An embodiment provides a method for deriving an amount of PFAS substances from a total organic fluoride measurement in a sample, including: removing inorganic fluoride from the sample using one or more of an ion exchange cartridge and an exclusion apparatus; preconcentrating, using a solid phase extraction, at least one PFAS substance in the sample; digesting, using a working electrode and a counter electrode, the at least one PFAS substance 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.

A method of calibrating a biological detector can include training a biological detector to detect a calibration compound, wherein the calibration compound comprises an odor that is detectable by the biological detector and is not used in an environment for which the biological detector is trained to detect odors, presenting the biological detector with a device comprising the calibration compound, and determining whether the biological detector will alert to the calibration compound.