title: Flow injection spectrophotometric determination of N-acetyl-L-cysteine as a complex with palladium(II).
abstract: We describe a new method using flow-injection analysis with spectro-photometric detection, suitable for the determination of N-acetyl-L-cysteine (NAC). The proposed method is appropriate for the determination of NAC in reaction with Pd(2+) ions in the concentration range from 1.0 × 10(-5) mol L(-1) to 6.0 × 10(-5) mol L(-1). The detection limit NAC was 5.84 × 10(-6) mol L(-1) and the recorded relative standard deviation of the method is in the range from 1.67 to 4.11%. NAC and Pd(2+) form complexes of Pd(2+):NAC molar ratios of 1:1 and 1:2, depending on the ratio of their analytical concentrations. The cumulative conditional stability constant for the Pd(NAC)(2)(2+) complex is β(12)' = 2.69 × 10(9) L(2) mol(-2). The proposed method was compared with the classic spectrophotometric determination of NAC, using the same reagent, PdCl(2), and had shown certain advantages: a) shorter analysis time; b) the use of smaller volumes of sample and reagents, which make the proposed method cheaper and faster for NAC determination in real samples without sample pretreatment.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry and Technology, Teslina 10/V, 21000 Split, Croatia. josipa@ktf-split.hr
authors.forename: Josipa
authors.initials: J
authors.lastname: Giljanović
authors.forename: Mia
authors.initials: M
authors.lastname: Brkljača
authors.forename: Ante
authors.initials: A
authors.lastname: Prkić
mesh_terms: D000111:Acetylcysteine / Q000737:chemistry*; D000465:Algorithms; D002138:Calibration; D056831:Coordination Complexes / Q000737:chemistry*; D017022:Flow Injection Analysis / Q000379:methods; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D010165:Palladium / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods
chemical_list: D056831:Coordination Complexes; D010165:Palladium; D000111:Acetylcysteine