Thromboxane B2 (TXB2) is a stable, biologically inert metabolite formed from the non-enzymatic hydrolysis of TXA2, which has a half-life of about 30 seconds. Urinary analysis of TXB2 accurately reflects intrarenal TXA2 synthesis, while measurement of 11-dehydro and 2,3-dinor TX metabolites gives the best estimate of systemic TXA2 secretion. TXB2 MaxSpec(R) standard is a quantitative grade standard of TXB2 (Cay-19030) that has been prepared specifically for mass spectrometry or any application 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 TXB2 MaxSpec(R) 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.