Cobalt Thiocyanate
Definition
Co(SCN)2 in aqueous solution; the active reagent in the Scott test for cocaine. Cocaine forms a lipophilic blue complex with cobalt thiocyanate that partitions into organic solvents such as chloroform, whereas most other bases do not survive the HCl wash step and chloroform partition with the same colour.
Related terms
- Duquenois-Levine Test
- A three-reagent presumptive test for cannabinoids: vanillin + acetaldehyde in ethanol (Reagent 1), concentrated hydrochloric acid (Reagent 2), and chloroform partition (Reagent...
- False Positive (Presumptive Test)
- A positive colour response from a compound that is not the targeted controlled substance. Common sources include diphenhydramine (Marquis orange, Scott blue),...
- Mandelin Reagent
- Ammonium metavanadate (NH4VO3) in concentrated sulphuric acid. Useful for amphetamines (orange-red), MDMA (dark blue-black) and cocaine (yellow-orange). The Mandelin-Marquis panel is recommended...
- Marquis Reagent
- A presumptive drug test reagent consisting of formaldehyde in concentrated sulphuric acid, first described by Edmund Marquis in 1896. It produces characteristic...
- Mecke Reagent
- Selenious acid (H2SeO3) dissolved in concentrated sulphuric acid. More selective than Marquis for the opioid alkaloid skeleton; morphine and heroin give a...
- NIK Polytesting
- A field drug testing approach using the NIK Public Safety sealed ampoule system, where multiple colour tests are run sequentially on the...
- Scott Test
- A three-step cobalt thiocyanate presumptive test for cocaine and its salts. Step 1: cobalt thiocyanate reagent (blue in aqueous phase). Step 2:...
- Simon's Test
- A presumptive test that uses sodium nitroprusside and sodium carbonate to detect secondary amines (N-methyl group). Methamphetamine and MDMA (secondary amines) give...
- SWGDRUG Category C
- The lowest tier in the Scientific Working Group for the Analysis of Seized Drugs classification. Category C methods (including colour tests, microcrystal...
Explained in
- Presumptive Colour Tests: Marquis, Mecke, Duquenois-Levine, Cobalt Thiocyanate and ScottCo(SCN)2 in aqueous solution; the active reagent in the Scott test for cocaine. Cocaine forms a lipophilic blue complex with cobalt thiocyanate that partitions...