高含氯水样高锰酸盐指数测定新方法

在高锰酸盐指数的测定中,干扰最为严重且难以消除的是氯离子(Cl-)的影响。高浓度氯离子的干扰会导致测定结果偏差大,无法界定高锰酸盐指数是否达标。对高含氯水样高锰酸盐指数测定新方法(改进的高锰酸盐指数法)的实验研究结果表明,在采用标准高锰酸钾法对高含氯水样进行的高锰酸盐指数测定中,利用稀释方法,在碱性条件下用硫酸锰作催化剂,可以避免氯离子的干扰,提高了高锰酸钾对有机物的氧化率,能真实地反映水样中有机物的污染程度。     

ICP-OES法直接测定海水中痕量铜

研究运用ICP-OES法直接测定海水中铜的含量。选择特征谱线,调节最佳仪器参数进行测定。研究表明:在0～50μg/L线性范围内,曲线相关系数可以达到0.999 8,方法检出限为0.5μg/L,加标回收率在102%～105%之间,RSD≤4.7。直接进样-电感耦合等离子体发射光谱法(ICP-OES法)测定海水中痕量铜,前处理简单,灵敏度高,检出限低,干扰少,线性范围宽,操作简单、快捷。     

苯胺对水中挥发酚测定干扰规律的研究

HJ 503-2009《水质挥发酚的测定4-氨基安替比林分光光度法》中,提到苯胺对本方法有干扰,但未进行具体情况的研究并给出具体的消除方法。实际监测工作中苯胺对实验的干扰情况复杂,需要依据具体的情况进行解决：当水样中苯胺浓度在1 mg/L以下时,苯胺对该方法测定水中挥发酚没有干扰;当苯胺浓度在1～10 mg/L时,可以用盐酸调节水样的pH值以消除苯胺干扰;当苯胺的浓度≥10 mg/L时,苯胺对该方法测定挥发酚产生显著的干扰,不适合采用光度法进行测定,建议萃取后采用气相色谱-质谱或液相色谱法进行测定。     

泥沙对总氮测定结果的干扰影响分析

分析了泥沙含量对总氮测定结果的干扰影响,结果表明:水样中泥沙的含量与其对水样总氮的贡献有显著的正相关性;泥沙对总氮测定结果有干扰影响,随泥沙含量增加,A275的测定值及总氮降低率逐渐增大,且当泥沙(SS)含量≥45 mg/L时,其A275/A220的值在20%以上,总氮降低率在15%以上,从而总氮测定值产生较大的误差。消解后离心法或消解后0.45μm滤膜过滤法能有效地消除泥沙的干扰,并均具有操作简单和准确度高的优点。     

不同预处理对纳氏试剂比色法测氨氮的影响

用纳氏试剂比色法测污水中氨氮含量,为了消除干扰物质对测定的影响,需根据水体受污染程度,对水样通过絮凝沉淀法或蒸馏法进行预处理.本文通过试验论证了即使对较清洁的水,也以蒸馏法预处理为佳,蒸馏法预处理后的测定值更接近真值.     

高氯低COD废水中COD的测定

以某污水厂的高氯低COD生化出水为研究对象,探讨了硫酸汞加入量、K2Cr2O7溶液浓度、反应酸度、取水样量等参数对COD测定的影响,探讨消除该厂Cl-干扰最简单有效方法,结果表明:控制硫酸汞与氯离子比为15∶1(质量比)、K2Cr2O7浓度为0.18 mol/L、水样稀释0.75倍、Ag2SO4-H2SO4加入量为28mL,皆可有效减少氯离子的干扰。该方法相对氯气校正法,操作简单、准确可靠。     

水中氯离子测定时干扰物的消除

用硝酸银滴定法测定水中氯离子时，存在S~2-、SO_3~2-、S_2_O_3~2-的干扰，原用H_2O_2消除干扰，但滴定到达终点后，颜色不太稳定，为此，我们采用过硫酸钾氧化法进行消除干扰的试验。实践证明,该方法对消除上述干扰物是可行的，对测定石油勘探开发废水中氯离子时消除干扰是适用的。     

ICP—OES法在测定降水中金属离子的研究

本文主要研究了应用电感耦合等离子体发射光谱法（ICP—OES法）同时测定降水中钾、钠、钙、镁金属离子的应用。通过多次测试待测标准物质，确定各待测元素的最佳分析谱线和仪器的工作参数。根据ICP-OES法测定模拟降水混合标准样品、降水样品及其加标样品的结果，与AAS法（原子吸收分光光度法）进行实验室间比对测定，得出ICP—OES法测定降水中钾、钠、钙、镁各离子的检出限、线性范围、标准偏差、准确度等均比AAS法得到的结果要好。ICP-OES法与国家标准方法——原子吸收分光光度法（GB13580．12—92，GB13580．13—92）相比，具有操作简单、多种元素同时测定、方便快捷、检出限低、线性范围宽、干扰少等优点；有良好的准确度和精密度，相对标准偏差在0．3％～1．5％之间，加标回收率在97％～105％之间；该方法明显优于国家标准方法。     

高氯离子水样COD测定方法的研究进展

COD是水质监测的一项重要指标，氯离子是COD测定中主要的干扰物之一。如何消除氯离子的干扰。提高COD测定的重复性和准确度。同时减轻二次污染，是广大环境监测者非常关注的问题。文章对高氯离子水样COD测定方法的研究进展作了简要综述。     

纳氏试剂分光光度法测定水中氨氮的影响因素浅析

纳氏试剂分光光度法测定水质氨氮受多种因素干扰,直接影响分析结果。针对此情况,结合环境监测工作实际,通过纳氏试剂配制、水样存放时间、稀释方式、显色条件4个方面对实验结果产生的影响进行了研究,并对这些干扰因素的消除进行了讨论,为确保纳氏试剂分光光度法测定水中氨氮结果的准确性提供了参考。     

A comparison of reliability of soil cadmium determination by standard spectrometric methods

Inductively coupled plasma emission spectrometry (ICP-OES) is the most common method for determination of soil Cd, yet spectral and matrix interferences affect measurements at the available analytical wavelengths for this metal. This study evaluated the severity of the interference over a range of total soil Cd by comparing ICP-OES and inductively coupled plasma mass spectrometry (ICP-MS) measurements of Cd in acid digests. Using the emission at 226.5 nm, ICP-OES was generally unable to quantify soil Cd at low (near-background) levels and gave unreliable values compared with ICP-MS. Using the line at 228.8 nm, a marked positive bias in Cd measurement (relative to the 226.5 nm measurement) was attributable to arsenic (As) interference even at soil As concentrations below 10 mg kg. This spectral interference in ICP-OES was severe in As-contaminated orchard soils, giving a false value for soil total Cd near 2 mg kg when soil As was 100 to 150 mg kg. In attempting to avoid these ICP emission-specific interferences, this study evaluated a method to estimate total soil Cd using 1 M HNO extraction followed by determination of Cd by flame atomic absorption (FAA), either with or without preconcentration of Cd using an Aliquat-heptanone extractant. The 1 M HNO extracted an average of 82% of total soil Cd. The FAA method had no significant interferences and estimated the total Cd concentrations in all soils tested with acceptable accuracy. For Cd-contaminated soils, the Aliquat-heptanone preconcentration step was not necessary, as FAA sensitivity was adequate for quantification of extractable soil Cd and reliable estimation of total soil Cd.     

标准加入分光光度法测定废水中氨氮

本文将标准加入法运用于分光光度分析中，排除了废水氨氮测定中复杂的基体干扰，操作简便，结果准确，适合于单个或小批量水样的直接测定。     

A Multilevel Model of the Impact of Farm‐Level Best Management Practices on Phosphorus Runoff1

Abstract: Multilevel or hierarchical models have been applied for a number of years in the social sciences but only relatively recently in the environmental sciences. These models can be developed in either a frequentist or Bayesian context and have similarities to other methods such as empirical Bayes analysis and random coefficients regression. In essence, multilevel models take advantage of the hierarchical structure that exists in many multivariate datasets; for example, water quality measurements may be taken from individual lakes, lakes are located in various climatic zones, lakes may be natural or man‐made, and so on. The groups, or levels, may effectively yield different responses or behaviors (e.g., nutrient load response in lakes) that often make retaining group membership more effective when developing a predictive model than when working with either all of the data together or working separately with the individuals. Here, we develop a multilevel model of the impact of farm level best management practices (BMPs) on phosphorus runoff. The result of this research is a model with parameters which vary with key practice categories and thus may be used to evaluate the effectiveness of these practices on phosphorus runoff. For example, it was found that the effect of fertilizer application rate on farm‐scale phosphorus loss is a function of the application method, the hydrologic soil group, and the land use (crop type). Further, results indicate that the most effective method for controlling fertilizer loss is through soil injection. In summary, the resultant multilevel model can be used to estimate phosphorus loss from farms and hence serve as a useful tool for BMP selection.     

联用技术在砷形态分析中的研究进展

摘要：目前用于元素砷的形态分析技术主要是色谱与原子光谱、质谱等的联用,最常用的是HPLC与ICP—OES、ICP—MS的联用,方法准确可靠,灵敏度高,但是不能提供砷化合物的分子结构信息。因此以色谱一电喷雾质谱（ESI—MS）的联用作为定性分析的主要手段,但是ESI—MS灵敏度低,易受基体干扰,因此需要复杂的前处理技术。     

微波消解-流动注射分光光度法测定土壤中的总磷

采用热效率高的微波消解系统对土壤中的总磷进行消解,建立了微波消解-流动注射分光光度法测定土壤中总磷的方法,该方法对比HJ632-2011碱熔-钼锑抗分光光度法具有快速、简便、节约试剂等特点。本文用两种分析方法对实际土壤样品及标准样品进行定量测定,所得结果表明微波消解法能快速测定大量土壤样品的总磷。     

Multi-angle Indicators System of Non-point Pollution Source Assessment in Rural Areas: A Case Study Near Taihu Lake

This study aims to identify key environmental risk sources contributing to water eutrophication and to suggest certain risk management strategies for rural areas. The multi-angle indicators included in the risk source assessment system were non-point source pollution, deficient waste treatment, and public awareness of environmental risk, which combined psychometric paradigm methods, the contingent valuation method, and personal interviews to describe the environmental sensitivity of local residents. Total risk values of different villages near Taihu Lake were calculated in the case study, which resulted in a geographic risk map showing which village was the critical risk source of Taihu eutrophication. The increased application of phosphorus (P) and nitrogen (N), loss vulnerability of pollutant, and a lack of environmental risk awareness led to more serious non-point pollution, especially in rural China. Interesting results revealed by the quotient between the scores of objective risk sources and subjective risk sources showed what should be improved for each study village. More environmental investments, control of agricultural activities, and promotion of environmental education are critical considerations for rural environmental management. These findings are helpful for developing targeted and effective risk management strategies in rural areas.     

Different formats of imprinted polymers for determining organotin compounds in environmental samples

Organotin compounds and their degradation products enter the environment mainly as a result of their use as biocides and antifouling paints. Analysis of these compounds in environmental samples has to be very sensitive and selective so that their concentrations corresponding to the low environmental target values can also be detected. Generally, analysis of a complex matrix leads to high interferences during the different process steps; clean-up procedures are recommended to overcome this problem. For the past many years, solid phase extraction by employing imprinted materials has been extensively used for many organic substances that are used for pre-concentration and clean-up purposes with excellent results. Here, we present three different imprinted polymers prepared via bulk, precipitation, and emulsion polymerization methods that use similar compositions. The synthesized polymer particles were characterized morphologically by employing scanning electron microscopy and Brunauer-Emmett-Teller analysis. Binding properties were calculated using the Langmuir-Freundlich isotherm. Depending on the properties of the materials, different analytical applications for complex matrices are proposed. These applications are mainly used on tributyltin and its degradation products for environmental analysis.     

NITROGEN AND PHOSPHORUS IN WATER AS RELATED TO ENVIRONMENTAL SEVI'ING IN NEBRASKA1

ABSTRACT: Spatial distributions of nitrogen and phosphorus in water were related to environmental setting as part of a regional water-quality assessment of the Central Nebraska Basins. The environmental settings (Sandhills, Loess Hills, Glaciated Area, and Platte Valley) were characterized by different concentrations of nitrogen and phosphorus in ground water and stream water. Statistically significant differences in nitrate concentrations in both ground-water and stream-water samples were related to regional distributions of cropland and rangeland. Nitrate concentrations were larger, especially in shallow ground water, in environmental settings dominated by cropland and associated fertilizer use than in settings dominated by rangeland. Similarly, total-nitrogen and nitrate concentrations were relatively large in selected streams draining primarily cropland. Comparative concentrations of phosphorus in stream water on the basis of environmental setting were similar to those of nitrogen, although the largest phosphorus concentrations probably relate to wastewater discharge into small streams. Nitrogen and phosphorus concentrations in much of the Platte River apparently reflected the quality of water entering the study unit from upstream and limited base-flow contributions from within the Platte Valley itself.