贵州草海湿地溶解性有机物的光谱特征及其与PFASs的相关性分析

为描述草海湿地DOM（dissolved organic matter，溶解性有机物）荧光特征，探究其对PFASs（per-and polyfluoroalkyl substances，全氟及多氟化合物）环境行为造成的影响，利用超高效液相色谱-质谱联用技术和三维荧光光谱技术，结合平行因子分析，开展DOM光谱学特性研究，分析ρ（DOM）与ρ（PFASs）的相关关系.结果表明:①草海湿地中共解析出3类4种荧光组分，分别为类腐殖酸λ_Ex（360 nm）/λ_Em（450 nm）]、长波段腐殖质λ_Ex（400 nm）/λ_Em（510 nm）]、类富里酸λ_Ex（330 nm）/λ_Em（400 nm）]和类色氨酸λ_Ex（280 nm）/λ_Em（350 nm）]，贡献率分别为48.6%、23.6%、22.9%和4.9%，其中类腐殖质总贡献率高达72.2%.在农业生产和人类活动的影响下，总荧光强度大致呈现从入湖区向出湖区逐渐降低、湖心区略高的趋势.②在草海湿地表层水中共检出了12种PFASs，ρ（PFASs）为233.18 ng/L，每种平均值为19.43 ng/L，PFBA（perfluorobutanoic acid，全氟丁酸）是主要污染物；草海湿地入湖区点源影响特征明显，生活污水和农业生产用水是主要的潜在污染源.③相关性分析结果显示，各荧光组分含量均与ρ（PFBS）（potassium perfluorobutanesulfonate，全氟丁烷磺酸）负相关；类色氨酸含量与ρ（PFHpA）（perfluororoheptanoic acid，全氟庚酸）负相关，与ρ（PFTriDA）（perfluorotrideanoic acid，全氟十三酸）则显著正相关.研究显示，草海湿地水体腐殖化程度高，外源特征明显，共检出12种PFASs，初步揭示了草海湿地水环境中ρ（DOM）与ρ（PFASs）的相关关系，其受水体性质及化合物结构等差异的影响，有待进一步开展深入研究. 

Spectral Characteristics of Dissolved Organic Matter and Its Correlation with PFASs in Caohai Wetland, Guizhou

Dissolved organic matter (DOM) has good environmental indications, can track the source of exogenous pollutants and affect their migration, transformation and bio-availability. Aiming at the aquatic environment of the typical karst plateau wetland in Guizhou, the fluorescence characteristics of DOM in the surface water of Caohai Wetland under special geological background were studied by three-dimensional fluorescence spectrometry combined with parallel factor analysis. The occurrence characteristics of PFASs were analyzed by ultra high-performance liquid chromatography tandem mass spectrometry. The relationship between DOM and PFASs as well as its influence on the environmental behavior of PFASs were discussed. The results showed that:(1) Four fluorescence components, including humic-like substances, long-band humic, fulvic acid-like substances and tryptophane-like substances, were detected in Caohai Wetland, which accounted for 48.6%, 23.6%, 22.9% and 4.9% to the total burden, respectively. Among them, the total contribution of humic-like substances was as high as 72.2%. Affected by agricultural production and human activities, a decreasing trend of the total fluorescence intensity were showed from the inlet to the outlet with slightly higher intensity in the center area. (2) A total of 12 PFASs were detected in the surface water of the Caohai Wetland. The ρ(PFASs) was 233.18 ng/L with the average concentration of 19.43 ng/L. PFBA was the most predominant compound. Point source such as domestic sewage and agricultural wastewater might be the main potential sources of pollution in the entry area of the Caohai Wetland. (3) The results of correlation analysis showed that the intensity values of all fluorescent components were negatively correlated with PFBS. Tryptophane-like substances was negatively correlated with PFHpA but positively correlated with PFTriDA. The study indicated that the aquatic environment of the Caohai Wetland was at high degree of humidification, which posed obvious exogenous characteristics. Twelve kinds of PFASs were detected in the Caohai Wetland. The correlation between DOM and PFASs were preliminary revealed. Considering the differences of chemical structures and aquatic property, more data are warranted in future study.