Effects of EDTA on signal stability during electrochemical detection of acetaminophen

• Published in: Journal of pharmaceutical and biomedical analysis Vol. 34; no. 5; pp. 871 - 878
• Main Authors: de Carvalho, Rosangela M, Freire, Renato S, Rath, Susanne, Kubota, Lauro T
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 10.03.2004; Elsevier Science
• Subjects: Acetaminophen; Acetaminophen - analysis; Analysis; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Edetic Acid - analysis; EDTA; Electroanalytical; Electrochemistry; Flow Injection Analysis - instrumentation; Flow Injection Analysis - methods; Fundamental and applied biological sciences. Psychology; General pharmacology; High performance method; Medical sciences; Pharmacology. Drug treatments; Solid electrodes; EDTA; High performance method; Acetaminophen; Electroanalytical; Solid electrodes; Antimigrainous agent; Electrochemical detector; Paracetamol; Sensitivity; Analgesic; Electrolyte; Antipyretic; Chelating agent
• DOI: 10.1016/j.jpba.2003.11.005
• ISSN: 0731-7085

The use of EDTA in the medium to avoid the passivation of a solid electrode during electrochemical analysis of acetaminophen is presented in this work. The performance of this system was investigated with respect to pH, applied potential and supporting electrolyte concentration. The major advantage in using EDTA in the supporting electrolyte is the significant increase in sensitivity, precision and stability of the measurements, when compared to the system in absence of the chelating agent. The sensitivity increases 5.5 times (21.5 and 3.9mAlmol−1 in the presence and the absence of EDTA, respectively), the repeatability (n=20) is 3.5 times better, expressed by within-run-precision of 4.0% for 6.0×10−5moll−1 acetaminophen in the presence of EDTA while, in its absence, the within-run-precision was higher than 14%. Moreover, the system showed excellent stability, allowing more than 120 measurements with no significant changes.