Test element and method for quantitative NIR spectroscopic analysis

摘要

The test element includes a support, and a constant light-path providing layer consisting essentially of a diffusely-reflecting material that is sufficiently porous in all directions as to allow a liquid to spread uniformly in all directions, and homogeneously and diffusively reflects at least 95% of near infrared (NIR) radiation. The element is free of reagents capable of reacting with the analyte, and a hydrophilic polymer layer that is both separate from the light-path providing layer, and has a thickness equal to or greater than 1 micron. The element further includes a mirror layer in-between the light-path providing layer and the support and in contact with the support. Such arrangement is effective to increase the path length of NIR radiation through the layer.