To study lipophilic compounds glass vials are widely used in labs. We were aiming to quantify the loss of one lipophilic compound in the tissue homogenization process using Precellys tubes with ceramic beads. For that, we selected one compound that shown to bind plastic extensively. The compound info is: small molecule; neural compound; MW>500; experimental / theoretical LogP >3; low water solubility.
Both compound extraction and LC-MS/MS analytical methods were validated and published previously. We assume that the binding of the compound to glass tubes is minimal and thus use glass tubes as controls. The percentage loss is 19.3 +/- 10.9 % (mean +/- SD), ranging from 9.3% to 34.5%. The data from the 2µg/mL group may be an outlier due to the big deviation from the other concentration groups. The percentage loss from the other three concentration groups is 14.2 +/- 4.8 % (mean +/- SD), ranging from 9.3% to 18.9%. The percentage lost due to Precellys tubes binding does not seem to depend on compound concentrations which is good for calculation that may account for the loss of the drug at an unknown concentration. The standard curves for the 3 conditions are shown in the figure 1.