A recent paper 22 focused on another technique for measuring bulk IEs based on ambientpressure experiments using water films (dip-and-pull method) instead of microjets and discussed the application of bias for determining the true bulk IEs from the photoelectron measurements. The authors estimated bias required to align the vacuum levels of the liquid and the analyzer to be equal +0.435 V (versus standard hydrogen electrode), which is close to the estimated optimal bias in the microjet experiment 12 . However, the extracted values of the core IEs of water were different.