9(S)-HODE-d4 is intended for use as an internal standard for the quantification of 9-HODE by GC- or LC-MS. (±)-9-HODE is formed via non-enzymatic oxidation of linoleic acid .¹ 9(S)-HODE and 9(R)-HODE are formed by lipoxygenase- and cyclooxygenase-mediated oxidation of linoleic acid, respectively.^2,3,4 9(S)-HODE-d4 MaxSpec® standard is a quantitative grade standard of 9(S)-HODE-d4 that has been prepared specifically for mass spectrometry and related applications where quantitative reproducibility is required. The solution has been prepared gravimetrically and is supplied in a deactivated glass ampule sealed under argon. The concentration was verified by comparison to an independently prepared calibration standard. This 9(S)-HODE-d4 MaxSpec® standard is guaranteed to meet identity, purity, stability, and concentration specifications and is provided with a batch-specific certificate of analysis. Ongoing stability testing is performed to ensure the concentration remains accurate throughout the shelf life of the product. Note: The amount of solution added to the vial is in excess of the listed amount. Therefore, it is necessary to accurately measure volumes for preparation of calibration standards. Follow recommended storage and handling conditions to maintain product quality.