Abstract
Reflectance UV-Vis spectroscopy and UV resonance Raman (UVRR) spectroscopy are both nondestructive techniques that are applicable to study trace concentrations of lignin in-situ. In this study, unbleached and bleached softwood kraft pulps were analyzed by reflectance UV-Vis (k/s) and UVRR spectroscopy to follow lignin and hexenuronic acid (HexA) contents and structural changes in residual lignin. The height of the lignin band in the UV-Vis spectra (280 nm) correlated well with the lignin band in the UVRR spectra (1605 cm-1) for semi- or fully-bleached pulps. However, the correlation was much weaker for unbleached pulps. Also the results for hexenuronic acid content by UV-Vis (240 nm) and UVRR (1658 cm-1) methods correlated well for most of the pulps, but for unbleached or peroxide-bleached samples the interference from other structures affecting these bands was obvious.
| Original language | English |
|---|---|
| Pages (from-to) | 1600-1619 |
| Number of pages | 20 |
| Journal | BioResources |
| Volume | 4 |
| Issue number | 4 |
| Publication status | Published - 2009 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- Bleaching
- Kraft pulps
- UV resonance Raman (UVRR) spectroscopy
- UV-Vis spectroscopy