{"data":{"id":"us-va/1vac30-45-812","jurisdiction":"us-va","citation":"1VAC30-45-812","heading":"Air testing: analytical variability/reproducibility","body":"Matrix spike duplicates (MSDs) or laboratory duplicates shall be analyzed at a minimum of one in 20 samples per sample batch. The laboratory shall document their procedure to select the use of appropriate types of spikes and duplicates. The selected samples(s) shall be rotated among sampling points or sampling locations so that various sample matrix problems may be noted and/or addressed. Poor performance in the spikes and duplicates may indicate a problem with the sample composition and shall be reported to the client.","path":["Title 1. Administration","Agency 30. Department of General Services","Chapter 45. Certification for Noncommercial Environmental Laboratories","Part II. Standards","Article 4. Quality System"],"source_url":"https://law.lis.virginia.gov/admincode/title1/agency30/chapter45/section812/","current_through":"2026 Regular Session (effective July 1, 2026)","vintage":"","retrieved_at":"2026-09-14T04:44:41Z","sha256":"a9096a2d3257cc0ea5b1c35656d0469bb2a330e331cb79f385ea548398823c54","source_id":"us-va-vac","stale":false,"prev":"us-va/1vac30-45-811","next":"us-va/1vac30-45-813"},"notice":"GroundRules: Original legal text. Not legal advice."}