Analyze illicit drugs on the street with the portable Agilent Forensics Analyzer
By Alan Rein and Shannon Richard Agilent Spectroscopy Specialists
Fourier transform infrared spectroscopy (FTIR) is a proven and powerful technology for the analysis of illegal substances and potentially hazardous compounds. The Agilent 4500a Forensics Analyzer uses FTIR to address the ever-growing need for portability, flexibility, and ease-of-use within the forensics community. While using the 4500a analyzer in the field, you can count on the rapid measurement of the molecular fingerprint of a substance and compare it with libraries of known compounds. Identity of unknown liquids or solids can also be determined in less than one minute. Little or no sample preparation is required, making identification of unknowns rapid and easy.
Onsite analysis by portable FTIR systems is particularly valuable since it can be used to establish probable cause, allowing for the seizure of materials for further analysis. It can also reduce the audit trail and shorten the evidence chain, minimizing the risk of a compromised investigation.
In this example, we used the Agilent 4500a Forensics Analyzer to analyze some common illicit street drugs.
Figure 1. After acquiring the unknown spectrum, a preloaded method automatically searched the on-board forensic library and displayed the identity of the unknown and quality of the match, as well as the spectrum of the material, on the PDA.
Figure 2. Spectrum of an unknown matched to a cocaine base spectrum using Agilent MicroLab FTIR Software for additional analyses of spectra. The identity of the substance, its spectrum and the spectrum of the best match from the on-board library are displayed, along with the numerical quality of the match.
Fast evidence gathering
We used solid samples (5 mg) of cocaine hydrochloride, cocaine base, diacetylmorphine, morphine hydrochloride, and ketamine. Samples were placed on the diamond attenuated total reflectance spectroscopy (ATR) sample interface, to simplify analysis and protect the sensor from damage. The ATR solids press was used to ensure proper contact between the sample and the diamond ATR sensor. After measurement, we wiped the sensor with a small amount of acetone to remove any remaining traces before conducting the next test. Spectra were collected at a resolution of 4 cm-1 with a total measurement time of less than a minute. The search algorithm was a simple similarity-index measurement for ease of matching. All data collected were date- and time-logged automatically.
The five spectra of the illegal drugs were searched against the reference compounds in the Agilent Forensic Library, which contains over 13,000 spectra. This spectrum matching made use of Agilent MicroLab FTIR Software with a handheld computer, and yielded excellent identifying matches (Figure 1).
Figure 2 shows the results of a subsequent analysis using the Agilent MicroLab FTIR Software on a laptop computer. In this case, the fully automated search function displays the spectrum of the unknown sample, the spectrum of the best library match, the identity of the unknown, and a quantitative measurement of the quality of the match. Full details of this analysis are available in Agilent Application Note 5991-3068EN.
On the street and on-the-spot
Agilent’s 4500a Forensics Analyzer is a portable, battery powered infrared spectrometer that delivers accurate, cost effective identification of illicit drugs. This portability enables actionable decisions to be made on-the-spot when gathering evidence, helping to reduce the likelihood of a compromised investigation. For a comprehensive introduction to the capabilities of the Agilent 4500a Forensics Analyzer, listen to the free webinar featured in the on-line May issue of Forensics Magazine.
After acquiring the unknown spectrum, a preloaded method automatically searched the on-board forensic library and displayed the identity of the unknown and quality of the match, as well as the spectrum of the material, on the PDA.
Spectrum of an unknown matched to a cocaine base spectrum using Agilent MicroLab FTIR Software for additional analyses of spectra. The identity of the substance, its spectrum and the spectrum of the best match from the on-board library are displayed, along witplayed, along wituality of the match.