Volume 23, Issue 1 (January 1978)
Unequivocal Determination of Cocaine in Simulated Street Drugs by a Combination of High Performance Liquid Chromatography and Infrared Spectrophotometry
Since the development of high performance liquid chromatography (HPLC) in the late 1960s papers have appeared in the literature describing the identification of drugs of abuse by this method. For example, Jane  reported a separation of a number of drugs on a Partisil column. However, while extremely useful in the forensic laboratory, HPLC has not attained its full potential because of the presumptive nature of the determination, that is, one cannot rule out the possibility that two compounds might have the same retention time. In an attempt to improve this situation a few companies are investigating the feasibility of interfacing the HPLC with a mass spectrometer. If such interfacing is successful, though, the cost probably will be prohibitive for most forensic laboratories. Also, some progress is being made in the technique of “absorbance ratioing” . In this method the drug is monitored at more than one wavelength and the ratio of these absorbances is reported to be solely characteristic of the particular compound. Although promising, this technique requires a more elaborate and expensive detector system. Also more data need to be collected to prove statistically the premise that no two compounds will have the same absorbance ratios.