Page 20 - Quality control of pharmaceuticals (07-PA 704)

Instrument Error

All measuring devices are sources of determinate errors, such as
uncalibrated pipets, burets, and volumetric flasks.

Minimise instrument errors by frequent calibrations for both
the apparatus such as volumetric flasks, burettes …etc.
and the electronic devices such as spectrometers.

2. Method Error
Errors inherent in a method are difficult to detect and are thus the most
serious of the the three types of determinate error.
Example:
Slowness of some reactions.
Incompletness of the reaction.
Possible occurrence of side reactions.
Impurities in reagents.

Three approaches to minimise Method errors:
analysis of certified standards
use 2 or more independent methods