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orldwide demand for clean freshwater is being fueled by rapid population, agricultural, and industrial growth. In addition to the increased use that is shrinking the supply of clean water, many of our agricultural and industrial activities are polluting renewable freshwater sources, and meeting our future freshwater needs with the existing supply will be a difficult challenge. Part of the effort will involve reclaiming rivers and streams that have been fouled and then maintaining these water sources at an acceptable level of quality. Meeting this challenge will require the ability to monitor the quality of freshwater in an accurate and timely fashion. In 1989, Hewlett Packard commemorated its 50th anniversary by organizing and supporting a project to help improve water quality along the Rhine River. The Rhine Basin Program brought together governments, water companies, and other stakeholders with technical experts from industry and academia. Because the program was soundly structured and supported—with funding and donated equipment as well as expertise—it dramatically shortened the time required for the development of appropriate technology and analytical methods. Distributed measurement
For the most part, water analysis has involved collecting samples from designated sites and transporting them to the laboratory where determinations are performed. If the number of collection points and the collection frequency are modest, this approach is appropriate and cost-effective. However, monitoring the water quality of an entire riparian basin is another matter entirely, especially when a river serves as water source and catchment for multiple uses, including farming, industry, and municipal drinking water. Although each user is concerned about water quality primarily at the point of use, regulators are
W i l l i a m Pipkin Piet v a n Hout Hewlett Packard 0003-2700/97/0369-21 A/$14.00/0 © 1996 American Chemical Society
Analytical Chemistry and the
Rhine Basin Program
Integrated analytical and data-processing technology has been developed for automated on-line monitoring of water quality in rivers and other freshwater reservoirs charged with the responsibility of maintaining quality throughout freshwater systems. For them, monitoring must be frequent and geographically widespread. It must also be linked to the kind of rapid data collection and centralized processing that supports good decision making. Therefore, users can make critical water assessments quickly, and regulators can locate and address point sources of pollution immediately while also monitoring the effects of abatement programs and trends in water quality. One approach for continually acquiring and processing the massive amount of analytical data needed to support comprehensive freshwater monitoring is based
on a system design known as distributed measurement. Instead of the collect/ transport/analysis scenario, a distributed measurement system uses an array of on-line sensors positioned at strategic sites along a river basin or other freshwater catchment. Analytical data collected by sensors are continually routed over data networks to a central collection point where they are processed and integrated to provide a constantly updated quality map of the monitored freshwater system. At present, the fully automated on-line analytical distributed measurement network does not exist, because such systems must be able to make measurements that currently can be performed only in the lab-
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Figure 1 . Schematic of the SAMOS analysis format. C1-C3, extraction cartridges; V1 -V4, valves.
oratory. Equipment developed to date is unsuitable for routine, widespread use because it is not sufficiently reliable and robust, requires a skilled operating staff, and is expensive to maintain. In addition, the appropriate configuration of hardware and software underpinning the seamless integration of unattended analyte sensing, data collection, and data processing has yet to be worked out. However, significant steps have been taken to realize this objective.
can gain acceptance more quickly in Europe than in the United States. Until recently, regulation of water pollution in Europe has varied with the laws of each country, and because freshwater moves across national borders, issues of sovereignty have obstructed the adoption of a wider approach to pollution control. As a result of the growing adoption of transnational regulations within the European Union, however, all the countries involved are now cooperating in the devel-
opment of consistent freshwater quality criteria, throughout the course of a river, for example. These same countries are working together to develop innovative solutions to the problems of monitoring freshwater quality. Increasing competition for freshwater throughout Europe has stimulated a movement to reclaim polluted water sources, and no body of water has posed more of a challenge in this regard than the Rhine River. Passing through Europe's industrial heartland, the Rhine has been one of Europe's most important waterways and freshwater sources. However, for years it has also been the dumping ground for hundreds of industrial plants situated along its banks, and cleaning up the Rhine was thought to be virtually impossible. In the early 1970s, a transnational effort was undertaken to prevent further pollution and to start cleaning up the Rhine River basin. The remediation campaign included passage of antidumping laws, organized cleanup activities, installation of water treatment works, and the creation of international surveillance committees targeted toward what was considered at that time to be the biggest pollution problem—the presence of large amounts of heavy metals. The result, in the 1980s, was a substantial improvement of river water quality. Coinci-
Europe takes the lead Although the United States has legislated significant regulation of water pollution for decades, it is Europe that is now making great strides in developing the automated distributed measurement system for monitoring freshwater. Currently, European water quality regulations are far less prescriptive and more flexible than those in the United States. To achieve acceptance by the U.S. Environmental Protection Agency (EPA), new analytical methods must meet stringent operational criteria—as well as the precision, accuracy, and detection limits of approved methods. Although instrument manufacturers continue to provide new analytical hardware and software to ease the compliance burden, appropriate change will come only after a reassessment of the existing regulatory framework. In contrast, most European regulatory bodies require that new methods meet the performance— but not the operational—criteria of approved methods. Consequently, innovators of new analytical technologies and methods
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Figure 2. SAMOS-LC analysis of Rhine River w a t e r spiked w i t h polar compounds. 100-mL sample; PLRPS solid-phase extraction cartridge; C16 LC separation; UV-Vis diode-array detection at 210 nm. A, blank; B, 0.25 ug/L; C, 0.5 ug/L; D, 1.0 jjg/L. Peak identity: 2, carbendazim; 4, metamitron; 5, chloridazon; 6, dimethoate; 7, monomethylmetoxuron; 8, aldicarb; 9, bromacil; 10, cyanazine; 12, chlorotoluron; 13, atrazine; 14, diuron; 15, metobromuron; 16, metazachlor; 17, propazine; 18, warfarin; 19, 3,3-dichlorbenzidine; 20, barban; 21, alachlor; 22, nitralin; 23, dinoseb; 24, dinoterb; 25, phoxim; 26, nitrofen; 27, trifluralin.
Analytical Chemistry News & Features, January 1, 1997
dent with the successful reduction of those pollutants initially investigated and targeted for cleanup, it became apparent that the river was also contaminated with a wide range of organic compoundsfroma variety of sources. Efforts to clean up this additional pollution focusedfirston the most easily detected organic pollutants. The Rhine Basin Program
At the outset, the Rhine Basin Program targeted areas for which monitoring was critical and formulated developmental strategies to address these concerns. The most important priorities included ensuring the availability of good-quality drinking water, assessing the environmental behavior and risks of chemicals in water and waste, alerting concerned parties to potential contamination dangers, and providing informational support for effective freshwater and wastewater management. Addressing these issues required the development of new approaches to monitoring freshwater quality, and the solution reached by the Rhine Basin Program participants integrated sample collection, inline cleanup, preconcentration, chromatographic separation, and detection. The requirement for detecting numerous analytes at very low levels was especially daunting and posed significant technical challenges in concentration methods and detection sensitivity. Analytical methods were developed for compound classes that are produced or used in theriverbasin in large quantities as well as those expected or known to be toxic. Table 1 lists the analyte groups selected, the analytical approach developed, and the detection limits of the individual methods. From the beginning, a major objective of the Rhine Basin Program has been the development of integrated analytical and data-processing technology for automated on-line monitoring of water quality in rivers and otherfreshwaterreservoirs. Results of the initial stage of this effort were called Systems for the Automatic Measurement of Organic micropollutants in Surface water (SAMOS) (Figure 1). SAMOS integrates the latest developments in instrument software automation. For example, all system operations can be controlled by a single data-management system operating under Windows software on a Hewlett-Packard ChemStation.
Table 1 . Analytical method development. Analytical method
Detection limits
Polar pesticides Trace-level determination in water using in-line water extraction and trace enrichment on cartridges (C18, PLRPS, other), separation by LC with UV-DAD detection. Analyses have been carried out in various types of water. Fully automated.
0.1 - 3 ug/L, depending on compound and matrix
Trace-level determination in water using in-line water extraction and trace enrichment on cartridges with an immunoadsorbent, separation by LC with UV-DAD detection. Combinations of anti-atrazine and anti-simazine are used for the extraction of triazines, and anti-isoproturon for phenylurea herbicides. Analyses have been carried out in various types of water. Semi-automated.
0.1-1 ug/L in river water
Target analysis in water using in-line water extraction and trace enrichment on cartridges (C18, PLRPS, other), separation by LC and detection by thermospray, particle-beam, or electrospray MS. Analyses have been carried out in various types of water. Fully automated.
Positive identification at 5-20 ng/L in river water
Phosphoric acid esters Trace-level determination in water using in-line water extraction and trace enrichment on cartridges or membrane disks (C18, polymer loaded), drying, elution of adsorbed compounds into the retention gap of a GC, separation by GC, detection using NPD or MSD. Analyses have been carried out in various types of water. Fully automated.
10-30 ng/L in tap water, 20-100 ng/L in river water
Organotin compounds Liquid-liquid extraction (hexane) for water samples and soxhlet extraction (hexane/octanol) for sediment and soil samples, separation by LC, UV photoconversion, postmorin complexation, fluorescence detection.
For fentin, cyhexatin, and fenbutatinoxide: 2-4 ug/g in sediment, 0.2-1 ug/g in soil, 0.02-0.04 ug/L in water
Liquid-liquid extraction (pentane) for water samples and soxhlet extraction (hexane/octanol) for sediment and suspended matter samples, methylation or pentylation, separation by GC, selected ion monitoring by MSD.
For fentin, cyhexatin, and fenbutatinoxide: 0.3-5 ng/g in sediment, 1-10 ng/g in suspended material, 1-10 ng/L in water
Aliphatic and aromatic sulphonic acids Trace-level determination in water applying in-line extraction and trace enrichment on C18 cartridges using ion-pair reagents, separation by ion-pair LC, fluorescence detection. Analyses have been carried out in various types of water. Fully automated.
0.1-1 ug/L in river water, drinking water, leachate from landfills and construction sites
Phthalate esters Solid-phase extraction (C18) for aqueous samples and liquid-liquid extraction (ethyl acetate) for sediments and suspended material, GC separation, detection by MSD.
0.01 -0.03 ug/L in water, 0.01-0.15 ug/L in sediment, 0.2-1.5 ug/L in suspended material
Fluorescent whitening agents Solid-phase extraction for aqueous samples and supercritical fluid extraction for sludge, LC separation, fluorescence detection.
0.1-5 ug/L in aqueous samples, 0.5-5 ug/g dry material in sludge
Three different SAMOS have been created: SAMOS-LC, SAMOS-GC, and SAMOS-LC/MS. All use a three-stage analysis format appropriate for automated operation. SAMOS-LC uses a precolumn for extraction/enrichment; a Prospekt solvent delivery/sample preparation unit to transfer the sample to the
LC column; an HP 1090 LC with a UVdiode array or other detector; and an HP ChemStation for system control, identification, quantitation, reporting, and communication. SAMOS-GC incorporates a precolumn, a solvent delivery/sample preparation unit, an HP 6890 GC with an HP 5973 Mass Selective Detector, and an
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Figure 3. On-line LC/TSP-MS of pesticides in Meuse River water. Ions at mlz 202, 216, 207, and 233 were monitored.
HP ChemStation. SAMOS-LC/MS incorporates a precolumn; a solvent delivery/ sample preparation unit; an HP 1090 LC; an HP MS with thermospray, electrospray, or particle-beam interface; and an HP ChemStation. For all three systems, different adsorbents can be used in the precolumn; for most applications, C18 and PLRPS are preferred. The precolumn can also be automatically exchanged prior to each analysis to prevent clogging or memory effects. Evolution of SAMOS-LC is farthest along, given the greater sensitivity in Europe to highly water-soluble agricultural pollutants, among which are a number of pesticides and herbicides. These compounds tend to be polar and thus are best suited to LC analysis. European regulators, water quality monitors, and water suppliers must cope with 300-400 pesticides, and the UV-diode-array detector library used in SAMOS-LC screening contains approximately 100 compounds. In one run, SAMOS can easily separate and detect as many as 30 pesticides at detection limits of 0.1-3 ug/L in river water (Figure 2). It should be noted that the presence of more than a few pesticides at the same time in concentrations above 0.1 ug/L is highly unlikely. In addition to deployment in the Rhine basin, units have been installed at sites along other European rivers. A simplified version of the SAMOS-LC technology is 24 A
currently under investigation as a fast, qualitative on-line screening of the same type of compounds in water. Like SAMOS-LC, SAMOS-GC uses precolumn extraction and enrichment, and water must be removed prior to transfer to the GC column. SAMOS-GC targets volatile and semivolatile analytes and has sufficient detection overlap with SAMOS-LC to cover a wide range of analyte volatilities. SAMOS-LC/MS using the particle beam interface allows library searching of conventional GC/MS elec-
tron impact spectra to identify unknowns. Electrospray MS extends the system application range to highly polar compounds, and excellent analytical results have been obtained for triazine pesticides, phenylurea herbicides, and many other environmental contaminants with detection levels in the 10-100 ng/L range (Figure 3). Software controls and the necessary hardware modifications have been implemented so that all three SAMOS systems are fully automated from precolumn extraction to report generation. It is now possible to run sequences of unattended analyses under different operational and analytical conditions, and the systems in corporate an automated sample tasking unit that can take grab samples or composite samples over programmed variable time spans. Sample aliquots are then delivered to SAMOS for enrichment and analysis. Future development
The Rhine Basin Program's development of the various SAMOS solutions represents a first attempt to build an automated system for on-line water sampling and analysis. It is only the first stage in creating truly self-contained, automated on-line monitoring systems. The second stage of the Rhine Basin Program involves the implementation of distributed measurement through a corn-
Figure 4. A detection node in a future distributed measurement freshwater monitoring system.
Analytical Chemistry News & Features, January 1, 1997
bination of automated on-line sampling and analysis with communication of data to a central facility (distributed measurement). Work is under way on the development of data-handling and communication software that will provide on-line screening of relevant monitoring data, evaluation, and presentation of results. The software will also provide the capability for monitoring stations to invoke a local alert, if required. An added benefit is that it will be possible to transmit alerts between stations and examine data across networked monitoring stations in real time. Such comparisons will be invaluable in the development of pollution-forecasting models. Intelligent data treatment software will enable the correlation of data from disparate analytical methods. Along with furnishing more reliable results, this could decrease the required number and cost of analyses by a sizeable margin. Figure 4 shows a detection node in a future distributed measurement freshwater monitoring system in which analytical data collected by sensors is continually routed over networks to a central collection point where it is processed and integrated to provide a constantly updated quality map of the monitored freshwater system. As a preliminary distributed measurement demonstration project, a number of SAMOS systems have been installed at key locations along the Rhine River. These instruments will be linked via a communication network for comparison and correlation of monitored data. The Rhine Basin Program continues to serve as a test bed for the invention and refinement of new water-pollution monitoring systems. It has stimulated substantial information exchange and coordination in the development of analytical techniques for water pollution, and emerging networks of stakeholders have adopted the program model in addressing different pollution concerns. As a result of its involvement with the Rhine Basin Program, Hewlett Packard has been asked to participate in other EU programs that are exploring monitoring methods for pollution control. Except for the SAMOS-LC system, SAMOS systems are not considered commercial products. Several SAMOS-LC
The program in action
Numerous companies have expressed interest in the application of SAMOS-LC systems for effluent monitoring driven by the rising cost of freshwater and the increasingly restrictive standards for discharged wastewater. Many plants are seeking to avoid the problem and lower environmental costs by recycling process water, but in order to do so, recyclers must be assured that effluent water meets process specifications. Monitoring systems equal to the task must perform at speeds sufficient to supply timely information for decision making with regard to water quality. Water that has been treated to remove contaminants and/or improve quality may also be monitored prior to use or discharge. On-line sensing will definitely facilitate the monitoring of effluents at multiple sites. Several organizations are currently using SAMOS systems for water quality control. WRK Water Works, Nieuwegein, in Amsterdam (The Netherlands) is testing for polar compounds and pesticides to ensure that their water supply is safe. The organizaton uses SAMOS in an on-line arrangement for intake protection, and it is designed to alert WRK if the drinking water does not meet specified qualificiations. WRK plans to purchase another
units have been sold in Europe to satisfy special requests in conjunction with freshwater monitoring. For now, Hewlett Packard, in concert with its consortium partners, will concentrate on design completion,fieldtesting, and validation of SAMOS prototypes. Thereafter, the team hopes to reduce the costs of the systems by simplifying and improving sensing technology. At the same time, parallel efforts will advance automation and data communications for distributed measurement systems. Clearly, the Rhine Basin Program is an incubator for freshwater analysis and monitoring methods and technology that will soon serve the global community.
SAMOS system to help monitor the concentration of pollutants in the water that comes from the Rhine. Acer Environmental in Runcorn (U.K.) is using SAMOS at their Bridgend laboratory for routine pesticide analysis. By increasing the sample size and lowering the detection limit, Acer was able to meet the regulations of the drinking-water inspectorate in the U.K., which demands a limit of detection (LOD) of 10 ng/L, 10 times lower than the level required by the EC. The system was developed in less than nine months and is used primarily for the analysis of traizine and uron herbicides. The performance data are excellent, and the system is being optimized to broaden the range of pesticides analysis. RIZA, located in Lelystad (The Netherlands), is responsible for surface-water quality control and uses SAMOS to conduct surface-water quality surveillance for the Rhine and Meuse rivers, testing for both polar compounds and pesticides. LUA in Dusseldorf (Germany) also uses SAMOS to test water quality on the Rhine; Northumbrian Water, in Newcastie (U.K.), uses the SAMOS system to test for intake protection on the River Trent; and Sagep, in Paris, uses a SAMOS system to check communal drinking water from the Seine.
The authors wish to thank Peter G. Stoks, WRK Water Works (Nieuwegein, The Netherlands); Geoffrey Matthews, World Bank (New York); and Linda Doherty, Hewlett Packard (Palo Alto, CA) for their valuable contributions to this article. William Pipkin is Worldwide Environmental Marketing Manager, Hewlett-Packard Company, Wilmington, DE. Piet van Hout is Hewlett Packard Manager for the Rhine Basin Program in Waldbronn, Germany. Address correspondence to Van Hout at Hewlett Packard GmbH, Hewlett Packard Strasse 8, 76337 Waldbronn, Germany, or to Pipkin at Hewlett Packard Company, 2850 Centerville Rd., Wilmington, DE 19808.
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