对水中六种多环芳烃固相萃取效率的研究

研究洗脱溶剂、上样速度、小柱填料三个因素对固相萃取水中多环芳烃回收率的影响。通过三组实验确定六种多环芳烃在固相萃取小柱上的洗脱条件并选择最佳的固相萃取小柱，从而优化检测水中多环芳烃的样品前处理方法。实验结果表明，以10mL／min流速上样，用4mL二氯甲烷洗脱含碳量17％～18％的ci8固相萃取小柱时的样品萃取回收率最好，回收率在61．71％-97．64％，适合作为高效液相色谱法分析水中六种多环芳烃的样品前处理方法。     

全自动固相萃取-气相色谱法测定饮用水中二氯乙酸和三氯乙酸

采用全自动固相萃取方法对饮用水中二氯乙酸和三氯乙酸进行萃取,并用气相色谱法测定其含量。水样经过酸化后通过全自动固相萃取仪进行萃取,采用甲醇作为萃取柱的活化剂,以硫酸-甲醇(10+90)作为洗脱液和衍生试剂,衍生温度为50℃,衍生时间为90min,衍生萃取剂为MtBE,加标回收率在85%～110%之间。     

固相微萃取-气相色谱-质谱联用测定环境水体中的痕量苯酚

研究快速而有效的苯酚检测手段具有重要的意义。本研究采用顶空固相微萃取-气相色谱-质谱联用技术对自来水和造纸厂污水中的痕量苯酚进行了萃取与分析。在不进行衍生化的情况下,对水中的苯酚进行直接萃取,并选用极性色谱柱进行分析,取得了良好的分析效果。同时研究和探讨了萃取纤维的选择,萃取时间,萃取温度等因素对萃取效果的影响。研究结果表明:100 mL水样,利用聚二甲基硅氧烷涂层纤维(100μm PDMS),pH值在2~3,并加入饱和的NaCl,在搅拌的条件下,萃取温度为90℃,萃取时间为40 min的萃取效果较好。本方法的检测限为0.5μg/L,在线性范围4.9~200μg/L内具有较好的线性关系,相关系数为0.9984。     

固相萃取新技术研究进展

在色谱分析化学中,试样的预处理是样品分析中至关重要的环节,前处理是否有效最终影响到分析方法的准确性和可靠性。液—液萃取和固相萃取是分离科学中最常用的样品前处理方式。其中,固相萃取(Solid phase extraction,SPE)是19世纪70年代后期由液—固萃取与柱液相色谱相结合发展来的新型样品处理技术。与传统的液—液萃取方法相比,固相萃取具有快速高效、有机溶剂用量少、无相分     

原水水质对南方某给水厂处理有机氯农药效果的影响

采用HLB柱固相萃取样品前处理技术和气相色谱仪／电子捕获检测器(GC／ECD)分析方法,研究了东江-深圳供水改造工程竣工前后原水改变对给水厂处理有机氯农药效果的影响。结果表明:原水更换前后不同工艺段出水中共检出10种有机氯农药,浓度为0.08~20.68 ng／L,主要是HCBs,DDXs,氯丹和硫丹,远低于《国家地表水环境质量标准》(GB 3838-2002)及《生活饮用水卫生规范》规定的限值,不必对此进行长期连续监测。通过原水改变前后传统处理工艺对有机氯农药去除效果的对比发现,当原水中有机氯农药降低到一定程度后,常规饮用水处理工艺并无明显处理效果。     

固相萃取技术及其在环境优先污染物监测中的应用

固相萃取(SPE)技术在环境样品前处理中主要应用于对水样的处理,同时应用于大气和土壤以及海洋生物样品的前处理。简单介绍了固相萃取的5个步骤,即吸附剂的活化与处理、加入样品、净化、洗脱、柱的再生,分析了吸附剂的选择依据为官能度、粒子大小及形状、表面积、孔径及化学惰性,指出吸附剂的选择困难限制了固相萃取技术的广泛应用,而对于优先污染物中几大类化合物吸附剂选择的研究目前还是空白。     

固相萃取-高效液相色谱三重四级杆质谱联用法在北方河流水体氯霉素类抗生素测定中的应用

建立了固相萃取-高效液相色谱三重四级杆质谱联用法,同时测定水中的4种氯霉素类抗生素(氯霉素、甲砜霉素、氟苯尼考和氟苯尼考胺)残留,采用MRM扫描方式在正/负模式下,在10 min内完成对氯霉素类抗生素的分析,该方法线性范围为1~100μg/L,相关系数R20.99,实际水样加标回收率为92.8%~117.48%。利用该方法对北方河流水样进行采样调查,其中氟苯尼考检出率较高为26%,达526.36 ng/L。该方法操作简便,灵敏度高,重现性好,具有一定的推广价值。     

固相萃取气相色谱法测定水中痕量有机磷农药

分别采用C8,C18和HLB小柱萃取水样中的痕量有机磷农药（敌敌畏、内吸磷、乐果、甲基对硫磷、马拉硫磷、对硫磷）,以毛细柱气相色谱火焰光度检测器（FPD）进行测定,用甲醇-丙酮（70/30,V/V））洗脱3种不同的固相萃取小柱。C18小柱萃取回收率最好,平均回收率89.22%-101.93%。     

新型含砷水样前处理技术开发研究

砷是一种对人体健康造成严重伤害的污染物,受管理规定和检测手段的限制,由砷诱发癌症的风险仍然较高。选取离子液体作为萃取溶剂,开发出一种基于离子交换机理的分散液液微萃取方法,应用于含砷水样的前处理。通过研究水样体积、pH值、离子液体用量等6项关键因素对该方法萃取效率的影响,以及对该方法的表现效果进行了优化和评价。本方法可在数分钟内完成对砷的萃取,富集因子可达到210,在0.05～10 μg/L范围内均有较好线性关系,相对标准偏差仅为1.5%;当本方法与石墨炉原子吸收光谱仪联用时,对砷的检出限可达到10 ng/L。另外,避免了传统样品前处理方法中使用的大量有机溶剂,因此更加绿色、环保。研究结果为水环境分析监测技术领域的开拓和发展提供了新思路。     

饮用水源地水体有机氯农药的测定

建立了以固相萃取(SPE) 、 气相色谱2三重串联四级杆质谱法(GC/ MS/MS) 测定饮用水源地中 15 中有机氯农 药残留的方法。用 Bond Elut C18 固相萃取柱净化富集水样, 优化色谱和质谱条件参数, 在多反应监测模式下进行 定性、 定量分析。该方法对饮用水源地水样中的 15种有机氯农药回收率为 70 1 3%~ 12715%, 相对标准偏差( RSD) 为 0 16%~ 1212%; 检出限范围为 0 1 08~ 0 138 ng/L, 满足饮用水源地痕量有毒有机物监测的需求。用该方法测定 天津市某重要饮用水源地表层水体中有机氯农药分布状况, 结果表明该水源地水体 15 种有机氯农药中, 除六六六 和 p, pc 2DDD、 p, pc 2DDT 外, 其他几种有机氯农药均未检出。三个监测站点中, 15种有机氯农药总量从高到低依次 是入库、 库心和坝前, 分别是 1 1 85 ng/L, 1138 ng/ L, 0 1 96 ng/ L。根据地表水环境质量标准( GB 3838- 2002) , 该水 源地表层水体中 15 种有机氯农药均不超过集中式生活饮用水地表水源地特定项目标准限值。     

地下水中21种半挥发性有机物测定方法的优化研究

为研究建立同时测定地下水中21种半挥发性有机物的固相萃取-气相色谱-串联质谱(SPE-GC/MS)法,采用C_(18)和HLB固相萃取柱对地下水样品进行富集萃取,DB-5MS毛细管柱(30 m×0.25 mm×0.25μm)进行气相分离,单离子监测(SIM)扫描模式进行分析,并对进样速率、洗脱剂和pH等样品前处理条件进行优化,建立了固相萃取-气相色谱-质谱测定地下水中21种半挥发性有机物的检测方法。研究结果显示:21种半挥发性有机物的标准曲线在0.1～1μg/mL范围内,线性关系良好。平均回收率基本在80%～120%之间,精密度在1.70%～8.79%之间,检出限在0.022～0.045μg/L之间,均低于《地下水质量标准》(GB/T 14848—2017)一类水限值。研究结果表明,本方法操作简便、有机试剂消耗量少、灵敏、准确,可用于地下水中多种半挥发性有机物的同时检测。     

Determination of brominated flame retardants in Jukskei River catchment area in Gauteng, South Africa

Brominated flame retardants (BFRs) are considered to be environmental pollutants due to their toxicity, persistence and ubiquity in the environment. Little information is known about the presence of brominated flame retardants in South Africa's water systems. Therefore, this study examined and compared different extraction methods (liquid-liquid (LL) vs. solid phase (SP) for water, Soxhlet extraction (SE) vs. ultrasonic for sediment) for extraction efficiencies in the determination of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls (PBBs) in water and sediment from Jukskei River. Clean-up of sample extracts was performed using disposable Pasteur pipettes containing neutral, acidified and basic silica gel. Final extracts, after concentration and dilution to 200 μL were analyzed by injecting 1 μL in the GC-ECD and GC-MS. Results obtained showed good recoveries for most of the tested analytes in water; for LLE, values ranged between 80.5 ± 10.22% and 126.6 ± 1.94%; SPE, 70.41 ± 2.01%-124.78 ± 3.78% (n = 3) and for sediment (73-114%, with an RSD <17%) using SE. The ultrasonic extraction method gave less than 50% recovery for most of the congeners. The concentrations of the BFRs in water samples were less than the detection limit while the concentrations in sediment ranged from 1.95 to 36.61 ng g(-1) dry weight for Σ(11) BFRs. Dichloromethane and n-hexane : acetone (2 : 1, v/v) gave optimum value of recovery for water and sediment respectively.     

水源地有机农药在线监测技术的应用研究

使用Aquapod SPE 250在线监测仪开发了9种微量有机农药的在线监测方法,对其在重点饮用水水源地平岗泵站的实际应用进行了研究,并对该仪器的突发污染预警能力进行了测试评估。结果显示,Aquapod SPE 250在线监测阿特拉津、甲萘威、对硫磷、2,4-二氯苯酚、2,4,6-三氯苯酚、五氯酚、苯酚、敌草隆和绿麦隆等农药残留值的检出限较低,满足GB3838-2002《地表水环境质量标准》的要求;平岗泵站2013年1-5月的有机农药残留值虽未超过我国标准,但已超出《欧盟饮用水水质指令》的检出限值;在实际水样中添加阿特拉津标准物质,Aquapod SPE 250的测定光谱异常,仪器出现报警信号,表明该仪器可用于有机农药的突发污染预警。     

Classification of algogenic organic matter concerning its contribution to the bacterial regrowth potential and by-products formation

The bacterial regrowth potential (BRP) and the by-products formation potential after the disinfection (DBP) are parameters recognized to be influenced by the origin of organic matter dissolved in water. A significant difference of the impact of humic compounds and algogenic organic matter (AOM), characteristic for raw waters from reservoirs, to both parameters can be assumed. In systematic laboratory experiments the influence of AOM on the BRP as well as DBP was examined. Different fractions of the AOM were chlorinated and treated with chlorine dioxide. In addition to that the influence of the ozonation was investigated. To assess the biodegradable fraction of the organic matter (BDOC) a large spectrum of byproducts (aldehydes and keto-acids) was analyzed. The BRP in the water was determined by the measurement of the increase of biomass in the water samples. It could be proved, that the chlorination of intact algae cells containing waters may cause a significant increase of the biodegradability in the water if the residual chlorine is totally required. In the case of the disinfection of the AOM containing waters with chlorine dioxide the relative increase of the BRP was lower in comparison to the chlorinated waters. The preozonation of the algae containing waters indicates an additional increase of the BRP, but only by ozonadon of the algae cells. The ozonation of the algae metabolites does not influence the BRP, but it causes a significant decrease of the THIvI-formation if chlorine is used for disinfection.     

Mathematical model for describing reactions of residual chlorine with organic matter in reclaimed wastewater.

Among several applications of urban wastewater reuse, use of reclaimed wastewater to sustain stream flows has become attractive in the urban area. Since these rivers are used for recreational purposes and for restoring aquatic eco-system, the adequate control of residual chlorine is essential. Mathematical model for describing reactions between residual chlorine and organic matter in reclaimed wastewater has been developed. The model considers the effect of molecular weight distribution of organic matter on the reaction rate. Lab-scale experiments were performed to estimate reaction rates constants and to examine their temperature dependency. The experiments showed that 1) the smaller organic matter gave the larger reaction rate; 2) temperature effect on reaction rate was described by the Arrhenius formula; 3) decline of free chlorine had more temperature dependency than combined chlorine. The comparison of computed results with data from lab-scale experiments confirmed the validity of the model. We used the one-dimensional dispersion model with proposed reaction model and examined the seasonal variation of residual chlorine profile along the river sustained by reclaimed wastewater in Sapporo. Simulation showed that seasonal variation of nitrification performance in secondary treatment as well as change in temperature caused seasonal variation in residual chlorine profile along the river.     

Generation of halogenated organic compounds in municipal waste water

Cleaning agents and disinfectants from housekeeping, hospitals and canteen kitchens are important sources of adsorbable halogenated organic compounds (AOX) in municipal waste water. They often contain inorganic compounds which are able to release activated chlorine. Together with organic waste water compounds the activated chlorine can generate halogenated organic compounds. Within the scope of this research project the generation of AOX through these active agents is compared. The effects of concentration, pH, time, temperature, presence of other oxidizing or reducing agents and synergetic effects are investigated and discussed.According to the results the potential of these active agents forming AOX is obvious. The AOX concentration of a municipal waste water increased by the factor of 13 after adding an hypochlorite containing disinfectant in common concentration. Most AOX can be formed within 30 minutes. In sewage with high amount of solid compounds the AOX generation can take a long time (several days). The amount of AOX generated strongly depends on the nature and concentration of dissolved and solid organic compounds, the concentration of active substances, temperature, pH and the reaction time.     

吹扫捕集/气相色谱-质谱法监测黄河干流水源地挥发性有机物

为了全面了解黄河干流重点城市水源地挥发性有机物的污染情况,采用吹扫捕集/气相色谱-质谱法对水源地38种挥发性有机物进行定性定量分析.该方法的加标回收率为94.4%～105.6%,精密度为1.7%～24.0%,检测限为0.02～0.04 μg/L,满足痕量有机物的分析要求.对3个城市水源地丰、平、枯水期进行监测分析.结果...     

水处理工艺过程中有机物分子量分布规律

针对太湖流域某湖泊水源有机物分子量分布的特性,考察饮用水处理各工艺单元对有机物的去除效应。结果表明:原水以小分子量有机物为主,小于1k Dalton的有机物占36.1%;常规工艺对大分子量有机物去除率高,尤其对分子量在10k Dalton以上的有机物去除率达32.7%以上,但对小分子量有机物去除率低,其中分子量小于1k Dalton的有机物反而增加了12.6%左右。超滤深度处理工艺中PES膜工艺对小分子量有机物,特别是分子量小于10kDalton的有机物去除率达76.4%,出水UV254值及SUVA值比砂滤出水分别下降了22.0%和11.2%;PVDF膜工艺对各分子量有机物均有较好的去除,但对大分子有机物去除效果优于小分子有机物,其出水UV254值及SUVA值比砂滤出水分别下降了28.8%和6.3%。     

Analysis of nonylphenol polyethoxylates and their metabolites in water samples by high-performance liquid chromatography with electrospray mass spectrometry detection.

Evidence that some alkylphenol polyethoxylates (APEOs) breakdown products are estrogenic has intensified the interest over their environmental and human health effects. Different quantitative methods but one single preparation and extraction method for the analysis of nonylphenol polyethoxylates (NPEOs) and their metabolites in water samples using solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) with electrospray mass spectrometry detection (ESI-MS), are described. Quantification limits range about the low ng/l for the enrichment of 500 ml water samples and mean recoveries of 70% are achieved. These methods were subsequently applied to water samples coming from Austrian treatment plants.     

毛乌素沙地典型湖滨带湿地有机碳、氮素空间分布特征

通过对陕西毛乌素沙地典型湖滨带湿地有机碳和氮素的空间分布特征进行研究,为探讨湿地生态系统如何在沙化环境下发挥其特有的功能提供科学依据。在巴吓采当湖泊湖滨带A~F类型区采集土壤,测定土壤的有机碳、全氮、有机氮、硝态氮和铵态氮等指标。利用方差分析、Spearman相关性分析和主成分分析等方法分析对湖滨带有机碳、氮素空间分布特征进行研究。土壤表层0~10cm的有机碳和全氮含量随水位升高呈增加趋势。除了铵态氮外,有机碳、全氮、有机氮和硝态氮含量垂直分布上随着土壤深度增加呈降低趋势。土壤有机碳、全氮含量分别与全磷、土壤容重、含水率、水位显著相关。铵态氮和全磷、含水率、土壤容重、全氮、有机碳和水位等显著相关。硝态氮与微生物生物量碳、氮的相关系数分别为r=0.637和r=0.617(中度正相关)。有机碳及氮素的含量与土壤粘粒含量相关性不高。主成分分析提取3个主成分,累积贡献率达76.15%。土壤全磷、土壤含水率、土壤容重和水位是影响湖滨带土壤有机碳、氮素空间分布的主要因子。