Opiates colour tests

Marquis Test (p. 139). Many basic drugs produce colours with diis reagent. It is a good test for opiates, stimulants, antihistamines, and pheno-thiazines. 

Table 5.1 Colour reactions observed on reacting opiates with common presumptive test reagents (see Appendix 1)...

This reagent is prepared as a 1% solution of ammonium metavanadate in concentrated sulfuric acid, which is then added directly to the test substrate. Orange colour reactions are observed with cocaine and related compounds, with olive green colours being produced if opiates are present. 

This is prepared by dissolving 5 ml of 40% formaldehyde in 100 ml of concentrated sulfuric acid. The reagent is then added directly to the test substrate. A purple-olive coloration is produced with opiates, and yellow-orange with amphetamine, methylamphetamine, psilocybin and psilocin, among others. A grey-purple colour reaction is obtained with ring-substituted amphetamines. 

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