Modern Analytical Techniques for the Quantification of Some Chemical Warfare Agents and Related Substances

Abstract

- The thesis content can be portrayed briefly as four chapters: • Chapter (I): General Introduction: - This chapter includes a brief review of the current state of the art in potentiometric solid-contact ion-selective electrodes and solid-contact ion selective electrodes. • Chapter (II): Screen-printed microsensors using polyoctyl-thiophene (POT) conducting polymer for ultra-trace detection of azides - This chapter describes the preparation, description and characterization of two novel all-solid-state potentiometric sensors for the detection of azide ion. The sensors are based on the utilization of iron II-phthalocyanine (Fe-PC) neutral carrier complex and nitron-azide ion-pair complex (Nit-N3-) as active detecting selective receptors, tetradodecylammonium tetrakis(4-chlorophenyl) borate (ETH 500) as lipophilic cationic additives and poly(octylthiophene) (POT) as the solid contact material on carbon screen-printed sensor made from a ceramic substrate. Varied pH ranged from 6 to 9 was applied, and the sensors display rapid, linear potentiometric response for low azide concentration and low detection limit for Fe-PC/POT/and Nit-N3-/POT based sensors. The high potential stability and sensitivity of the designed sensors are confirmed by electrochemical impedance spectroscopy (EIS) and constant-current chronopotentiometry measurement methods. Strong membrane adhesion and absence of delamination of the membrane are also verified. The fabricated sensors are successfully applied for azide quantification in synthetic primer mixture samples.