With the lack of standardized validation protocols across the forensic chemistry community, validation of instrumentation can be a challenging and time-consuming task. However, this process is crucial to understand the associated capabilities and limitations, especially for nascent technologies. Rapid GC-MS is one such emerging analytical technique being increasingly implemented in forensic laboratories due to its fast and informative screening capabilities. However, a full validation for forensic samples has yet to be published since its debut. This work presents the results of a comprehensive validation of an in-house rapid GC-MS system for seized drug and ignitable liquid analyses through the assessment of nine components: selectivity, matrix effects, precision, accuracy, range, carryover/contamination, robustness, ruggedness, and stability. Single- and/or multi-compound test solutions of commonly encountered seized drug or ignitable liquid compounds were used for each study to assess method and system performance. Results met the designated acceptance criteria for a majority of components. For example, retention time and mass spectral search score % RSDs were ≤ 10 % for precision and robustness studies. Limitations were identified for components that did not meet the acceptance criteria (e.g., inability for isomer differentiation). The study designs are part of a larger validation package developed for rapid GC-MS that includes validation plans and automated workbooks for each forensic application. The template, available for adoption by laboratories as needed, ultimately aims to reduce the barrier of implementation for rapid GC-MS technology.
Use of immunoassay test strips for the detection of fentanyl in drug samples has become increasingly commonplace in harm reduction, law enforcement, public health, customs, and forensic science settings. With the increase of xylazine in the drug supply in recent years, use of xylazine test strips has also begun to take root. As adoption and implementation of this tool continues, a desire to implement test strips for other drugs may emerge. However, since these strips are designed for urine testing, it is important to understand their applicability to testing drugs themselves. In this work, we investigate the utility of seven types of urine immunoassay test strips – amphetamine, benzodiazepine, cocaine, methamphetamine, nitazene, opiate, and xylazine – for drug checking applications. Reproducibility, sensitivity, cross-reactivity, and the effect of prolonged exposure to elevated temperatures were studied. Generally, the tests were found to be reproducible, able to detect trace (µg/mL) levels of the analyte of interest, and minimally affected by prolonged storage at elevated temperatures. Nearly all tests showed cross-reactivity with compounds other than the analyte of interest, highlighting the need to better understand these limitations prior to implementation in a drug checking scenario (that may involve additional chemical analysis on or off site). The viability of expired cocaine, fentanyl, and methamphetamine and test strips was also interrogated, and little to no change in sensitivity was found even though the tests were multiple years expired.
Analysis of ignitable liquids in fire debris samples can be a time-consuming process, from extraction of volatile compounds to instrumental analysis. Rapid gas chromatography-mass spectrometry (GC-MS) is a screening technique that can be utilized prior to confirmatory GC-MS analysis to provide an informative screening approach and possibly reduce the need to further analyze negative samples. Though rapid GC-MS is fast (less than two minutes), extraction techniques such as passive headspace extraction remain a bottleneck for decreasing overall workflow times. In this work, solid phase microextraction (SPME) was implemented with rapid GC-MS for ignitable liquid analysis for a faster, more sensitive screening approach compared to extraction with passive headspace. Using optimized inlet conditions, limits of detection as low as 27 ng/mL per compound were achieved. Gasoline and diesel fuel were extracted and analyzed, and major compounds in each liquid were identified in the resulting chromatograms. Extracted ion profiles (EIPs) and deconvolution methods were useful for additional compound identifications. Lastly, the SPME-rapid GC-MS workflow was extended to the analysis of gasoline and diesel fuel in mock burn samples using carpet and wood substrates. From SPME sample extraction to rapid GC-MS instrumental analysis and data processing, the total workflow for a single sample was reduced to under 20 min. These results indicate that SPME is a suitable injection technique for rapid GC-MS to provide a fast and sensitive screening approach for fire debris applications.
Remediation of clandestine laboratory and processing operations for fentanyl and its analogs (i.e., fentalogs) may involve application of oxidants, most commonly household hypochlorite bleach, to chemically degrade the fentanyl to enable disposition of the site. While the chemical degradation of fentanyl has been reported, the degradation of immediate precursors has not been. Chemical degradation of fentanyl and fentalogs can cause these immediate precursors to reform. The immediate precursors of fentanyl investigated here are norfentanyl and 4-ANNP, which are controlled substances, along with norcarfentanil, precursor for carfentanil and remifentanil. The 4-ANNP was degraded within minutes in chlorine bleach, somewhat faster than fentanyl itself, whereas norfentanyl and norcarfentanil showed apparent degradation half lives up to days. Also, degradation rates were reduced in the presence of common diluents, like cutting agents, with apparent half-lives of several weeks for fully dissolved solutions. When the fentalog was added as a powder, globules were observed which could indefinitely prevent contact between the chlorine and the contents of the globules, prolonging persistence unless the globules are mechanically or otherwise broken. Because of shared structural characteristics among fentalogs, such as presence of reactive nitrogen groups, the results of this study may be applicable to a wide array of fentalogs. This study may also help inform remediation and waste management strategies to provide not only effective remediation of contamination, but also reduce the possibility that wastes of controlled substances are handled inappropriately, e.g., leading to continued personnel exposure and/or reprocessing of controlled substances.
An LC-MS/MS method for the analysis of 53 benzodiazepines, including various designer benzodiazepines, was developed. The developed method was applied to a total of 79 illicit street drug samples collected in Chicago, IL. Of these samples, 68 (84%) had detectable amounts of at least one benzodiazepine. Further, of the 53 benzodiazepines included in the developed method just 14 were measured in samples. Clonazolam, a potent designer benzodiazepine and derivative of clonazepam, was the most frequently measured benzodiazepine in 63% of samples and was measured in the highest concentrations. Other benzodiazepines measured in more than 10% of samples included clonazepam, alprazolam, flualprazolam, and oxazepam. Mixtures of benzodiazepines were frequently measured in samples, with just 24% of samples containing just one benzodiazepine. To determine the response of benzodiazepines on a rapid, point-of-use drug checking tool, all 53 benzodiazepine standards were screened on a lateral flow immunoassay benzodiazepine test strip. Sixty eight percent of standards gave a positive BTS response at a concentration of 20 μg/mL, demonstrating BTS have response to a wide variety of benzodiazepines, including many designer benzodiazepines. A comparison of this data to previous data reported for the same samples demonstrated all samples containing a benzodiazepine also had an opioid present, with fentanyl being present in 94% of benzodiazepine samples. These results highlight high rates of polysubstance drug presence in Chicago, IL illicit drug samples, posing an increased risk of drug overdoses in people who use drugs.
