a tiny bit of your substance on a white ceramic plate. Place one drop of reagent on the sample. (Some reagents require a drop from two separate bottles.) Compare the color change to the color bars in the chart below. Most color changes happen fast. Some can take up to five minutes. Colors and times are approximate. Multiple factors can cause slight variations. Remember, reagents cannot detect purity. Just presence. Store them in a refrigerator. Wash the plate thoroughly when done.
