이원재 (서울대학교)

조주연 (서울대학교)

이원재 (서울대학교)

채우리 (서울대학교)

조주연 (서울대학교)

This study aimed to establish and validate a reliable LC-MS/MS-based method for the

simultaneous quantification of 1-methylnicotinamide (1-MNA) and nicotinamide (NA), in

human plasma. These two metabolites were selected as biomarker candidates for predicting of

biologic response in patients with severe asthma.

Validation parameters included accuracy, precision, matrix effect, parallelism, and carry-over.

Accuracy and precision met the ±15% acceptance criteria across low, medium, and high QC

levels. Matrix effect was evaluated using charcoal-stripped plasma as a surrogate matrix, and

values were within the acceptable range (0.8 to 1.2), as confirmed by internal standard

normalization. Parallelism was demonstrated by consistent dilution linearity between plasma

samples and calibration standards, with recovery rates of 99.79%, 103.57%, and 102.07% for 1-

MNA, and 90.48%, 101.74%, and 100.78% for NA at low, medium, and high concentrations,

respectively. In addition, carry-over was negligible, with no detectable signal in blank samples

after high-concentration injections.

This validated analytical method enables reliable quantification of 1-MNA and NA in plasma

and may support future biomarker discovery and clinical applications in asthma and other

inflammatory diseases.