Determination of dissolved organic carbon by inductively coupled plasma atomic emission spectrometry

Dissolved organic carbon (DOC) present in soil solutions was measured by inductively coupled plasma atomic emission spectrometiy (ICPAES) using the two C(I) lines at 193.09 nm and 247.856 nm. Carbon standards, prepared from sucrose in the range 100 to 1,000 mg/L, produced linear coefficients of determination of r2 ≥ 0.9998 for each of the lines with calculated detection limits of 0.034 and 1.094 mg/L for each line, respectively. Inorganic carbon was eliminated from solution by the addition of concentrated nitric acid and sparging with high purity nitrogen for 30 min. A comparison of the DOC values for soil solutions extracted from nine soil samples by ICPAES and dichromate oxidation showed a high degree of correlation (r2 ≥ 0.9982).