1
|
Johnson CR, Sabatini HM, Aderorho R, Chouinard CD. Dependency of fentanyl analogue protomer ratios on solvent conditions as measured by ion mobility-mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5070. [PMID: 38989742 DOI: 10.1002/jms.5070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/13/2024] [Accepted: 06/18/2024] [Indexed: 07/12/2024]
Abstract
Recently, our group has shown that fentanyl and many of its analogues form prototropic isomers ("protomers") during electrospray ionization. These different protomers can be resolved using ion mobility spectrometry and annotated using mobility-aligned tandem mass spectrometry fragmentation. However, their formation and the extent to which experimental variables contribute to their relative ratio remain poorly understood. In the present study, we systematically investigated the effects of mixtures of common chromatographic solvents (water, methanol, and acetonitrile) and pH on the ratio of previously observed protomers for 23 fentanyl analogues. Interestingly, these ratios (N-piperidine protonation vs. secondary amine/O = protonation) decreased significantly for many analogues (e.g., despropionyl ortho-, meta-, and para-methyl fentanyl), increased significantly for others (e.g., cis-isofentanyl), and remained relatively constant for the others as solvent conditions changed from 100% organic solvent (methanol or acetonitrile) to 100% water. Interestingly, pH also had significant effects on this ratio, causing the change in ratio to switch in many cases. Lastly, increasing conditions to pH ≥ 4.0 also prompted the appearance of new mobility peaks for ortho- and para-methyl acetyl fentanyl, where all previous studies had only showed one single distribution. Because these ratios have promise to be used qualitatively for identification of these (and emerging) fentanyl analogues, understanding how various conditions (i.e., mobile phase selection and/or chromatographic gradient) affect their ratios is critically important to the development of advanced ion mobility and mass spectrometry methodologies to identify fentanyl analogues.
Collapse
Affiliation(s)
| | - Heidi M Sabatini
- Department of Chemistry, Clemson University, Clemson, SC, USA, 29634
| | - Ralph Aderorho
- Department of Chemistry, Clemson University, Clemson, SC, USA, 29634
| | | |
Collapse
|
2
|
Hollerbach AL, Ibrahim YM, Lin VS, Schultz KJ, Huntley AP, Armentrout PB, Metz TO, Ewing RG. Identification of Unique Fragmentation Patterns of Fentanyl Analog Protomers Using Structures for Lossless Ion Manipulations Ion Mobility-Orbitrap Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:793-803. [PMID: 38469802 DOI: 10.1021/jasms.4c00049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
The opioid crisis in the United States is being fueled by the rapid emergence of new fentanyl analogs and precursors that can elude traditional library-based screening methods, which require data from known reference compounds. Since reference compounds are unavailable for new fentanyl analogs, we examined if fentanyls (fentanyl + fentanyl analogs) could be identified in a reference-free manner using a combination of electrospray ionization (ESI), high-resolution ion mobility (IM) spectrometry, high-resolution mass spectrometry (MS), and higher-energy collision-induced dissociation (MS/MS). We analyzed a mixture containing nine fentanyls and W-15 (a structurally similar molecule) and found that the protonated forms of all fentanyls exhibited two baseline-separated IM distributions that produced different MS/MS patterns. Upon fragmentation, both IM distributions of all fentanyls produced two high intensity fragments, resulting from amine site cleavages. The higher mobility distributions of all fentanyls also produced several low intensity fragments, but surprisingly, these same fragments exhibited much greater intensities in the lower mobility distributions. This observation demonstrates that many fragments of fentanyls predominantly originate from one of two different gas-phase structures (suggestive of protomers). Furthermore, increasing the water concentration in the ESI solution increased the intensity of the lower mobility distribution relative to the higher mobility distribution, which further supports that fentanyls exist as two gas-phase protomers. Our observations on the IM and MS/MS properties of fentanyls can be exploited to positively differentiate fentanyls from other compounds without requiring reference libraries and will hopefully assist first responders and law enforcement in combating new and emerging fentanyls.
Collapse
Affiliation(s)
- Adam L Hollerbach
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Yehia M Ibrahim
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Vivian S Lin
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Katherine J Schultz
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Adam P Huntley
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - P B Armentrout
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Thomas O Metz
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Robert G Ewing
- Nuclear, Chemistry & Biology Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| |
Collapse
|
3
|
Application of mass spectrometry fragmentation patterns for rapid screening and structure identification of fentanyl analogues in suspicious powder. Forensic Chem 2023. [DOI: 10.1016/j.forc.2023.100485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
|
4
|
Shan X, Lee L, Clewes RJ, Howle CR, Sambrook MR, Clary DC. Computational analyses of the vibrational spectra of fentanyl, carfentanil and remifentanil. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 270:120763. [PMID: 35007908 DOI: 10.1016/j.saa.2021.120763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 11/30/2021] [Accepted: 12/12/2021] [Indexed: 06/14/2023]
Abstract
The infrared (IR) spectra of fentanyl, carfentanil and remifentanil, and protonated salts, are computed using quantum chemistry methods. New experimental FTIR spectra are also reported and compared to the calculations. The accuracy of two density functional theory methods, B3LYP and M06-2X, are tested against higher level theories (MP2) and the experimental data. Gas phase IR spectra are calculated for both the neutral and protonated molecules in order to compare with the experimental data measured for various salts of fentanyl and its analogues. Key vibrational modes are selected and studied in detail using a vibrational mode locality calculation. The main contributing atomic movements in these vibrational modes are identified.
Collapse
Affiliation(s)
- Xiao Shan
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Linda Lee
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Rhea J Clewes
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Christopher R Howle
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Mark R Sambrook
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - David C Clary
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom.
| |
Collapse
|
5
|
Denis EH, Bade JL, Renslow RS, Morrison KA, Nims MK, Govind N, Ewing RG. Proton Affinity Values of Fentanyl and Fentanyl Analogues Pertinent to Ambient Ionization and Detection. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:482-490. [PMID: 35041405 DOI: 10.1021/jasms.1c00320] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Proton affinity is a major factor in the atmospheric pressure chemical ionization of illicit drugs. The detection of illicit drugs by mass spectrometry and ion mobility spectrometry relies on the analytes having greater proton affinities than background species. Evaluating proton affinities for fentanyl and its analogues is informative for predicting the likelihood of ionization in different environments and for optimizing the compounds' ionization and detection, such as through the addition of dopant chemicals. Herein, density functional theory was used to computationally determine the proton affinity and gas-phase basicity of 15 fentanyl compounds and several relevant molecules as a reference point. The range of proton affinities for the fentanyl compounds was from 1018 to 1078 kJ/mol. Fentanyl compounds with the higher proton affinity values appeared to form a bridge between the oxygen on the amide and the protonated nitrogen on the piperidine ring based on models and calculated bond distances. Experiments with fragmentation of proton-bound clusters using atmospheric flow tube-mass spectrometry (AFT-MS) provided estimates of relative proton affinities and showed proton affinity values of fentanyl compounds >1000 kJ/mol, which were consistent with the computational results. The high proton affinities of fentanyl compounds facilitate their detection by ambient ionization techniques in complex environments. The detection limits of the fentanyl compounds with AFT-MS are in the low femtogram range, which demonstrates the feasibility of trace vapor drug detection.
Collapse
Affiliation(s)
- Elizabeth H Denis
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Jessica L Bade
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Ryan S Renslow
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Kelsey A Morrison
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Megan K Nims
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Niranjan Govind
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Robert G Ewing
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States
| |
Collapse
|
6
|
Guo X, Shang Y, Lv Y, Bai H, Ma Q. Suspect Screening of Fentanyl Analogs Using Matrix-Assisted Ionization and a Miniature Mass Spectrometer with a Custom Expandable Mass Spectral Library. Anal Chem 2021; 93:10152-10159. [PMID: 34254788 DOI: 10.1021/acs.analchem.1c01117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reliable identification of fentanyl and its analogs is of great significance for public security. However, with the growing prevalence of fentanyl compounds, current analytical strategies cannot fully meet the need for fast and high-throughput detection. In this study, a simple, rapid, and on-site analytical protocol was developed based on a miniature mass spectrometer. A dramatically simplified workflow was implemented using matrix-assisted ionization, bypassing complex sample pretreatment and chromatographic separation. The tandem mass spectrometry (MS/MS) capability afforded by the miniature ion trap mass spectrometer facilitated the investigation of fragmentation patterns for 49 fentanyl analogs during collision-induced dissociation, revealing valuable information on marker fragment ions and characteristic neutral loss. Calculations on Laplacian bond order values further verified the mass spectrometric behavior. A computation-assisted expandable mass spectral library was constructed in-house for fentanyl compounds. Smart suspect screening was carried out based on the full-scan MS and MS/MS data. The present study demonstrates an appealing potential for forensic applications, enabling streamlined screening for the presence of illicit fentanyl compounds at the point of seizures of suspect samples.
Collapse
Affiliation(s)
- Xiangyu Guo
- Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Yuhan Shang
- Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Yueguang Lv
- Chinese Academy of Inspection and Quarantine, Beijing 100176, China.,School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hua Bai
- Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Qiang Ma
- Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| |
Collapse
|