SAFETY

Avoid skin contact with all known and unknown solutions and precipitates.

Be particularly careful with solutions and precipitates containing chromium, barium or lead ions. These substances are toxic and can be absorbed through the skin. Wash your hands immediately upon contact with any of these solutions or precipitates.

The dimethylglyoxime used in the Ni confirmation test is dissolved in ethyl alcohol. Ethyl alcohol is highly flammable and will ignite if brought close to an open flame.

Use care in handling all acids and bases.

Nitric acid (HNO₃) is not only a strong acid but also a strong oxidizing agent. The proteins in human skin will be oxidized through the xanthoproteic reaction upon exposure to concentrated HNO₃ solution. This process is painful and produces a yellow discoloration of the skin that does not wash off!

Flush with water immediately if any acid or base is spilled on the skin.

Be sure the centrifuge is properly balanced before use by placing a tube containing water directly opposite your sample tube. Allow the centrifuge to coast to a stop before removing the test tubes.

Dispose of all chipped or cracked test tubes in the broken glass container.

Wash your hands thoroughly before leaving the lab.