SAFETY

Wear safety goggles at all times!

Avoid skin contact with the known and unknown solutions or precipitates containing any chromium, lead or barium 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. Exercise care in using acids and bases. HNO3 is not only a strong acid but also a strong oxidizing agent. This property is the basis for the xanthoproteic reaction where the majority of proteins, such as skin, react with HNO3 to give a yellow color. This yellow color will not wash off! Flush with water immediately if acid or base is spilled on the skin.

Always wash your hands before leaving the laboratory.

The dimethylglyoxime is dissolved in ethyl alcohol, which will ignite if brought too close to an open flame. Be sure the centrifuge is balanced to prevent personal injury or damage to the centrifuge. Allow the centrifuge to coast to a complete stop before removing test tubes. Because the lip of a test tube may have a small unnoticeable chip, cuts can result from contact with the rapidly spinning glass if you attempt to stop the centrifuge with your hand. You should discard any chipped test tubes into the glass disposal container.