Solid Contact Nitrate Ion-selective Electrode Based on Cobalt(II) Complex with 4,7-diphenyl-1,10-phenanthroline

Nitrates are a group of compounds widely distributed in the natural environment with many applications in various industries. Due to their ambiguous impact on the human body and suspicions of their carcinogenic activity, they have been very popular for decades and are the subject of research by many scientists in the field of medicine, biology and chemistry. Due to the need to monitor their content in environmental and food samples, various methods for their determination are developed. This paper proposes the use of a nitrate ion-sensitive ion selective electrode with a membrane containing as the active ingredient a new cobalt(II) complex with 4,7-diphenyl-1,10-phenanthroline (Bphen) of the formula Co(Bphen)(2)(NO3)(2)(H2O)(2). The obtained sensor showed the theoretical slope of the characteristic curve, a wide measuring range, as well as short response time and very good potential stability. It was successfully used for the determination of nitrates in real samples: in mineral water, tap water and river water from eastern Poland.