Determination of free calcium in guinea-pig cochlea perilymph by capillaryelectrophoresis with direct injection

At present, the tinnitus mechanism is still not clear. Our experiments demo nstrated that the concentration of free calcium in cochlea perilymph of tin nitus model guinea-pigs is lower than that in normal guinea-pigs. However, the volume of conchlea perilymph is so small that only 5-10 mu L of sample can be obtained from each animal. We describe the application of CE to the detectionl of free calcium in guinea-pig cochlea perilymph. Direct injectio n was employed in this study. The separation was carried out at 10 kV. The capillary temperature was maintained at 20 degrees C, and indirect UV detec tion at 214 nm was employed. The samples were vacuum injected for 3 s. The run buffer was 0.005 mol/L imidazole with a pH of 4.30-4.50. The concentrat ion of free calcium in the normal group was found to be in accordance with the reference data. The method has been applied to research on the tinnitus mechanism and for medical treatment.