Method Validation

CompuChem validates all analytical methods before they become analytical services to our clients. To validate a method, one of our senior chemists reviews the published method description, assessing the instrumentation needed to perform the method, the QA/QC requirements, and any potential safety hazards. Based on his/her review, the chemist formulates a plan of testing and submits this plan to laboratory management for approval. If the chemist's proposal is approved, a full-scale method validation study is performed. All method validation studies must include:

• a method detection limit (MDL) determination (repeated annually)
• a precision and accuracy determination

Once the method validation study has been approved by our Quality Assurance department, the laboratory in which the method is performed must write a standard operating procedure (SOP) describing the laboratory procedures involved. All SOPs must comply with CompuChem's internal SOP writing guidelines, as well as the NELAC Standards and are subject to our document control program. Our QA department approves all SOPs before they are distributed within the laboratories.

The laboratory performs annual MDL determinations for all methods currently in use. Included in CompuChem's MDL studies are verification of Practical Quantitation Limits (PQLs).

Method Validation Studies

Prior to analysis of any samples for approved methods not previously offered for sale by the laboratory, a method validation study must first be performed. A chemist familiar with the extraction/preparation procedures and the instrumental detection systems reviews the as-written method. The chemist looks for safety hazards, applicability of available instrument systems, new equipment requirements, any discrepancies in the written method, and the QA/QC requirements. A plan of testing approach is discussed with the laboratory director, technical directors, and executive management. Analyses of laboratory spiked matrices are performed to determine overall method recoverability. A draft SOP is written after the method validation study has been performed.

Documentation includes an MDL study, a precision and accuracy determination, and a draft SOP. This and any other pertinent information is then forwarded to the QA department for final approval. Any deviations from the published method must be noted in the SOP. Once approval by QA and SOP document control is completed, product codes can be developed and the new method can be offered to clients.

Data Quality Objectives

Data quality objectives (DQOs) are used in planning environmental data collection activities. They establish the level of data that are needed to support decisions regarding the site. They establish the level of uncertainty in results that a decision-maker is willing to accept. They can be used to define QA/QC programs specific to a project or data collection activity. DQOs have been established for programs under which the laboratory provides analytical services. Internal project support staff work closely with the client and regulatory agencies to ensure that DQOs will be met by the analytical results provided. The project management team conveys project- and client- specific requirements to the laboratory via the Element LIMs, which drives all analyses. Additionally, the Project Managers meet with the lab staff weekly, or more often, if necessary, to discuss specific project issues/needs.