Test Catalog Search Home Test Catalog Search Testing Choices: From the standard to the extraordinary × Search Clear Filter by: Clear all Method(s) High Performance Liquid Chromatography/ Tandem Mass Spectrometry (LC-MS/MS) (1) Sample Type (-) Blood (1) Serum or Plasma (2) Urine (1) Test Area Drugs of Abuse (1) Test Category Analgesics (3) (-) Depressants (1) Test Sub-Category (-) Opiates/Opioids (1) Other (1) Test Test Name 2276B Heroin Metabolites - Free (Unconjugated), Blood