In which procedure may the reagent EDTA be utilized?

The utilization of the reagent EDTA (Ethylenediaminetetraacetic acid) is primarily associated with the procedure of conductivity testing. EDTA acts as a chelating agent that can bind metal ions in a solution. Its ability to complex with these ions is crucial in minimizing their interference in various analytical measurements, including conductivity.

When assessing conductivity, the focus is on the ionic strength of the solution, which is influenced by the presence of various ions, including metal cations. By employing EDTA, analysts can eliminate specific cations that could skew the conductivity measurements, allowing for a more accurate representation of the overall ionic content of the water sample. This aspect is particularly important in water analysis, where a precise understanding of ionic concentration is necessary for assessing water quality.

In contrast, the other options involve different analytical methods where EDTA does not play a central role. Filtration is a physical separation process; pH testing relies on colorimetric methods or pH meters without the need for chelating agents; and turbidity analysis measures the cloudiness of water, which is not directly influenced by the presence of metal ions or the properties of EDTA. Thus, the association of EDTA with conductivity testing stands out clearly in the context