Dataset allowing for the identification of three new synthetic cannabimimetics featuring a norbornyl methyl side chain by spectrometric and spectroscopic techniques

Synthetic cannabimimetics (SC) are a diverse group of new psychoactive substances with varying potency and harm potential. New SCs appear on the drug market every year, and reliable and correct identification of these new derivatives independent from the matrix relies on the availability of verified spectra. Three new synthetic cannabimimetics featuring a norbornyl methyl side chain and varying core structure elements were identified in different seizures and forms. Cumyl-BC[2.2.1]HpMeGaClone and Cumyl-BC[2.2.1]HpMINACA were laced onto herbal blends, whereas Cumyl-BC[2.2.1]HpMICA was seized as a pure solid powder. The data collection process involves a comprehensive set of orthogonal analytical techniques allowing for the unambiguous identification of the respective endo- and exo-isomers. Furthermore, the diversity of analytical techniques allows a greater number of laboratories working in the field of forensic chemistry to confidently identify the substances described in our original research article [1]. Structure elucidation and analytical characterisation were performed within the EU-project ADEBAR plus using gas chromatography-mass spectrometry (GC-MS), gas chromatography-solid state infrared spectroscopy (GC-sIR), as well as solid and neat IR spectroscopy, Raman spectroscopy, liquid chromatography-electrospray ionisation-mass spectrometry (LC-ESI-MS), and high resolution (HR)-LC-ESI-MS, and nuclear magnetic resonance (NMR) spectroscopy. The raw analytical data files are included in the Mendeley repository alongside the individual spectra in a universally importable format. The use of the universal JCAMP format for storage of the spectra facilitates database maintenance and enables seamless integration of the verified spectra. Thus, the dataset enables other researchers worldwide to identify these three new SCs confidently.


Keywords:
Synthetic cannabinoid NPS Structure elucidation Legislation Norbornyl methyl side chain laced onto herbal blends, whereas Cumyl-BC[2.2.1]HpMICA was seized as a pure solid powder. The data collection process involves a comprehensive set of orthogonal analytical techniques allowing for the unambiguous identification of the respective endo-and exo-isomers. Furthermore, the diversity of analytical techniques allows a greater number of laboratories working in the field of forensic chemistry to confidently identify the substances described in our original research article [1] . Structure elucidation and analytical characterisation were performed within the EU-project ADEBAR plus using gas chromatography-mass spectrometry (GC-MS), gas chromatography-solid state infrared spectroscopy (GC-sIR), as well as solid and neat IR spectroscopy, Raman spectroscopy, liquid chromatographyelectrospray ionisation-mass spectrometry (LC-ESI-MS), and high resolution (HR)-LC-ESI-MS, and nuclear magnetic resonance (NMR) spectroscopy. The raw analytical data files are included in the Mendeley repository alongside the individual spectra in a universally importable format. The use of the universal JCAMP format for storage of the spectra facilitates database maintenance and enables seamless integration of the verified spectra. Thus, the dataset enables other researchers worldwide to identify these three new SCs confidently.
© 2021 Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )  Table 2.

Specifications
LC-ESI-MS/MS data was acquired using a Thermo Accela 1250 HPLC chromatograph coupled to a Thermo Velos Pro (linear ion trap) spectrometer with electrospray ionization; software: Xcalibur 4.0. Additional method parameters can be found in Table 3.
ATR-FT-NIR data were acquired using Perkin Elmer 100 N FT-NIR spectrometer at ambient temperature through a glass vial.
Raman data was averaged from ten consecutive scans acquired through a BAC151B Raman Video Microsampling System (B&W TEK, DE, USA). Additional details on the method parameters can be found in Table 5.
NMR data were acquired using a AVANCE III HD 500 and 5 mm CryoProbe Prodigy BBO probe with z-gradient (BRUKER BioSpin, Rheinstetten, DE). Additional acquisition parameters can be found in Table 4

Value of the Data
• The confident identification of synthetic cannabimimetics requires verified analytical reference data from orthogonal techniques. • The analytical dataset serves as verified analytical data for all laboratories working in the field of Forensic Chemistry tasked with the identification and differentiation of synthetic cannabimimetics • The analytical data is supplied in readily importable formats enabling the rapid implementation into existing methods and workflows by other researchers around the world.

Data Description
The word document substance_profile.docx contains the overview on the three SCs including the IUPAC name, synonyms, molecular weight, retention indices derived from GC and LC analysis, and the sample ID assigned to the analysed seizures.
The analytical data files are stored in separate folders for each individual substance.
The files 20_ADB-063_2nd_deposit.Absorbance.spc and 20_ADB-063_2nd_deposit.Multifile. cgm contain the raw analytical data on the GC-sIR analysis of the herbal blend extract. The dataset is the result of two consecutive injections that were deposited on top of each other following chromatographic separation. The resulting solid IR spectra of the individual endo-and exo-isomers can be found in 20_ADB-063_endo_isomer_(GC-sIR).jdx and 20_ADB-063_exo_isomer_(GC-sIR).jdx.
A neat IR spectrum of the herbal blend extract using chloroform as solvent was acquired and can be found in 20_ADB-063_neat_(CHCl3)_(mixture_of_isomers).jdx. 1D 1 H and 13 C NMR spectra acquired on the mixture of endo-and exo-isomers were exported from the raw data file after signal assignment and can be found in
A neat IR spectrum of the substance using chloroform as solvent as acquired and can be found in 21_ADB-004 neat (CHCl3)_IR.jdx. The solid IR spectrum of the sample as received can be found in the file 21_ADB-004 solid.jdx. The solid Raman spectra at wavelengths of 785 nm and 1064 nm can be found in the files 21_ADB-0 04_mc_785_10 0_30 0 0_10 and 21_ADB-004_mc_1064_100_65000_10, respectively. The file named 21_ADB-004_NIR.jdx contains the NIR spectrum of the sample as received. 1D 1 H and 13 C NMR spectra acquired on the mixture of endo-and exo-isomers were exported from the raw data file after signal assignment and can be found in the repository under 1H
The files 20_ADB-085.Absorbance.spc and 20_ADB-085.Multifile.cgm contain the raw analytical data on the GC-sIR analysis of the herbal blend extract. The resulting solid IR spectra of the individual endo-and exo-isomers can be found in 20_ADB-085_endo_isomer_(GC-sIR).jdx and 20_ADB-085_exo_isomer_(GC-sIR).jdx.
A neat IR spectrum of the herbal blend extract using chloroform as solvent as acquired and can be found in 20_ADB-085_neat_(CHCl3)_(mixture_of_isomers).jdx. 1D 1 H and 13 C NMR spectra acquired on the mixture of endo-and exo-isomers were exported from the raw data file after signal assignment and can be found in   were not seized in the form of a pure powder but laced onto herbal plant material. The SCs were extracted from the herbal matrix using chloroform as solvent. The organic solvent and the herbal material were swirled only for a few seconds to decrease the amount of co-extracted constituents from the herbal matrix. The organic solvent was filtered through a 0.45 μm Whatman filter (GE Healthcare Life Sciences, BKM, UK) and kept for LC-MS, GC-sIR and NMR analyses. GC-MS data were acquired using a 1:10 dilution of the chloroform extract. GC-EI-MS parameters are outlined in Table 1 .

GC-EI-MS analyses
The chromatographic separation on a DB-1 column was insufficient to facilitate the extraction of individual EI-MS spectra. Furthermore, the γ -carbolinone required the "310" temperature program to achieve elution from the column. The DB-5 column material was employed to achieve separation of the endo-and exo-isomers of Cumyl-BC[2.2.1]HpMeGaClone. For the GC-EI-MS analysis of Cumyl-BC[2.2.1]HpMICA, 2 mg of the compound were dissolved in 2 mL of chloroform. The extraction of spectra for the individual compounds and respective isomers as well as the determination of the Kovats retention index was done at the beginning of the peak resulting in a basepeak intensity that is below the saturation threshold of 108 for the instrument used. Background subtraction was performed at two points close to the analyte peak before exporting the resulting spectrum into the .jdx file format.

GC-sIR analyses
The sample preparation has been optimized to extract only minor fractions from the herbal blend to increase the concentration of the SC in the analysed solution as the analysis using GC-sIR requires a greater concentration of the analyte compared to GC-EI-MS. The rotating ZnSe disk is cleaned prior to the analysis of a new batch of samples to decrease the amount of ghost peaks caused by dust particles accumulating over time. Acetonitrile is used to wipe down the disk and residual, visible dust particles are removed using a stream of nitrogen just prior to reinserting the disk into the holding mechanism. Parameters of the GC-sIR analysis are outlined in Table 2 .
The GC-sIR analysis of the herbal blend extract of Cumyl-BC[2.2.1]HpMeGaClone was deposited onto the cryogenically cooled twice to achieve a greater band intensity by overlaying two injections.
Following the acquisition of the GC-sIR data, the analyte peak is identified, and manual background subtraction is performed at one point next to the peak using GRAMS/AI Ver. 9.1 (Grams Spectroscopy Software Suite, Thermo Fisher). Next, multi-point baseline correction was performed over the complete scan range and the spectrum exported into the .jdx format [2] .

LC-ESI-MS/MS analyses
MS/MS spectra are acquired for the SCs using the syringe pump to elucidate the collision induced fragmentation pathway and facilitate identification of the SCs via LC-MS/MS analysis workflows. The herbal blend extract was reconstituted in MeOH, diluted 1:10 injected into the ion source via a T-connector at a constant flow rate of 3-10 μL/min. 100% MeOH was supplied via the pump at a constant flow rate of 30 μL/min to aid in the stability of the ion spray at the interface. The collision gas was helium and the isolation width 1.2 (m/z).
The acquisition of the ESI-MS/MS collision spectra was performed with and without wideband excitation to account for different methods of operation by other forensic laboratories depending on the manufacturer used. In each case, the spectrum which shows the molecular ion with nearly 10% of the base peak intensity was chosen to retain the information on the [M + H] + ion species in the MS spectrum.
The LC-MS/MS acquisition method includes a full scan and consecutive scans of product ions created from collision induced dissociation of the 7 and 5 most intense precursor ions in positive ion mode and negative ion mode, respectively, identified in the full scan. Additional method parameters can be found in Table 3 .
The relative retention time (RRT) of the analyte using fluoresceine as internal standard was calculated using

NMR analysis
For the measurement, the extracts were dissolved in deuterated acetone to which 0.1% TMS (trimethylsilane) was added as a reference for the spectra. Detailed parameters of the NMR data acquisition are detailed in Table 4 .
After spectra acquisition, all spectra were imported into MNova, and the 1 H and 13 C spectra were saved in .jdx format (raw spectra). The imported spectra were referenced to TMS at 0 ppm for assignment. Phase and baseline corrections were also performed for the 1 H and 13 C spectra. Peak picking was performed using the GSD method in MNova (5 fitting cycles). For subsequent matching with other spectra, all previously fitted substance signals were converted to  new spectra. These then contain neither noise, nor signals from minor components. The spectra were saved in jdx format (extracted spectra).

IR and Raman analysis
The solid powder of Cumyl-BC[2.2.1]HpMICA was analysed as received and no correction or modification of the spectrum was performed after the acquisition. Parameters of the Raman analyses are detailed in Table 5  spectroscopy without a GC-sIR instrument, neat IR spectra using chloroform as solvent were acquired. The neat IR spectra are of the mixture of isomers as well as minor impurities from the herbal blend matrix material.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.