The theoretical development of the concept of detection limit in multi
component systems has only begun very recently and its practical appli
cations are limited to a few specific techniques such as emission spec
trometry (ICP-OES) or high performance liquid chromatography (HPLC-DAD
). This paper critically reviews the theoretical approaches advanced u
p to the present, describes the hypotheses and theoretical backgrounds
on which they are based and discusses the advantages and limitations
of the different techniques and derived estimators. The connection wit
h the derivation of the detection limits based on the var(c(un)) varia
nce associated to the predicted response of an individual observation
in regression theory is introduced and finally, some suggestions as to
potential areas of interest for future development are envisaged.