基于PARAFAC分析的西藏昌都大骨节病地区水体腐殖质性质研究

Characteristics of Humic Substances in KBD-Affected Region of Changdu,Tibet Based on PARAFAC of Fluorescence

基于荧光平行因子分析法(PARAFAC),对西藏昌都大骨节病病区与非病区饮水及沉积物中腐殖质进行研究。腐殖质总有机碳含量在病区和非病区样本间未表现显著差异。PARAFAC识别出5个荧光成分:成分1为类氧化醌,成分2为类色氨酸,成分3为陆地源类腐殖质,成分4为类还原醌,成分5为类酪氨酸。病区水中富里酸(FA)的成分1 (p<0.10)、成分4 (p<0.05)以及水中胡敏酸(HA)的成分4 (p<0.10)等类醌成分含量高于非病区,并且存在显著差异。对比水中腐殖质醌氧化还原系统在病区和非病区之间的差异,发现还原醌形态的差异大于氧化醌形态,FA醌系统的差异大于HA醌系统。虽然HA中还原醌含量较高,但HA在水中的碳含量很低,对大骨节病影响较弱,在病区与非病区之间差异较小。沉积物中腐殖质还原醌含量较高,且与水中腐殖质存在一定的相互转化关系,但在病区和非病区之间未表现显著差异。深入了解腐殖质不同组分以及醌的不同氧化还原形态在病区与非病区之间的差异,对病区改水工程有重要意义。

Humic substances(HS) in Kaschin-Beck disease(KBD) affected regions were analyzed based on parallel factor analysis(PARAFAC) of fluorescence. Total organic carbon content of HS did not show significant difference between endemic and disease-free areas. Five fluorescence components were identified with PARAFAC,i.e. component 1(oxidized quinone-like), component 2(tryptophan-like), component 3(terrestrial humic-like),component 4(reduced quione-like) and component 5(tyrosine-like). Component 1(p<0.10), component 4(p<0.05)of aquatic fulvic acid(FA) and component 4(p<0.10) of aquatic humic acid(HA) in endemic areas showed higher content than disease-free areas. Lager differences of the quinone redox system in aquatic HS between endemic and disease-free areas exhibited in reduced quinone state than that in oxidized quinone state, and in FA than that in HA.HA showed higher content of reduced quinone than FA, but smaller differences between endemic and disease-free areas for its weaker influence on KBD due to extremely low carbon content in drinking water. Sediment HS showed mutual transformation with aquatic HS and higher content of reduced quinone, but no significant differences between endemic and disease-free areas. Intensive understanding on the differences of different fractions of HS and different state of quinone between endemic and disease-free areas can help guiding water improvement project in endemic areas.