Fluorescence inner filtering in double-pass cell configurations. Part 2. Validity of assumptions for primary inner filtering diagnosis

Abstract

In Part 1 relationships were derived for primary inner filtering in double-pass cell configurations leading to an equation that is useful for diagnosing primary inner filtering. Unfortunately, the non-linearity of the experimental curve represented a significant departure from the linear theoretical model although some artifacts associated with the instrumentation predicted a minor departure of the experiment from linearity. Other assumptions such as beam collimation and fluorescence emission radiating from a point source centred in the cuvette were used, although invalid for most spectrofluorimeters. In this paper these two assumptions are evaluated, bringing the experimental working curves into closer agreement with the theoretical relationship.