14.3.1 Data Validation Data validation involves all procedures used to accept or reject data after collection and prior to use, including editing, screening, checking, auditing, verifying, and reviewing. Data- validation procedures ensure that the standards for data accuracy and precision were met, that data were generated in accordance with the QA study plan and SOPs, and that data are traceable and defensible. It is important for all reported data to be properly validated following standardized procedures to ensure that data are of consistent and documented quality. Chemical Quality Control Chemical QC specifications are the ranges considered acceptable for instrument calibration, analyte recovery, data accuracy, and data precision. Instrument calibration involves determining a linear response over the range of data to be collected.
Recovery is determined by analyzing a sample spiked with a known amount of chemical.
Procedural accuracy is established by including a series of spiked and blank samples in each analysis. Precision is established by analyzing replicate samples. QC procedures are discussed in more detail for sediment, water, and tissue analyses in Sections 9.3.3, 9.4.3, and 9.5.3, respectively. These activities provide an independent quality assurance check on activities being performed and on data being generated. When sufficient reference-toxicant data have been generated for a particular species, it may be possible to stipulate an acceptable LC50 range for that species with the reference toxicant.