Lignocaine ion-selective electrodes based on its ion-associates with cobalt thiocyanate, phosphomolybdate and reineckate complex ions

✍ Scribed by Yousry M. Issa; Adel F. Shoukry; Mahmoud S. Rizk; Ehab M. Atia

• Publisher: Wiley (John Wiley & Sons)
• Year: 1995
• Tongue: English
• Weight: 485 KB
• Volume: 64
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/jctb.280640410

✦ Synopsis

Lignocaine (Lg) selective PVC membrane electrodes based on the ionassociates lignocaine-cobalt thiocyanate (I), lignocaine-phosphomolybdate (11) and lignocaine-reineckate (111) were constructed. The electrodes exhibited linear response over the concentration ranges 0.02-100, 0.01-100 and 0.01-100 mM for I, I1 and 111, respectively. pH did not affect the electrodes performance within the ranges 3-6, 3-7 and 3-6.5 for lo-', lo-' and M LgHCl, respectively. Interferences are negligible for many inorganic cations, sugars and amino acids. The isothermal coefficients were found to be O~OOO 459, 0. OOO 698 and 0.000404 V "C-' for I, I1 and 111, respectively. The life spans of the electrodes are more than 2 months of continuous work. Potentiometric titration and the standard addition method were used to determine LgHCl in pure solutions and in pharmaceutical preparations with high accuracy and precision.