Quantification of Captopril in Urine Through Surface-Assisted Laser Desorption/Ionization Mass Spectrometry Using 4-Mercaptobenzoic Acid-Capped Gold Nanoparticles as an Internal Standard

We have developed a new internal standard method for the determination of the concentration of captopril (CAP) through surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using gold nanoparticles (Au NPs). This approach provided linearity for CAP over the concentration range 2.5–25 μM (R2 = 0.987), with a limit of detection (signal-to-noise ratio = 3) of 1.0 μM. The spot-to-spot variations in the concentration of CAP through SALDI-MS analyses performed in the absence and presence of the internal standard were 26% and 9%, respectively (15 measurements). This approach provides simplicity, accuracy, precision, and great reproducibility to the determination of the levels of CAP in human urine samples.

Graphical AbstractAccurate quantification of CAP in urine through SALDI-MS analysis using MBA-Au NPs as an internal standard.Figure optionsDownload full-size imageDownload high-quality image (115 K)Download as PowerPoint slide