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Infrared attenuated total reflection (IR‐ATR) spectroscopy for detecting drugs in human saliva
Author(s) -
Hans Kerstin M.C.,
Müller Susanne,
Sigrist Markus W.
Publication year - 2012
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.346
Subject(s) - saliva , drug detection , attenuated total reflection , chemistry , spectroscopy , infrared spectroscopy , drug , chromatography , analytical chemistry (journal) , pharmacology , medicine , biochemistry , organic chemistry , physics , quantum mechanics
The consumption of drugs is of great concern worldwide. Various drug tests for humans have been developed but there is no compact and easy‐to‐use test device available yet for direct semi‐quantitative drug testing in the field. We suggest using attenuated total reflection (ATR) infrared spectroscopy as a sensing method to analyze human saliva samples with respect to drugs. In this paper, we present ATR spectra in the infrared range between 2300 and 900 cm −1 as a first step towards such a device. We emphasize the common drug cocaine and its metabolites and investigate the problems of spectral interferences of selected diluents, masking agents, common medication, and soft drinks. Furthermore, spectra of saliva samples are recorded and a time‐dependent change of the spectral signatures after alcohol consumption is presented. To the best of our knowledge, it is the first time that not only spectra of the drug of interest (cocaine) dissolved in water and in saliva but also spectra of interfering compounds possibly present in the saliva sample of a tested subject are discussed. This paper presents the most appropriate spectral range for strong cocaine absorption (including its metabolites) and minimum interference by the investigated substances. This spectral window is found to be between 1800 and 1710 cm −1 . In addition, we demonstrate the feasibility to identify cocaine in saliva at a concentration of 0.020 mg/ml with IR‐ATR‐spectroscopy without any separation or extraction procedures. For example, this technique could also be applied for drug detection in waste water. Copyright © 2011 John Wiley & Sons, Ltd.