Cobalt(II) thiocyanate

The structures of Co(SCN)2 and its hydrate Co(SCN)2(H2O)3 have been determined using X-ray crystallography. :CoSO4 + Ba(SCN)2 → BaSO4 + Co(SCN)2 or the reaction of the hexakisacetonitrile cobalt(II) tetrafluoroborate and potassium thiocyanate, precipitating KBF4 :[Co(NCMe)6](BF4)2 + 2KSCN → 2KBF4 + Co(SCN)2. The anhydrate can then be prepared via addition of diethylether as an antisolvent. ==Scott's test==

'''Scott's Test or Scott Test''' refers to a rapid and low-cost method of preliminary testing for cocaine. It is a mixture of an acid medium and 2% cobalt(II) thiocyanate. While typically used for cocaine, it will also indicate the presence of ketamine hydrochlorides, heroin, and dibucaine in amounts higher than 1 mg, as well as diltiazem and lidocaine in amounts higher than or equal to 5 mg. When the cobalt thiocyanate reagent interacts with cocaine hydrochloride, the solution turns from a reddish-brown to a vibrant blue. ==Cobalt thiocyanate test==

Detailed procedures for the cobalt thiocyanate test, often sold as the "morris reagent" are available. The reagent consists of 2% cobalt thiocyanate dissolved in dilute acid. Glycerol is added when using the reagent for Thin-layer chromatography as it stabilises the cobalt complex, ensuring it only goes blue when in contact with an analyte and not due to drying on the plate. Addition of the cobalt thiocyanate reagent to cocaine hydrochloride results in the surface of the particles turning a bright blue (faint blue for cocaine base). The solution changes back to pink upon adding some hydrochloric acid. Addition of chloroform, results in a blue organic layer for both cocaine hydrochloride and cocaine base. Diphenhydramine and lidocaine also give blue organic layers. These compounds are known false positives for cocaine. Lidocaine is commonly used to adulterate or mimic cocaine due to its local anaesthetic effect. If the procedure is adjusted to basify the sample with 0.1 N sodium hydroxide rather than acidifying it, the test can be used to test for ketamine hydrochloride. ==References==