Development of an Optode Detector for Determination of Anionic Surfactants by Flow Injection Analysis.

A flow-injection analysis (FIA) method for assaying an anionic surfactant (AS) using AS optode detector was demonstrated. The optode membrane consists of 2-nitrophenyl octyl ether as a plasticizer, lactone form rhodamine B (L-RB) and poly(vinyl chloride). The linear response concentration range of the AS optode to AS was 20 - 100 μmol dm-3 in the FIA system. The sampling rate for an AS ion (40 μmol dm-3 sodium dodecylbenzenesulfonate) in the proposed FIA system was ca. 5 samples h-1. The AS level in commercially available laundry detergents by the proposed FIA system was determined.