HPLC Analysis of CHG Receptor and Tape Samples

HPLC analysis of both CHG receptor phase and tape strip samples used the method detailed previously (42 (link)). A Thermo Scientific guard column with replaceable guard cartridges was used to ensure HPLC pressure remained stable throughout the study. The limit of detection (LoD) and limit of quantification (LoQ) were calculated from this calibration graph according to the following Eqs.  (43 (link)): $$LoD=\frac{3\times standarddeivation}{\mathit{slope}}$$ $$LoQ=\frac{10\times standarddeivation}{\mathit{slope}}$$
The mobile phase was used as the solvent for all CHG extractions and was validated on the Shimadzu system (r² value 0.9992). The LoD was calculated to be 0.362 µg/mL and the LoQ was calculated to be 1.098 µg/mL.