Speciation of Mn(II) and Mn(VII) by on-line spectrophotometric sequential injection analysis

• Published in: Analytica chimica acta Vol. 499; no. 1; pp. 129 - 137
• Main Authors: van Staden, J.F, Mulaudzi, L.V, Stefan, R.I
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 04.12.2003; Elsevier
• Subjects: 4-(2-Pyridylazo) resorcinol; Analytical chemistry; Chemistry; Exact sciences and technology; Mn(II); Mn(VII); On-line; Sequential injection analysis; Speciation; Spectrometric and optical methods; Sequential injection analysis; Mn(VII); 4-(2-Pyridylazo) resorcinol; Mn(II); On-line; Speciation; Resorcinol derivatives; Manganese II; Injection; Azo compound; Absorption spectrometry; Sequential method; Detection limit; Manganese VII; Sampling; Ultraviolet visible spectrometry
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/S0003-2670(03)00883-3

An on-line sequential injection analysis system with spectrophotometric detection using 4-(2-pyridylazo) resorcinol as reagent is proposed for the speciation of Mn(II) and Mn(VII). The sampling frequency is 30 determinations per hour. The linear range for Mn(II) is 0.020–0.500 mg/l with a detection limit of 0.005 mg/l and for total Mn 0.025–0.550 mg/l with a detection limit of 0.008 mg/l. The % RSD is 0.27 and 0.34 for Mn(II) and Mn(VII), respectively ( n=10). Chemical masking of Fe and Al was achieved by on-line addition of a 0.1 mol/l NaF solution. The proposed system yielded results that compare very well with standard methods.