Abstract
A method based on flow injection was developed for the automated determination of chemical oxygen demand (COD) that provided a number of possibilities for improvement of the limitations of the standard manual methods. The strong oxidizing agent used is cerium(IV) sulphate, which resulted in a high degree of sample oxidation under mild operating conditions. The reaction between samples and cerium(IV) ion produced a sensitive and reproducible signal, i.e., a decrease in absorbance. The detection limit and relative standard deviation of the method were 0.5 mg l-1 and 0.6% (n = 10), respectively, for a standard sample consisting of l-glutamic acid and lactose in a ratio of 5:1. When 50-μl samples were injected at a frequency of 20 h-1, the determination range was 0.5-130 mg l-1 COD. Chloride was tolerated up to a concentration of 30 g l-1 without any masking agents. COD values for various types of wastewater samples correlated well with those obtained by standard manual methods.
Original language | English |
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Pages (from-to) | 237-244 |
Number of pages | 8 |
Journal | Analytica Chimica Acta |
Volume | 272 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 12 1993 |
Keywords
- Cerium(IV) sulphate
- Chemical oxygen demand
- Flow injection
- UV-Visible spectrophotometry
- Waters
ASJC Scopus subject areas
- Analytical Chemistry
- Biochemistry
- Environmental Chemistry
- Spectroscopy