Analytical and Bioanalytical Chemistry

, Volume 411, Issue 10, pp 2141–2148 | Cite as

Stabilization of formaldehyde into polydimethylsiloxane composite: application to the in situ determination of illicit drugs

  • Neus Jornet-MartínezEmail author
  • Rosa Herráez-Hernández
  • Pilar Campíns-Falcó
Research Paper


The Marquis test is the most frequently used spot color assay for the screening of unknown drugs such as amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-metilenedioxymethamphetamine, and morphine. However, this test involves the use of the toxic reagent formaldehyde, as well as the manipulation of concentrated sulfuric acid. Here, we report a new format of this test that improves the sustainability and safety for the operator by immobilizing formaldehyde into a polydimetylsiloxane composite. In contact with a solution (or suspension) of the suspected sample in sulfuric acid, the dispositive delivers formaldehyde and the reaction takes place in a few seconds. Under the proposed conditions, only small amounts of the drug (μg) are necessary to produce intense changes of color. In addition, the percentage of the drug in the sample can be established by obtaining pictures of the test vials and subsequent analysis of the digitalized images. The responses were linear for amphetamine-like drugs up to a concentration of 100 mg L−1, and the precision achieved was adequate (relative standard deviations, RSDs < 10%). The developed composites were tested for the determination of MDMA in several drug street samples, and a good correlation with the results obtained by a reference method based on liquid chromatography was found. The main advantages of the proposed approach over the traditional Marquis test format are better portability and safety for the operator at a lower cost and the possibility of using it for quantitative analysis.


Polydimethylsiloxane Digital images colorimetry Harm reduction Drug street samples In situ analysis 


Funding information

The authors are grateful to EU FEDER and the Spanish AEI (CTQ2017-90082-P) and the Generalitat Valenciana (PROMETEO 2016/109) for the financial support received. N. J.-M. expresses her gratitude to the European Commission through the LIFE programme (LIFE-LIBERNITRATE 16 ENV/ES/000419) for her funding.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


  1. 1.
    United Nations Office on Drug and Crime (UNODC). World Drug Report. Viena: UNODC; 2017.Google Scholar
  2. 2.
    Harper L, Powell J, Pijl EM. An overview of forensic drug testing methods and their suitability for harm reduction point-of-care services. Harm Reduct J. 2017;14:52–65.CrossRefGoogle Scholar
  3. 3.
    Capitán-Vallvey LF, López-Ruiz N, Martínez-Olmos A, Erenas MM, Palma AJ. Recent developments in computer vision-based analytical chemistry: a tutorial review. Anal Chim Acta. 2015;899:23–56.CrossRefGoogle Scholar
  4. 4.
    Choodum A, Daeid NN. Rapid and semi-quantitative presumptive test for opiates drug. Talanta. 2011;86:284–92.CrossRefGoogle Scholar
  5. 5.
    Choodum A, Daeid NN. Digital image-based colourimetric tests for amphetamine and methylamphetamine. Drug Test Anal. 2011;3:277–82.CrossRefGoogle Scholar
  6. 6.
    Musile G, Wang L, Bottoms J, Tagliaro F, McCord B. The development of paper microfluidic devices for presumptive drug detection. Anal Methods. 2015;7:8025–33.CrossRefGoogle Scholar
  7. 7.
    Velapoldi RA, Wicks SA. The use of chemical spot tests kits for the presumptive identification of narcotics and drugs of abuse. J Forensic Sci. 1974;19:636–56.CrossRefGoogle Scholar
  8. 8.
    O’Neal CK, Crouch DJ, Fatah AA. Validation of twelve chemical spot tests for the detection of drugs of abuse. Forensic Sci Int. 2000;109:189–201.CrossRefGoogle Scholar
  9. 9.
    Choodum A, Kanatharana P, Wongniramaikul W, NicDaeid N. A sol–gel colorimetric sensor for methamphetamine detection. Sens Actuators B Chem. 2015;215:553–60.CrossRefGoogle Scholar
  10. 10.
    Argente-García A, Jornet-Martínez N, Herráez-Hernández R, Campíns-Falcó P. A solid colorimetric sensor for the analysis of amphetamine-like street samples. Anal Chim Acta. 2016;943:123–30.CrossRefGoogle Scholar
  11. 11.
    Argente-García A, Jornet-Martínez N, Herráez-Hernández R, Campíns-Falcó P. A passive solid sensor for in-situ colorimetric estimation of the presence of ketamine in illicit drug samples. Sens Actuators B Chem. 2017;253:1137–44.CrossRefGoogle Scholar
  12. 12.
    Jornet-Martínez N, Gómez-Ojea R, Tomás-Huercio O, Herráez-Hernández R, Campíns-Falcó P. Colorimetric determination of alcohols in spirit drinks using a reversible solid sensor. Food Control. 2018;94:7–16.CrossRefGoogle Scholar
  13. 13.
    Wu N, Feng L, Tan Y, Hu J. An optical reflected device using a molecular imprinted polymer film sensor. Anal Chim Acta. 2009;653:103–8.CrossRefGoogle Scholar
  14. 14.
    Okachi T, Onaka M. Formaldehyde encapsulated in zeolite: a long-lived, highly activated one-carbon electrophile to carbonyl-ene reactions. J Am Chem Soc. 2004;126:2306–7.CrossRefGoogle Scholar
  15. 15.
    Kiba N, Sun L, Yokose S, Kazue MT, Suzuki TT. Determination of nano-molar levels of formaldehyde in drinking water using flow-injection system with immobilized formaldehyde dehydrogenase after off-line solid-phase extraction. Anal Chim Acta. 1999;378:169–75.CrossRefGoogle Scholar
  16. 16.
    Herráez-Hernández R, Campíns-Falcó P, Verdú-Andrés J. Sensitive determination of methylenedioxylated amphetamines by liquid chromatography. Analyst. 2001;126:581–6.CrossRefGoogle Scholar
  17. 17.
    Technical data sheet of Sylgar 184 Dow Corning. Accessed 25 Aug 2018
  18. 18.
    Jornet-Martínez N, Moliner-Martínez Y, Herráez-Hernández H, Molins-Legua C, Verdú-Andrés J, Campíns-Falcó P. Designing solid optical sensors for in situ passive discrimination of volatile amines based on a new one-step hydrophilic PDMS preparation. Sens Actuators B Chem. 2016;223:333–42.CrossRefGoogle Scholar
  19. 19.
    United Nations International Drug Control Program. Rapid testing methods of drug of abuse: manual for the use by national law enforcement and narcotics laboratory personnel. Vienna: United Nations; 1994.Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Neus Jornet-Martínez
    • 1
    Email author
  • Rosa Herráez-Hernández
    • 1
  • Pilar Campíns-Falcó
    • 1
  1. 1.MINTOTA Research Group, Departament de Química Analítica, Facultat de QuímicaUniversitat de ValènciaBurjassotSpain

Personalised recommendations