Abstract: Methods and apparatus for electrochemical analysis of water include acid cleaning a quartz crystal microbalance (QCM), stabilizing a QCM in analyte solution, and analyzing the solution by chronoamperometry and measuring a frequency shift of the QCM. The method may further include cleaning the QCM in an acid solution prior to stabilizing the QCM in analyte solution. The apparatus may provide at least semi-automated electrochemical analysis of water including determining a concentration of an analyte in a water sample, and communicating the concentration of the analyte over a network. The analyte may be manganese.