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Journal of Systems Biology & Proteome Research
|
Volume 2
J u n e 2 5 - 2 7 , 2 0 1 8 | D u b l i n , I r e l a n d
MASS SPECTROMETRY
AND PROTEOMICS
International Conference on
Rastislav Monošík, J Syst Biol Proteome Res 2018, Volume 2
DRIED URINE SWABS AS A TOOL
FOR MONITORING METABOLITE
EXCRETION BY UPLC–MSMS
Rastislav Monošík
University of Copenhagen, Denmark
W
e tested a large set (n=181) of dried urine samples spotted on regular
cosmetic cotton swabs for quantitative UPLC–MSMS analysis of
various metabolites. The agreement of measurements between conventional
24h urines and dried urine spots made from them in situ was evaluated by
Passing–Bablok regression and Bland–Altman analysis after creatinine
correction. There was full agreement in qualitative results making dried urine
spots a simple method for urine sample collection, suitable for metabolomics
profiling and for screening of compliance in clinical trials. The dried urine
samples were stable for at least 9 months. This allows samples to be stored
at room temperature and analysed later, thereby making logistics much easier
in human studies. Quantitative analysis exposed certain limitations of dried
urine spots. Results were underestimated in the range from 11–23% in case
of tartaric acid, indoxyl sulfate, pyroglutamyl proline and DHEAS. However,
full agreement was found in case of the alcohol intake related metabolites,
ethyl sulfate and ethyl glucuronide. Partial overestimation ranging from
10–20% was observed in case of cresol sulfate. As a secondary objective,
we examined variance of individual total daily creatinine excretion, which
was found to be maximally 16%. This finding suggests that the individual
creatinine correction factor calculated as an average individual value factor
could be used in long–term clinical trials for correction of measurements in
dried urine spots, provided that muscle mass is unchanged and the level of
analytical offset is acceptable for the research purpose.
Rastislav Monošík has been a post–doc at the
University of Copenhagen since 2015. He re-
ceived his master’s degree in food engineering
and PhD in food biosensors from Slovak Uni-
versity of Technology. He was awarded FAPESP
fellowship in 2013 to work at the University of
São Paulo on microfluidic devices. His current
focus as Marie–Curie fellow is on developing an
objective tool for assessment of recent dietary
intakes using multiplex UPLC–MSMS analysis
of validated food intake biomarkers and improv-
ing the tool by a novel sampling technique (dried
urine spots) and addition of promising food bio-
markers following their validation.
ram@nexs.ku.dkBIOGRAPHY