A sample of analyte free media (supplied by the laboratory) taken to the site and returned to the laboratory unopened. The trip blank as well as duplicate blank are prepared by the laboratory. The duplicates that are prepared at the same time and under the same conditions are retained at the laboratory in a contaminant free location for possible future comparison.
Frequency and Purpose
1 per water submission. Most typically for VOCs (Volatile Organic Compounds).
Identifies any potential cross-contamination that may occur from other samples, ambient conditions, or other sources that samples may be exposed to.
Application and Regulatory Criteria
Evaluates the impact on data for results >2x the RDL or that which approaches the concentration reported in the sample.
Analyse the laboratory trip blank duplicate retained by the laboratory.