苏州市太湖饮用水源地异味物质种类及其与环境因子相关性分析

于2013年每月测定了苏州太湖饮用水源地9种异味物质含量及TP、TN、水温、藻密度等指标,结果表明,苏州太湖饮用水源地主要检出的异味物质有2-甲基异崁醇、土臭素、β-环柠檬醛和β-紫罗兰酮等4种。2-甲基异崁醇年均值是其嗅觉阈值的2.9倍,水体主要表现为土霉味。根据异味物质与环境因子相关性分析结果及相关文献讨论,水温是影响异味物质含量的重要因素。微囊藻等藻类对β-环柠檬醛和β-紫罗兰酮有明显贡献。     

阳澄湖水源中典型嗅味物质测定与来源分析

以阳澄湖水源为研究对象,采用固相微萃取-气质联用法测定水中2-甲基异莰醇(2-MIB)、土臭素(GSM)、2,4,6-三氯苯甲醚(2,4,6-TAC)、2,3,4-三氯苯甲醚(2,3,4-TAC)、2,3,6-三氯苯甲醚(2,3,6-TAC)、2-异丙基-3甲氧基吡嗪(IPMP)、2-异丁基-3甲氧基吡嗪(IBMP)、β-环柠檬醛、β-紫罗兰酮、异氟尔酮等10种典型嗅味物质,并分析可能的来源藻类.以2018年1月-12月阳澄湖水源中优势藻种为基础,建立以上述嗅味物质为变量的多元线性回归模型.结果表明,水源中2-MIB、GSM、β-环柠檬醛、β-紫罗兰酮、异氟尔酮5种嗅味物质与直链藻、针杆藻、鱼腥藻、色球藻、颤藻、微囊藻、束丝藻7种藻类有较强的相关性.     

太湖水源水主要异味物质变化规律及来源初探

采用顶空固相微萃取-气相色谱/质谱联用测定技术,以太湖某饮用水源地水体中甲基异莰醇-2和土臭素为主要研究对象,通过环境因子相关性分析,对异味物质的变化规律和来源作初步分析。研究结果表明,该水源地2013年的主要异味物质为甲基异莰醇-2,超标时段主要集中在夏秋高温季节(5—9月);水体中的硅藻可能是异味物质的重要产生者,底泥中的藻类和微生物次生代谢活动可能是水体产生异味的主要原因。     

搅拌棒萃取-热脱附/气质联用法测定水中2-MIB和土臭素

采用搅拌棒萃取-热脱附/气质联用法测定水中2-甲基异莰醇和土臭素，优化了搅拌棒萃取和热脱附进样的条件。试验表明：两种目标化合物在1．00 ng/L～200 ng/L范围内线性良好，2-甲基异莰醇的相关系数为0．9993，土臭素的相关系数为0．9997，方法检出限分别为0．31 ng/L和0．15 ng/L；空白和实际样品的加标回收率为82．4％～116％，测定结果的RSD＜10％。     

固相微萃取-气相色谱-质谱法测定饮用水中土嗅素和2-甲基异茨醇

采用固相微萃取法富集,气相色谱-质谱联用法定性和定量测定饮用水中致嗅物质土嗅素和2-甲基异茨醇。研究并讨论优化了纤维头的类型、盐的种类和浓度、温度、萃取时间等因素对异味化合物萃取量的影响。土嗅素和2-甲基异茨醇的检出限分别为1.02、2.13 ng/L,相对标准偏差分别为4.96%、7.74%。2种异味化合物在5~1 000 ng/L的范围内线性关系良好,相关系数均大于0.985。因此,用该方法能够很好地分析水中痕量的异味化合物。     

动态固相微萃取-气相色谱质谱法测定水中多种异味有机物

采用动态固相微萃取技术富集水样中2-异丙基-3-甲氧基吡嗪、2-异丁基-3-甲氧基吡嗪、2-MIB、β-环柠檬醛、2,4,6-三氯苯甲醚、GSM、α-紫罗酮和β-紫罗酮等8种异味有机物,并用气相色谱质谱法测定。通过优化试验条件,使方法在2. 00 ng/L～100 ng/L范围内线性良好,方法检出限为1. 0 ng/L～4. 4 ng/L。空白水样3个质量浓度水平的加标回收率为81. 0%～121%,6次测定结果的RSD为1. 7%～8. 9%。将该方法用于一水库实际水样的测定,结果 2-MIB、β-环柠檬醛、α-紫罗酮和β-紫罗酮检出,其余均为未检出。     

HS/SPME-GC/MS/MS法测定水中痕量2-甲基异莰醇和土臭素

建立了测定水中痕量2-甲基异莰醇(2-MIB)和土臭素(GSM)的顶空固相微萃取-气相色谱/二级质谱联用法(HS/SPME-GC/MS/MS),并对HS/SPME条件进行优化。优化后的方法 2-MIB和GSM在1.00~50.0 ng/L范围内,线性良好(r≥0.999 4),RSD分别为7.36%和7.75%,方法检出限分别为0.226和0.239 ng/L,加标回收率分别为87.0%~97.0%和85.2%~112%。结果表明,所建立的方法操作简便、准确度高、重现性好、灵敏度高,无需有机溶剂,适用于水中痕量2-MIB和GSM的测定。     

吹扫捕集-GC/MS法测定饮用水中致嗅物质

采用吹扫捕集-气相色谱/质谱联用法测定饮用水中6种致嗅物质,优化了吹扫捕集条件。方法线性良好,甲硫醚、二甲二硫、甲苯、异佛尔酮、癸醛、β-环柠檬醛的检出限分别为10.5μg/L、0.558μg/L、0.862μg/L、47.4μg/L、4.75μg/L、3.77μg/L,标准溶液平行测定的RSD≤10.9%,加标回收率为71.0%～125%。     

气相色谱法测定空气中氯苯类、贲亭酸甲酯和异戊烯醇方法探索

目前,长江三角洲地区沿江化工产业带已初具规模,随着化学工业园企业的陆续建成投产,在不利气象条件下化工园排放的有机污染物异味扰民时有发生,严重影响化工园周边地区群众的生活.某化工园废气特异指标氯苯类、贲亭酸甲酯和异戊烯醇是异味的主要来源,其相应的监测分析方法氯苯类国内已有标准方法,贲亭酸甲酯和异戊烯醇国内未见报道.为掌握监测数据资料,对某化工因特异指标氯苯类、贲亭酸甲酯和异戊烯醇的定量监测分析方法进行了探索.该方法使用活性炭吸附、二硫化碳解析和GC-FID(气相色谱-氢火焰光度法)分析一并完成3个有机化合物的定量监测分析,简单快捷、成本低廉.     

DNPH衍生化采样-溶剂解析-高效液相色谱法同时测定木制品中25种醛酮化合物

建立了DNPH衍生化采样-溶剂解析-高效液相色谱测定木制品中醛酮化合物的方法。采样时需在2,4-二硝基苯肼吸附管前串联一只SEP-PAK脱臭氧小柱;采样体积应≤10 L,流量≤400 m L/min。该法对25种醛(酮)化合物对应的衍生物分离效果良好,在0.005~3 mg/L范围内线性良好,相关系数R2≥0.999 6,回收率为85.3%~113.5%,精密度为2.67%~4.56%。采样量为10 L时,25种醛(酮)化合物的检出限和定量限分别≤0.16和0.50μg/m3。     

锅炉烟尘测试中锅炉负荷率的计算方法探讨

GB5468 -91规定 ,锅炉烟尘测试时 ,必须对锅炉的运行负荷进行测试 ,而实际监测过程中 ,许多锅炉房不具备测试的计量条件 ,为了解决这一问题 ,文章提出利用烟气量和空气过剩系数计算锅炉负荷率。在实际监测工作中 ,该方法方便、易于操作 ,所得结果和标准规定方法所得结果有很好的一致性     

城市空气质量周报效用分析

介绍了世界上一些发达国家的空气污染预报的做法和采取的措施,阐述了我国开展空气质量预报的方针和方法,指出了周报是预报的基础工作。叙述了我国空气质量周报的污染参数的选取、污染指数的分级及其浓度限值和污染指数计算及确定,分析并总结了开展城市空气质量周报所发挥的效用是提高公众的环保意识,加大了治理污染的力度,转变了环境监测的职能,促进了环境监测事业的发展     

水中总硬度测量不确定度的评定

采用EDTA滴定法测定水质总硬度的测量不确定度评定。充分考虑测量重复性、标准溶液的配制、滴定等过程对测量的影响,计算水中总硬度的测量相对合成标准不确定度为1·81×10-3。     

贵州黔东南州三板溪水库春季拟多甲藻水华特征

2011年3月13日对贵州省黔东南州三板溪水库进行春季浮游植物调查的结果表明,三板溪水库Ⅱ号采样点(下革东)发生以佩纳形拟多甲藻为优势种的拟多甲藻水华,细胞密度高达1.15×10⁷cell/L;板溪水库总氮的最低值为2.09 mg/L,总磷的最低值为0.95 mg/L,三板溪水库的总氮、总磷含量较丰富,不存在总氮或总磷是限制性因子;通过SPSS16.0统计软件分别进行Pearson 积距相关系数分析表明,氮磷比是三板溪水库发生拟多甲藻水华的主要影响原因。     

Environmental Assessment of the Impact of Ozone to the Neuston of the Sea-Surface Microlayer of the Gulf of Mexico

Substantial amounts of NOx (146 000 t/y) and total hydrocarbons (294 000 t/y) are released to the marine atmosphere by the large number of oil and gas operations over Federal waters of the Gulf of Mexico (GOM). Under appropriate meteorological conditions these emissions react to form ozone (0–54 g/m3 over-water) which can affect the marine environment. Using a dry deposition model, this work examines the amount of ozone derived from oil and gas offshore operations and deposited in the sea surface of the Gulf of Mexico, and assesses its impact on the neuston of the sea-surface microlayer. Surface integrated estimates of ozone deposited from oil and gas operations over the sea surface ranges from 400 kg to 1800 kg which results in sea surface concentrations of 15 g/m3. This estimate and the actual toxic ozone levels suggest no acute, toxic impacts to the neuston. However, indirect effects may occur through changes to the pelagic foodwebs and organic carbon pathways. Another potential pathway for ozone impacting the environment is through the production of bromate. Based on the concentrations and time scales (11–139 days) only sublethal effects appear to occur, but uncertainties associated with this assessment need to be further studied. From an ecological perspective, the environmental impacts and risks of NOx and VOC discharges from offshore platforms need to be assessed for neuston and other components of the marine ecosystem.     

实验室质量管理体系内部审核的实施

在实施GB/T15481-2000 idt ISO/IEC17025:1999标准《检测和校准实验室能力的通用要求》的过程中,通过实验室质量管理体系内部审核的实践与系统分析,识别出内部审核实施阶段的关键环节,提出召开首次会议、收集审核证据、确定审核发现和召开末次会议的技术方法,对提高内部审核的质量和有效性、获得可靠的审核结论具有重要意义。     

Fractionation of heavy metals and assessment of contamination of the sediments of Lake Titicaca

Chemical weathering is one of the major geochemical processes that control the mobilization of heavy metals. The present study provides the first report on heavy metal fractionation in sediments (8–156 m) of Lake Titicaca (3,820 m a.s.l.), which is shared by the Republic of Peru and the Plurinational State of Bolivia. Both contents of total Cu, Fe, Ni, Co, Mn, Cd, Pb, and Zn and also the fractionation of these heavy metals associated with four different fractions have been determined following the BCR scheme. The principal component analysis suggests that Co, Ni, and Cd can be attributed to natural sources related to the mineralized geological formations. Moreover, the sources of Cu, Fe, and Mn are effluents and wastes generated from mining activities, while Pb and Zn also suggest that their common source is associated to mining activities. According to the Risk Assessment Code, there is a moderate to high risk related to Zn, Pb, Cd, Mn, Co, and Ni mobilization and/or remobilization from the bottom sediment to the water column. Furthermore, the Geoaccumulation Index and the Enrichment Factor reveal that Zn, Pb, and Cd are enriched in the sediments. The results suggest that the effluents from various traditional mining waste sites in both countries are the main source of heavy metal contamination in the sediments of Lake Titicaca.     

二乙氨基二硫代甲酸银试剂质量对测砷的影响

用简单合成了二乙氨基二硫代甲酸银试剂，并比较了自制和市售的二乙氨基二硫人 银对测砷的影响。结果表明，采用自制的二乙氨基二硫代甲酸银能大大降低试剂空白，提高方法的灵敏度和降低检出限，试剂质量明显优于市售产品。     

氨氮测量不确定度的评定

采用纳氏试剂光度法测定水质氨氮的测量不确定度评定,应该考虑工作曲线、测量重复性、标准溶液、仪器读数分辨率等对测量的影响.     

Evaluation of method of preparation of passive diffusion tubes for measurement of ambient nitrogen dioxide

This study was carried out in response to suggestions that the measurement of NO(2) by Palmes-type passive diffusion tubes (PDT) is affected by the method of preparation of the triethanolamine (TEA) absorbent coating on the grids. The following combinations of factors were investigated: TEA solvent (acetone or water), volume composition of TEA in solvent (50% or 20%), and grid coating method (dipping in solution prior to assembly or pipetting solution on after assembly). Duplicate PDTs prepared by each of the 8 methods were exposed in parallel, in urban air, for a total of 80 separate 1 week exposures. NO(2) concentrations derived from PDTs prepared by pipetting methods were significantly less precise than concentrations from dipping methods, with mean RSDs for duplicate measurements of 13.8% and 8.5%, respectively (n= 316 each category). Pipetting methods using solutions of 50% TEA composition were particularly imprecise (mean RSD 17.2%). Data from PDTs prepared by pipetting methods were systematically more poorly correlated with each other and with data from co-located chemiluminescence analysers, than corresponding data from PDTs prepared by dipping methods, indicating that more consistent accuracy was also obtained by the latter PDTs. The statistical evidence suggested that PDTs prepared by pipetting 50% TEA in water generally gave lower NO(2) concentrations. Although this is in agreement with a previous study, it is also possible that such an observation here may be a statistical artefact given the demonstrably poorer precision of this method. The general tendency of PDTs to show positive bias in NO(2) measurement in urban air in 1 week exposures was again evident in this study (mean biases at roadside and urban centre locations of +35% (n= 475) and +18% (n= 112), respectively) consistent with augmentation of within-tube NO(2) flux by chemical reaction between co-diffusing NO and O(3). Overall, it is recommended that the pipetting method of PDT grid preparation is avoided, or at least investigated further, because of the apparent degradation in precision and accuracy of NO(2) measurement. Potential reasons for the effect are discussed.