A linear regression was found within 2.25e34.5 mg/mL for the standards GABA and DOP, 1.15e28.5 mg/mL for standards PUT, CAD, HIST, and 2.50e48.5 mg/mL for standards TYRA, SPD, SPM with the correlation coefficient (r2) in the range of 0.997e0.998.
A linear regression wasfound within 2.25e34.5 mg/mL for the standards GABA and DOP, 1.15e28.5 mg/mL for standards PUT, CAD,HIST, and 2.50e48.5 mg/mL for standards TYRA, SPD, SPM with the correlation coefficient (r2) in the rangeof 0.997e0.998.