Analysis of forensic samples for drugs and toxic
substances
By Elphas Shikokoti Siayi BSc. MLS
+254759491446
Considerations for Forensic Toxicological Analysis
Forensic specimens may be very little. One can imagine that a given method may need more
sample volume or weight than another method. Therefore the amount of specimen available is a
critical determinant of methods to choose for proper toxicological analysis. It is necessary to know
the nature of the toxicant to test. In a particular case, is it relevant to detect the parent compound,
its metabolites, or all of these? Furthermore toxicant biotransformation must be taken into account
when doing the analyses and making interpretations. A low concentration of a toxic parent
compound may reflect biotransformation as opposed to a low level of exposure. Conversely, a
low-level presence of a nontoxic parent compound may be associated with a sufficient
concentration of a biotransformation product that was high enough to cause the insult.
Furthermore both forms (parent and metabolites) may have contributed to the adverse outcome.
Analytical schemes for toxicant detection forensic samples
The circumstances surrounding the case will usually determine the types of toxicological tests
that are required. There are different screens specific for the type of substance to be assayed. A
given laboratory will follow an algorithm to handle the analysis. Figure below shows a typical
toxic/drug analysis algorithm to adequately identify the drug (or at least drug class) that may be
present in a tested specimen.
substances
By Elphas Shikokoti Siayi BSc. MLS
+254759491446
Considerations for Forensic Toxicological Analysis
Forensic specimens may be very little. One can imagine that a given method may need more
sample volume or weight than another method. Therefore the amount of specimen available is a
critical determinant of methods to choose for proper toxicological analysis. It is necessary to know
the nature of the toxicant to test. In a particular case, is it relevant to detect the parent compound,
its metabolites, or all of these? Furthermore toxicant biotransformation must be taken into account
when doing the analyses and making interpretations. A low concentration of a toxic parent
compound may reflect biotransformation as opposed to a low level of exposure. Conversely, a
low-level presence of a nontoxic parent compound may be associated with a sufficient
concentration of a biotransformation product that was high enough to cause the insult.
Furthermore both forms (parent and metabolites) may have contributed to the adverse outcome.
Analytical schemes for toxicant detection forensic samples
The circumstances surrounding the case will usually determine the types of toxicological tests
that are required. There are different screens specific for the type of substance to be assayed. A
given laboratory will follow an algorithm to handle the analysis. Figure below shows a typical
toxic/drug analysis algorithm to adequately identify the drug (or at least drug class) that may be
present in a tested specimen.
