Development and Validation of a Novel Kinetic Spectrophotometric Method for Determining N-acetyl-L-cysteine
Year: 2025
Type: article
Abstract: N-acetyl-L-cysteine (NAC) is a precursor of glutathione and a natural antioxidant. It is used to treat paracetamol overdose and to dissolve thick bronchial mucus. A novel, simple, reproducible, and rapid kinetic spectrophotometric method for determining NAC in pharmaceutical formulations is proposed. The method is based on a redox reaction where NAC reduces bis(bathocuproinedisulfonate)cuprate(II), forming a yellow-orange complex of bis(bathocuproinedisulfonate)cuprate(I). The resulting stable complex exhibited maximum absorbance at λ = 483 nm. Under optimised chemical reaction parameters, both the fixed-time and initial-rate methods were used to generate calibration curves. For the fixed-time method, the curve was linear in the concentration range of 3.0 · 10−7 to 7.0 · 10−5 mol l−1, with the equation y = 13140x − 0.0005 and a coefficient of determination of R2= 0.9999. For the initial-rate method, the curve was linear in the concentration range of 7.0 · 10−7 to 7.0 · 10−5 mol l−1 with the equation y = 1.040x + 3.220 and R2 = 0.9991. The slope of the logarithmic form of the calibration curve (1.040) for the initial-rate method confirmed the pseudo-first order nature of the reaction. The proposed method was successfully applied for the determination of NAC in commercial pharmaceutical preparations, yielding results comparable to those obtained using the recommended method according to the pharmacopoeia.
Source: Kemija u industriji
Institutions: University of Split, University of Mostar
Language: English
Subfield: Analytical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4410405285