Anal. Chem. 1999, 71, 181R-215R
Water Analysis Susan D. Richardson
National Exposure Research Laboratory, U.S. Environmental Protection Agency, Athens, Georgia 30605 Review Contents General Reviews New Regulations/Regulatory Methods Drinking Water Microorganisms Water Quality/Nutrients QA/QC Studies Miscellaneous Applications Literature Cited
181R 182R 186R 195R 201R 207R 207R 207R
This review covers developments in water analysis from November 1996 to the end of October 1998, as found in the Chemical Abstracts Service CA Selects for gas chromatography, mass spectrometry, inorganic analytical chemistry, and pollution monitoring. In addition, because developments in the measurement of microorganisms is a fast-growing area, an effort was made to include up-to-date, important results as presented at the most recent Water Quality Technology Conference in November 1998. Microorganism studies have not appeared in previous Water Analysis reviews, but due to their increased importance, particularly with regard to outbreaks of illness from pathogenic organisms in drinking water and to new regulations for controlling them, they are included in this review. Also, in general, health effects studies are not covered in this review; however, a few significant ones are presented, as they relate to the ingestion of drinking water or to the toxicity of surface water. Numerous abstracts were consulted before choosing the best ones to present here. If an abstract was generally unclear or ambiguous, it was generally excluded. If the subject matter of the abstract appeared to be of a routine nature, with no new, significant findings, it was also generally excluded. For the most part, criteria used for inclusion of a paper are in keeping with previous criteria used by former authors of prevous Water Analysis reviews. Further details of these criteria can be found in the 1991 Water Analysis review (Anal. Chem. 1991, 63, 301R-342R). Also, previous reviews of water analysis have focused mostly on methods development. This review contains not only important new methods but also important new findings or studies that were very comprehensive or particularly interesting. Because most water analysis publications involve environmental samples, this review was carefully coordinated with the Environmental Analysis review to minimize redundancies. In dividing the material to be covered, it was decided to cover drinking water entirely in this review, along with regulatory methods/regulations, microorganisms, general water quality/ nutrients, and QA/QC. Studies of pesticides and other pollutants in surface waters, groundwaters, seawaters, and wastewaters can be found in the Water Analysis Applications section of the 10.1021/a19900060 This article not subject to U.S. Copyright. Published 1999 Am. Chem. Soc. Published on Web 05/04/1999
Environmental Analysis review, also found in this issue of Analytical Chemistry. GENERAL REVIEWS Many reviews have been published in the last two years that relate to water analysis. A review of drinking water disinfection byproducts (DBPs) was published that covers all of the DBPs identified to-date (from chlorine, ozone, chlorine dioxide, chloramines, and combinations of these), along with any known health effects (A1). The history, production, and control of drinking water DBPs was also covered (A2). National reports of drinking water quality were also published for the United Kingdom, Norway, Argentina, and Taiwan (A3-A6). Microorganisms were the focus of some reviews. Cryptosporidium, a resistant microorganism that has caused many outbreaks of illness, has received much interest in the last two years. One review covered ongoing research on Cryptosporidium contamination of drinking water, including sources and occurrence, analytical methods for measuring Cryptosporidium, and human health research (A7). Another review covered research on Cryptosporidium and Giardia contamination and treatments for their control (A8). The use of microorganisms as tracers in groundwater injection and recovery experiments was reviewed by Harvey (A9). Risks from exposure to waterborne rotavirus and coxsackievirus in contaminated drinking water or recreational waters were reviewed with 88 references (A10). Janssens and coworkers discussed the problems with micropollutants in drinking water production and wastewater treatment (A11). Cullen et al. reviewed optical detection methods for measuring algal blooms (A12). Pollutants were the focus of three reviews. The state of the art for analyzing polar pesticides in environmental waters was presented (A13). The chemistry of aluminum was covered in another review, which also addressed the use of aluminum salts in drinking water treatment and recent studies showing a relationship between Alzheimer’s disease and aluminum in drinking water (A14). An overview was presented of metals permitting alternatives and the importance of clean chemistry techniques for trace metal sampling of domestic wastewater and paper mill effluents (A15). Water quality reviews included a review of analytical techniques for measuring organic and inorganic chemicals in surface water, wastewater, and drinking water (A16, A17). These articles, authored by Labreche, Dietrich, and Dacosta, provided a review of the 1996 and 1997 literature with numerous references (A16, A17). These reviews included new chemical methods (chemical sensors, titrimetric methods, electrochemical methods, spectroscopic methods, separation technologies), new biological methods (biosensors, immunosensors), and sample preparation techniques. Analytical Chemistry, Vol. 71, No. 12, June 15, 1999 181R
Table 1. New U. S. Rules/Regulations rule/regulation
refs
Safe Drinking Water Act Amendments (1996) Stage I D/DBP Rule Interim Enhanced Surface Water Treatment Rule (IESWTR) Information Collection Rule (ICR) National Emission Standards for Hazardous Air Pollutants: pulp and paper industry; Effluent Limitations Guidelines (“Cluster Rules”) National Emission Standards for Hazardous Air Pollutants: pharmaceuticals production
B1 B11 B12 B13 B18 B20
Websites: for all regulations (proposed/final), http://www.epa.gov/ogwdw/regs.html U.S. EPA homepage, http://www.epa.gov Federal Register (details of rules/regulations), http://www.gpo.gov/su_docs/aces/aces140.html information on the Contaminant Candidate List (CCL), http://www.epa.gov/ogwdw/ccl/cclfs.html
Haddad reviewed the use of ion chromatography and capillary electrophoresis for the determination of inorganic anions (A18). Analytical development work carried out by the Swiss Federal Institute for Environmental Science and Technology (EAWAG) for the determination of hydrophilic and amphiphilic organic pollutants in the aquatic environment was also published (A19). The measurement of the electrolytic conductivity, including methods and applications, was summarized (A20), along with a summary of methods for pH measurement (A21). Sensor reviews included reports of microbial and enzyme sensors (A22) and remote electrochemical sensors (A23) for monitoring pollutants and nutrients. A general review of analytical tools was presented for monitoring source water quality (including enzyme-linked immunosorbent/immunosorption assay (ELISA) tests, sensitive gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) analyses, genetic fingerprinting of bacteria, and simplified microbial sampling and testing methods) (A24). Monitoring, sampling, and automated analysis for pollutants in aquatic samples was reviewed by Shamas (A25), and the improvement of water quality surveillance with integrated physicochemical and biological sensors was presented (A26). A review carried out by members of EAWAG discussed a surveillance strategy for longterm, continuous monitoring for assessing pollution (A27). Analytical methods for water analysis were reviewed by Sadler (with 85 references) with particular emphasis on methods of use to the water industry (A28). Water quality studies also were the subject of several reviews. The role of phosphorus in the eutrophication of receiving waters was summarized by Correll (A29). It was pointed out that excessive concentrations of phosphorus is the most common cause of eutrophication in freshwater lakes, reservoirs, streams, and headwaters of estuarine systems, whereas nitrogen is the key mineral nutrient controlling eutrophication in the ocean. Nonpoint source pollution of surface water and groundwater was discussed by Line et al., with 298 references (A30). The effects of organic pollutants on water quality were reviewed (A31), and the current state of water quality of purified municipal wastewaters was discussed (A32). Paul published a review on the use of conductivity and resistivity measurements for measuring water quality (A33). The history of water quality pollution in The Netherlands over the last 20 years is summarized by Tonkes and Stoks (A34), and the impact of human activities on freshwater aquatic systems was summarized by Skurlatov and Ernestova (A35). This review included a discussion of the roles of oxygen and its activated species (superoxide radicals, hydrogen peroxide, hydroxyl radicals) and sulfur compounds, in relation to the biological quality 182R
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and self-cleaning capacity of freshwater systems (A35). Two reviews related to seawater quality were published. The nutrient biogeochemistry of coastal waters was reviewed with 70 references (A36), and marine sulfur emissions was reviewed (A37). Three reviews of the effects of contamination on water quality were published. The genotoxic hazards of domestic wastes in surface waters was presented by White and Rasmussen (A38); the effects of bromate on aquatic organisms and the toxicity of bromate to oyster embryos was presented (A39); and the effects of sewage contamination on marine systems was reviewed (A40). NEW REGULATION/REGULATORY METHODS New U. S. Regulations. (a) Drinking Water. A few developments in new regulations and regulatory methods have taken place in the last 2-3 years that impact water analysis. Table 1 lists the new U. S. regulations, and Table 2 summarizes the new regulatory methods. Excellent, detailed reviews of the new drinking water regulations have been published in the Journal of the American Water Works Association (B1-B10). In these reviews, explanations are provided for new regulations (along with details on the negotiations behind the regulations), as well as specific impacts on different drinking water utilities. In these articles, overviews are given for the 1996 Safe Drinking Water Act Amendments (B1), the Information Collection Rule (B2), the Disinfectants/Disinfection Byproduct (D/DBP) Rule (B3, B10), the Interim Enhanced Surface Water Treatment Rule (B3, B8, B10), limits on lead content in plumbing materials (B4), an upcoming Groundwater Disinfection Rule (B6), and impacts on small drinking water systems (B7). In addition, one of these references gives a complete, up-to-date listing of all of the contaminants regulated under the Safe Drinking Water Act and Amendments, as well as new regulations which are expected in the next few years (B5). The U.S. Environmental Protection Agency (EPA) also has an excellent website that lists and discusses all of the drinking water regulationssboth proposed and final: http://www.epa.gov/ ogwdw/regs.html. The U.S. EPA homepage is also a useful source of information and has links to the Federal Register, enabling easy assess to the published rules. This site is, http://www.epa.gov. A direct link to the Federal Register can be made with the following address: http://www.gpo.gov/su_docs/aces/aces140.html. The Stage I D/DBP Rule was promulgated in December 1998 and set new maximum contaminant levels (MCLs) for total trihalomethanes (THMs), five haloacetic acids (HAA5), bromate, and chlorite (B11). This rule also promulgated maximum residual disinfectant levels (MRDLs) for chlorine, chloramines, and chlorine dioxide (B11) and also precursor removal treatment
Table 2. New Regulatory Methods method EPA Method 321.8 EPA Method 556 EPA Method 551.1 EPA Method 552.2 EPA Method 515.3 EPA Method 300.1 EPA Method 1622 EPA Method 1600 MI agar membrane filter method for total coliforms and E. coli 66 radionuclide analytical methods
EPA Method 1613 EPA Method 1650 EPA Method 1653 EPA Method 1666 EPA Method 1667 EPA Method 1671
analytes/analytical method
refs
Drinking Water: DBPs, Pollutants bromate (IC/ICPMS) aldehydes (derivatization-GC/ECD) chlorinated DBPs, chlorinated solvents, halogenated pesticides/herbicides (GC/ECD) 9 haloacetic acids, Dalapon (GC/ECD) chlorinated acids (GC/ECD) inorganic anions (IC)
B21 B22 B24 B25 B26 B27
Microorganisms Cryptosporidium (filtration/IMS/FA) enterococci (membrane filter test) total coliforms,E. coli (membrane filter/fluorescence)
B28 B29 B30
Radionuclides gross R, gross β, tritium, uranium, radium-226, radium-228, γ emitters, radioactive cesium, iodine, strontium Wastewater: Pollutants chlorinated dioxins, furans (GC/HRMS) organic halides (adsorption/coulometric titration) chlorinated phenolics (acetylation/GC/MS) VOCs, pharmaceuticals (isotope dilution-GC/MS) formaldehyde, isobutyraldehyde, furfural (LC) VOCs, pharmaceuticals (GC/FID)
Table 3. Stage I Requirements of the D/DBP Rule
a
DBP
MCL (mg/L)
THMs 5 haloacetic acidsa bromate chlorite
0.080 0.060 0.010 1.0
disinfectant
MRDL (mg/L)
chlorine chloramines chlorine dioxide
4.0 4.0 0.8
Chloro-, dichloro-, trichloro-, bromo-, and dibromoacetic acids.
requirements that result in monitoring for total organic carbon (TOC), alkalinity, specific UV absorbance (SUVA), pH, and Mg hardness. Table 3 summarizes the new MCLs and MRDLs. A Stage II D/DBP Rule is anticipated later. The Interim Enhanced Surface Water Treatment Rule (IESWTR) was also promulgated in December 1998 and currently applies to systems serving more than 10 000 people using surface water or groundwater under the influence of surface water (B12). This rule, which is aimed at reducing the threat of waterborne pathogens in drinking water, requires tighter turbidity performance, individual filter monitoring, 2-log removal of Cryptosporidium for filtered systems, and disinfection benchmark provisions to ensure continued levels of microbial protection while facilities take the necessary steps to comply with new DBP standards (B12). A long-term Enhanced Surface Water Treatment Rule (ESWTR), which will extend the IESWTR to systems serving 10 000 or fewer people, is under development and is expected to be promulgated in November 2000 (B5). The Information Collection Rule (ICR), which was promulgated in May 1996, required large public water systems (serving 100 000 people or more) to monitor for disinfectant residuals, DBPs, microorganisms, and several water quality parameters (B13). Water utilities carried out sampling for 18 months, from July 1997 to December 1998. Table 4 summarizes the chemicals and parameters monitored under the ICR. The U.S. EPA carried out analyses for bromate, cyanogen chloride, and aldehydes. DBP precursor removal studies were also required if the TOC of the
B33
B34 B18 B18 B20 B20 B20
water was higher than the specified limits (B13). For surface water, that limit was an influent TOC of 4.0 mg/L; for groundwater, the limit was a TOC of 2.0 mg/L for the finished water. Groundwater systems serving 100 000 people or more were required to collect data for all but microorganisms, and groundwater systems serving 50 000-99 999 people were required only to perform DBP precursor removal studies (unless the TOC criteria were met) (B13). The purpose of the ICR was to provide the U.S. EPA with information on the occurrence of drinking water DBPs and disease-causing microorganisms. This information was being collected because a Regulatory Negotiation on disinfectants and DBPs concluded that additional information was needed to assess the extent and severity of risk in order to make sound regulatory and public health decisions (B13). The U.S. EPA will use the information gathered by the ICR, along with concurrent research, to determine whether revisions need to be made to EPA’s current drinking water filtration and disinfection rule and to determine the need for new regulations (B13). Wysock et al. discussed data validation and analyses processes for the 18-month ICR monitoring program in a recent paper (B14). The 1996 Safe Drinking Water Act (SDWA) Amendments require the U.S. EPA to establish a list of contaminants to aid in priority-setting for EPA’s drinking water program. By August 6, 1999, and every 5 years thereafter, the U.S. EPA must issue a list of no more than 30 unregulated contaminants to be monitored by water utilities (B1). This list is termed the “Contaminant Candidate List”, and the U.S. EPA published a draft of the first Drinking Water Contaminant Candidate List (CCL) in the October 6, 1997, Federal Register (B15). Further information on the CCL can be obtained at http://www.epa.gov/ogwdw/ccl/cclfs.html. In addition, the SDWA amendments expanded restrictions on lead plumbing and pipes, prohibiting the sale of lead pipe, plumbing fittings, and plumbing fixtures after August 6, 1998. Also, the use and sale of leaded solder and flux were prohibited unless the solder or flux is clearly labeled to prevent its use in plumbing that delivers water for human consumption (B1). Analytical Chemistry, Vol. 71, No. 12, June 15, 1999
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Table 4. DBPs, Microorganisms, and Parameters Monitored under the Information Collection Rule DBPs THMs 6 haloacetic acids chloro-, dichloro-, trichloro-, bromo-, dibromo-, and bromochloroacetic acids) haloacetonitriles di- and trichloroacetonitrile bromochloroacetonitrile dibromoacetonitrile haloketones 1,1-dichloropropanone 1,1,1-trichloropropanone chloral hydrate chloropicrin Additional DBP Monitoring chlorine dioxide chlorite (ClO2-) chlorate (ClO3-) bromate (BrO3-) aldehydesa ozone bromate (BrO3-) aldehydesa chloramines cyanogen chloride (CNCl) hypochlorite chlorate (ClO3-) Microorganisms Cryptosporidium Giardia total culturable viruses total coliforms fecal coliforms or E. coli Water Quality Parameters pH, alkalinity, calcium hardness, temperature turbidity TOX (total organic halide; also considered a DBP surrogate) TOC (total organic carbon) UV absorbance at 254 nm simulated distribution system test total hardness ammonia chlorine demand test a Aldehydes include formaldehyde, acetaldehyde, propanal, butanal, pentanal, hexanal, heptanal, octanal, nonanal, decanal, glyoxal, methyl glyoxal, and benzaldehyde.
In the next two years, new regulations are expected to be proposed for other contaminants in drinking water. In particular, new regulations are expected for arsenic, radon, and sulfate, and for the recycling of filter backwash water within the treatment process of a public water system (B1). Also, there is currently a Groundwater Disinfection Rule (GWDR) under development to improve the microbial quality of groundwater. This rule will apply an approach different from that used for surface water (B6). (b) Water Quality. In October 1997, the U.S. EPA removed human health criteria for polychlorinated biphenyls (PCBs) that were promulgated with the final Water Quality Guidance for the Great Lakes System in March 1997 (B16). The U.S. EPA has recently proposed replacement criteria in draft form (B17); interim criteria are given in this reference (B16). (c) Industrial Wastewater. Two new rules were promulgated recently for wastewater effluents. The first promulgates limitations guidelines and standards under the Clean Water Act for a portion of the pulp, paper, and paperboard industry, as well as emission standards for hazardous air pollutants under the Clean Air Act 184R
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(B18). Nichols discusses these new “cluster” rules, which are an attempt by the U.S. EPA to combine air and water requirements into an ecosystem-wide approach for regulating the pulp and paper industry (B19). The second rule limits the discharge of pollutants by pharmaceutical manufacturing facilities, revising limitations and standards previously set for pharmaceutical manufacturers (B20). New U.S. Regulatory Methods. (a) Drinking Water. Several new regulatory methods for drinking water measurements have been published recently by the U.S. EPA. EPA Method 321.8, “Determination of Bromate in Drinking Waters by Ion Chromatography Inductively Coupled Plasma-Mass Spectrometry”, provides a lower detection limit for bromate of 0.3 µg/L and provides a degree of selectivity that was not available with former methodologies (B21). EPA Method 556, “Determination of Carbonyl Compounds in Drinking Water by Pentafluorobenzylhydroxylamine Derivatization and Capillary Gas Chromatography with Electron Capture Detection”, provides a method to analyze 14 aldehydes and cyclohexanone in water at detection limits of approximately 1 µg/L (B22). This method introduces quality control (QC) criteria, the use of KHP for pH control, and a new combination of effective preservation agents to a previous method that was published in Standard Methods for the Examination of Water and Wastewater (B23). EPA Method 551.1, “Determination of Chlorinated Disinfection Byproducts, Chlorinated Solvents, and Halogenated Pesticides/Herbicides in Drinking Water by LiquidLiquid Extraction and Gas Chromatography with Electron Capture Detection (ECD)”, is applicable to a broad range of organic compounds, including THMs, haloacetonitriles, selected DBPs, chlorinated solvents, and pesticides (B24). EPA Method 552.2, “Determination of Haloacetic Acids and Dalapon in Drinking Water by Liquid-Liquid Extraction, Derivatization and Gas Chromatography with Electron Capture Detection”, is applicable to nine haloacetic acids and Dalapon in drinking water (B25). EPA Method 515.3, “Determination of Chlorinated Acids in Drinking Water by Liquid-Liquid Extraction, Derivatization and Gas Chromatography with Electron Capture Detection”, is applicable to a broad range of chlorinated acids in drinking water (B26). EPA Method 300.1, “Determination of Inorganic Anions in Drinking Water by Ion Chromatography”, is applicable to a broad range of inorganic anions in drinking water (B27). EPA Methods 551.1, 552.2, and 300.1 have been approved for drinking water compliance monitoring; EPA Method 515.3 has been proposed for use in drinking water compliance monitoring, but has not yet been approved. Three methods have been developed or modified for measuring microorganisms in drinking water. EPA Method 1622, “Cryptosporidium in Water by Filtration/IMS/FA”, has been proposed in draft form (B28). This performance-based method for measuring Cryptosporidium oocysts in water uses filtration, immunomagnetic separation (IMS) of oocysts, and an immunofluorescence assay (FA) for determining oocyst concentrations, with confirmation through vital dye staining and differential interference contrast microscopy (B28). This method was originally developed in December 1996 and was later revised, peerreviewed, validated in a round-robin laboratory validation study, and published in draft form in September 1998. EPA Method 1600, “Membrane Filter Test Method for Enterococci in Water”, was published for use in the Beaches Environmental Assessment
Closure and Health (BEACH) Program (B29). This method is a revision of EPA’s previous enterococci method, and it reduces the analysis time to 24 h and improves analytical quality. Indicator bacteriasEscherichia coli and enterococciswere found to provide a better correlation with swimming-associated gastrointestinal illness than previous criteria using fecal coliform bacteria. Another EPA method, “MI Agar Membrane Filter Method for Total Coliforms and Escherichia coli”, is a modification of the membrane filter method and introduces the use of a new MI agar medium that produces a bright fluorescence when cleaved by total coliforms or a blue color when cleaved by E. coli (B30-B32). This modification significantly improves the recoveries of total coliforms and greatly reduces background counts. Improved recoveries of E. coli were observed, but the differences were not statistically significant (B30). A final rule was published for the measurement of radionuclides in drinking water (B33). This rule, which was promulgated on March 5, 1997, approved the use of 66 additional radionuclide analytical methods for compliance monitoring of drinking water. The methods are applicable to gross R, gross β, tritium, uranium, radium-226, radium-228, γ emitters, and radioactive cesium, iodine, and strontium. (b) Wastewater. Six new regulatory methods have been published for measuring chemical pollutants in wastewater (B18, B20, B34). These new methods support rules that were promulgated from 1997 to 1998. EPA Method 1613, “Tetra- Through OctaChlorinated Dioxins and Furans by Isotope Dilution High Resolution Gas Chromatography/High-Resolution Mass Spectrometry (HRGC/HRMS)”, extends the minimum levels of quantitation of chlorine-substituted dibenzo-p-dioxins and dibenzofurans into the low-parts-per-quadrillion (ppq) range for aqueous matrixes and the low-parts-per-trillion (ppt) range for solid matrixes (B34). EPA Method 1650, “Adsorbable Organic Halides by Adsorption and Coulometric Titration”, and EPA Method 1653, “Chlorinated Phenolics in Wastewater by In Situ Acetylation and GC/MS”, apply to certain pulp and paper mills regulated under the Pulp and Paper Cluster Rule (B18). EPA Method 1666, “Volatile Organic Compounds (VOCs) Specific to the Pharmaceutical Manufacturing Industry by Isotope Dilution GC/MS”, EPA Method 1667, “Formaldehyde, Isobutyraldehyde, and Furfural by Derivatization and High-Pressure Liquid Chromatography (LC)”, and EPA Method 1671, “Volatile Organic Compounds Specific to the Pharmaceutical Manufacturing Industry by GC/flame ionization detection (FID)”, represent revised pharmaceutical methods that are part of a compendium (B20). These methods support the Effluent Guidelines Rule (B20). State Regulations and Regulatory Studies. The State of California initiated testing programs for perchlorate and methyl tert-butyl ether (MTBE) and established a pilot surveillance system for quantifying the extent of cryptosporidiosis in the San Francisco Bay area (B35-B37). The California Department of Health Services (DHS) began a study in February 1997 in northern California and in April 1997 elsewhere in California to determine the concentrations of perchlorate in well water (B35). Perchlorate is used in the manufacture of rocket propellant munitions and fireworks and can contaminate well water in areas where this manufacturing or rocket testing occurs (B35). The primary human health concern related to perchlorate is its ability to interfere with
the function of the thyroid gland, affecting metabolism, growth, and development. The DHS found numerous well water samples contaminated with perchlorate and established an action level of 18 ppb (B35). In 1996, the DHS Division of Drinking Water and Environmental Management, which regulates drinking water quality in California, asked the systems it regulates to begin testing their water supplies for MTBE and, subsequently, made the testing mandatory in February 1997 (B36). MTBE, which is a gasoline additive used to promote more complete combustion and reduce emissions of carbon monoxide and organic compounds, has been shown to contaminate groundwater through leaking underground storage tanks and pipelines. It has also been found to a lesser extent in some reservoirs (B36). Results of the DHS study indicate that only 21 of the >1800 drinking water sources measured have tested positive for MTBE (B36). In another action, the state of California, along with water utilities and local health departments, initiated a pilot surveillance system for measuring the extent of cryptosporidiosis in the San Francisco Bay area (B37). This new program was added to the California Emerging Infectious Program and aims to detect Cryptosporidium outbreaks early enough to prevent continuing transmission. Regulations and Regulatory Studies in Europe. A few papers were published that related to regulations in European countries. Claes et al. published an inventory of regulations and analysis techniques used by water supply companies in eastern and western Europe (B38). Van den Hoven and Tielemans presented European Union (EU) standards for lead in drinking water and discussed remedial actions being taken in The Netherlands to reduce lead in drinking water (B39). Van Dijk and De Haan summarized a report by the Health Council of The Netherlands, which dealt with the question of whether ecotoxicological criteria should be taken into consideration, along with human health criteria, for evaluating the risks posed by pesticides in groundwater (B40). Schmidt presented new parameters for drinking water analysis that are now part of the German Standard Method (B41). Other Regulatory Studies. (a) Pollutants. Maull and Lash reviewed the metabolism, mode of action, and regulatory considerations for trichloroethylene (B42). This paper points out that the U.S. EPA is currently conducting a new human health risk assessment for trichloroethylene and has commissioned state-ofthe-science papers from experts in the field on important issues for risk characterization of trichloroethylene; information obtained will be integrated into a policy paper (B42). Mahaffey and Rice published a report to the U.S. Congress that assessed the exposure of the U.S. general population to methylmercury through the consumption of fish and shellfish (B43). (b) Water Quality. Parry published a U.S. EPA perspective on agricultural phosphorus and water quality, which discussed the regulatory and nonregulatory programs developed by the U.S. EPA to control water pollution from agricultural sources (B44). Hanley discussed the U.S. EPA’s watershed-based approach for improving water quality and the development of the total maximum daily load (TMDL) program (B45). This TMDL program determines allowable pollutant discharge levels between all point and nonpoint sources in the watershed, and it authorizes states to impose more restrictive discharge limits on point sources than may be imposed by categorical discharge limits (B45). Galya and Analytical Chemistry, Vol. 71, No. 12, June 15, 1999
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Table 5. Drinking Water DBP Methods analytes polar/nonpolar DBPs MX carbonyl compounds polar DBPs
aldehydes aldehydes hydrogen peroxide carboxylic acids cyanogen chloride
THMs bromate bromate, iodate, chlorite bromate bromate, nitrite bromate
methods/comments GC/MS, GC/IR, LC/MS; derivatization with DNPH for highly polar DBPs derivatization with 2-propanal, GC/MS derivatization with PFBHA, followed by solid-phase microextraction, GC/ECD unified approach for analysis of polar DBPs from a single aqueous sample: preconcentration, followed by IC (for organic acids); fluorometric detection (for organic peroxides); PFBHA derivatization, followed by chemical ionization-ion trap-MS (for carbonyl compounds) study of quenching agents, preservation options derivatization with PFBHA, GC/ECD; introduces QA criteria, pH control, effective preservation agents catalytic reduction/fluorometric method IC MTBE extraction, followed by GC/ECD EPA Method 524.2, problems with interferences purge-and-trap-GC/ion trap MS 3 analytical techniques compared: purge-and-trap-GC/MS, headspace-GC/ECD, liquid/liquid extraction with GC/ECD rapid colorimetric method solid-phase microextraction IC postcolumn derivatization, followed by conductivity detection (no sample pretreatment) IC postcolumn derivatization, followed by UV detection (no sample pretreatment) IC/ICPMS high-capacity resin with photometric detection IC 3 analytical methods compared: modified selective anion concentration method, EPA Method 300.1, postcolumn reagent method
Gerath discussed the evolution of the regulatory and technical framework used for developing water quality-based permit limitations, as part of the National Pollutant Discharge Elimination System (NPDES) permitting process (B46). As this framework has evolved, the focus on NPDES permitting of toxics has gradually turned from technology-based restrictions only to water quality-based permitting, involving chemical-specific limits and whole effluent toxicity testing. Pawlisz et al. presented the Canadian water quality guidelines for chromium (B47). DRINKING WATER Disinfection Byproduct Methods. Disinfection byproduct methods continue to be the focus of much research, particularly with new rules and regulations that have been introduced. As mentioned earlier, under the Stage I D/DBP Rule, there are lower MCLs for THMs, and other DBPs are now regulated for the first time: haloacetic acids, chlorite, and bromate. As a result of these new rules and regulations, methods have been developed and improved. Bromate has received much interest, mostly because health effects studies of bromate suggest that it should be regulated at a lower value than the current stage I MCL of 10 ppb. Consequently, many groups have been working to develop methods that would lower the detection limit to low- and sub-ppb levels. Alternative disinfectants, such as ozone, chlorine dioxide, and chloramines, also have been the focus of methods development work to aid in the identification of DBPs that were not previously known. These drinking water DBP methods are summarized in Table 5. Richardson et al. presented the use of GC/MS, LC/MS, and GC/IR techniques for identifying unknown polar and nonpolar DBPs in drinking water (C1). High-resolution mass spectrometry, chemical ionization mass spectrometry, and infrared (IR) spectroscopy were coupled with GC to obtain structural information for compounds amenable to gas chromatography. Dinitrophenylhydrazine (DNPH) derivatization coupled with LC and electrospray mass spectrometry was presented for the identification of 186R
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refs C1 C2 C3 C4
C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17-C21 C22 C23 C24
polar carbonyl DBPs in ozonated drinking water (C1). Also, a new method was developed for MX (3-chloro-4-(dichloromethyl)-5hydroxy-2(5H)-furanone), the highly mutagenic, and recently determined carcinogenic, DBP that is formed by chlorination of drinking water (C2). This method, which involves derivatization of MX with 2-propanol, followed by detection with GC/MS, significantly lowers the detection limit of MX, which is generally present at ppt (ng/L) levels. Bao et al. published a method for determining carbonyl compounds in water, which uses pentafluorobenzylhydroxylamine (PFBHA) derivatization followed by solidphase microextraction and detection by GC/ECD (C3). Most carbonyls (except glyoxal and methylglyoxal) showed detection limits in the range of 0.006-0.2 µg/L. Weinberg and Glaze presented a unified approach for the analysis of polar DBPs, which permits the simultaneous recovery and preconcentration of monoand multifunctional carbonyl-containing species from a single aqueous matrix (C4). Peldszus and Huck studied the use of different quenching agents and preservation options for analyzing aldehydes in drinking water (C5), and Munch and co-workers have presented a refined method for aldehyde analysis with PFBHA derivatization and GC/ECD detection (C6). Problems with aldehyde analysis are presented, and this method introduces QC criteria, the use of KHP for pH control, and a new combination of effective preservation agents. Schick et al. published a new fluorometric method for the determination of low concentrations (0.2 µg/L) of hydrogen peroxide in water (C7). This method involves the catalytic reduction of hydrogen peroxide in the presence of p-hydroxyphenylacetic acid. Another paper presents a new ion chromatographic method for the detection of carboxylic acids (acetic, formic, and oxalic acid) in water (C8). Several methods were developed or tested for cyanogen chloride, a DBP that was monitored under the Information Collection Rule and is formed by disinfection with chloramine or chlorine. One paper proposes a method based on MTBE extraction, followed by GC/ECD (C9);
another paper discusses the use of EPA Method 524.2, and the potential problem with interference from vinyl chloride, a closely eluting compound (C10). Another paper proposed a method using purge-and-trap/GC/ion trap mass spectrometry (C11), where detection limits of 0.02 µg/L were achieved. And, the final paper on cyanogen chloride detection compared three common analytical techniques for determining cyanogen chloride (purge-and-trap/ GC/MS, headspace/GC/ECD, and liquid/liquid microextraction with GC/ECD detection) (C12). In this study, the liquid/liquid microextraction/GC/ECD method was found to work well in various matrix waters and was the least expensive analytical technique (C12). Two methods were published for the measurement of THMs. The first was a commercially available colorimetric method that is a much more rapid and inexpensive method than the commonly used GC method (C13). This method is not intended to replace the GC method but can supplement it by providing rapid analyses that can allow water treatment facilities to respond quickly to changes in water quality. Another THM method involved the use of solid-phase microextraction and GC/ ECD, which lowered the time of analysis significantly (C14). In response to the need to develop bromate methods with lower detection limits, many researchers have proposed new methods. Two methods involve the use of ion chromatography (IC) followed by postcolumn derivatization, which converts bromate into tribromide, and is then detected either by conductivity (C15) or by UV spectroscopy (at 267 nm) (C16). Detection limits were 0.35 µg/L and 0.2 µg/L, respectively. The second method also published the simultaneous detection of iodate and chlorite; both methods require no sample pretreatment. Methods involving the use of IC with inductively coupled plasma mass spectrometry (ICPMS) were also developed (C17-C21). Using this methodology, Creed et al. demonstrated bromate detection limits of 0.10.2 µg/L, which could be lowered to 50 ng/L (ppt) by coupling the preconcentrator column to an ultrasonic nebulizer (C17). Yamanaka et al. achieved detection limits of 0.45 µg/L for bromate and 0.034 µg/L for iodate with IC/ICPMS (C18). Nowak and Seubert achieved detection limits of 50-65 ng/L for bromate by using a high-capacity, high-performance, microbore anion exchanger with IC/ICPMS (C19). No pretreatment was required, and analysis time was only 8-15 min. Elwaer and co-workers used on-line separation with an activated aluminum microbore column in a flow injection system coupled to ICPMS to achieve a detection limit of 60 ng/L for bromate (C20). In addition, Creed et al. published a paper on the determination of bromate in the presence of brominated haloacetic acids (C21). Another paper by Kohler et al. described the use of a high-capacity resin with photometric detection for determining bromate and nitrite (C22). The use of IC alone has also been presented for detection of bromate at 5 µg/L (C23). Wagner et al. compared three methods for measuring bromate: a modified selective anion concentration method, EPA Method 300.1, and a postcolumn reagent method (C24). Disinfectant Methods. Four publications addressed the determination of residual chlorine in water. One paper compared various methods and kits for colorimetric determination of residual chlorine (C25); another presented a method using a chemiluminescence Cl sensor and flow injection analysis, which provided a detection limit of 8 ppb for ClO- (C26). Sakai et al. published a new method using flow injection analysis with a Pb(II) ion-sensitive
electrode detector (C27). Dossier-Berne et al. developed a method for the automated analysis of chlorine demand measurements (C28). New methods were also presented for the measurement of chlorine dioxide. One method, which utilized reaction with 4-aminoantipyrine and phenol, followed by flow injection analysis, was effective for eliminating interferences from hypochlorite, chlorite, chlorate, and metal ions (C29). A variation of this method was also shown to be useful for simultaneously determining chlorine dioxide and hypochlorite with the use of LC detection (C30). Hofmann et al. compared three spectroscopic methods for measuring chlorine dioxide (C31); Quentel and co-workers presented a new electrochemical method for measuring trace levels of chlorine dioxide (C32). Muller et al. developed a new field method for measuring chlorine dioxide (C33). AOC and NOM Methods. A new bacterial indicator species was proposed for the determination of assimilable organic carbon (AOC) in ozonated water (C34). This species, Acinetobacter calcoaceticus, was found to produce results similar to the commonly used P17 and NOX strains (C34). Ultrafiltration was used for determining the molecular weight distribution of natural organic matter (NOM) in natural waters (C35) and also for studying dissolved organic carbon (DOC), biodegradable organic carbon (BDOC), and total organic halide (TOX) of natural waters and waters treated with chlorine (C36). Finally, a new analytical instrument was created to measure TOC in difficult liquid matrixes (C37). This new instrument, the Phoenix 8000 TOC analyzer (from Tekmar), utilizes a UV/persulfate method. Disinfection Byproduct and NOM Studies. Many DBP studies are published each year on the occurrence of THMs and other commonly monitored DBPs. Articles will only be mentioned here if new or significant findings were presented or if the scope of the study was very comprehensive. Richardson et al. presented the identification of new DBPs from ozone and ozone followed by chlorine or chloramine (C1). Also, the identification of DBPs from TiO2/UV disinfection (an experimental disinfection method that does not produce THMs) and TiO2/UV followed by secondary chlorine treatment was presented (C38). In a study by Romero et al., MX was identified and quantified in chlorine-treated water (C39). The MX contribution to the mutagenicity of the drinking water ranged from 8 to 20%. In a study of Canadian drinking water, the effects of applied disinfectants (chlorine, chloramine, ozone), seasonal variation (winter, summer), and spatial variation (treatment plant, distribution system) were examined (C40). Chloroform, dichloroacetic acid, and trichloroacetic acid were the major DBPs found, and total haloacetic acid concentrations often equaled or exceeded the total THM concentrations. In a study mentioned earlier (C36), which utilized nanofiltration to isolate molecular weight fractions of NOM, amino acids, aldehydes, and low-molecular-weight fatty and aromatic acids were found to be the primary components of the NOM permeate studied, with amino acids making up the major fraction (60%) of DOC studied. Sugars were believed to make up an important portion of the remaining DOC that was not identified (C36). Khiari et al. also utilized nanofiltration for studying the molecular weight distribution of dissolved organic halide (DOX) that is formed by chlorination and chloramination (C41). For both chlorination and chloramination, the percentage of DOX in the Salmonella. Bale et al. identified a new barophilic sulfate-reducing bacterium from deep sediment layers in the Japan Sea (D103). Several studies focused on the examination of microorganisms in bathing beach waters. Enteroviruses and adenoviruses were measured in the coastal waters of southwest Greece using nested PCR (D104). No correlation was observed between the presence of enteroviruses or andenoviruses and the presence of fecal bacterial indicators. Nuzzi and Burhans compared total coliform and fecal coliform bacteria standards (which are currently used to evaluate bathing water quality) to a proposed enterococcus standard (D105). Enterococcus values were found to correlate well with the total coliform and fecal coliform values; however, the enterococcus standard would have resulted in increased beach closures. Microbiological quality of coastal bathing waters in the United Kingdom, Greece, Italy, and Spain was studied (D106). The microbiological quality and health implications of bathing water quality of Barry Island, Wales, a popular vacation resort, was also investigated (D107). Twenty-four percent of swimmers had illnesses, compared to 5% for nonswimmers, and levels of fecal coliforms and fecal streptococci were found to be significantly high (45 000/mL and 16 000/mL, respectively). Roll and Fujioka investigated sources of fecal indicator bacteria in a brackish, tropical stream and their impact on recreational water quality (D108). Muscillo et al. used cell culture, PCR, and polyacrylamide gel electrophoresis to measure enteric viruses in Adriatic seawater and estuary water off the coast of Italy (D109). The results showed widespread viral contamination of the waters tested, particularly in late summer. Bosch et al. studied the persistence of human astrovirus in seawater at 4 and 20 °C (D50). Methods for Microorganisms in Wastewater. Bonnet et al. used immunofluorescence to study Nitrobacter populations from a wastewater treatment plant (D110). Puig et al. examined the use of a strain of Bacteroides fragilis to selectively detect bacteriophages in urban sewage (D111). Fiksdal et al. used enzymic
hydrolysis of fluorogenic substrates to rapidly detect indicators of fecal water pollution (coliform and thermotolerant coliform bacteria) (D112). Guyander et al. applied a RT-PCR internal control to evaluate viral removal in sewage samples (D113). This internal control was based on the poliovirus genome, and it was cloned into a transcription plasmid to obtain a competitor RNA. This method was found useful for providing a quantitative estimation of viral contamination. Studies of Microorganisms in Wastewater. Bukhari et al. studied the occurrence of Cryptosporidium oocysts and Giardia cysts in sewage influents and effluents from treatment plants in England (D114). Small numbers of oocysts were detected in the sewage influent and effluent samples; larger numbers of cysts were observed. Sludge samples from one out of five sites contained oocysts, whereas cysts were detected at all five sites. Montuelle et al. studied the fate of microorganisms from a wastewater treatment plant after discharge into a river (D115). Bacteria numbers and mean cell volumes determined by epifluorescence microscopy revealed a plume that did not disappear until 1.5 km downstream. Niemi et al. examined the influence of wastewater treatment on the bacteriological quality of a river in Finland (D116). Results showed that the bacteriological quality of the river has improved steadily as treatment plants using the activated sludge process have increased and become more effective. Tanaka et al. investigated the safety of wastewater reclamation and reuse using enteric virus monitoring data (D117). Raman and Sambandan studied the distribution of fungi in tannery effluent-polluted soils; of the 22 plant species screened for fungal colonization, 19 plant species showed infection (D118). WATER QUALITY/NUTRIENTS Surface Water/Watersheds and Groundwater Methods. (a) Multiple Inorganic Ion Determinations.. Because many of the water quality methods were developed for both surface waters and groundwater, they are combined here in this section. Table 9 provides a cross-reference of these surface water/groundwater methods to other water quality methods. There were several methods developed for groups of inorganic anions in water. Ionexchange chromatography with chemiluminescence detection was used to determine inorganic ions (chloride, bromide, nitrite, nitrate, sulfate) in water (E1). A new single-column ion chromatography method was presented for measuring inorganic ions (Cl-, NO3-, SO42-, Na, K, Mg, Ca, Sr, Ba) in oil field water (E2). Karmarkar presented an optimized chromatography method for the rapid determination of chloride, nitrate, phosphate, and sulfate in discharge waters (E3), and Aoki et al. presented a rapid FIA method for the successive determination of ammonia, nitrate, and nitrite in water by gas-phase chemiluminescence (E4). (b) Halides. Halide methods were the focus of three papers. Amelin published a test method for determining halides, which used indicator paper impregnated with complexes specific for fluoride, bromide, or iodide (E5). Cheregi and Danet published a FIA method for determining chloride ions (E6), and Chandrawanshi et al. published a FIA method for determining iodide at nanogram levels in water (E7). (c) Ammonia and Total Nitrogen. A sequential injection analysis using the indophenol blue method was used to determine ammonia in water (E8). This system was fully computerized and
could monitor ammonia at a frequency of 16 samples/h. A flow system with a diffusion cell coupled to an ammonium ion-selective sensor was developed to measure ammonium ion (E9). Recoveries of 95-104% were obtained when ammonium ion was measured in rain and river water. Total inorganic and ammoniacal nitrogens in water were measured by gas-phase molecular absorption spectrometry in a paper by Nakamoto et al. (E10). A detection limit of 0.01 mg/L was obtained for both NH3 and total inorganic N. Frankovich and Jones presented a rapid, automated method for the accurate determination of total combined nitrogen in natural waters (E11). This method was reported to perform total nitrogen analyses at a rate of 3 times that of previous techniques and had a detection limit of 2.0 µM in freshwater. 15N analysis was used to monitor nitrogen pollution from sugar cane runoff (E12). (d) Nitrate and Nitrite. Several methods were published for the determination of nitrate and nitrite in surface and groundwaters. Yao et al. used long-path-length absorbance spectroscopy to determine nanomolar concentrations of nitrate and nitrite in natural waters (E13). Horita et al. used a diazotizable aromatic amine and coupling agent, along with preconcentration, to spectrophotometrically determine nitrate and nitrite in soil and water (E14). Gabriel et al. used a novel FIA configuration for the simultaneous determination of nitrate and nitrite (E15). The sampling rate of this system was 180 samples/day, with low relative standard deviations (RSDs). Gil et al. (E16) and Danet and David (E17) presented a flow injection biamperometric method for determining nitrate and nitrite. Wang et al. presented a spectrophotometric method for determining nitrate and nitrite, which was based on a diazotization coupling reaction for nitrite determination and a reduction of nitrate to nitrite using a Cd-Cu reductor column for nitrate determination (E18). Three methods were published for the analysis of nitrates only (E19-E21). Lapa et al. presented a method using direct potentiometry using an ion-selective electrode (E19). This method was shown to give more precise measurements of nitrate than methods using other electrodes. An adaptation of the U.S. EPA’s cadmium column reduction method (method 353.3) was published (E20). This adaptation involves the use of a shaker bath and removes the need to purchase expensive probes, analyzers, or specialized glassware. Holm et al. compared UV spectrophotometry with other methods (IC, ion-selective electrode potentiometry) for measuring nitrate in water (E21). Several methods were published for the analysis of nitrites only (E22-E30). Manzoori et al. developed a highly sensitive and selective method based on the effect of nitrite on the oxidation of carminic acid with bromate (E22). The reaction was monitored spectrophotometrically and gave a detection limit of 0.04 µg/L for nitrite. Nagaraja et al. presented a new spectrophotometric reagent for nitrite determination, based on p-aminobenzoic acid coupled with N-(1-naphthyl)ethylenediamine dihydrochloride in an acid medium (E23). In another study, column preconcentration (on biphenyl) was used for the spectrophotometric determination of nitrite at a detection limit of 14 µg/L (E24). Satake used a diazotization coupling method with column preconcentration on a naphthalene-tetradecyldimethylbenzylammonium iodide absorbent for measuring nitrite (E25). Detection limits were 27-65 µg/L. Jain et al. used a reaction of nitrite with 2-aminobiphenyl Analytical Chemistry, Vol. 71, No. 12, June 15, 1999
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in an acidic medium, followed by GC detection (E26). West and Wen developed a nitrite-sensitive electrode for the determination of nitrite in water and wastewater (E27). Silva et al. used ultramicroelectrodes to achieve detection limits of 2.6-9.7 µM (E28). van Staden used a sequential injection system for the online monitoring of nitrite in fertilizer process streams, natural waters, and wastewater effluents (E29). This system was based on the diazotization of nitrite with N-(1-naphthyl)ethylenediammonium dichloride to form a highly colored azo dye, which was measured at 525 nm. A sampling rate of 49 samples/h with an RSD of
