API Publ 4721-2002 pdf free download

API Publ 4721-2002 pdf free download.Analytical Detection and Quantification Limits: Survey of State and Federal Approaches.
The American Petroleum Institute (API) conducted a review of state policies related to analytical detection and quantification limits, with particular focus on water quality and wastewater issues in permitting and compliance. Ten states were reviewed: Alabama, California, Illinois, Louisiana, New Jersey, Ohio, Oklahoma, Pennsylvania, Texas, and Washington. Summary findings of this review are: § Every state incorporates detection or quantification terms in its regulations. Terms referenced in regulations are usually defined in the regulations, but not always. The most frequently used terms are detection limit/level, method detection limit (MDL), and practical quantitation level (PQL). Minimum level (ML) is used by Alabama, California, Illinois, and Ohio.` § The states vary in the extent to which detection and quantification terms are incorporated into their regulatory language. Some states prefer to have the most detailed policies in their water quality implementation procedures; other states prefer to put the detail directly in the regulations. § The states will set wastewater permit limits at or below detection or quantification levels, where considered protective of water quality. Most states specify, either in their regulations or implementation procedures, how compliance is demonstrated in such cases. Compliance with a maximum concentration limit is demonstrated by a Òless-thanÓ analytical result (a detection or quantification limit, as applicable). Where a mass load or average concentration is calculated, most states specify that zero be used in lieu of less-than values. In some situations, one-half the detection limit must be used.
Overview of Report Presented first is an overview of approaches for analytical detection and quantification limits in environmental programs. The overview describes various detection and quantification terms, including method detection limit (MDL), minimum level (ML), practical quantitation (or quantification) level (PQL), alternative minimum level (AML), interlaboratory quantification estimate (IQE), and others. Next, the policies of the ten selected states are presented. Lastly, recommendations are provided for setting effluent limits and compliance monitoring requirements in wastewater discharge permits. Overview of Approaches This section provides an overview of selected approaches for determining analytical detection and quantification levels used in environmental programs. Table 1 lists the terms most often used in these programs, as well as two alternatives (AML, IQE) that have been suggested by others. In the following sections, these terms, as they are used in wastewater programs, are discussed in detail, and their similarities and differences are compared. Terms used in other environmental programs, both state and federal, are identified. Water and Wastewater Programs The most common detection and quantification limits in water and wastewater programs are the MDL, ML, and PQL. The MDL can be used to calculate both the ML and the PQL. Variations of these and other related terms can be found in water and wastewater programs. The LOD is calculated as three times the standard deviation, s , at either zero (blank) or the lowest level of measurement. It differs from the USEPAÕs MDL in the multiplying factor [3 versus 3.143 (or other StudentÕs t value)] and in not having a recommended number of replicate analyses. Use of s , the population standard deviation, implies an infinite number of analyses, or at least a very large number. In practice, the sample standard deviation, s, would be used as a substitute for s . Other Detection Terms Other detection terms used in state programs are discussed in the section on State Policies . Those found in federal regulations are listed in Table 2. Quantification Levels The USEPAÕs approaches to the ML and PQL are described in the following sections. Although the term LOQ is not used per se in these programs, a description of the term is also provided because of its relation to the ML. The AML and IQE, which have been promoted to the USEPA as improved quantification levels, are also described. Following these descriptions is a summary of other quantification terms used in water and wastewater programs. Minimum Level The ML is a quantification term defined by the USEPA as: ÒThe concentration at which the entire analytical system must give a recognizable signal and acceptable calibration point. The ML is the concentration in a sample that is equivalent to the concentration of the lowest calibration standard analyzed by a specific analytical procedure, assuming that all of the method-specified sample weights, volumes, and processing steps have been followed.Ó 1 The ML concept and how it is calculated have evolved over time. Currently, MLs are usually either calculated as 3.18 times the MDL, or set equal to the lowest calibration standard. The factor of 3.18 is derived from another quantification term, the LOQ (see description later in this section).