20-HETE-d6 is intended for use as an internal standard for the quantification of 20-HETE by GC- or LC-MS. 20-HETE is a cytochrome P450 (CYP450) metabolite postulated to play an autacoid role in the renal and cerebral vasculature.¹ In rat cerebral microvessels, 20-HETE is a vasoconstrictor that mediates pressure-induced autoregulatory vasoconstriction.² 20-HETE is excreted mainly as the glucuronide conjugate. The concentration of free 20-HETE (20-40 pg/ml in human urine) is about 10-fold lower than the corresponding concentration of the 20-glucuronide.³ 20-HETE-d6 MaxSpec® standard is a quantitative grade standard of 20-HETE-d6 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 20-HETE-d6 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.