Fluorescence inner filtering in double-pass cell configurations. Part 1. Primary inner filtering

Abstract

Relationships are derived for primary inner filtering in double-pass cells and compared with observed inner filtering. It appears that a significant contribution to single-pass inner filtering is caused by a double-pass component in conventional measurement as a direct result of reflection from cell walls. It is possible to determine qualitatively if inner filtering is present and quantification can be effected over a limited absorbance range. The method described is inexpensive and suitable for automation.