Validation interlaboratory trial for ISO 12010: Water quality—Determination of short-chain polychlorinated alkanes (SCCP) in water

A validation interlaboratory trial was carried out to prepare ISO 12010: Water quality??Determination of short-chain polychlorinated alkanes (SCCP) in water??Method using gas chromatography/mass spectrometry (GC-MS) and electron capture negative ionisation (ECNI). The task was to determine the sum of short-chain polychlorinated n-alkanes with carbon chain lengths of C₁₀?CC₁₃ and a chlorine content between 49% (g/100?g) and 67% (g/100?g) in water by GC-ECNI-MS. The quantification had to be performed by multiple linear regression as described in ISO/DIS 12010, the compulsory method. Samples distributed were real river samples, and waste water spiked with a target concentration of 0.4 and 0.6???g/L for the sum of SCCPs, i.e. a concentration around the environmental quality target level according to the European Water Framework Directive. The different types of water samples tested were surface water with <150?mg/L suspended matter, surface water with 0.5?g/L suspended matter, and filtered waste waster. The interlaboratory trial included the extraction of the water samples, a column chromatographic clean up, a concentration step, and integration of chromatographic unresolved complex mixtures as well as the calibration and quantification by multiple linear regression. The reproducibility standard deviation of the standard concentration was 11.9%. Reproducibility standard deviations of concentrations in the three different water samples between 27.8 and 34.2% were achieved by 10?C12 participating laboratories from six countries.     

Needs for reliable analytical methods for monitoring chemical pollutants in surface water under the European Water Framework Directive

The state of the art in monitoring chemical pollutants to assess water quality status according to Water Framework Directive (WFD) and the challenges associated with it have been reviewed. The article includes information on environmental quality standards (EQSs) proposed to protect the aquatic environment and humans against hazardous substances and the resulting monitoring requirements. Furthermore, minimum performance criteria for analytical methods and quality assurance issues have been discussed. The result of a survey of existing standard methods with a focus on European (EN) and international standards (ISO) for the analysis of chemical pollutants in water is reported and the applicability of those methods for the purpose of compliance checking with EQSs is examined. Approximately 75% of the 41 hazardous substances for which Europe-wide EQSs have been proposed can be reliably monitored in water with acceptable uncertainty when applying existing standardised methods. Monitoring in water encounters difficulties for some substances, e.g., short-chain chlorinated paraffins (SCCPs), polybrominated diphenyl ethers (PBDEs), tributyltin compounds, certain organochlorine pesticides and six-ring PAHs, mainly due to a lack of validated, sufficiently sensitive methods that are applicable in routine laboratory conditions. As WFD requires monitoring of unfiltered samples for organic contaminants more attention needs to be paid to the distribution of chemical pollutants between suspended particulate matter and the liquid phase. Methods allowing complete extraction of organic contaminants from whole water samples are required. From a quality assurance point of view, there is a need to organise interlaboratory comparisons specifically designed to the requirements of WFD (concentrations around EQSs, representative water samples) as well as field trials to compare sampling methodologies. Additional analytical challenges may arise when Member States have identified their river basin specific pollutants and after revision of the list of priority substances.     

Preparation and evaluation of sufficiently homogeneous and stable reference materials for priority hazardous substances in whole water

We have prepared and evaluated three whole water test materials containing eight polycyclic aromatic hydrocarbons (PAHs), six polybrominated diphenyl ethers (PBDEs) and tributyltin (TBT) with respect to homogeneity and short-term stability. The test materials were used as samples in two inter-laboratory comparisons. The materials were composed of natural mineral water and model suspended particulate matter (SPM) containing the target compounds at ng L^?1 levels. The expanded uncertainty of the estimated mass concentrations in the final test materials was obtained by combining contributions from the homogeneity, the stability and the model SPM characterization. The whole water materials were sufficiently homogeneous and stable at 4 °C for their intended use. In total, 12 out of 15 investigated target parameters could be assessed to be present with a relative combined expanded uncertainty below 25 %. The outcome of the two inter-laboratory comparisons confirmed the good quality of the test materials and the level of uncertainties associated with the estimated mass concentrations. These findings are an important contribution towards the development of whole water matrix reference materials certified for PAH, PBDE and TBT in support of the Water Framework Directive of the European Union.     

Evaluation of preconcentration methods in the analysis of synthetic musks in whole‐water samples

According to the European Water Framework Directive, environmental assessment of organic compounds should be made in whole‐water samples, but due to their hydrophobicity and strong attraction to organic content these compounds can be found bound to suspended particle matter or in the dissolved fraction. In this work, the extraction of musk compounds was studied in whole‐water samples exhibiting different amounts of dissolved organic carbon and suspended particulate matter using polyethersulfone preconcentration technique. Matrix effects in estuarine and wastewater (both influent and effluent) were evaluated for filtered and unfiltered samples. For unfiltered samples, estuarine water exhibited matrix effects <20%, while for effluent it was up to 48% and for influent ranged from 85 to 99%. To compensate matrix effects and determine total concentrations in unfiltered samples, different quantification approaches were tested: the use of deuterated analogues and standard additions. Standard additions provided the best results for unfiltered samples. Finally, filtered and unfiltered samples were analyzed using both polyethersulfone preconcentration and membrane‐assisted solvent extraction and results showed a good agreement between the two methods. In both cases unfiltered samples provided concentrations 1.5–2.6 times higher than filtered samples.     

Estimation of measurement uncertainty in the determination of orthophosphates in seawater by continuous flow analysis (CFA)

Phosphorus is the second most important limiting nutrient for the growth of autotrophic organisms in coastal and oceanic environments and is present in a wide range of chemical forms both dissolved and particulate. Within the dissolved inorganic fraction of phosphorus, orthophosphates are the so-called soluble reactive phosphorus. This nutrient, as a central element in coastal and oceanic biogeochemical cycles, is one of the compounds measured for the physico-chemical quality indices established by the Water Framework Directive 2000/60/EC and one of the characteristics to be measured in the Marine Strategy Framework Directive 2008/56/EC. In this work, an estimation of the measurement uncertainty in the determination of orthophosphates in seawater by continuous flow analysis, based on ISO 15681-2:2003, in the range of 10–150 μg/L as P was carried out by means of a global model of uncertainty quantification from validation data. The results were coherent with previous interlaboratory comparisons of orthophosphates in seawater. Expanded uncertainty did not exceed 6.5 % in the entire range.     

Laboratory intercomparison study on the analysis of short-chain chlorinated paraffins in an extract of industrial soil

Short-chain chlorinated paraffins (SCCPs) comprise a class of organic pollutants used in many industrial applications and released into the environment. The analytical determination of SCCPs is very challenging. Although there is at present no fully validated measurement procedure that might be applied in routine monitoring, the European Union Water Framework Directive (WFD) has required regular monitoring of this class of compounds at river-basin scale since 2007.To assess the status quo of the analysis of SCCPs in relation to the requirements of the WFD, we organized an interlaboratory comparison on the quantification of SCCPs in an extract of an industrial soil. Six laboratories participated in the exercise using three different techniques [i.e. gas chromatography (GC) coupled to mass spectrometry (MS) in electron-capture negative ionization mode, GC with atomic emission detection, and carbon-skeleton GC-MS]. The results reported were in the range 8.5–3200 mg/L. This confirms that reliable quantification of SCCPs is still very difficult to achieve and that the comparability of SCCP data reported to the European Commission is at least questionable.     

Metrological concept for comparable measurement results under the European water framework directive: demonstration of its applicability in elemental analysis

Within the scope of a project of the “European Association of National Metrology Institutes??(EURAMET), a European metrological dissemination system (network) providing traceable reference values assigned to matrix materials for validation purposes is described and put to the test. It enables testing laboratories (TL) to obtain comparable results for measurements under the “EU Water Framework Directive 2000/60/EC??(WFD) and thus, to comply with a core requirement of this very directive. The dissemination system is characterized by the fact that it is available to all laboratories throughout Europe which intend to perform measurements in the context of the WFD and that it can ensure sustainable metrological traceability to the International System of Units (SI) as a reference point for the measurement results. This dissemination system is set up in a hierarchical manner and links up the level of the national metrology institutes (NMI) with that of the TLs via an intermediate level of calibration laboratories (CL) by comparison measurements. The CLs are expert laboratories with respect to the measurement of the analytes considered here (within the project, the CLs are called potential calibration laboratories (PCL)) and are additionally involved in the organization of comparison measurements within the scope of regional quality assurance (QA) systems. Three comparison measurements have been performed to support the approach. A total of about 130 laboratories participated in this exercise with the focus on the measurement of the priority substances Pb, Cd, Hg, and Ni defined in the WFD. The elemental concentrations in the water samples roughly corresponded to one of the established environmental quality standards (EQS), the annual average concentration (AA-EQS), which is defined in the daughter Directive 2008/105/EC of the WFD. It turned out that a significant number of TLs still need to improve their measurement methods in order to be able to fulfill the minimum requirements of the WFD, in particular, with regard to the elements Cd and Hg probably due to their low EQS values. Furthermore, it became obvious that the hierarchical dissemination system suggested here actually corresponds to the measuring capabilities of the three participating groups (NMIs, PCLs, and TLs).     

Collaborative study for the quality control of trace element determinations in paint coatings Part 1. Interlaboratory study

Since the adoption of the European Standard EN71: Part 3 on toy safety, there has been dissatisfaction with the poor reproducibility obtained between laboratories using the test method for the determination of the migration of certain elements from paints to toys. This lack of quality control could result in toys being judged unacceptable with regard to the requirements of the EC Directive 88/378/EEC, which creates a potential barrier to trade. In order to improve the methods of measurements and testing, the Standards, Measurements and Testing Programme (SM&T) is currently supporting a project of which the final aim is to produce paint reference materials. The first step of this collaborative project is aimed to assess and possibly improve the state-of-the-art of trace element determinations in paint coatings through an interlaboratory study, the results of which are presented in this paper.     

Development of an analytical procedure for the determination of polybrominated diphenyl ethers in environmental water samples by GC–ICP-MS

Polybrominated diphenyl ethers (PBDEs) are flame retardants, which due to their widespread use are frequently present as pollutants in the environment. In the EU Water Framework Directive (WFD) six PBDE congeners (BDE 28, BDE47, BDE 99, BDE 100, BDE 153 and BDE 154) are listed as priority substances. The uncertainty of the analytical method used for their determination in water samples at environmental quality standard (EQS) level (0.5 ng L⁻¹ for the ΣPBDEs) should be equal or less than 50% and the limit of quantification (LOQ) for ΣPBDEs below 0.15 ng L⁻¹. To meet these requirements, an analytical procedure for the determination of these six PBDEs in environmental water samples by gas chromatography–inductively coupled plasma mass spectrometry (GC–ICP-MS) was developed. The acidification of water samples to pH 2 maintained the stability of PBDEs for at least 20 days. The use of Tris–citrate buffer enabled efficient desorption of PBDEs from suspended particulate matter (SPM) and humic acids (HA), and their further quantitative solvent extraction into 2 mL of iso-octane. When 300 mL of water sample was used for analysis and the organic phase concentrated to 25 μL, the expanded uncertainty for determination of PBDEs at EQS level was found to be around 40% (a coverage factor for a confidence level of 95%, k = 2), and the LOQ for the ΣPBDEs 0.109 ng L⁻¹. Finally, to demonstrate the applicability of the newly developed GC–ICP-MS procedure, PBDEs were determined in river and sea water samples.     

How can immunochemical methods contribute to the implementation of the Water Framework Directive?

Immunochemical methods (in particular immunoassays) have been applied to spring and surface water samples, respectively, which were set-up as reference materials (RM) within two proficiency testing campaigns. For the first set of proficiency tests (PTs) described here (which were actually the second round of PTs organized, spring 2005), three ELISAs (enzyme-linked immunosorbent assays) were employed in the enzyme tracer format for isoproturon, diuron, and atrazine, respectively. Results were evaluated in comparison with conventional reference methods (LC, GC). Based on their Z-score laboratory performances, the results for isoproturon and diuron were satisfactory, both for fortified spring water and for the blind solution. The results for atrazine were strongly influenced by other triazines present and needed detailed interpretation. For the second set of PTs described here (which were actually the third round of PTs organized, spring 2006), two ELISAs in the coating antigen format were used for isoproturon and diuron, and the result was included with the results obtained by conventional methods during the PTs. The results (the Z-scores) for isoproturon were again classified as satisfactory, in both fortified surface water and blind solution. The results for diuron in ELISA showed an influence of the water matrix, while the analysis of the blind solution was satisfactory. In addition, an ELISA in the enzyme tracer format was applied to analyze isoproturon, diuron, and atrazine in surface water samples, which had been set-up and spiked during a field trial (tank experiment) at the Maas River at Eijsden, The Netherlands. The immunoassay results were compared with those from an in-house on-line SPE LC/MS–MS used as reference. Although the immunochemical results were sometimes higher than those determined in the reference analysis, the general concentration trends in the samples were similar. The contribution of immunochemical methods to the implementation of the European Water Framework Directive is also discussed.     

Integration of metrological principles and performance evaluation in a proficiency testing scheme in support of the Council Directive 98/83/EC

Proficiency testing as a means of external quality assessment plays the role of independent evidence of laboratories’ performance. To enable laboratories to fulfil the requirements stated in legislation, methodology for evaluation of laboratories’ performance in proficiency testing schemes should incorporate principles of measurement results which are fit for intended use and incorporate evaluation of laboratories’ performances based on independent reference value. A proficiency testing scheme was designed to support Drinking Water Directive (98/83/EC) specifically. The methodology for performance evaluation, which takes into account a “fitness for purpose”-based standard deviation for proficiency assessment, is proposed and discussed in terms of requirements of the Drinking Water Directive. A ζ′-score, modified by application of target uncertainty was developed in a way that fulfils requirements defined in the legislation. As an illustration, results are reported for nitrate concentration in water. The approach presented can also be applied to other fields of measurements.     

First proficiency testing to evaluate the ability of European Union National Reference Laboratories to detect staphylococcal enterotoxins in milk products

The European Commission has designed a network of European Union-National Reference Laboratories (EU-NRLs), coordinated by a Community Reference Laboratory (CRL), for control of hygiene of milk and milk products (Council Directive 92/46/ECC). As a common contaminant of milk and milk products such as cheese, staphylococcal enterotoxins are often involved in human outbreaks and should be monitored regularly. The main tasks of the EU-CRLs were to select and transfer to the EU-NRLs a reference method for detection of enterotoxins, and to set up proficiency testing to evaluate the competency of the European laboratory network. The first interlaboratory exercise was performed on samples of freeze-dried cheese inoculated with 2 levels of staphylococcal enterotoxins (0.1 and 0.25 ng/g) and on an uninoculated control. These levels were chosen considering the EU regulation for staphylococcal enterotoxins in milk and milk products and the limit of detection of the enzyme-linked immunosorbent assay test recommended in the reference method. The trial was conducted according to the recommendations of ISO Guide 43. Results produced by laboratories were compiled and compared through statistical analysis. Except for data from 2 laboratories for the uninoculated control and cheese inoculated at 0.1 ng/g, all laboratories produced satisfactory results, showing the ability of the EU-NRL network to monitor the enterotoxin contaminant.     

Optimisation of pressurised liquid extraction for the ultra-trace quantification of 20 priority substances from the European Water Framework Directive in atmospheric particles by GC-MS and LC-FLD-MS/MS

Atmospheric deposition plays an important role in environmental pollution and human health. However, very few information is available on the presence, in atmospheric particles, of organic priority substances in contrast to inorganic fraction. A method for the extraction and quantification of 20 priority organic substances listed in the European Water Framework Directive in atmospheric particles was developed. This method consists in a combination of gas chromatography coupled with mass spectrometry and ultra-high-pressure liquid chromatography coupled with tandem mass spectrometry and fluorescence. Optimized pressurized liquid extraction using a hexane/dichloromethane/isopropanol mixture was used as extraction procedure from atmospheric particulate matter. The influence of several extraction experimental factors related to the PLE was investigated. The optimized extraction method (80°C, 40 bar, 10 min, 1 cycle) exhibited average recoveries of target analytes higher than 62%. The method detection limits (MDL) were between 0.3 ng g(-1) and 83 ng g(-1). This extraction method, combined with sensitive analytical techniques, leads to satisfactory reliability, sensitivity, and accuracy. The method was applied to real samples, collected from two urban sites by an atmospheric sampling prototype developed in this study. The first results reveal a systematic presence of PAHs at high levels (ranging from 500 ng g(-1) to 10 μg g(-1)) and a variable and lower presence of pesticides at concentrations below 50 ng g(-1) in the samples.     

Optimisation and assessment of an innovative high sensitivity 90-degree reflecting ICP-MS ion optics system for the validation of simultaneous determination of arsenic and selenium in water matrices

A routine ICP-MS method for the determination of As and Se in fresh and sewage water has been developed. After a first phase of optimisation, where the torch alignment, flow of gases and ion optic adjustments were calibrated, the method was validated successfully. The parameters limits of detection, linearity, working range, sensitivity and the interferences, precision and accuracy were studied with three procedures for the method: measuring two SRMs (BCR-714 of influent wastewater and NIST 1643e of groundwater); spiking four different matrices at three levels of concentration; and doing a proficiency test. The limits of detection obtained were 0.2 and 0.8?µg?L^?1 for As and Se, respectively. The percentages of linearity obtained were 99.2% for As and 99.8% for Se. All recovery values were according to the AOAC intervals, from 95.3% for As in the wastewater matrix to 106.4% for Se in the seawater matrix. The accuracy was also studied determined via a proficiency testing resulting in acceptable Z-scores of 0.65 and 0.4 respectively for As and Se. The complete method allowed analysis of water samples according to European Directive 2000/60 EC and the different guides for method validation.     

Occurrence of Selected Metals in Wastewater Effluent and Surface Water in Ireland

Metals occur naturally in the environment and as constituents of the Earth’s crust. They have many uses, and metals such as iron, copper, and zinc are widely used in industries. Elevated levels of metals in the environment also occur as a result of human activities (municipal, residential, and traffic–related activities). A list of 15 metals chosen for this study included priority substances and those listed in the European Union Water Framework Directive 2000/60/EC. The concentrations of heavy metals in the environment are affected by several factors that must be taken into account when monitoring heavy metals released into the environment through wastewater treatment plants (WWPTs). This work examines the concentrations of metals found in WWPTs and the effects of treatment type on dissolved metal concentrations. Effluent samples were collected from the outflow of nine WWPTs in Dublin and Cork, Ireland from July 2009 to June 2011. All samples were found to contain priority metals that exceeded environmental quality standards in several cases. We present the frequency of occurrence and concentrations of metals in effluents of studied WWPTs and discuss relationships between the occurrence of heavy metals, the influence of factors such as industrial inputs, levels of treatment at WWPTs, and percentage urban area in an agglomeration. The results of this study are an indication that WWPTs may be contributing to the high levels of heavy metals found at discharge points back into river systems.     

Occurrence and chemical speciation analysis of organotin compounds in the environment: A review

Environmental concerns regarding organotin compounds have increased remarkably in the past 20 years, due in large part to the use of these compounds as active components in antifouling paints [mainly tributyltin (TBT)] and pesticide formulations [mainly triphenyltin (TPhT)]. Their direct introduction into the environment, their bio-accumulation and the high toxicity of these compounds towards “non-target” organisms (for example: oysters and mussels) causes environmental and economic damage around the world. As a consequence, the presence and absence of organotin compounds is currently monitored in a range of environmental matrices (e.g., water, sediment and shellfish) to examine the utility of controls meant to regulate the level of contamination as required in some EC Directives and the Water Framework Directive 2000/60/EC. To evaluate the environmental distribution and fate of these compounds and to determine the effectives of legal provisions adopted by a number of countries, a variety of analytical methods have been developed for organotin determination in the environment. Most of these methods include different steps such as extraction, derivatisation and clean up. The aim of the present review is to evaluate the environmental distribution, fate and chemical speciation of organotin compounds in the environment.     

The EC Standards, Measurements and Testing Programme in support of the quality control of waste analysis

Projects funded within the EC Standards, Measurements and Testing Programme (SM&T) of the European Commission aim to contribute to the harmonization and improvement of methods and measurements carried out within the European Union and hence to the comparability of data necessary for e.g. trade activities, monitoring of environment, food and health control, etc. This goal may be achieved by e.g. the organization of interlaboratory studies and certifications of reference materials, the development of new methods and pre-normative research. Examples of projects undertaken in support of the quality of waste analysis are given in this paper, covering different aspects, namely interlaboratory study and certification of extractable trace metals in sewage sludge amended soil reference materials, pre-normative research for the characterisation of stabilized waste (interlaboratory study), and development of field-measurement device for the monitoring of waste water quality; this paper gives also an account of a network aimed at harmonising leaching/extraction tests used for environmental risk assessment. Finally, the main topics of the workshop on Standards, Measurements and Testing for Solid Waste Management are given in the annex, along with a list of participants.     

Evaluation of a multiresidue method for measuring fourteen chemical groups of pesticides in water by use of LC-MS-MS

European Council Directive 98/83/EC on the quality of water intended for human consumption brought a new challenge for water-quality control routine laboratories, mainly on pesticides analysis. Under the guidelines of ISO/IEC 17025:2005, a multiresidue method was developed, validated, implemented in routine, and studied with real samples during a one-year period. The proposed method enables routine laboratories to handle a large number of samples, since 28 pesticides of 14 different chemical groups can be quantitated in a single procedure. The method comprises a solid-phase extraction step and subsequent analysis by liquid chromatography-mass spectrometry (LC-MS-MS). The accuracy was established on the basis of participation in interlaboratory proficiency tests, with encouraging results (majority |z-score| <2), and the precision was consistently analysed over one year. The limits of quantitation (below 0.050 μg L⁻¹) are in agreement with the enforced threshold value for pesticides of 0.10 μg L⁻¹. Overall method performance is suitable for routine use according to accreditation rules, taking into account the data collected over one year. Figure Simultaneous SPE extraction system for high thoughput analysis Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Notes: IAREN is an accredited laboratory under the ISO/IEC 17025:2005 for 165 analytical determinations and part of the NORMAN Network of Reference laboratories for monitoring of emerging environmental pollutants in the European Union. This work was presented (podium presentation) at the 12th Symposium on Sampling and Handling of the International Association of Environmental Analytical Chemistry (IAEAC), Zaragoza, 2006.     

Sorption of copper by suspended particulate matter

The sorption of copper by suspended particulate matter from river water was investigated as a function of pH and solids concentration. Water was collected from the Delaware River and particulate matter was concentrated using Tangential-Flow Filtration (TFF). The adsorption of copper increased with increasing pH until pH 9.0. A decrease in copper adsorption was found for higher pH values. The adsorption of copper was greater for the samples with added copper than for the suspension for which no metal was added. An increase of copper adsorption proportional to particulate matter concentration was also observed. At both pH 6.0 and 7.0, there was a decrease in the adsorption of copper with increasing copper concentration.     

Multi-residue analysis and ultra-trace quantification of 36 priority substances from the European Water Framework Directive by GC-MS and LC-FLD-MS/MS in surface waters

A multi residue analysis was developed for screening, quantification and confirmation of 36 priority organic compounds included in the 2000/60/EC European Water Framework Directive. The compounds analyzed included 19 pesticides, 8 PAH, 5 endocrine-disruptors and 4 organochlorine compounds. The method was developed in three steps. First, automated off-line solid-phase extraction using Strata X cartridges was optimized to trap simultaneously the 36 studied compounds. Second, the more volatile compounds were analysed by gas chromatography coupled to mass spectrometry with electron impact ionisation in selected ion monitoring mode (SIM). Third, the last 20 compounds were detected and quantified, in one run, by liquid chromatography coupled to fluorescence detector and tandem mass spectrometry. The excellent selectivity and sensitivity allowed us satisfactory quantification and confirmation at levels as low as 0.2-67 ng L⁻¹ with recoveries between 59 and 105%. Such methodology was then applied to French surface waters: all the waters present organic contaminants, and their concentration varied according to the origin and nature of substances.