Assay of levodopa in brain by CE

This article reports a CE (capillary electrophoresis) method for the determination of Levodopa (L-DP) in rabbit brain tissue. L-DP was separated and determined on a fused quartz capillary (75 microm ID, 75 cm length, 50 cm effective length, Beckman Co.) with a mobile phase of phosphate buffer (pH = 2.5, 20 mmol/L THAM, 3% carboxymethyl-beta-cyclodextrin), sample pressure 0.6 kPa x 6 s, separation voltage 20 KV, detected at 280 nm and temperature 25 degrees C. The calibration curve was linear (r = 0.9999, n = 6) within the range of 0.5-16 microg/ml for L-DP. The recovery ratio was 87.87%. The mean relative standard deviation (RSD) was 2.73% (n = 5). This method is convenient, rapid, accurate, and brings about good recovery; it can be used for content determination of levodopa in rabbit brain tissue.