Dille–Koppanyi reagent

The Dille–Koppanyi reagent is used as a simple spot-test to presumptively identify barbiturates. It is composed of a mixture of two solutions. Part A is 0.1 g of cobalt(II) acetate dihydrate dissolved in 100 ml of methanol mixed with 0.2 ml of glacial acetic acid. Part B made up of is 5% isopropylamine (v/v) in methanol.^[1][2] Two drops of A are dropped onto the substance followed by one drop of B and any change in colour is observed.

The test turns phenobarbital, pentobarbital, amobarbital and secobarbital light purple^[1] by complexation of cobalt with the barbiturate nitrogens.^[3] The test, in a slightly different formulation, was developed in the 1930s by the Hungarian-American pharmacologist Theodore Koppanyi (1901–1985) and the American Biochemist, James Madison Dille (1928–1986).^[4][5]

See also

• Drug checking
• Marquis reagent
• Froehde's reagent
• Zwikker reagent

References

1. O’Neal, C. L.; Crouch, D. J.; Fatah, A. A. (2000). "Validation of twelve chemical spot tests for the detection of drugs of abuse". Forensic Science International. 109 (3): 189–201. doi:10.1016/S0379-0738(99)00235-2. PMID 10725655.
2. "Color Test Reagents/Kits for Preliminary Identification of Drugs of Abuse" (PDF). Law Enforcement and Corrections Standards and Testing Program. July 2000. Retrieved 2011-07-24.
3. Lancashire, Robert J. (2011-10-13). "Unit 9: Crime - Reagent Kits". University of the West Indies, Mona Campus. Retrieved 2014-03-17.
4. Koppanyi, T.; Dille, J. M.; Murphy, W. S.; Krop, S. (1934). "Studies on barbiturates. II. Contributions to methods of barbital research". Journal of the American Pharmaceutical Association. 23 (11): 1074–1079. doi:10.1002/jps.3080231103.
5. Dille, J. M.; Koppanyi, T. (1934). "Studies on barbiturates. III. Chemical assay of barbiturates". Journal of the American Pharmaceutical Association. 23 (11): 1079–1084. doi:10.1002/jps.3080231104.