Abstract:

The article deals with a quite usual laboratory activity – pipetting. This method of measuring the volume of liquids appears to be relatively safe in comparison with other chemical operations. But, on the other hand, the use of classical glass pipettes is connected with many security and health risks. The usual chemical hazards associated with inhalation of the pipetted substance or its intrusion into the mouth are repeatedly mentioned to the pupils and students and they are trained to prevent these situations. However, the health risks associated with the use of glass pipettes are being nearly never mentioned at schools, and that is why Czech pupils and students are aware of them only exceptionally.

In the introduction to our article we explain the safety risks and health risks, advantages and disadvantages associated with different pipetting methods. Afterwards, we do analyze the results of a questionnaire survey between the students of chemistry teaching, focused on their favorite pipetting method and reasons to their decision. The last part of our research is the analysis of the results of different methods of pipetting carried out by the 3rd grade students of chemistry teaching at Faculty of Education, Masaryk University, Czech Republic. The analysis is focused on the correctness of pipetting (mean value of the pipetted volume) and accuracy of pipetting (relative standard deviation in repeated pipetting of the same volume).

Keywords:

Chemistry, laboratory, safety, intoxication, health.