International regulations require the specification of an uncertainty estim
ate related to experimental data. In chemistry, the situation that a straig
htforward statistical machinery is not available for assessing the uncertai
nty of a datum extracted from complex systems often occurs. Non-linearity,
non-normality, correlation and other nuisance factors add to the complicati
ons. Monte Carlo resampling algorithms, in combination with abundant fast c
omputing power, have made techniques feasible that do not require profound
mathematical insight, but, nevertheless, are fairly general. Assessment of
confidence limits at different levels of correctness is discussed using sta
ndard and bootstrap methods. Inferiority of standard normal approaches beco
mes evident even in mildly non-linear situations. (C) 2000 Elsevier Science
B.V. All rights reserved.