Abstract: An embodiment provides a method for deriving an amount of polyfluoroalkyl substances and perfluoroalkyl substances (PFAS) from a total organic fluoride measurement in a sample, including: removing inorganic fluoride from the sample, and preconcentrating, using an extraction, the PFAS on an extraction device, wherein the inorganic fluoride passes through the extraction device; digesting, using a working electrode, a counter electrode, and at least two secondary electrodes between the working electrode and the counter electrode, the amount of PFAS to an amount of total organic fluoride; and determining, using an analyzer, the amount of total organic fluoride in the sample. Other aspects are described and claimed.

Abstract: An embodiment provides a method for moving precise volumes of fluid using a linear peristaltic pump, including: operating the pump for a first portion of a pump cycle, wherein the operating the first portion dispenses a first reagent, wherein the pump comprises a motor and a cam; pausing the pump for a period of time; and operating the pump for a second portion of the pump cycle, wherein the operating the second portion dispenses a second reagent. Other aspects are described and claimed.