固相萃取-高效液相色谱法测定水中微囊藻毒素质量控制指标研究

采用固相萃取－液相色谱法，通过统计全国多家实验室的测定数据，对水中微囊藻毒素测试的平行样测定相对偏差、空白加标回收率、实际样品加标回收率、空白加标回收率平行样相对偏差以及样品加标回收率平行样相对偏差5个质控指标进行了研究，并给出了质控指标评价标准，提出在概率P和γ均为0.90时，其平行样测定允许最大相对偏差应控制在7.3%；空白加标质量浓度为0.005~20 μg/L时，回收率的控制范围为61%~125%；样品测定浓度为未检出、加标质量浓度在0.2~3.6 μg/L时，实际样品加标回收率控制范围为66%~108%；空白加标、样品加标回收率平行样最大相对偏差应分别控制在3.9%和8.9%。在概率P和γ均为0.95时，其平行样测定允许最大相对偏差应控制在8.3%；空白加标质量浓度为0.005~20 μg/L时，回收率的控制范围为49%~137%；样品测定浓度为未检出、加标质量浓度在0.2~3.6 μg/L时，实际样品加标回收率控制范围为60%~114%；空白加标、样品加标回收率平行样最大相对偏差应分别控制在5.2% 和14.8%。     

固体废物氰化物总量和浸出毒性测定方法的比较

中国现行的固体废物氰化物总量和氰化物浸出毒性的分析方法存在缺陷，不便于广泛指导监测工作，笔者优化了固体废物氰化物测定的前处理方法，明确了固体废物氰化物总量、氰化物浸出毒性测定时的样品粒径、浸提方法和消解方法，建立了容量法、分光光度法、流动注射法测定固体废物氰化物总量和浸出毒性的方法，并与标准方法（离子色谱法）进行比较。实验结果表明：容量法、分光光度法、流动注射法测定结果与离子色谱法无显著差异，3种方法测定固体废物氰化物总量加标回收率为80.5%~102%，平行样测定相对标准偏差为3.0%~6.9%，3种方法测定固体废物氰化物浸出毒性加标回收率为80.1%~107%，平行样测定相对标准偏差为7.8%~9.5%，3种方法测定结果精密度和准确度良好，均能够满足固体废物氰化物总量和氰化物浸出毒性的测定要求。其中容量法、分光光度法由于其仪器设备简单、操作简便，可用于突发环境事件应急监测等情况下固体废物氰化物的测定。但容量法检出限较高，不能满足评价标准较低的分析测试工作要求，离子色谱法、分光光度法和流动注射法检出限均能满足一般分析测试要求。     

环境空气中气态和颗粒态总氟化物分析方法优化

对双层磷酸氢二钾浸渍滤膜采集-氟离子选择电极测定环境空气中1、24 h气态和颗粒态总氟化物的方法进行了优化研究。方法采用小流量采集(24 h采样流量为16.7 L/min,1 h采样流量为50 L/min),解决了现有方法在样品采集上的问题,优化了样品制备中超声提取和静置方法。采样体积为3、24 m~3时,方法检出限分别为0.5、0.06μg/m~3,测定下限分别为2.0、0.24μg/m~3。实际样品测定,采样1 h时,加标回收率为87.9%~109%;采样24 h时,加标回收率为80.2%~99.3%,平行样测定的精密度为0.3%~2.9%,方法精密度和准确度良好,适用于环境空气中氟化物的测定。     

便携式分光光度计在地表水环境应急监测中的适用性分析

考察了便携式分光光度计对地表水中化学需氧量(COD)、氨氮(NH_3-N)、氟化物(F~-)、总磷(TP)和六价铬(Cr~(6+))的应急监测的适用性。对方法精密度和准确度进行测定,并将便携式方法与实验室方法的测定结果进行比对。结果表明,方法精密度为2.3%~7.4%,标准样品除Cr6+外,其他均在保证值范围内;加标回收率为86.0%~110%,2种方法比对的相对偏差为2.9%~6.4%。该方法精密度与准确度良好,可以较好地应用于地表水环境应急监测中。     

火电厂废水监测中的质量控制

论述了确保火电厂废水监督监测质量控制的几个方面。采样过程中的平行双样；空白试验。标准曲线的绘制与检验；实验室内精密度与准确度控制，加标回收率等。     

原子荧光光谱法与ICP-MS法测定水中总铅的比对研究

对测定水中铅的原子荧光法和ICP-MS法进行了对比分析。通过标准曲线、方法检出限、精密度、准确度的测定对比,结果表明,原子荧光法标准曲线在0～50μg/L内线性良好,相关系数为0.9995,检出限为0.06μg/L,精密度为1.44%～3.83%,实际样品加标回收率为92.0%～104%;ICPMS法标准曲线在0～100μg/L内线性良好,相关系数为1.0000,检出限为0.02μg/L,精密度为1.02%～3.67%,实际加标回收率为95.0%～106%。     

关于环境空气监测质量保证的建议

精密度和准确度是环境空气常规监测质量保证中重要而较方便的质控手段 ,由于受环境空气样品溶液体积的限制 ,建议分以下两种情况求其精密度和准确度 :1自动连续采样 :此法样品溶液体积一般为 5 0毫升 ,而分析只需 5毫升样品 ,故可参照水质监测分析质量控制 ,用同一样品同时分取两份进行平行样、加标样测定。2间断的手工采样 :此法目前在三、四级环境监测站仍然广泛使用 ,由于样品溶液体积仅为 5毫升 ,不能满足同一样品平行样、加标样的测定 ,建议采用每批样品带一定数量的标准已知样或密码样 ,通过这些样品的分析结果来评价分析测试的精密度…     

海水中总氮的测定方法比较研究

通过标准曲线、检出限和测定范围、方法精密度、方法准确度、实际海水样品测定结果、加标回收率、分析效率和物料消耗这几方面比较了过硫酸钾氧化法、流动注射分析法和高温氧化-化学发光检测法这3种测定海水中总氮(TN)方法的优缺点。结果表明,流动注射分析法和高温氧化-化学发光检测法的测定范围更宽,精密度、准确度更好,3种样品的加标回收率达到96.2%~101%;高温氧化-化学发光检测法分析效率高、物料消耗少、节能环保,适用于一般海水样品的批量分析,且由于测定范围大,该法也适用于TN浓度较高的海水样品的批量分析,流动注射分析法因其较低的检出限更适用于TN浓度较低的海水样品的批量分析。     

连续流动分析法测定地表水中总氮

采用50 mm流动检测池,建立了连续流动分析法测定地表水中总氮。方法检出限为0.02 mg/L,水样加标回收率为100%~101%,平行样品相对偏差为0.10%~0.27%,精密度(RSD,n=6)为0.72%~1.10%。实验结果表明,该方法准确可靠、灵敏度高、重现性好、分析速度快、操作简便,适用于地表水中总氮的分析。     

吹扫捕集- GC/MS法测定水中卤代烃的质量控制指标研究

采用吹扫捕集-气相色谱/质谱联用法,通过实际样品测试及全国多家实验室测定数据统计两种方法,针对水中三氯甲烷、四氯化碳、溴仿、二氯甲烷、1,2-二氯乙烷、1,1-二氯乙烯、三氯乙烯、四氯乙烯等8种卤代烃的平行样测定相对偏差、空白加标回收率及实际样品加标回收率等3个指标,研究了每种卤代烃的质控指标评价标准,提出其平行样测定...     

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.     

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.     

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.     

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.     

污染物总量控制中载体水流量的测定

示踪剂法测定河水流量是较为准确的办法 ,利用河流动力模型计算出示踪剂投放点 ,利用示踪剂投放量与测定浓度之间的关系可方便地获得河水流量结果