Table 2.

Toxicological screening

Toxicological screening methods			Comments–interpretation
Rapid screening methods on an automated chemistry analyzer	Immunological and enzymatic	Urine screens for illicit drugs and/or their metabolites (cocaine, amphetamines, opiates, etc.) without assay	Useful for “conventional” drugs, excluding NPS
			These tests need to be carefully interpreted (molecule identified by antibody, toxicokinetics, screening window, interferences, etc.)
			Limits of interpretation on urine
		Specific drug or toxin screens with blood and/or urine assays	Useful for blood assays (drugs, ethanol, etc.)
			Limits of interpretation on urine
		Drug class screens (benzodiazepines, tricyclic antidepressants, etc.) in blood and/or urine	Limits of interpretation for a drug of the class identified by antibody due to cross-reactions with other drugs of the same class and possible interferences
			Need for biological interpretation with respect to the toxicity thresholds of each drug
			Limits of interpretation for urine
Chromatographic confirmation of screening methods	Liquid or gas chromatography	Detection by diode arrays and/or mass spectrometry in blood and/or urine	Useful for broader targeted screening (up to 1200 molecules and/or metabolites)
			Need for biological interpretation of the nature of the molecules identified, the level of screening (sensitivity) and interpretation with respect to reported toxic concentrations
			A semiquantitative approach can be used simultaneously with screening for certain molecules
			Limits of interpretation on urine
	Liquid chromatography	High-resolution mass spectrometry (HRMS)	Useful to identify unknown chemical structures (non-targeted screening) (e.g. NPS)