Indeterminate error of dilution with pipette and flask is studied base
d on experiments, statistics, Monte Carlo simulation and probability t
heory. Equations which describe the error of sample concentration afte
r the dilution are probabilistically derived and verified experimental
ly and statistically. The uncertainty structure of dilution is shown t
o be different for the pipette-pipette dilution and the pipette-flask
dilution. The theory for dilution error developed here will be a basis
to predict the precision of some chemical analyses such as the intern
al standard method in chromatography.