Optimization and validation of a chiral GC-MS method for the determination of free D-amino acids ratio in human urine: application to a gestational diabetes mellitus study

A dried urine spot method for measuring 14 amino acids was validated using filter paper and mass spectrometry, offering a stable alternative to liquid urine that supports patient self-collection and remote analysis.

Dried urine spot (DUS) applied for sampling prior to the accurate HILIC-MS/MS determination of 14 amino acids — Meikopoulos et al., Talanta (paywalled) · source ↗

• dct
• metabolome
• dried
• urine
• validation
• biomarkers

Adding polyethylene glycol to first-void urine before centrifugation markedly improved cell-free DNA recovery in the pellet, whereas low-speed centrifugation alone removed cellular DNA while keeping cell-free DNA in the supernatant. Pseudovirions pelleted reliably under all conditions, but the study revealed substantial variation between self-collected samples, highlighting the need for standardised protocols in decentralised HPV screening programmes.

Concentration strategies for spiked and naturally present biomarkers in non-invasively collected first-void urine — Téblick et al., European journal of medical research · source ↗

• first-void
• hpv
• liquid-biopsy
• liquid
• urine
• validation
• biomarkers

In adults given EPA or DHA for 12 weeks, first-void urine analysed by MSI-CE-MS showed increased S-carboxypropylcysteamine and other candidate metabolites that correlated with the Omega-3 Index measured in erythrocytes, suggesting urine could support non-invasive monitoring of omega-3 status.

Urinary Metabolite Profiling to Non-Invasively Monitor the Omega-3 Index: An Exploratory Secondary Analysis of a Randomized Clinical Trial in Young Adults — MacIntyre et al., Metabolites · source ↗

• urine
• first-void
• metabolome
• biomarkers

In fifteen men consuming a controlled salt intake, second-void urine provided more reliable estimates of 24-hour urinary sodium excretion than first-void urine, with the sodium-to-potassium ratio in first-day second-void samples showing significant correlation with measured 24-hour output. This suggests spot second-void sampling could replace cumbersome 24-hour collections for sodium intake assessment in decentralised nutrition monitoring.

Development of objective indicators for quantitative analysis of sodium intake: the sodium to potassium ratio of second-void urine is correlated with 24-hour urinary sodium excretion — Kim et al., Nutrition research and practice · source ↗

• first-void
• urine
• validation
• biomarkers

The review concludes that first-void urine is a feasible source for molecular biomarkers, such as host and viral gene methylation, to triage high-risk HPV infections, offering a non-invasive and preferred method for women that may improve screening adherence.

First-void urine: A potential biomarker source for triage of high-risk human papillomavirus infected women — Van Keer et al., European journal of obstetrics, gynecology, and reproductive biology (paywalled) · source ↗

• urine
• first-void
• self-collection
• validation
• hpv
• biomarkers
• liquid-biopsy