Fluorescent Microscopic Determination of Quinidine Sulfate in Serum Samples with Self-ordered Ring Technique by Capillary Flow Effect

In a 0.01 mol/L H2SO4medium with the aid of poly (vinyl alcohol)-124 (PVA-124), quinidine sulfate (QDS) can form a self-ordered ring (SOR) on the surfaces of hydrophobic glass slides based on the capillary effect. The maximal fluorescence intensity of the ring is proportional to the content of quinidine sulfate. An SOR method for determination of quinidine sulfate was established in the range 0.2–1.4×10−12 mol, and the limit of detection (3σ) was 2.6×10−14mol. Determination of quinidine sulfate in serum samples was successfully made with the recovery of 93.3%–101.3%.