A
system and method are provided for determining a concentration of an
analyte in a material sample. The method includes providing a sample element with a
sample chamber at least partially defined by at least one window formed from a material having greater than about 1%
wavelength-domain variation in absorbtivity of
electromagnetic radiation incident thereon. The method further includes employing the sample element with an
analyte detection
system which determines the concentration of the
analyte with clinically acceptable accuracy.