Application of polyaniline for potentiometric recognition of salicylate and its analogues

Presented work proofs usability of polyaniline (PANI) as a receptor for potentiometric detection of salicylates. The potentiometric selectivity of PANI-coated membranes based on tridodecylmethylammonium chloride (TDDMACl) towards salicylate is at least as good as the selectivity of membranes based on “conventional” specific supramolecular receptor systems such as Sn(IV) and Al(III) phthalocyanates. X-ray diffraction (XRD) and electric impedance spectroscopy (EIS) techniques are used to insight into the phenomena leading to improvement of salicylate-selectivity of PANI. These studies reveal the relative role of sodium chloride during the PANI polymerization that leads to preparing of partially crystalline polymer and decreasing of the “bulk” resistance of membrane. The “bulk” resistance change is attributed to introduction of the electronic conductivity into the system PANI/Salicylate. Determination of acetylsalicylate in pharmaceutical preparations with recovery at about 98-100% is reported. Additionally, the ability to detect (0.11 ±  0.01) × 10−3 M of salicylate present in a synthetic serum sample is demonstrated.