Evidence map›Paper›PMID 41779284›Full record

ArticleForensic toxicology2026

High-throughput measurement for micro-segmental hair analysis using parallel column regeneration in liquid chromatography/tandem mass spectrometry.

Kenji Kuwayama, Hajime Miyaguchi, Tatsuyuki Kanamori, Kenji Tsujikawa, Tadashi Yamamuro, Yuki Okada, Yuko T Iwata

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Article in Forensic toxicology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

Authors and funding

7 authors.

Kenji KuwayamaNational Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882, Chiba, Japan. kuwayama@nrips.go.jp.ORCID 0000-0002-0782-8842
Hajime MiyaguchiNational Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882, Chiba, Japan.
Tatsuyuki KanamoriNational Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882, Chiba, Japan.
Kenji TsujikawaNational Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882, Chiba, Japan.
Tadashi YamamuroNational Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882, Chiba, Japan.
Yuki OkadaNational Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882, Chiba, Japan.
Yuko T IwataNational Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, 277-0882, Chiba, Japan.

Funding

JSPS KAKENHI 24K13565
6 · The paper itself

Abstract

purposeWe previously developed micro-segmental analysis (MSA), which measured detailed distributions of drugs in hair by segmenting a single hair strand at a 0.4-mm interval. MSA is effective in estimating the day of ingestion of hypnotics in drug-facilitated crimes. However, the disadvantage is that it needs considerable time to provide analytical results because hundreds of segments are analyzed using liquid chromatography (LC)-tandem mass spectrometry. In this study, the LC conditions were modified to improve the throughput of measurements.

methodsInstrumental parts and parameters for LC were optimized to shorten the cycle time while maintaining separation between etizolam and triazolam, which have relatively similar retention times and the same nominal mass. Additionally, parallel column regeneration (PCR) available in two-dimensional LC system, which can switch channels through two identical columns, was used.

resultsThe cycle time was reduced from 429 s to 235 s by changing the sample needle volume (from 15 to 30 µL), column length (from 150 to 50 mm) and injection volume (from 50 to 30 µL), and steepening the mobile phase gradient. Moreover, the use of PCR reduced the cycle time to 194 s by paralleling sample measurements with washing and equilibration of the lines. The effectiveness of the LC method modified using PCR was confirmed by the MSA of a long hair (978 segments) collected from a participant who had ingested hypnotics.

conclusionsThis high-throughput measurement greatly contributed to saving machine time and early providing evidence of drug-facilitated crimes, showing detailed distributions of drugs in hair.

Indexed as

HairHypnotics and SedativesLiquid Chromatography-Mass SpectrometrySubstance Abuse DetectionTandem Mass SpectrometryChromatography, LiquidForensic ToxicologyHigh-Throughput Screening AssaysHumansTriazolamHypnotics and SedativesTriazolamHairHigh-throughput measurementHypnoticMicro-segmental analysisParallel column regeneration

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.