Research Article

Comparing the Heterogeneity of Copper-Binding Characteristics for Two Different-Sized Soil Humic Acid Fractions Using Fluorescence Quenching Combined with 2D-COS

Table 1

Specific UV absorbance (SUVA) values and fluorescence distributions for the two different size fractions of a soil humic acid and the mixture.

SampleSUVA ( L (mg C)−1m−1) 𝐸 4 / 𝐸 6 %PLF%HLF%THLF

1–10 K 4 . 0 6 ± 0 . 0 2 1 1 2 . 4 ± 1 . 9 1 0 . 8 ± 0 . 1 3 8 . 5 ± 0 . 2 6 0 . 7 ± 0 . 4
>100 K 3 . 8 7 ± 0 . 0 5 4 . 4 ± 0 . 2 0 . 0 ± 0 . 0 3 9 . 1 ± 0 . 3 6 0 . 9 ± 0 . 5

1Standard deviation based on triplicate samples.