Which of the following is NOT an example of Total Dissolved Solids (TDS) in water?

Total Dissolved Solids (TDS) refer to the combined content of all inorganic and organic substances present in a liquid in molecular, ionized, or micro-granular (colloidal) suspended form. TDS primarily includes salts, metals, cations, and other compounds that dissolve in water, contributing to its overall mineral content.

Organic compounds, while they can be present in water, are generally not included in the category of constituents that are quantified as TDS. The TDS measurement typically focuses on inorganic materials that can be dissolved in water like cations (positively charged ions such as calcium and magnesium), salts (ionic compounds like sodium chloride), and metals (like iron and copper), which can all significantly affect water quality. These substances contribute to factors such as salinity and conductivity, which are essential in assessing water quality and suitability for various uses.

Consequently, the option regarding organic compounds is the one that does not fit the definition of TDS, as they represent a separate category of water quality constituents that are often analyzed differently than inorganic dissolved solids.