The purity of cocaine bought on the street varies dramatically. Cutting agents include levamisole, a compound normally used to kill parasites. Search the literature for a reversed-phase liquid chromatography method with diode array detection for the determination of the purity of street cocaine.

(a) Give the citation (authors, title, journal name, year, volume, pages) for the research paper that fi ts the criteria of this analysis.
(b) What alternative methods could be used for analysis of adulterated street cocaine?
(c) What is the range of purity of street cocaine?
(d) What type of analytical column was used for the analysis?
(e) How was the method validated?
(f) What is “robustness of an analytical method?”