Hasse diagram technique as a tool for water quality assessment

The management of the quality large water catchments is a complex problem which requires intelligent data analysis on various levels – analytical, spatial, and temporal. Recently, a successful approach is developed combining advanced multivariate data treatment approaches like self-organizing maps of Kohonen (SOM) and Hasse diagram technique (HDT). In the first step of the environmetric analysis the monitoring data were subject to pre-processing using SOMs to reduce the number of objects and/or water quality parameters. In the next step HDT for partial ranking (both in spatial and temporal aspect) was applied according to the pre-selected set of the water quality parameters. The use of the water quality norms issued by the Bulgarian environmental authorities revealed important details in assessing the Maritsa River water quality. Thus, the relations between different water quality patterns and sampling stations could be used by water management authorities during the period of observation.     

Design of air quality monitoring networks and its application to NO2 and O3 in Cordova, Spain

Air monitoring networks are necessary to assess air quality in order to reduce pollution to levels which minimise harmful effects on human health and the environment. This paper describes a method to design air quality monitoring networks for nitrogen dioxide and ozone and its application in Cordova, Andalusia, southern Spain. The city has a population of 325,453 inhabitants and traffic is its main source of air pollution. The first step of this method made it possible to determine from historical data that two control stations for NO₂ and one control stations for O₃ are necessary according to the legislation. Sampling campaigns with passive diffusion samplers at 81 sites were then carried out to obtain information on the pollution distribution in Cordova. The sampling campaigns in 2001–2002 revealed an average concentration of 19.5 μg/m³ for NO₂ with maximum values up to 28.6 μg/m³ in Cordova city centre. The average ozone concentrations were recorded downwind from the emission source, reaching 91.8 μg/m³; the average ozone value in Cordova was 65.3 μg/m³. After spatial interpolation of the obtained values with Geographical Information Systems, a selection of the best locations for the monitoring stations was made, in line with the macro- and microscale siting requirements of the European Directive 2008/50/EC on ambient air quality and cleaner air for Europe. A second sampling campaign with diffusive samplers was carried out in 2007 to control if the locations of the air quality assessment stations were still representative for their zone.     

Collaborative sampling trial in the context of quality assurance in the German marine monitoring programme for the North Sea and the Baltic Sea

This paper presents the assessment of a collaborative trial in sampling in the Baltic Sea in the framework of quality assurance in the German marine monitoring programme for the North Sea and the Baltic Sea. The objective of investigations was to determine the influence of sampling on analytical results for selected monitoring parameters and to harmonize the procedure for sampling of sea water to a large extent. In these studies the staff of three vessels took replicate sea water samples, 1 m below the surface and below the halocline, at two monitoring stations. Mass concentration mean values for different nutrient parameters were obtained from each sample, all in one laboratory. Data produced from the hierarchical design were treated with robust analysis of variance (ANOVA) to generate uncertainty estimates, as standard uncertainties (“u” expressed as standard deviation), for geochemical variation (s _geochem), primary sampling (s _sampling), and chemical analysis (s _analysis). Geochemical variation dominated the total variance in all cases. Sampling and analytical uncertainties contributed together up to 15% of the total variance and had a relative measurement uncertainty (u%) of less than 2% for all the parameters investigated. Thus for this study the sampling protocol and the analytical method could be regarded as fit-for-purpose. M. Gluschke was formerly affiliated to the Federal Environmental Agency, P.O. Box 33 00 22, 14191 Berlin, Germany.     

Implementation of the EU Water Framework Directive in monitoring of small water bodies in Hungary, I. Establishment of surveillance monitoring system for physical and chemical characteristics for small mountain watercourses

The EU Water Framework Directives (WFD) prescribes to achieve a good status of surface waters by 2015. To keep this deadline of a new three level (surveillance, operational and investigative) monitoring system is required, including hydro-morphological, biological and chemical elements. The status of a water body should be related to the reference conditions, depending on surface water types. In Hungary, the standard monitoring network for surface water quality has been operated for rivers and large lakes; however no satisfactory information is available for small water bodies. Therefore, there is an urgent need to design a methodology to develop a monitoring network for small watercourses. For this purpose a slightly impacted mountain stream (Nagy Stream in Mátra Mountains), was selected and intensively monitored during three years (May 2002 → May 2005). Hydrological, biological and chemical parameters required by WFD were monitored in this program. Variability of parameters vs. time and space was also investigated. The minimum frequency of sampling was determined for chosen physico-chemical components to meet the WFD standards for confidence. It was found that the minimum frequency of sampling suggested by WFD in space and time may not be adequate for precise and accurate characterization of water quality.     

Sampling and sampling strategies for environmental analysis

Sampling errors are generally believed to dominate the errors of analytical measurement during the entire environmental data acquisition process. Unfortunately, environmental sampling errors are hardly quantified and documented even though analytical errors are frequently yet improperly reported to the third decimal point in environmental analysis. There is a significant discrepancy in directly applying traditional sampling theories (such as those developed for the binary particle systems) to trace levels of contaminants in complex environmental matrices with various spatial and temporal heterogeneities. The purpose of this critical review is to address several key issues in the development of an optimal sampling strategy with a primary goal of sample representativeness while minimizing the total number of samples and sampling frequencies, hence the cost for sampling and analysis. Several biased and statistically based sampling approaches commonly employed in environmental sampling (e.g. judgmental sampling and haphazard sampling vs. statistically based approaches such as simple random, systematic random, and stratified random sampling) are examined with respect to their pros and cons for the acquisition of scientifically reliable and legally defensible data. The effects of sample size, sample frequency and the use of compositing are addressed to illustrate the strategies for a cost reduction as well as an improved representativeness of sampling from spatially and temporally varied environmental systems. The discussions are accompanied with some recent advances and examples in the formulation of sampling strategies for the chemical or biological analysis of air, surface water, drinking water, groundwater, soil, and hazardous waste sites.     

Comparative study on formamide–water complex

The hydrogen bonding of 1:1 complexes formed between formamide and water molecule have been investigated systematically using Hartree–Fock (HF), hybrid density functional theory (B3LYP), and post‐Hartree–Fock (MP2 and CCSD(T)) methods with range of basis sets 6‐31G(d), cc‐pVXZ (X = D, T, Q) and aug‐cc‐pVYZ (Y = D, T). Three stable structures are considered on the potential energy surface of formamide and water system. The optimized geometric parameters and interaction energies for various isomers at different levels are estimated. The IR frequencies, intensities, and frequency shifts are reported. This study shows that B3LYP/aug‐cc‐pVDZ method gives better performance for formamide‐water complexes. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010.     

On-line monitoring of trihalomethane concentrations in drinking water distribution systems using capillary membrane sampling-gas chromatography

Trihalomethane concentrations are not typically monitored continuously in drinking water distribution systems. This means that data is not immediately available to operators so that they can make decisions that directly affect water quality. Monitoring data could be useful to researchers and operators who might want to better understand disinfection by-product formation and removal in their distribution systems. In this paper, a capillary membrane sampler (CMS), which uses a silicone membrane to directly sample trihalomethanes from a water sample, shows promise as a sampling device that can be used to introduce samples directly into a gas chromatograph for on-line monitoring. The construction, optimization, operation and evaluation of this capillary membrane sampling-gas chromatograph (CMS-GC) are discussed. The result of optimization, method detection limit, accuracy, precision and linearity studies are presented. Side-by-side studies have been done comparing the CMS-GC method to USEPA Method 502.2. While the CMS-GC method is not meant to replace USEPA Method 502.2, it does offer advantages for on-line monitoring and meets several of the criteria proposed as desirable for on-line monitoring of THM concentrations in drinking water distribution systems.     

Chemical and environmental sampling: quality through accreditation, certification and industrial standards

Executive summary In the CEN/STAR Trends Analysis workshop on Sampling, initiated by request of the Nordic Innovation Centre, specially invited experts provided presentations on demands about regulation concerning sampling quality, sampling standard developments, quality assurance systems and practical experience from different sampling situations and cases. The workshop arrived at recommendations on the importance of proper sampling for environmental and product control purposes, especially to support European regulations, trade agreements and monitoring of environment. Sampling is an integrated part of the whole measurement process and should therefore be especially considered from the viewpoint of the end-user of the results. There is a need for raising quality control issues in sampling and for the establishment of a more uniformly co-ordinated European quality system for sampling. With the standard methods available, there are in principle two different ways of achieving third party assessment of the sampling protocols and procedures: accreditation of sampling organisations based upon international, national, or in-house standards and methods, and certification of individual samplers’ competences for sampling. Several activities or efforts as well as research and standardisation needs for raising the quality issues in sampling were identified and presented in a paper by the workshop.All the presentations and Workshop Proceedings are electronically available on the Nordic Innovation Centre's web site at and more specifically at     

Determination of chromium in whole blood by DRC–ICP–MS: spectral and non-spectral interferences

Quantification of chromium in whole blood has been performed by ICP–quadrupole MS. The spectrometer was equipped with a dynamic reaction cell (DRC) with ammonia as reaction gas. The rejection parameter q (RPq) of the DRC and the flow rate of ammonia (NH₃) were optimized and set at 0.7 and 0.6 mL min⁻¹, respectively. Blood was diluted 1:51 (v/v) with an aqueous solution containing 0.1 mg L⁻¹ NH₄OH, 0.1 g L⁻¹ EDTA, 5 mg L⁻¹ n-butanol, and 0.1‰ Triton X100. Non-spectral matrix effects observed when using the DRC were confirmed by use of vanadium. External calibration with blank and standard solutions prepared in purified water led to biased results for quality control samples. Standard addition calibration was therefore used and its validity verified. By comparing the slopes and calculating residues, it was proved that the plot obtained with standard additions and the plot obtained from blood samples of different concentrations were aligned down to 0.05 μg L⁻¹ after dilution.     

流动注射光度法测定地热水中可溶性硅

提出了基于正硅酸与钼酸铵的显色反应和流动注射分析装置的流动注射光度法测定地热水中可溶性硅量的方法。对仪器的各项工作参数,包括显色反应所需钼酸铵溶液的浓度及要求的酸度条件,各反应圈的长度,试剂环的定量体积,流动注射系统出口的流量等做了试验并予以优化,所提出的装置可达到每小时60个样品的进样频率。测定二氧化硅的线性范围为20~800 mg.L-1。应用此法对实样的测定结果与国家标准方法(GB/T 12148-2006)测得的结果相符。     

膜萃取-气相色谱/微分离子迁移谱检测水中的1,4-二恶烷

利用膜萃取-气相色谱/微分离子迁移谱（ME-GC/DMS）对水中的1,4-二恶烷污染物进行了检测。考察了射频电压、采样流速、膜渗透时间、Trap预富集时间等参数对检测二恶烷的影响规律。结果显示：在优化条件下,二恶烷的定量线性范围为2.0~20.0 μg/L,检出限为0.67 μg/L。实验证明,二恶烷与5种氯代烃的混合物在ME-GC/DMS的二维分离谱图中得到特异性响应,增加了识别的准确性。该研究为发展现场实时监测地下水中污染物的方法提供了重要参考。     

Pesticide levels in ground and surface waters of Primavera do Leste Region, Mato Grosso, Brazil

Residues of the herbicides simazine, metribuzin, metolachlor, trifluralin, atrazine, and two metabolites of atrazine, deisopropylatrazine (DIA) and deethylatrazine (DEA), are surveyed in the surface and groundwater of the Primavera do Leste region, Mato Grosso, Brazil during September and December 1998 and April 1999. Different water source sampling stations of groundwater (irrigation water well, drinking water well, and water hole) and surface water (dam and river) are set up based on agricultural land use. A solid-phase extraction procedure followed by gas chromatography-nitrogen-phosphorus detection is used for the determination of these compounds. All compounds are detected at least once in water samples. A temporal trend of pesticide contamination is observed, with the highest contamination frequency occurring in December during the main application season. Metribuzin shows the highest individual detection frequencies throughout the monitoring period, followed by metolachlor, simazine, and DEA. The maximum mean concentrations of pesticides in this study are in the range from 0.14 to 1.7 microg/L. We deduct that the contamination of water resources is predominantly caused by non-point pollution of pesticides used in intensive cash-crop cultures of the Cerrado area. Therefore, a continuous monitoring of pesticide concentrations in water resources of this tropical region is necessary to detect the longer term contamination trends and developing health risks.     

Sum frequency generation-compressive sensing microscope

A new sum frequency generation imaging microscope using a novel sampling theory, compressive sensing (CS), has been developed for surface studies. CS differentiates itself from the conventional sampling methods by collecting fewer measurements than the traditional methods to reconstruct a high quality image. Pseudorandom patterns were applied to a light modulator and reflected the sum frequency (SF) signal generated from the sample into a photomultiplier tube detector. The image of the sample was reconstructed using sparsity preserving algorithms from the SF signal. The influences of the number of CS testing patterns applied and the number of SF pulses acquired for each pattern on the quality of the images was investigated and a comparison of the image quality with the traditional raster scan was made at varying resolutions for a gold patterned Si surface. Our results demonstrate the CS technique achieved 16 times the pixel density beyond the resolution where the raster scan strategy lost its ability to image the sample due to the dilution of the SF signal below the detection limit of the detector.     

改进的离子色谱系统监测重庆嘉陵江水质（英文）

The w ater quality monitoring operation to evaluate the w ater quality of polluted river is an extremely im po rtant task fo r the river-w atershed m anagem ent/co ntro l based o n the enviro nm ental po licy.In this study,the no vel,sim ple and co nvenient w ater quality m o nito ring o f Jialing-River in Cho ngqing,China w as carried o ut using an advanced io n chro m ato graphy(IC) co nsisting o f io n-ex clusio n/catio n-ex change chro m ato graphy(IEC/CEC) with conductivity detection for determining simultaneously the common anions such as SO 2 4,Cl,and NO 3 and the catio ns such as Na +,NH + 4,K +,Mg 2 +,and Ca 2 +,the ion-exclusion chromatography(IEC) w ith visible detectio n fo r determ ining sim ultaneo usly the nutrient co m po nents such as pho sphate and silicate io ns,and the IEC w ith the enhanced co nductivity detectio n using a po st co lum n o f K +-fo rm catio n-ex change resin fo r determ ining HCO 3-alkalinity as an ino rganic-carbo n so urce fo r bio m ass synthesis in bio lo gical reactio n pro cess under the aero bic co nditio ns.Acco rding to the io nic balance theo ry betw een the to tal equivalent co ncentratio ns o f anio ns and catio ns,the w ater quality evaluatio n o f the Jialing-River w aters taking at different sam pling sites in Cho ngqing m etro po litan area w as carried o ut using the advanced IC system.As a result,the effectiveness o f this no vel w ater quality m o nito ring m etho do lo gy using the IC system w as dem o nstrated o n the several practical applicatio ns to a typical bio lo gical sew age treatm ent plant o n Jialing-River o f Cho ngqing.     

Selection of modulation frequency of FT-IR equipped with an MCT detector for thin-film analysis

Optimal modulation frequency (scan rate) of an FT-IR equipped with a mercury–cadmium–telluride (MCT) detector has been investigated for obtaining high quality spectra of a monolayer-level thin film. Since an MCT detector is a semiconductor light device, it does not respond to modulation frequency significantly in comparison to a pyroelectric detector. A very thin film, however, requires high-throughput measurements to have high signal-to-noise ratio. In this study, a balance of throughput and measurement time has been investigated by varying modulation frequency by using two spectrometers that have different sampling frequencies. In this study, the stability of the baseline of absorbance spectra was also investigated depending on modulation frequencies, which suggested that 60 kHz was most suitable for quantitatively reliable transmission measurements of Langmuir–Blodgett films.     

Theoretical studies on vibrational spectra of some halides of group IVB elements

The vibrational spectra of group IVB elements halides MX4 (M=Ti(IV), Zr(IV), Hf(II); X=F, Cl, Br and I), have been investigated by ab initio RHF, MP2 and density functional theory B3LYP method with LanL2DZ basis sets. The optimized geometries, calculated vibrational frequencies and Far-IR intensities of MX4 are evaluated via comparison with experimental data. The vibrational frequencies, calculated by these methods, are compared to each other. The results indicate that B3LYP method is more reliable than RHF and MP2 methods for the frequencies calculations for these compounds. With this method, some vibrational frequencies of M2X6(2+)(M=Ti(IV), Zr(IV) and Hf(II); X=F, Cl, Br and I) are also predicted.     

Sampling of water, soil and sediment to trace organic pollutants at a river-basin scale

Sampling is considered a crucial step in the analysis of organic compounds in the environment. This review describes field sampling techniques and provides detailed step-by-step procedures for collection and preservation of all major environmental matrices (water, sediment and soil) integrated as part of the river-basin water cycle. Attention is given to the prerequisites for obtaining reliable samples, and the practical issues of sample collection (planning, field sampling, sampling strategies and equipment and data quality assessment) are considered. Considering the heterogeneity of environmental matrices, special considerations for each matrix are given to solve typical problems and to find the most appropriate solutions to ensure the quality of the sample. The procedures described in the next sections are commonly used protocols that reflect true field conditions and current state-of-the-art techniques used in the sampling of organic compounds. The aim is to signify the importance of sampling to the overall analytical procedure. Finally, quality control issues to be considered in environmental sampling are given.     

Strategies for monitoring the emerging polar organic contaminants in water with emphasis on integrative passive sampling

Although polar organic contaminants (POCs) such as pharmaceuticals are considered as some of today's most emerging contaminants few of them are regulated or included in on-going monitoring programs. However, the growing concern among the public and researchers together with the new legislature within the European Union, the registration, evaluation and authorisation of chemicals (REACH) system will increase the future need of simple, low cost strategies for monitoring and risk assessment of POCs in aquatic environments. In this article, we overview the advantages and shortcomings of traditional and novel sampling techniques available for monitoring the emerging POCs in water. The benefits and drawbacks of using active and biological sampling were discussed and the principles of organic passive samplers (PS) presented. A detailed overview of type of polar organic PS available, and their classes of target compounds and field of applications were given, and the considerations involved in using them such as environmental effects and quality control were discussed. The usefulness of biological sampling of POCs in water was found to be limited. Polar organic PS was considered to be the only available, but nevertheless, an efficient alternative to active water sampling due to its simplicity, low cost, no need of power supply or maintenance, and the ability of collecting time-integrative samples with one sample collection. However, the polar organic PS need to be further developed before they can be used as standard in water quality monitoring programs.     

Industrial application of green chromatography--I. Separation and analysis of niacinamide in skincare creams using pure water as the mobile phase

In this work, chromatographic separation of niacin and niacinamide using pure water as the sole component in the mobile phase has been investigated. The separation and analysis of niacinamide have been optimized using three columns at different temperatures and various flow rates. Our results clearly demonstrate that separation and analysis of niacinamide from skincare products can be achieved using pure water as the eluent at 60 °C on a Waters XTerra MS C18 column, a Waters XBridge C18 column, or at 80 °C on a Hamilton PRP-1 column. The separation efficiency, quantification quality, and analysis time of this new method are at least comparable with those of the traditional HPLC methods. Compared with traditional HPLC, the major advantage of this newly developed green chromatography technique is the elimination of organic solvents required in the HPLC mobile phase. In addition, the pure water chromatography separations described in this work can be directly applied in industrial plant settings without further modification of the existing HPLC equipment.