Z19 动、植物体内有毒害物质分析方法 标准查询与下载

ASTM E1367-03(2008) 用河口和海洋处生长的无脊椎动物作静态沉淀污染物毒性的标准试验方法

General: Sediment provides habitat for many aquatic organisms and is a major repository for many of the more persistent chemicals that are introduced into surface waters. In the aquatic environment, most anthropogenic chemicals and waste materials including toxic organic and inorganic chemicals eventually accumulate in sediment. Mounting evidences exists of environmental degradation in areas where USEPA Water Quality Criteria (WQC; Stephan et al.(67)) are not exceeded, yet organisms in or near sediments are adversely affected Chapman, 1989 (68). The WQC were developed to protect organisms in the water column and were not directed toward protecting organisms in sediment. Concentrations of contaminants in sediment may be several orders of magnitude higher than in the overlying water; however, whole sediment concentrations have not been strongly correlated to bioavailability Burton, 1991(69). Partitioning or sorption of a compound between water and sediment may depend on many factors including: aqueous solubility, pH, redox, affinity for sediment organic carbon and dissolved organic carbon, grain size of the sediment, sediment mineral constituents (oxides of iron, manganese, and aluminum), and the quantity of acid volatile sulfides in sediment Di Toro et al. 1991(70) Giesy et al. 1988 (71). Although certain chemicals are highly sorbed to sediment, these compounds may still be available to the biota. Chemicals in sediments may be directly toxic to aquatic life or can be a source of chemicals for bioaccumulation in the food chain. The objective of a sediment test is to determine whether chemicals in sediment are harmful to or are bioaccumulated by benthic organisms. The tests can be used to measure interactive toxic effects of complex chemical mixtures in sediment. Furthermore, knowledge of specific pathways of interactions among sediments and test organisms is not necessary to conduct the tests Kemp et al. 1988, (72). Sediment tests can be used to: (1) determine the relationship between toxic effects and bioavailability, (2) investigate interactions among chemicals, (3) compare the sensitivities of different organisms, (4) determine spatial and temporal distribution of contamination, (5) evaluate hazards of dredged material, (6) measure toxicity as part of product licensing or safety testing, (7) rank areas for clean up, and (8) estimate the effectiveness of remediation or management practices. A variety of methods have been developed for assessing the toxicity of chemicals in sediments using amphipods, midges, polychaetes, oligochaetes, mayflies, or cladocerans (Test Method E 1706, Guide E 1525, Guide E 1850; Annex A1, Annex A2; USEPA, 2000 (73), EPA 1994b, (74), Environment Canada 1997a, (75), Enviroment Canada 1997b,(76)). Several endpoints are suggested in these methods to measure potential effects of contaminants in sediment including survival, growth, behavior, or reproduction; however, survival of test organisms in 10-day exposures is the endpoint most commonly reported. These short-term exposures that only measure effects on survival can be used to identify high levels of contamination in sediments, but may not be able to identify moderate levels of contamination in sediments (USEPA USEPA, 2000 (73); Sibley et al.1996, (77); Sibley et al.19......

Standard Test Method for Measuring the Toxicity of Sediment-Associated Contaminants with Estuarine and Marine Invertebrates

ASTM E1391-03(2008) 用于收集底栖无脊椎动物取样器的选择和毒理测定用沉积物的收集,存储,表征和操作方法的标准指南

Sediment toxicity evaluations are a critical component of environmental quality and ecosystem impact assessments, and are used to meet a variety of research and regulatory objectives. The manner in which the sediments are collected, stored, characterized, and manipulated can influence the results of any sediment quality or process evaluation greatly. Addressing these variables in a systematic and uniform manner will aid the interpretations of sediment toxicity or bioaccumulation results and may allow comparisons between studies. Sediment quality assessment is an important component of water quality protection. Sediment assessments commonly include physicochemical characterization, toxicity tests or bioaccumulation tests, as well as benthic community analyses. The use of consistent sediment collection, manipulation, and storage methods will help provide high quality samples with which accurate data can be obtained for the national inventory and for other programs to prevent, remediate, and manage contaminated sediment. It is now widely known that the methods used in sample collection, transport, handling, storage, and manipulation of sediments and interstitial waters can influence the physicochemical properties and the results of chemical, toxicity, and bioaccumulation analyses. Addressing these variables in an appropriate and systematic manner will provide more accurate sediment quality data and facilitate comparisons among sediment studies. This standard provides current information and recommendations for collecting and handling sediments for physicochemical characterization and biological testing, using procedures that are most likely to maintain in situ conditions, most accurately represent the sediment in question, or satisfy particular needs, to help generate consistent, high quality data collection. This standard is intended to provide technical support to those who design or perform sediment quality studies under a variety of regulatory and non-regulatory programs. Information is provided concerning general sampling design considerations, field and laboratory facilities needed, safety, sampling equipment, sample storage and transport procedures, and sample manipulation issues common to chemical or toxicological analyses. Information contained in this standard reflects the knowledge and experience of several internationally-known sources including the Puget Sound Estuary Program (PSEP), Washington State Department of Ecology (WDE), United States Environmental Protection Agency (USEPA), US Army Corps of Engineers (USACE), National Oceanic and Atmospheric Administration (NOAA), and Environment Canada. This standard attempts to present a coherent set of recommendations on field sampling techniques and sediment or interstitial water sample processing based on the above sources, as well as extensive information in the peer-reviewed literature. As the scope of this standard is broad, it is impossible to adequately present detailed information on every aspect of sediment sampling and processing for all situations. Nor is such detailed guidance warranted because much of this information (for example, how to operate a particular sampling device or how to use a Geographical Positioning System (GPS) device) already exists in other published materials referenced in this standard. Given the above constraints, this standard: (1) presents a discussion of activities involved in sediment sampling and sample processing; (2) alerts the user to important issues that should be considered within each activity; and (3) gives recommendations on how to best address the issues raised such that appropriate samples are collected and analyzed. An attempt is made to alert the user to different considerations pertaining to sampling and sample processing depending on the objectives of the study (for example, remedi......

Standard Guide for Collection, Storage, Characterization, and Manipulation of Sediments for Toxicological Testing and for Selection of Samplers Used to Collect Benthic Invertebrates

ASTM E1525-02(2008) 设计沉淀物生物试验的标准指南

Contaminated sediments may affect natural populations of aquatic organisms adversely. Sediment-dwelling organisms may be exposed directly to contaminants by the ingestion of sediments and by the uptake of sediment-associated contaminants from interstitial and overlying water. Contaminated sediments may affect water column species directly by serving as a source of contaminants to overlying waters or a sink for contaminants from overlying waters. Organisms may also be affected when contaminated sediments are suspended in the water column by natural or human activities. Water column species and nonaquatic species may also be affected indirectly by contaminated sediments by the transfer of contaminants through ecosystems (7, 8). The procedures described in this guide may be used and adapted for incorporation in basic and applied research to determine the ecological effects of contaminated sediments. These same methods may also be used in the development and implementation of monitoring and regulatory programs designed to prevent and manage sediment contamination. Sediment tests with aquatic organisms can be used to quantify the acute and chronic toxicity and the bioavailability of new and presently used materials. Sediment toxicity may also result from environmental processes such as ammonia generation, pH shifts, or dissolved oxygen fluctuation. In many cases, consideration of the adverse effects of sediment-associated contaminants is only one part of a complete hazard assessment of manufactured compounds that are applied directly to the environment (for example, pesticides) and those released (for example, through wastewater effluents) as by-products from the manufacturing process or from municipalities (7). Sediment tests can be used to develop exposure-response relationships for individual toxicants by spiking clean sediments with varying concentrations of a test chemical and determining the concentration that elicits the target response in the test organism (Guide E 1391). Sediment tests can also be designed to determine the effects that the physical and chemical properties of sediments have on the bioavailability and toxicity of compounds. Sediment tests can provide valuable information for making decisions regarding the management of contaminated sediments from hazardous waste sites and other contaminated areas. Biological tests with sediments can also be used to make defensible management decisions on the dredging and disposal of potentially contaminated sediments from rivers and harbors. ((7, 8), Test Method E 1706.)1.1 As the contamination of freshwater and saltwater ecosystems continues to be reduced through the implementation of regulations governing both point and non-point source discharges, there is a growing emphasis and concern regarding historical inputs and their influence on water and sediment quality. Many locations in urban areas exhibit significant sediment contamination, which poses a continual and long-term threat to the functional condition of benthic communities and other species inhabiting these areas (1). Benthic communities are an important component of many ecosystems and alterations of these communities may affect water-column and nonaquatic species. 1.2 Biological tests with sediments are an efficient means for evaluating sediment contamination because they provide information complementary to chemical characterizations and ecological surveys (2). Acute sediment toxicity tests can be used as screening tools in the early phase of an assessment hierarchy that ultimately could include chemical measurements or bioaccumulation and chronic toxicity tests. Sediment tests have been applied in both saltwater and freshwater environments

Standard Guide for Designing Biological Tests with Sediments

ASTM E1525-02 设计沉淀物生物试验的标准指南

1.1 As the contamination of freshwater and saltwater ecosystems continues to be reduced through the implementation of regulations governing both point and non-point source discharges, there is a growing emphasis and concern regarding historical inputs and their influence on water and sediment quality. Many locations in urban areas exhibit significant sediment contamination, which poses a continual and long-term threat to the functional condition of benthic communities and other species inhabiting these areas (1). Benthic communities are an important component of many ecosystems and alterations of these communities may affect water-column and nonaquatic species.1.2 Biological tests with sediments are an efficient means for evaluating sediment contamination because they provide information complementary to chemical characterizations and ecological surveys (2). Acute sediment toxicity tests can be used as screening tools in the early phase of an assessment hierarchy that ultimately could include chemical measurements or bioaccumulation and chronic toxicity tests. Sediment tests have been applied in both saltwater and freshwater environments (). Sediment tests have been used for dredge material permitting, site ranking for remediation, recovery studies following management actions, and trend monitoring. A particularly important application is for establishing contaminant-specific effects and the processes controlling contaminant bioavailability(2-6).1.3 This guide is arranged as follows: SectionReferenced Documents2Terminology3Application4Summary of Guide5Significance and Use6Hazards7Sediment Test Types8Biological Responses9Test Organisms10Experimental Design Considerations11Data InterpretationKeywords1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 7.

Standard Guide for Designing Biological Tests with Sediments

ASTM E1192-97(2008) 鱼类、大型无脊椎动物和两栖动物身上流出的含水物质进行剧毒试验的标准指南

An acute effluent toxicity test is conducted to obtain information concerning the immediate effects on test organisms of a short-term exposure to an effluent under specific experimental conditions. One can directly examine acute effects of complex mixtures of chemicals as occurs in effluents and some ambient waters. Acute effluent toxicity tests can be used to evaluate the potential for designated-use or aquatic life imperiment in the receiving stream, lake, or estuary. An acute toxicity test does not provide information about whether delayed effects will occur, although a post-exposure observation period, with appropriate feeding if necessary, might provide such information. Results of acute effluent tests might be used to predict acute effects likely to occur on aquatic organisms in field situations as a result of exposure under comparable conditions, except that (1) motile organisms might avoid exposure when possible, (2) toxicity to benthic species might be dependent on sorption or settling of components of the effluent onto the substrate, and (3) the effluent might physically or chemically interact with the receiving water. Results of acute effluent tests might be used to compare the acute sensitivities of different species and the acute toxicities of different effluents, and to study the effects of various environmental factors on results of such tests. Acute tests are usually the first step in evaluating the effects of an effluent on aquatic organisms. Results of acute effluent tests will depend on the temperature, composition of the dilution water, condition of the test organisms, exposure technique, and other factors.1.1 This guide covers procedures for obtaining laboratory data concerning the adverse effects of an aqueous effluent on certain species of freshwater and saltwater fishes, macroinvertebrates, and amphibians, usually during 2 to 4-day exposures, depending on the species, using the static, renewal, and flow-through techniques. These procedures will probably be useful for conducting acute toxicity tests on aqueous effluents with many other aquatic species, although modifications might be necessary. 1.2 Other modifications of these procedures might be justified by special needs or circumstances. Although using appropriate procedures is more important than following prescribed procedures, results of tests conducted using unusual procedures are not likely to be comparable to results of many other tests. Comparison of results obtained using modified and unmodified versions of these procedures might provide useful information concerning new concepts and procedures for conducting acute toxicity tests on aqueous effluents. 1.3 This guide is based in large part on Guide E 729. The major differences between the two guides are (1) the maximum test concentration is 100 % effluent or ambient sample, (2) testing is not chemical specific, and (3) the holding time of effluent and ambient samples is often considerably less than that for chemicals and other test materials. Because the sample is often a complex mixture of chemicals, analytical tests cannot generally be used to confirm exposure concentrations. 1.4 Selection of the technique to be used in a specific situation will depend upon the needs of the investigator and upon available resources. Static tests provide the most easily obtained measure of acute toxicity, but should not last longer than 48 h. Renewal and flow-through tests may last longer than 48 h because the pH and concentrations of dissolved oxygen and effluent are maintained at desired levels and degradation and ......

Standard Guide for Conducting Acute Toxicity Tests on Aqueous Ambient Samples and Effluents with Fishes, Macroinvertebrates, and Amphibians

ASTM E1242-97(2008) 用辛醇水分配系数测定鱼因麻醉的中长致死浓度的标准实施规程

This procedure can be used to limit the need for screening tests prior to performing a test for estimating the LC50 of a non-reactive and non-electrolytic chemical to the fathead minnow. By eliminating the screening test, fewer fish need be tested. The time used for preparing and performing the screening test can also be saved. The value obtained in this procedure can be used as the preliminary estimate of the LC50 in a full-scale test. Estimates can be used to set testing priority of groups of non-reactive and non-electrolytic chemicals. If the estimated value is more than 0.3 times the experimental value, the mechanism of action is probably narcosis. If less, the effect concentration is considered to reflect a different mechanism of action. This practice estimates a maximum LC50, that is, non-reactive and non-electrolytic chemicals are at least as toxic as the practice predicts, but may have a lower LC50 if acting by a more specific mechanism. Data on a chemical indicating a lower toxicity than predicted should be considered suspect or an artifact because of limited solubility of the test material.1.1 This practice covers a procedure for estimating the fathead minnow (Pimephales promelas) 96-h LC50 of nonreactive (that is, covalently bonded without unsaturated residues) and nonelectrolytic (that is, require vigorous reagents to facilitate substitution, addition, replacement reactions and are non-ionic, non-dissociating in aqueous solutions) organic chemicals acting solely by narcosis, also referred to as Meyer-Overton toxicity relationship. 1.2 This procedure is accurate for organic chemicals that are toxic due to narcosis and are non-reactive and non-electrolytic. Examples of appropriate chemicals are: alcohols, ketones, ethers, simple halogenated aliphatics, aromatics, and aliphatic substituted aromatics. It is not appropriate for chemicals whose structures include a potential toxiphore (that structural component of a chemical molecule that has been identified to show mammalian toxicity, for example CN is known to be reponsible for inactivation of enzymes, NO2 for decoupling of oxidative phosphorylation, both leading to mammalian toxicity). Examples of inappropriate chemicals are: carbamates, organophosphates, phenols, beta-gamma unsaturated alcohols, electrophiles, and quaternary ammonium salts.

Standard Practice for Using Octanol-Water Partition Coefficient to Estimate Median Lethal Concentrations for Fish Due to Narcosis

ASTM E1768-95(2008) 淡水鱼的肺换气行为毒理学试验用标准指南

Responses that reflect oxygen consumption or utilization have often been targeted as useful indicators of incipient toxic conditions (26, 27, 28, 29, 30). In addition, sustained acute fish ventilatory behavioral responses reflect a physiological change in the organism and therefore might have ecological relevance. For some time, the technological means have been available to log and display ventilatory signals over time. As a result, there are a considerable number of studies which examined ventilatory behavior of fish and other aquatic organisms. A large number of substances at lethal levels have been shown to elicit ventilatory responses relatively quickly (13, 19, 20, 31, 32, 33, 34). For many pollutants, a significant response was often generated in less than 1 h of exposure to concentrations approaching the 96 h LC50. Studies performed using subacutely toxic samples of effluents or individual pollutants (concentrations well below the reported LC50 concentration), often documented responses within 1 to 10 h of exposure (11, 18, 21, 30, 35, 36). Given the data obtained thus far, it appears that fish ventilatory behavior may be a very sensitive and rapid indicator of acute toxicity if various aspects of this behavior (that is, rate and amplitude) are assessed and analyzed simultaneously. It appears that the more aspects of ventilatory behavior that are assessed, the more sensitive and rapid the system is (11, 12, 21, 22). Although a variety of organisms have been examined including crayfish (37), aquatic insect larvae (31), and bivalves (13), most research in aquatic ventilatory behavior has used freshwater fish species. This is largely because fish are generally more ecologically “visible” in their importance in aquatic systems and many species (particularly the salmonids and centrarchids) have large opercular flaps that yield relatively clear ventilatory signals for measurement and evaluation. Species eliciting relatively small bioelectric ventilatory signals are more difficult to use given the electrode and amplification systems referenced in this guide. Changes in ventilatory behavior have been shown to be a reliable indicator of accidental toxic spills or “slugs” of pollutants in wastewater and drinking water systems (15, 20, 23, 24, 33).1.1 This guide covers information on methods to measure and interpret ventilatory behavioral responses of freshwater fish to contaminants. 1.2 Ventilatory responses are often some of the first prelethal symptoms exhibited by animals to environmental stressors (1, 2, 3, 4, 5, 6, 7, 8, 9, 10). Continued, abnormal ventilatory behavior (that is, rapid or shallow breathing, erratic breathing) can indicate physiological damage that may be irreversible. Such damage could eventually result in decreased survival, growth, or reproduction of the organism, or all of these. 1.3 Ventilatory responses of some fish species can be measured relatively easily and quickly, providing a useful tool for biomonitoring studies of wastewaters, pure chemicals, surface water, and ground water. 1.4 Appropriate studies of ventilatory responses can yield definitive endpoints such as no observable effect concentration (NOEC) or an EC50, often more rapidly than standard toxicity test methods (11, 12). 1.5 The mode of action of test substances and the type of chemical toxicant can be determined by examining ventilatory behavioral responses in conjunction with oth......

Standard Guide for Ventilatory Behavioral Toxicology Testing of Freshwater Fish

ASTM E1711-95(2008) 鱼类毒性试验过程中特性测量的标准指南

Protection of a species requires the prevention of detrimental effects of chemicals on the survival, growth, reproduction, health, and uses of individuals of that species. Behavioral toxicity tests provide information concerning the sublethal effects of chemicals and signal the presence of toxic test substances. The locomotory, feeding, and social responses of fish are adaptive and essential to survival. Major changes in these responses may result in a diminished ability to survive, grow, avoid predation, or reproduce and cause significant changes in the natural population (8). Fish behavioral responses are known to be highly sensitive to environmental variables as well as toxic substances. Results from behavioral toxicity tests may be useful for measuring injury resulting from the release of hazardous materials (9). Behavioral responses can also be qualitatively assessed in a systematic manner during toxicity tests to discern trends in sublethal contaminant effects (5). The assessment of locomotory, feeding, and social behaviors is useful for monitoring effluents and sediments from contaminated field sites as well as for defining no-effect concentrations in the laboratory or under controlled field conditions. Such behavioral modifications provide an index of sublethal toxicity and also indicate the potential for subsequent mortality. Behavioral toxicity data can be used to predict the effects of exposure likely to occur in the natural environment (10). Results from behavioral toxicity tests might be an important consideration when assessing the hazard of materials to aquatic organisms. Such results might also be used when deriving water quality criteria for fish and aquatic invertebrate organisms. Results from behavioral toxicity tests can be used to compare the sensitivities of different species, the relative toxicity of different chemical substances on the same organism, or the effect of various environmental variables on the toxicity of a chemical substance. Results of behavioral toxicity tests can be useful in guiding decisions regarding the extent of remedial action needed for contaminated aquatic and terrestrial sites. The behavioral characteristics of a particular organism need to be understood and defined before a response can be used as a measure of toxicity (11). Swimming, feeding, and social behavior varies among species as well as among life stages within a species; the most effective test methods are therefore those tailored to a particular life stage of a single species. The range of variability of any behavioral response of unexposed organisms is influenced by genetic, experiential, physiological, and environmental factors. It is thus important to avoid selecting test organisms from populations that may vary in these factors. Results of behavioral toxicity tests will depend on the behavioral response measured, testing conditions, water quality, species, genetic strain, life stage, health, and condition of test organisms. The behavioral response may therefore be affected by the test environment. No numerical value or range of values has been defined as the norm for swimming, feeding, or social behavior for any fish; the detection of abnormal activity is therefore based on comparisons of the responses of exposed fish, either with activity measured during a baseline or pre-exposure period or observations of fish under a control treatment (10). These measures are incorporated readily into standard toxicity test protocols, with minimal stress to the test organism.1.1 This guide covers some general information on methods for qualitative and quantitative assessment of the behavioral responses of fish during standard laboratory toxicity tests to measu......

Standard Guide for Measurement of Behavior During Fish Toxicity Tests

ASTM E1525-94a 设计用沉积物的生物试验

1.1 As the contamination of freshwater and saltwater ecosystems continues to be reduced through the implementation of regulations governing both point and non-point source discharges, there is a growing emphasis and concern regarding historical inputs and their influence on water and sediment quality. Many locations in urban areas exhibit significant sediment contamination, which poses a continual and long-term threat to the health of benthic communities and other species inhabiting these areas (1). Benthic communities are an important component of many ecosystems and alterations of these communities may affect water-column and nonaquatic species. 1.2 Biological tests with sediments are an efficient means for evaluating sediment contamination because they provide information complementary to chemical characterizations and ecological surveys (2). Acute sediment toxicity tests can be used as screening tools in the early phase of an assessment hierarchy that ultimately could include chemical measurements or bioaccumulation and chronic toxicity tests. Sediment tests have been applied in both saltwater and freshwater environments (2-6). Sediment tests have been used for dredge material permitting, site ranking for remediation, recovery studies following management actions, and trend monitoring. A particularly important application is for establishing contaminant-specific effects and the processes controlling contaminant bioavailability. 1.3 This guide is arranged as follows: Section Referenced Documents 2 Terminology 3 Application 4 Summary of Guide 5 Significance and Use 6 Hazards 7 Sediment Test Types 8 Biological Responses 9 Test Organisms 10 Experimental Design Considerations 11 Data Interpretation 12 Keywords 13 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 7.

Standard Guide for Designing Biological Tests with Sediments

ASTM E1279-89(2008) 用摇瓶衰减弱法作生物降解的标准试验方法

Most of the simpler methods used to screen chemicals for biodegradation potential employ measurements that are not specific to the test substance, such as loss of dissolved organic carbon, evolution of respiratory carbon dioxide, or uptake of dissolved oxygen. Such methods generally are used to evaluate the transformation of the test substance to carbon dioxide, water, oxides or mineral salts of other elements, or products associated with the normal metabolic processes of microorganisms (ultimate biodegradability), or both. These methods require the use of relatively high initial concentrations of the test substance, generally 10 mg/L or higher, unless the tests are conducted using 14C-radiolabeled test compounds. Biodegradation tests measuring 14C-CO2 evolution, for example, can be conducted using initial concentration of test compound at parts per billion. These tests, however, require specialized equipment and the custom preparation of appropriately labeled compound is often very expensive. Die-away biodegradation methods are simple simulation methods that employ water collected from natural water sources and follow the disappearance of an added amount of the test substance resulting from the activity of microorganisms in the water sample. The chemical-specific analytical techniques used to follow the disappearance of the test substance, typically are employed using relatively low initial concentrations of the test substance. Most environmental pollutants are present in the environment at relatively low concentrations (less than 1 mg/L) and it has been observed that biodegradation rates obtained using high test compound concentrations may be quite different from those observed at lower concentrations (6). The transformation of the test substance to an extent sufficient to remove some characteristic property of the molecule, resulting in the loss of detection by the chemicalspecific analytical technique, is referred to as primary biodegradation. For many purposes, evidence of primary biodegradation is sufficient, especially when it is known or can be shown that toxicity, or some other undesirable feature, associated with the test compound is removed or significantly reduced as a result of the primary biodegradation. A determination of ultimate biodegradation, on the other hand, is usually required only when treatability or organic loading are issues of concern. Furthermore, many of the simpler methods, such as those measuring CO2 evolution (see 4.1), may not detect primary biodegradation. The use of low substrate concentration enhances the probability of observing first-order, or pseudo first-order, kinetics. Thus, a rate constant for the primary biodegradation reaction and a half-life can be derived from the test compound under defined incubation conditions. Rate constants are required in many environmental fate mathematical models.1.1 This test method describes procedures for assessing the biodegradation of chemicals in natural surface water samples. 1.2 This test method provides an opportunity to evaluate rates of biodegradation in the presence and absence of natural sediment materials. It also may provide limited information on the abiotic degradation rate, and sorption to sediment and vessel walls. 1.3 This test method allows for the development of a first-order rate constant, based on the disappearance of the test compound with time, and a second-order rate constant, normalized for changes in microbial biomass. 1.4 This test method requires a chemical specific analytical method and the concentrations of test substance employed are dependent on the sensitivity of the analytical method. 1.5 This test method is designed to be applicable to compounds that are not inhibitory to bacteria at the concentrations used in the test m......

Standard Test Method for Biodegradation By a Shake-Flask Die-Away Method