Characterization of Material Study
Characterization of Kratom material
Metabolomics experiment using sample K51
Comparison with Literature:
A recent report  found that depending on source material, mitragyninewas detected in kratom (M. speciosa) products at a concentration range between 1 and 6% of leaf content (10 to 60 mg/g) and that 7-hydroxymitragynine levels ranged from 0.01 to 0.04% (0.1 to 0.4 mg/g). Thus, the reported values we have provided are consistent with literature precedent.
Kikura-Hanajiri, R., Kawamura, M., Maruyama, T. et al. Forensic Toxicol(2009) 27: 67. https://doi.org/10.1007/s11419-009-0070-52
|Sample||Compound measured||Value||Measurement||Study sequence||Additional information||N replicates|
For product extraction, 1.9 g of sample and 100 mL of 90 °C water were added to a 250 mL beaker. Mixture was stirred using glass stir rod and left at room temperature for 25-30 minutes. Mixture was decanted and filtered using a standard coffee filter and stored at -20°C until analysis.
MS data were acquired using a Q Exactive Plus quadrupole orbitrap mass spectrometer with an electrospray ionization source coupled to an
Acquity UPLC system. Samples were
Restek Raptor Biphenyl Column (2.7 μm , 2.1 ×50 mm)
Ultraperformance (UP) LC-MS data were acquired using a Q ExactivePlus quadrupole-orbitrap mass spectrometer with an electrospray ionization source coupled to an AcquityUPLC system. Samples were eluted from a RestekRaptor Biphenyl Column (2.7 μm, 2.1 ×50 mm) at a flow rate of 0.6 mL/min using the following binary gradient with solvent A consisting of H2O (with 2mM ammonium formateand 0.1% formic acid added) and solvent B consisting of CH3OH (with 2mM ammonium formateand 0.1% formic acid added): initiated at a composition of 95:5 (A:B) and increased linearly to 65:35 over 1 min, followed by a linear increase to 20:80 over 9 min. Followed by an increase to 0:100 over 1 min to wash column. Gradient returned to starting conditions of 95:5 held isocratic again for 1 min. The mass spectrometer was operated in the positive ionization mode over a full scan range of m/z 150-900 with the following settings: capillary temperature, 275 °C; probe temperature, 450 °C; spray voltage, 3.50 kV; sheath gas flow, 55; auxiliary gas flow, 15; sweep gas flow, 3.
1/x2weighted least-squares linear regression
Quantification of the major alkaloid components of the kratom products used relevant purified reference standards for mitragynine, 7-hydroxymitragynine, and rotundifoline. LC-MS analysis was conducted as described. Standards were prepared in spectrometric-grade MeOH and diluted in a two-fold dilution series ranging from 9.8-5000 ng/mL before injection. A calibration curve was constructed by plotting the area of the selected ion chromatogram for the detected ion representing each standard versus nominal concentration. Concentrations of each standard in the extracts were determined by 1/x2weighted least-squares linear regression.