Analytical Sciences


Abstract − Analytical Sciences, 24(6), 803 (2008).

Simultaneous Determination of Potassium and Nitrate Ions in Mouthwashes Using Sequential Injection Analysis with Potentiometric Detection
N. ZÁRATE,* E. IRAZU,* A. N. ARAÚJO,** M. C. B. S. M. MONTENEGRO,** and R. PÉREZ-OLMOS*
*Dpto. Química Analítica, Escuela Universitaria de Ingeniería Técnica Industrial, Universidad del País Vasco, Plaza de la Casilla 3, 48012 Bilbao, Spain
**REQUIMTE, Dpto. de Química Física, Faculdade de Farmacia, Universidade do Porto, Rua Anibal Cunha 164, 4050 Porto, Portugal
Two methods for the determination of potassium nitrate in mouthwashes, used against dentin hypersensitivity, have been simultaneously implemented in an sequence injection analysis (SIA) system. In addition to in-line dilution of the samples, the equipment simultaneously detected potassium and nitrate using two tubular potentiometric detectors, selective to each ion, providing a real-time assessment of the quality of the results. Both determinations were shown to be precise and accurate and the obtained results do not statistically differ from those furnished by applying the AES and HPLC reference methods.