Determination of fentanyl in human breath by solid-phase microextraction and gas chromatography–mass spectrometry

Detection of abused drugs in human exhaled breath using mass spectrometry: A review

RATIONALE

Human breath analysis has been attracting increasing interest in the detection of abused drugs in forensic and clinical applications because of its noninvasive sampling and distinctive molecular information. Mass spectrometry (MS)-based approaches have been proven to be powerful tools for accurately analyzing exhaled abused drugs. The major advantages of MS-based approaches include high sensitivity, high specificity, and versatile couplings with various breath sampling methods.

METHODS

Recent advances in the methodological development of MS analysis of exhaled abused drugs are discussed. Breath collection and sample pretreatment methods for MS analysis are also introduced.

RESULTS

Recent advances in technical aspects of breath sampling methods are summarized, highlighting active and passive sampling. MS methods for detecting different exhaled abused drugs are reviewed, emphasizing their features, advantages, and limitations. The future trends and challenges in MS-based breath analysis of exhaled abused drugs are also discussed.

CONCLUSIONS

The coupling of breath sampling methods with MS approaches has been proven to be a powerful tool for the detection of exhaled abused drugs, offering highly attractive results in forensic investigations. MS-based detection of exhaled abused drugs in exhaled breath is a relatively new field and is still in the early stages of methodological development. New MS technologies promise a substantial benefit for future forensic analysis.

Characterization of fentanyl HCl powder prior to and after systematic degradation

Fentanyl HCl is of particular interest in forensic cases but there is a notable gap in literature regarding its analysis. This study utilized a multi-method approach to characterize fentanyl HCl powder, both fresh and following a forced degradation process. Using sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) and direct injection gas chromatography-mass spectrometry (GC-MS), five compounds were identified in fresh fentanyl HCl powder. The identified compounds were: N-phenylpropanamide, 1-phenethyl-4-propionyloxypiperidine (1-P-4-POP), 4-anilino-N-phenethylpiperidine (4-ANPP), acetylfentanyl, and fentanyl; all identified compounds but acetylfentanyl and fentanyl decreased in quantity as the sample was degraded. Fresh headspace samples analyzed with solid phase microextraction (SPME)-GC-MS identified four compounds in common with the powder analyses: N-phenylpropanamide,1-P-4-POP, 4-ANPP, and fentanyl. Acetylfentanyl was not present in the headspace samples, although two additional compounds were: N-phenylacetamide and N-phenethyl-4-piperidinone (NPP). Where direct analysis of degraded fentanyl HCl showed decreased quantities of the identified compounds, headspace samples of the degraded fentanyl HCl resulted in higher quantities, implying that the degradation process drove those compounds to volatilize. Notably, fentanyl was identified in the headspace, implying that this could be an appropriate target for standoff detection. Finally, thermogravimetric analysis (TGA) and differential scanning calorimetry (DCS) confirmed that the forced degradation process had little permanent effect on the powder.

Rapid quantitative determination of fentanyl in human urine and serum using a gold-based immunochromatographic strip sensor

Fentanyl is a typical opioid that is used in surgical anesthesia. However, when abused, fentanyl can lead to addiction and even death. To better control the use of fentanyl, it is necessary to develop rapid and sensitive detection methods. In this study, an ultrasensitive monoclonal antibody (mAb) was prepared and used to develop an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and a colloidal gold-based immunochromatographic strip (CG-ICS) for the analysis of fentanyl in urine and serum. Under optimum conditions, the anti-fentanyl mAb belonging to the subtype of IgG2b showed a half-maximal inhibitory concentration (IC50) of 0.11 ng mL-1 and a linear range of detection of 0.020-0.50 ng mL-1. Fenanyl-spiked original urine and serum diluted eight times were used for the analysis of fentanyl by ic-ELISA and CG-ICS. IC50 from the standard curves was 0.46 ng mL-1 for urine and 2.6 ng mL-1 for serum in ic-ELISA and 1.6 ng mL-1 for urine and 6.27 ng mL-1 for serum in CG-ICS. The recovery test revealed that the ic-ELISA and CG-ICS, with a recovery rate of 87.0-108.4% and a coefficient of variation of 3.3-10.9%, were the same reliable tools as the liquid chromatography tandem mass spectrometry for fentanyl analysis in real samples.

Application of Microextraction-Based Techniques for Screening-Controlled Drugs in Forensic Context-A Review

The analysis of controlled drugs in forensic matrices, i.e., urine, blood, plasma, saliva, and hair, is one of the current hot topics in the clinical and toxicological context. The use of microextraction-based approaches has gained considerable notoriety, mainly due to the great simplicity, cost-benefit, and environmental sustainability. For this reason, the application of these innovative techniques has become more relevant than ever in programs for monitoring priority substances such as the main illicit drugs, e.g., opioids, stimulants, cannabinoids, hallucinogens, dissociative drugs, and related compounds. The present contribution aims to make a comprehensive review on the state-of-the art advantages and future trends on the application of microextraction-based techniques for screening-controlled drugs in the forensic context.

Determination of Verapamil in Exhaled Breath Condensate by Using Microextraction and Liquid Chromatography

Background:

Developing a simple analysis method for quantification of drug concentration is one of the essential issues in pharmacokinetic and therapeutic drug monitoring studies.

Objective:

A fast and reliable dispersive liquid-liquid microextraction procedure was employed for preconcentration of verapamil in exhaled breath condensate (EBC) samples and this was followed by the determination with high-performance liquid chromatography-ultraviolet detection.

Methods:

A reverse-phase high-performance liquid chromatography (RP-HPLC) combined with a dispersive liquid-liquid microextraction method (DLLME) was applied for quantification of verapamil in the EBC samples. The developed method was validated according to FDA guidelines.

Results:

Under the optimum conditions, the method provided a linear range between 0.07 and 0.8 µg.mL-1 with a coefficient of determination of 0.998. The intra- and inter-day relative standard deviation and relative error values of the method were below 15%, which indicated good precision and accuracy. The proposed method was successfully applied for the analysis of verapamil in two real samples with concentrations of 0.07 and 0.09 µg.mL-1.

Conclusion:

The established HPLC-UV-DLLME method could be applied for the analysis of verapamil in human EBC samples.

Real-time monitoring of exhaled drugs by mass spectrometry

Future individualized patient treatment will need tools to monitor the dose and effects of administrated drugs. Mass spectrometry may become the method of choice to monitor drugs in real time by analyzing exhaled breath. This review describes the monitoring of exhaled drugs in real time by mass spectrometry. The biological background as well as the relevant physical properties of exhaled drugs are delineated. The feasibility of detecting and monitoring exhaled drugs is discussed in several examples. The mass spectrometric tools that are currently available to analyze breath in real time are reviewed. The technical needs and state of the art for on-site measurements by mass spectrometry are also discussed in detail. Off-line methods, which give support and are an important source of information for real-time measurements, are also discussed. Finally, some examples of drugs that have already been successfully detected in exhaled breath, including propofol, fentanyl, methadone, nicotine, and valproic acid are presented. Real-time monitoring of exhaled drugs by mass spectrometry is a relatively new field, which is still in the early stages of development. New technologies promise substantial benefit for future patient monitoring and treatment.

Mandatory naltrexone treatment prevents relapse among opiate-dependent anesthesiologists returning to practice

OBJECTIVE

Anesthesiologists with opioid use disorders are at high risk for relapse. In 2005, the impaired professionals monitoring program of the State of Florida implemented a policy whereby anesthesiologists referred for opiate use disorders were contractually obligated to take naltrexone for 2 years. Naltrexone ingestion was witnessed and verified via random urine drugs screens or administered via intramuscular injection.

METHOD

Charts were reviewed for the 11 anesthesiologists who underwent mandated pharmacotherapy with naltrexone, and 11 anesthesiologists who began monitoring immediately before implementation of this policy.

RESULTS

Eight of 11 anesthesiologists who did not take naltrexone experienced a relapse on opiates. Only 1 of 11 anesthesiologists experienced a relapse on opiates after taking naltrexone, whereas another relapsed on an inhalant (nitrous oxide). It is noteworthy that 5 of the 11 anesthesiologists who took naltrexone had relapsed before naltrexone treatment, and 7 of the 11 anesthesiologists who did not take naltrexone experienced multiple documented relapses. Only 1 of the 11 anesthesiologists who did not take naltrexone successfully returned to the practice of anesthesiology. This individual suffered primarily from alcohol dependence, and suspected opiate abuse was never verified. Others who attempted return to anesthesiology (n = 7) suffered a relapse. In comparison, 9 of the 11 anesthesiologists who took naltrexone have returned to the practice of anesthesiology without a relapse (as verified by continued random urine and hair testing).

CONCLUSION

Mandatory naltrexone treatment may provide anesthesiologists with an additional safeguard to successfully return to work.

Intravenous fentanyl is exhaled and the concentration fluctuates with time

Previous studies have reported that fentanyl is eliminated predominantly by hepatic biotransformation, and that some is eliminated unchanged in urine and stools. No reports have described the elimination of fentanyl via the lungs. In this study, exhaled gas samples from eight anaesthetized patients undergoing cardiac surgery were analysed using solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Results confirmed that fentanyl was exhaled by patients after intravenous administration, that the concentration of exhaled fentanyl fluctuated with time and peak concentrations were reached approximately 15 - 20 min after intravenous fentanyl administration. Thus, in addition to hepatic biotrans formation and elimination via urine and faeces, fentanyl is also eliminated unchanged by the lungs. The potential risk to operating theatre personnel from long-term exposure to low levels of exhaled anaesthetic agents following intravenous administration to patients during surgery warrants further research.

Analytical methods used in conjunction with solid-phase microextraction: a review of recent bioanalytical applications

Integration of sampling and sample preparation with various analytical instruments is a highly desirable feature for any analytical method. This is most conveniently achieved by using microextraction techniques or various microdevices. Among these techniques, solid-phase microextraction (SPME) is particularly remarkable due to its simplicity and effectiveness. This review discusses the most recent applications of SPME in bioanalysis, grouped according to the analytical instrument that SPME is coupled to. It is shown that one of the most important aspects of such analytical methods is the ability of SPME to perform direct and selective extraction of analytes from complex biological samples. By far, the most popular method continues to be SPME coupled to GC. Nevertheless, the last 2 years have witnessed significant advances in other areas, such as successful automation of SPME coupled to liquid chromatography and the development of new coatings suitable for direct extraction from biological samples. Furthermore, a few bioanalytical applications based on direct coupling of SPME to MS, ion mobility spectrometry, CE and analytical chemiluminescence have been reported.