Lighten Caseloads with Real-Time MS Analysis Technique

Forensic laboratories frequently struggle with a growing caseload of samples that require fast and accurate analysis. Whether from criminal cases or environmental disasters, the evidence collected is often complex and contaminated with substances. Additionally, tight budgets and growing backlogs present a challenge to getting work done in an economical fashion.

Forensic drug chemistry analysis is the testing of suspected controlled substances or seized drugs to determine their composition. Typically, a suspected controlled substance should undergo at least two tests. The first is a presumptive or screening test, which indicates if the sample could be a controlled substance. However, such tests sometimes produce false positives, so substance-specific confirmatory tests are always performed to positively identify the substance.

The need for fast analysis to identify compounds in a variety of samples has been increasing over time, especially for seized drugs. Positive identification of drugs and other chemicals in bulk samples is critical during screening in crime laboratories. Presumptive or screening tests include color tests or physical examination. Conventional drug analysis often requires sample preparation that includes dissolution, dilution, and several reagent-based assays to classify the type of drugs, followed by confirmatory tests like gas chromatography/mass spectrometry (GC/MS) or liquid chromatography/mass spectrometry (LC/MS) analysis.

The Agilent QuickProbe is a real-time MS analysis technique that enables you to presumptively screen and confidently identify compounds with little or no sample preparation in under a minute. The easy-to-use probe, combined with an Agilent GC/MS system, provides fast data analysis with automated library identification. The result: near instantaneous determination of sample composition at a fraction of the cost. For overloaded forensic laboratories, QuickProbe is the perfect solution to quickly determine the composition (including the presence of controlled substances) of tablets, powders, and liquids.

Separation in under a minute followed by EI library identification

The QuickProbe technique is based on a vaporization inlet that is open to ambient air while having helium purged-flow protection to eliminate air leakage into the QuickProbe and MS ion source. QuickProbe includes Agilent’s innovative sample introduction technology and provides rapid heating with the inlet followed by a short separation column. It interfaces on top of your standard Agilent GC/MS to obtain in-vacuum electron ionization, followed by quadrupole-based mass analysis. QuickProbe analysis can be run without changes to the existing GC column, in under a minute. After components in the mixture are separated by QuickProbe and identified by MS detection, QuickProbe allows for fast data analysis, using an EI library such as NIST or Wiley to identify names and structures, even at the isomer level.

Demonstration of a fast analysis workflow for forensic applications

The figure below demonstrates a sub-minute screening analysis (without sample preparation) of various forensic case samples, including a cannabis edible, black tar heroin, and “magic” mushroom. Comparison spectra (head-to-tail) are shown for the main target compounds in each sample. The analyses were performed rapidly with the positive identification of drug components by NIST library match and known origin.

Find more details on how QuickProbe can lighten caseloads in forensic laboratories by visiting the QuickProbe GC/MS system product page.

For Forensic Use.

Note: This is a sponsored section of Evidence Technology Magazine.


Item of Interest

The language barrier between English-speaking investigators and Spanish-speaking witnesses is a growing problem. (Updated 28 February 2011)