Validation of a Sensitive, Simple and High-Throughput UPLC-MS/MS Method for Quantification of Catecholamines and...

A sensitive, simple and high-throughput UPLC-MS/MS method has been validated for the simultaneous quantification of catecholamines and their metabolite levels in serum and urine for clinical applications. The analytes and their isotope-labeled internal standards were extracted using a 96-well solid-phase extraction cartridge and then separated on an HSS PFP column with a 4-min gradient elution. The linear ranges were 10 ~ 5000 pg/mL for dopamine (DA), epinephrine (E), metanephrine (MN) and normetanephrine (NMN), 2 ~ 5000 pg/mL for norepinephrine (NE), and 2 ~ 2000 pg/mL for 3-methoxytyramine (3-MT). The limits of quantification were 10 pg/mL for DA and E, 5 pg/mL for MN and NMN, 2 pg/mL for 3-MT, and 20 pg/mL for NE. The accuracy was excellent with relative bias all within 10%, and the intra-day and inter-day precision values were also within the tolerance range (RSD < 15%), and the recovery was in the range of 86.0-107.7% with RSD < 15%. After correction using IS, no significant matrix effects were observed. Moreover, the discrepancies in the analyte levels between plasma and serum were investigated for the first time. The analyte levels in the two biological matrices exhibited a significant correlation (P < 0.001) and significant differences (P < 0.001).