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E <br />Data <br />i <br />• y.As ses sm. <br />t sNot J J6ust Pushing Paper <br />Rigorous quality assurance is the best way to guarantee <br />the reliability of data from laboratory analysis. <br />By Taryn G. Scholz,. Louise McGinley and Donald A. Flory <br />ecently, the environmental <br />arena has expanded dramati- <br />LAcally, pushing technology to <br />new limits and encouraging <br />innovation in an ever-changing regulato- <br />ry atmosphere. One environmental issue <br />dominates the science of identifying and <br />quantitating regulated chemicals or lab- <br />oratory analysis. <br />Data from laboratory analysis is essen- <br />dal to risk assessments, extent of contam- <br />ination studies, feasibility studies and <br />compliance monitoring. A tremendous <br />amount of resources is expended, based <br />on laboratory analytical results. This, plus <br />the legal aspects surrounding environ- <br />mental issues, makes it imperative that <br />the laboratory results be "of known and <br />acceptable quality for the intended use. <br />Quality Assurance <br />Quality assurance (QA) is the total inte- <br />grated process for assuring the reliability <br />and defensibility of decisions based on <br />analytical data. The process is extremely <br />rigorous due to the complexity of labo- <br />ratory analyses; the number of different <br />analytical methods, each with different <br />criteria; various agency standards for val- <br />idating results; the abundance of labora- <br />tories, each with varying strengths and <br />weaknesses; and the diverse scope of <br />measurement purposes. In other words, <br />it takes a lot of paper pushing. <br />Few will argue that it is a necessary <br />evil to ensure laboratory data is legally <br />defensible. However, it is also necessary <br />30 1 Environmental PROTECnON <br />to ensure data is technically valid -2 de- <br />termination that is interpretive and re- <br />quires a thorough understanding of ana- <br />lytical chemistry. Many data users do not <br />realize that it is the norm, rather than <br />the exception, for laboratory data to <br />have some bias. If not accounted for, the <br />bias can lead to disastrous decisions. <br />It doesdt necessarily take a laboratory <br />failure to introduce bias. In many cases, <br />bias is introduced solely by the sample <br />matrix, even when the laboratory follows <br />the analytical method exactly. Of course, <br />compliance <br />monitoring_ <br />laboratory data should never be blindly <br />accepted—laboratories today are more <br />automated, which means less reliance on <br />experienced analytical chemists. <br />Laboratory QA reviews are generic for <br />all clients and often inadequate and not <br />suited to a particular use. The U.S. <br />Environmental Protection Agency guide- <br />lines make it clear the data user has the <br />final responsibility for the dare quality: <br />"If the data are collected by a contract <br />laboratory, it is the permittee's responsi- <br />bility to see that all of the requirements in <br />the method are met by the contract labo- <br />ratory and that all (associated) data are <br />provided."—EPA Guidance on Eval- <br />uation, Resolution, and Documentation <br />of Analytical Problems Associated with <br />Compliance Monitoring. <br />Data Quality Assessment <br />The fundamental principle of quality as- <br />surance is data quality assessment. <br />Third -parry data quality assessment is <br />the best way to ensure laboratory data is <br />legally defensible and technically valid. <br />It eliminates potential conflicts of inter- <br />est and is more efficiently and reliably <br />performed by specialists. A complete <br />data quality assessment includes: <br />• Data validation, <br />• Data qualificarion/review (flagging), <br />• Suitability determination, <br />• Data rescue and <br />• Data validation. <br />Quality control (QC) is a set of mea- <br />sures within a sample analysis merhodol- <br />September 1996 <br />