Levulinic acid, also known as 4-oxopentanoic acid or γ-ketovaleric acid, is the simplest and most important γ-oxocarboxylic acid with the formula C₅H₈O₃. It is a white crystalline solid that is soluble in water and polar organic solvents.

Pyruvic acid, also known as 2-oxopropanoic acid, pyroracemic acid, or α-ketopropionic acid, is an important α-oxocarboxylic acid with the formula C₃H₄O₃. It is a colorless liquid with an odor similar to that of acetic acid that plays an important role in energy metabolism in living organisms.

Succinic acid, also known as butanedioic acid, is a dicarboxylic acid with the chemical formula C₄H₆O₄. It is a colorless crystalline solid that is found in amber, in numerous plants (e.g., algae, lichens, rhubarb, and tomatoes), and in many lignites.

Fumaric acid, also known as trans-butenedioic acid, is a dicarboxylic acid with the formula C₄H₄O₄. It is widely found in nature and appears as a white, crystalline solid with a fruit-like taste.

Maleic acid, also known as cis-butenedioic acid, is a dicarboxylic acid with the formula C₄H₄O₄. It appears as a colorless, crystalline solid with a faint odor.

Ethylenediaminetetraacetic acid, better known as EDTA, is an aminopolycarboxylic acid with the formula C₁₀H₁₆N₂O₈. It is a white solid that is insoluble in water and is one of the most commonly used chelating agents in diverse industries.

Thioglycolic acid, also known as mercaptoacetic acid, is the simplest and industrially most important mercaptocarboxylic acid with the formula HSCH₂COOH. It is a colorless liquid with a strong, unpleasant odor.

Gluconic acid, also known as 1,2,3,4,5-pentahydroxy pentane-1-carboxylic acid, is an organic acid with the formula C₆H₁₂O₇. It is a white, odorless, crystalline powder that is naturally found in humans and other organisms and also in food products such as wine and honey.

Nitrilotriacetic acid, also known as NTA or N,N-bis(carboxymethyl)glycine, is a tricarboxylic acid with the formula C₆H₉NO₆. It is a colorless solid that belongs to the family of aminopolycarboxylic acids and is one of the most important chelating agents, along with EDTA.