Figure 1

Representative chromatogram of calibration standards. LLOQ standard shows peaks corresponding to [Pyr1]apelin-13 at 1 ng/ml (A) and [Pyr1]apelin-13 internal standard at 25 ng/ml (B). Upper limit of quantification shows peaks corresponding to [Pyr1]apelin-13 (C) and [Pyr1]apelin-13 internal standard at 25 ng/ml (D). MRM = multiple reaction monitoring.