Time RC1/DOC RC2/DOC RC3/DOC N 3.31-4.2 0.1893 0.309* 0.3069* 77 4.9-4.10 0.121 0.2089 0.1068 50 4.19-4.20 -0.3045* -0.1982 0.0635 45 5.13-5.15 0.1422 0.301** 0.4483** 72 5.25-5.27 0.1488 0.3209* 0.3385* 57 *significant level P<0.05 **significant level P<0.01

Table 5: Relationship between fluorescence intensity of three components and DOC.