Table 2.
Analytical methods for the identification and/or quantification of Mitragyna speciosa in leaves and plant material.
| Compounds | Sample (Amount) | Analytical Technique | Extraction | LOD | LOQ | Recovery (%) | Reference |
|---|---|---|---|---|---|---|---|
| Several secondary metabolites | Mature leaves (100 mg) | LC–ESI–TOF–MS | Ice cold methanol | - | - | - | [31] |
| Mitragynine | Dried leaves (1.13 kg) | icELISA and HPLC–DAD | Methanol maceration, acid-base extraction, and silica gel column chromatography | 32.47 μg/mL | - | - | [109] |
| Mitragynine | Leaves (5 kg) | HPLC–DAD | Methanol maceration and liquid extraction (chloroform) | 0.25 μg/mL | 0.5 μg/mL | 95–101 | [107] |
| Ketum drink (1 mL) | Direct injection | ||||||
| Mitragynine 7-OH mitragynine |
Raw materials and powdered extracts (100 mg) and capsules | HPLC–UV | For dry test materials (0.5 M acetic acid in 70% methanol) For beverages (dilution with methanol) |
0.002% (w/w) | 0.006% (w/w) | 94–95 | [111] |
| Liquid finished products and/or beverages | 0.2 μg/mL | 0.6 μg/mL | |||||
| 7-hidroxymitragynine | Raw materials, powdered extracts, and capsules | 0.004% (w/w) | 0.011% (w/w) | 96–99 | |||
| Liquid finished products and/or beverages | 0.4 μg/mL | 1.1 μg/mL | |||||
| Mitragynine | Ketum cocktail | HPLC–DAD | Freeze drying and reconstitution with methanol:water (80:20, v/v) | 1.000 μg/mL | 3.000 μg/mL | 95 | [122] |
| Mitragynine | Dried plant material (2 g) | TLC and HPLC–UV | Ethanol | 1 μg /mL | - | - | [106] |
| Mitragynine | Kratom (powder or ground leaves material (100 mg); ¼ tea-spoon, liquid: 250 μL, capsule: 1) | IMS and LC–MS/MS | Methanol and ultrasonic bath sonication | 0.5 ng/μL | - | - | [108] |
| 2000 μg/mL | 6000 μg/mL | ||||||
| Mitragynine, 7-hydroxymitragynine, and mitraphylline (stereoisomers, mitraciliatine, speciogynine, speciociliatine) |
Plant material as fresh leaves (1.0 cm × 0.5 cm) | HR–DART–MS | Ethanol | - | - | - | [32] |
DAD: Diode-array detection; DART: Direct analysis in real time; HPLC: High-performance liquid chromatography; HPLC–UV: High-pressure liquid chromatography with ultraviolet detector; HR: High resolution; icELISA: Indirect competitive enzyme-linked immunosorbent assay; IMS: Ion mobility spectrometry; LC: Liquid chromatography; LDA: Linear discriminant analysis; LOQ: Limit of detection; LOQ: Limit of quantitation; MS: Mass spectrometry; MS/MS: Tandem mass spectrometry; TLC: Thin layer chromatography; TOF: Time of flight.