CA-12 is a new carboxylic extraction agent for rare earths. Its acidic property is higher than naphthenic acid. It is used for extracting Yttrium and the Lanthanide and for the separation of heavy Rare earth and light to medium-weight Rare earth. It is also used for extracting Lanthanum from light Rare earth elements.

Chemical Name: Secondary-octyl phenoxy acetic acid

Constitutional Formula :S－C₈H₁₇C₆H₄OCH₂COOH

Empirical Formula:C₁₆H₂₄O₃

Molecular Weight:264.35

Appearance: brownish yellow viscous liquid

Content %:85

Specific Weight: （）1.028

Refractive Index:  ()1.5041