Evidence map›Paper›PMID 41989682›Full record

ArticleForensic toxicology2026

Rapid semi-quantitative estimation of cocaine purity by infrared absorption spectroscopy and Raman spectroscopy combined with multivariate analysis.

Hiroki Segawa, Kenji Tsujikawa, Tadashi Yamamuro, Tatsuyuki Kanamori, Yuko T Iwata

Abstract read
PubMed Publisher
In one paragraph

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.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Hiroki SegawaCollege of Engineering, Shibaura Institute of Technology, 3-7-5, Toyosu, Koto-ku, Tokyo, 135-8548, Japan. segawa@sic.shibaura-it.ac.jp.ORCID 0000-0001-7626-3331
Kenji TsujikawaNational Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan.
Tadashi YamamuroNational Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan.
Tatsuyuki KanamoriNational Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan.
Yuko T IwataNational Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeCocaine is one of the most widely abused drugs, and the analysis of seizures including drug profiling is a critical task for forensic practitioners. Street cocaine samples frequently contain additives, and they could hinder conventional drug analysis. In this study, a multivariate analysis method was made to rapidly estimate the composition and quantity of cocaine and its additives using Fourier transformation-infrared absorption (IR) spectroscopy and Raman spectroscopy.

methodsIR and Raman spectra of standard cocaine samples and 21 additive samples were acquired. Training dataset was synthetically constructed by making linear combinations of the standard spectra with randomly generated weight and noises. Four different models of non-negative least square regression (NNLS), non-negative matrix factorization (NMF), non-negative elastic net (Enet) and multilayer perceptron (MLP), were constructed. The constructed models were applied to street samples whose components were previously characterized by conventional methods.

resultsThough all four methods gave good root-mean-square errors on the training dataset, application to street samples gave different results. NNLS provided the sparsest and the most appropriate results. MLP also provided similar level prediction capability. NMF could not retrieve the original standard spectra. Enet could not give sparse results and application to the street samples showed large fitting residuals. Based on these results, a decision procedure to predict the contents of cocaine seizure was constructed by the combination of NNLS and MLP.

conclusionVibrational spectroscopy combined with multivariate analysis demonstrated significant potential for the rapid, semi-quantitative prediction of cocaine seizures with the information on diluents/adulterants.

Indexed as

CocaineDrug ContaminationIllicit DrugsNarcoticsSpectrum Analysis, RamanLeast-Squares AnalysisMultilayer PerceptronsMultivariate AnalysisSpectroscopy, Fourier Transform InfraredCocaineIllicit DrugsNarcoticsAdulterantsChemometricsCocaineDiluentsInfrared absorption spectroscopyRaman spectroscopy

Identifiers

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.