Highly Sensitive Visual Fluorometry of Aluminium at ppb Level with Ring-like Solid Phase of Poly(vinyl alcohol)

By constructing a self-ordered nearly perfect ring system, a new type of visual test method has been developed. Poly(vinyl alcohol) forms a sharp ring–like solid phase (10.6 mm diameter) when a 100-(mu)l drop of its aqueous solution was evaporated on a poly(vinyl chloride) plate. Aluminium ion of 1 – 30 ppb has been determined visually as a fluorescent 1:1 chelate of 2,2ʹdihydroxyazobenzene concentrated into the ring.