Resumen

EXPOSITO DE GOIKOETXEA, CL. Cromatografía en Capa Fina y Espectrofotometría en luz Ultravioleta:: Validez actual y Aplicabilidad para detectar Cocaína o Benzoilecgonina en Orinas de Pacientes Farmacodependientes En proceso de Rehabilitación. RFM [online]. 2003, vol.26, n.1, pp.49-54. ISSN 0798-0469.

ABSTRACT      This study intended to evaluate the current validity and the applicability, as a routine analytical method, of thin layer chromatography (TLC) and UV spectrophotometry methods in the detection of cocaine and its major metabolite -benzoylecgonine- among drug addicts seeking treatment at the ambulatory center "Parque Miranda" of the "José Félix Ribas" Foundation, as employed in the Laboratory of Toxicology, School of Bioanálisis, Facultad de Medicina, Central University of Venezuela, using heterogeneous immunoassay (ELISA) as reference technique. Cocaine and benzoylecgonine were isolated by alkaline extraction with chloroform in 124 urine samples. The T1 system was employed for TLC method, while for the UV spectrophotometry assay the Shimadzu UV-160 was used.. 78 (70,96%) positive results were obtained with ELISA and none with TLC or UV spectrophotometry; 36 (29,03%) negative results were obtained with ELISA and 124 (100%) with TLC and UV spectrophotemetry. A significant statistically difference (p<0,05) was observed when comparing results from the three methods, suggesting that they cannot be applied as used en our laboratory- for presumptive or screening techniques in toxicology analysis of urine samples.

Palabras clave : Thin layer chromatography (TLC); UV spectrophotometry; Cocaine; Benzoylecgonine; Drug addicts.