Side-View Type of Waveguide Flow Cells for Fluorimetry as a Detector for Flow Injection Analysis of Lead

Abstract

Several types of cells made of Pyrex® ( n_D²⁰ = 1.474) capillaries were constructed for fluorimetry from the standpoint of waveguiding of the excitation source. Fluorescence intensity detected from a vortex cell is virtually linearly dependent on the refractive index of the solvent containing the fluorophore. This type of cell is applied as the fluorimctric detector for the flow injection analysis of the lead(II) ion. The lead ion was incorporated into a macrocyclic ligand, cryptand 2.2.2, and the resulting compound was ion-paired with eosine (fluorescent dye). This complex ([Pb(cryptand 2.2.2)]eosine) was extracted into chlorobenzene ( n_D²⁰ = 1.5248) and was introduced into the above vortex cell. An Ar⁺ laser operated at 514.5 nm was used as the light source, and the fluorescence of eosine at 600 nm was detected. Two ng/mL of Pb(II) ion was obtained as the detection limit.