Evaluation of three qualitative tests for detection of chloroquine in urine—agreement with plasma concentrations determined with liquid chromatography

Abstract

Three qualitative tests for detection of chloroquine in urine were compared and evaluated against concomitant plasma concentrations determined with liquid chromatography.

All urine tests from five volunteers taking a single dose of 5 mg chloroquine base kg⁻¹ were positive for at least ten days with the Haskins test, and for at least three days with the Wilson Edeson test. Even on the first day, the Dill-Glazko test indicated chloroquine in the urine of one volunteer only. After a single dose of 10 mg kg⁻¹ to five other volunteers the Haskins test was uniformly positive for 14 days while the Wilson Edeson test was positive for four days. The Dill—Glazko test was positive for one day only. No false negative results were obtained with the Haskins test when plasma concentrations were above 0·03 μmoll⁻¹, as compared to 0·11 μmoll⁻¹ with the Wilson Edeson test. The Dill—Glazko test was uniformly positive when plasma concentrations were above 0·38 μmoll⁻¹ The Dill—Glazko test was affected by low urinary pH and by addition of erythrocytes to urine.

We conclude that the Dill—Glazko test should not be used.