FI-Chemiluminescence Determination of Cocaine Hydrochloride in Microemulsion Medium

It was found that in an acidic medium, an ion association complex was formed between AuCl4- and the protonated nitrogen atom of cocaine hydrochloride, and this complex was extracted with dichloromethane and the extract was transfered into a reversed micellar microemulsion prepared by mixing cetyltrimethylammonium chloride (CTAC) and luminol. Then AuCl4- was released and reacted with luminol to produce chemiluminescence. Based on these facts, a FI-CL method for indirect determination of cocaine hydrochloride was proposed. Linearity range of the working curve was kept between 0.001-10 mg·L-1, with detection limit (3σ) of 0.01 μg·L-1. Test for recovery was made by standard addition method using samples of urine and blood serum as matrixes, results of recovery found were in the range of 95.0%-102.0% with RSD′s (n=5) in the range of 1.8%-3.2%.