Determination of tobramycin in eye drops with an open-source hardware ion mobility spectrometer

摘要

The analysis of tobramycin was demonstrated successfully as an example for electrospray ionization on an open-source hardware ion mobility spectrometer. This instrument was assembled inexpensively in-house, and required only very few purpose-made components. The quantitative determination of tobramycin required 20 s for a reading. The calibration curve for the range from 50 to 200 mu M was found to be linear with a correlation coefficient of r= 0.9994. A good reproducibility was obtained (3 relative standard deviation) and the limit of detection was determined as 8 mu M. As the concentration of the active ingredient in the eye drops (ophthalmic solutions) is too high for the sensitivity of the instrument, the samples had to be diluted appropriately.