Contamination with chemicals

One example of a situation where the lack of accuracy can lead to faulty results is in contamination with other chemicals.

You should always make sure that the glassware and equipment you apply is clean. Consider your washing procedure: After rinsing glassware with clean water you should also rinse with demineralized water.

Why? Because the regular water contains minerals, and when the water evaporates from the surface of the glassware, the minerals will still stick to the glassware. If you are analyzing for a certain element or ion, you don’t want to include the minerals from the water in that analysis. The same goes without saying when you are using water as a solvent: Always use demineralized water.

The chemicals and solvents in the lab can easily be contaminated as well. To avoid that it is important that you always use clean spatulas for dipping into solids, and clean pipettes for liquid chemicals.