水环境中26种类固醇激素的分析方法研究

建立了固相萃取-超高效液相-串联质谱法同时测定水环境中26种类固醇激素的分析方法。明确了取样体积为500 m L,Cleanert PEP为富集柱,乙酸乙酯为洗脱剂,甲醇为溶剂进行提取操作。选择了正离子模式,以0. 1%甲酸/甲醇-水为流动相,负离子模式以0. 1%氨水/乙腈-水为流动相,试样经AcquityTMUPLC BEH C18色谱柱分离后,选用质谱检测模式进行定性、定量分析。通过方法验证,26种类固醇激素的方法检出限为0. 3～1. 5 ng/L,测定下限为1. 2～6. 0 ng/L,代表性样品测定结果的相对标准偏差为2. 6%～13. 7%(n=6),加标回收率为71. 2%～121%。该方法操作便捷,灵敏度高,精密度和准确度良好,可适用于水环境中多种痕量、超痕量类固醇激素的定性定量分析。     

望虞河西岸九里河中四种除草剂的污染现状

基于气相色谱-质谱联用(GC-MS)法结合固相萃取(SPE)前处理技术,建立了水中4种除草剂氯草定、阿特拉津、乙草胺和异丙甲草胺残留的分析方法,于2018年春(4、5月)、秋(9、10月)和冬(1、3月)季对太湖流域望虞河西岸九里河水体中4种除草剂的污染现状进行调查分析。结果表明,4种除草剂的加标回收率为71. 2%～108%,RSD均10%,方法检出限为3. 5～6. 0 ng/L。九里河水体中氯草定、阿特拉津、乙草胺和异丙甲草胺4种除草剂质量浓度分别为未检出～0. 025 7,0. 019 1～1. 19,未检出～0. 026 0和未检出～0. 094 3μg/L。4种除草剂中阿特拉津最高值接近《地表水环境质量标准》(GB 3838—2002)限值,其他3种其值较低,氯草定首次在太湖流域水体中检出。     

水中乙醛和丙烯醛分析方法的对比

对测定水中乙醛和丙烯醛的3种方法——2,4-二硝基苯肼衍生化法、顶空气相色谱法和吹扫捕集一气相色谱质谱法进行概述和总结,并对各方法的试验条件、方法原理、测定影响因素以及效能验证等分析、比对,突出表现各自的优势和特点。用3种方法同时测定实际水样,结果无显著差异,精密度、准确度满足监测要求。     

Adsorption thermodynamics and kinetic investigation of aromatic amphoteric compounds onto different polymeric adsorbents

The adsorption behavior of p-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature.Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm.The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest,which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid.The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid.Thermodynamic studies suggested the exothermic,spontaneous physical adsorption process.Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step.     

Leaching of styrene and other aromatic compounds in drinking water from PS bottles

Bottled water may not be safer, or healthier, than tap water. The present studies have proved that styrene and some other aromatic compounds leach continuously from polystyrene （PS） bottles used locally for packaging. Water sapmles in contact with PS were extracted by a preconcentration technique called as ＂purge and trap＂ and analysed by gas chromatograph-mass spectrometer （GC/MS）. Eleven aromatic compounds were identified in these studies. Maximum concentration of styrene in PS bottles was 29.5 μg/L. Apart from styrene, ethyl benzene, toluene and benzene were also quantified but their concentrations were much less than WHO guide line values. All other compounds were in traces. Quality of plastic and storage time were the major factor in leaching of styrene. Concentration of styrene was increased to 69.53 μg/L after one-year storage. In Styrofoam and PS cups studies, hot water was found to be contaminated with styrene and other aromatic compounds. It was observed that temperature played a major role in the leaching of styrene monomer from Styrofoam cups. Paper cups were found to be safe for hot drinks.     

Impacts of converting from leaded to unleaded gasoline on ambient lead concentrations in Jakarta metropolitan area

Total suspended particulate mater （TSP） concentrations were monitored for one year from July 2000 and for one year from April 2003 in Jakarta City. Thirteen elemental TSP components, aluminum （Al）, sodium （Na）, iron （Fe）, lead （Pb）, potassium （K）, zinc （Zn）, titanium （Ti）, manganese （Mn）, bromine （Br）, copper （Cu）, chromium （Cr）, nickel （Ni）, and vanadium （V） were analyzed by a sequential X-ray fluorescence spectrometer. Al, Na, Fe, K, and Pb were major components at most of the sampling locations in 2000. However, only Pb in 2003 dramatically decreased to one tenth. The phase-out of leaded gasoline began on July 1, 2001 in Jakarta City and lead content in gasoline decreased to one tenth, too. The decrease in Pb concentration was a result of the phase-out of leaded gasoline, as lead emissions mainly are exhaust gas from vehicles.     

基于快速消解的海洋沉积物重金属ICP-MS测定条件优化

准确测定海洋沉积物中重金属元素的含量,是开展海洋生态环境评价与管理的基础。比较研究了当前生态环境监测领域几种主要的检测标准方法和近年热门的土壤快速消解法对海洋沉积物中重金属的检测效果。通过研究不同消解体系、消解压力、校准溶液配制方法以及内标元素、内标浓度等条件对海洋沉积物重金属测定效果的影响,优化了海洋沉积物样品的快速消解过程和测定条件。结果表明:优化后的快速消解方法针对Cr、Ni、Cu、Zn、Cd和Pb的方法检出限为0.004~0.8 mg/kg,测定下限为0.016~3.2 mg/kg,回收率为95.4%~109.2%,相对标准偏差为0%~3.22%,方法准确可靠、快速高效,满足海洋沉积物样品(尤其是大批量样品)的重金属测试需求。     

长沙市冬季人行道PM2.5污染特征及影响因素

了解不同气象条件下城市人行道细颗粒物(PM_2.5)时空分布特征对于指导城市环境评价及街道空间规划布局具有重要意义。选取长沙市车流量及人流量较大的4条道路旁0、5、10 m处的人行道,在冬季晴天、阴天和大风天开展PM_2.5质量浓度、风速、温度及相对湿度监测,探讨PM_2.5分布特征与气象因子的关系。结果表明:冬季晴天、阴天及大风天的人行道PM_2.5质量浓度变化呈现双峰双谷特征,峰值均出现在06:00—08:00,其次为18:00—20:00,谷值出现在14:00—16:00及22:00—24:00;距离机动车道10m处的人行道PM_2.5含量低于机动车道旁(即距离机动车道0 m)的人行道PM_2.5含量,这种差异在大风天气下更为显著;人行道PM_2.5质量浓度与温度、风速呈显著负相关关系,与空气湿度呈显著正相关关系,低温不利于PM_2.5扩散,但在大风天温度对PM_2.5的影响极小,风对PM_2.5含量的变化影响极大,在远离机动车道的人行道更为显著,而高湿度天气有利于PM_2.5的凝结。低温、高湿天气下06:00—08:00、18:00—20:00人行道PM_2.5质量浓度较高,大风对PM_2.5质量浓度具有一定削减作用,早晚高峰减少人行道洒水以降低空气湿度,有利于PM_2.5质量浓度的降低,减少PM_2.5积累。     

邯郸市物质流分析

利用邯郸市统计年鉴数据和实地调研资料,采用城市物质流分析框架研究邯郸市2005年物质流全景和1993─2005年物质输入和输出结构的时间序列变化.结果表明:13年间邯郸市地区生产总值增长3.4倍,物质输入增长1.1倍,物质生产力增长1.1倍,由1993年的151.8元/t上升至2005年的320.9元/t,反映了邯郸市前期经济发展与资源投入具有明显的“脱钩"现象;另一方面,邯郸市仍然遵循着“高投入、高排放"的发展模式,2005年物质净存量仅占全年物质通量的12.2%,大部分物质在开采当年并不进入经济系统而直接排放到生态系统中;同时,邯郸市经济发展的对外依存度逐年升高,从该市外调入的物质量所占比例由1993年的10.2%上升至2005年的39.2%,表明邯郸市经济发展将面临更大的资源      

曝气强度对膜生物反应器污泥混合液可滤性的影响

主要研究了曝气强度对膜生物反应器(MBR)膜污染的影响.2套MBR采用恒流出水模式连续运行60 d,曝气强度分别为500及100 L/h,应用死端过滤装置来检测不同阶段污泥混合液的可滤性.实验中对不同曝气强度下的溶解性微生物代谢产物(SMP)分子质量分布、颗粒粒径分布、胞外聚合物(EPS)含量进行了测定.结果表明,过高的曝气强度将恶化污泥混合液的可滤性,增加了膜污染速率.进一步研究表明,曝气强度的增加导致了污泥混合液上清液中相对分子质量>10000的SMP浓度的增加,此部分大分子有机物浓度直接影响了污泥混合液的可滤性.过高的曝气强度也导致了污泥絮体中1～10μm细小颗粒和EPS含量的增加.