Ion exchange paper adsorption and thin-layer chromatography for detection of chloroquine in urine for the study of chemosensitivity of Plasmodium falciparum.

With a view to determining the chemosensitivity of Plasmodium falciparum to chloroquine, two qualitative tests for the detection of this antimalarial agent in urine were compared in Central African schoolchildren: the test of Dill and Glazko and a thin-layer chromatography technique involving ion exchange and extraction. Results obtained with 149 subjects showed the marked superiority in specificity and sensitivity of the chromatography test. This is of particular interest when selecting subjects before a therapeutic trial is undertaken. After administration of a single dose of chloroquine (10 mg kg-1) to 14 schoolchildren, both urinary detection tests gave positive results at 24 and 48 hours. However, on day 7 all results with the chromatography test were positive, while 57% of false negatives were recorded by the Dill and Glazko test.