Separation of ortho, meta and para isomers of methylmethcathinone (MMC) and methylethcathinone (MEC) using LC-ESI-MS/MS: Application to forensic serum samples

Maas, Alexandra; Sydow, Konrad; Madea, Burkhard; Heß, Cornelius

doi:10.1016/j.jchromb.2017.01.046

Cited by 22 publications

(14 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Natural coumarins are mainly classified into six types based on the chemical structure of the compounds, which include simple coumarins, furano coumarins, dihydrofurano pyrano coumarins, phenyl coumarins, and bicoumarins coumarins . Liquid chromatography–mass spectrometry (LC‐MS)/MS is a wildly used approach for the rapid structural identification of chemical components in nature products, which are difficult to be obtained as a pure sample with sufficient amount for nuclear magnetic resonance (NMR) analysis . Abundant structure information of fragment ions and fragmentation patterns of coumarin are valuable and necessary for inferring an unknown structure of coumarins solely by mass spectrometry …”

Section: Introductionmentioning

confidence: 99%

Fragmentation pathways of protonated coumarin by ESI‐QE‐Orbitrap‐MS/MS coupled with DFT calculations

et al. 2020

View full text Add to dashboard Cite

Coumarin is one of the basic structures of naturally oxygen heterocyclic compound, which was investigated in this paper for its gas-phase fragmentation behaviors using electrospray quadrupole extractive orbitrap mass spectrometry in the positive mode.The possible fragmentation pathways were proposed based on electrospray ionization (ESI)-mass spectrometry (MS)/MS data and theory calculation. The elimination of two CO and CO 2 was observed for protonated coumarin, which was followed by the formation of a stabilized seven-, six-, and five-membered ring carbocation by loss of C2H2. The possible protonation sites occurred at Oxygen 11 atom of coumarin were the main fragmentation pathways. The relative abundance of characteristic fragment ions and the energy-resolved breakdown curves were used to confirm the cleavage mechanism of protonated coumarin. The methodology and results of present work would contribute to the chemical structure identification of other coumarins. K E Y W O R D S breakdown curves, fragmentation pathways, coumarin, DFT calculations MASS SPECTROMETRY 6 of 9 SUN ET AL. Journal of MASS SPECTROMETRY time, it should not emerge that ion D5 (m/z 91) transform into A (m/z 147), because two CO are respectively lost in path (b). After 55 eV, the relative abundance of product ions C (m/z 103) and D (m/z 91) may be decided by the above-mentioned cause. According to the maximal ΔG' of losing C 2 H 2 in Figure 3 (67.3 kcal/mol), which was lower than that of losing first CO (69.7 Kcal/mol) in Figure 1, the relative abundance of ion F (m/z 65) should be higher than B (m/z 119) and D (m/z 91). The results of relative abundance of ion F was lower than D before 140 eV, and higher after 140 eV in Figure 6. According to the maximal ΔG' in Figure 3, the maximal ΔG' of ion D (m/z 91) transformed into F (m/z 65) (67.3 kcal/mol, from ion D to TD 1 , black line) was higher than D (m/z 91) to D5 (m/z 91) (61.3 kcal/mol, from ion D to TD 4 , red line). So the process ion D to D5 was the favorite path and the result consistent with the curve of ions D (m/z 91) and F (m/z 65) when the NEC was lower than 140 eV. For the same reason, the red line part in Figure 3 (ion D transformed into D5) was a reversible reaction, on which the ions D (m/z 91) and D5 (m/z 91) could be transformed into each other. On the other hand, the black line part in Figure 3 would be an irreversible process, with losing of C 2 H 2 and ion F (m/z 65) turned to F1 (m/z 65), when the NEC was higher than 140 eV. Ion C (m/z 103) transformed into TC 1 (75.6 kcal/mol in Figure 4) and ion E2 into TE 3 (70.5 kcal/mol in Figure 5) with higher maximal ΔG' than process of losing CO 2 (ion A2 to TA 3 , 68.6 kcal/mol), both were endothermic reaction. The results were well consistent with the relative abundance of ion C (m/z 103), E (m/z 77)and G (m/z 51) in Figure 6. Therefore, it was further confirmed that the determining factor was the maximal ΔG' in each cleavage pathway for ESI mass.

show abstract

Section: Introductionmentioning

confidence: 99%

Fragmentation pathways of protonated coumarin by ESI‐QE‐Orbitrap‐MS/MS coupled with DFT calculations

et al. 2020

View full text Add to dashboard Cite

show abstract

“…A and 2B), the method ensures a very good resolution between 2‐MMC, 3‐MMC, and 4‐MMC. In spite of the fact that the simultaneous enantioseparation of 2‐MMC does not take place, this separation of the ring isomers is in fact better than that of the comparable methods reported in the literature which provide no chiral effect . In contrast, the enantiomers of α‐PVP are almost totally resolved from each other and from the rest of analytes.…”

Section: The Values Of Validation Parameters Obtained For MC 3‐mmc Amentioning

confidence: 72%

Simultaneous enantioseparation of methcathinone and two isomeric methylmethcathinones using capillary electrophoresis assisted by 2‐hydroxyethyl‐β‐cyclodextrin

et al. 2018

View full text Add to dashboard Cite

Methcathinone (ephedrone), 4-methylmethcathinone (mephedrone), and 3-methylmethcathinone (metaphedrone) are toxicologically-important cathinone derivatives used commonly as designer drugs. In this work we show the first method allowing to separate simultaneously all these molecules in a chiral medium, ensuring good resolution between all enantiomers. Eight cyclodextrins have been tested as potential chiral selectors, the best results were obtained with 2-hydroxyethyl-β-cyclodextrin, unreported so far for efficient separation of cathinones. After optimization, the method was calibrated and validated with and without the use of internal standard. The addition of standard improved an overall repeatability and precision, the use of electrophoretic mobility ratio was especially favorable (RSD < 1%). It was demonstrated that the method may be easily extended by introducing the additional cathinone-related drugs to the sample, maintaining satisfactory separation efficiency.

show abstract

“…Various publications are focusing on identification of positional isomers using gas chromatography–mass spectrometry (GC–MS; with and without derivatization) while methods for liquid chromatography–tandem mass spectrometry (LC–MS/MS) are scarce in this field. An example is the liquid chromatography–electrospray ionization–tandem mass spectrometry (LC–ESI–MS/MS) method developed by Maas et al using a biphenyl column to separate methylethcathinone and methylmethcathinone isomers in serum samples. Takeda et al presented an isocratic liquid chromatography quadrupole time‐of‐flight mass spectrometry (LC–QTOF–MS) method using a naphtylethyl column for separation of 12 synthetic cathinones and McLaughlin et al described an isocratic LC–ESI–MS method using a phenylhexyl column for separation of 2‐, 3‐, and 4‐fluorophenmetrazine.…”

Section: Introductionmentioning

confidence: 99%

Separation of positional isomers of nine 2‐phenethylamine‐derived designer drugs by liquid chromatography–tandem mass spectrometry

Grumann

Auwärter

2018

Drug Testing and Analysis

View full text Add to dashboard Cite

The synthesis of positional isomers of designer drugs is a common way of bypassing legal restrictions. For forensic case work, and especially for the legal assessment of cases, there is a need for screening methods capable of the unequivocal identification of positional isomers. The presented liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method facilitates separation of positional isomers of 9 2-phenethylamine-derived designer drugs in different matrices including seized materials, hair, serum, and urine specimens. Chromatographic separation was achieved on a biphenyl phase using gradient elution with a total runtime of 26 minutes. The limit of detection was 25 pg/mg for hair samples and ranged from 0.1 ng/mL to 0.5 ng/mL for serum and from 0.2 ng/mL to 1.2 ng/mL for urine samples. The method proved to be selective and sensitive and showed good chromatographic resolution (R ≥ 1.2). The method was successfully applied to routine case samples.

show abstract

Separation of ortho, meta and para isomers of methylmethcathinone (MMC) and methylethcathinone (MEC) using LC-ESI-MS/MS: Application to forensic serum samples

Cited by 22 publications

References 18 publications

Fragmentation pathways of protonated coumarin by ESI‐QE‐Orbitrap‐MS/MS coupled with DFT calculations

Fragmentation pathways of protonated coumarin by ESI‐QE‐Orbitrap‐MS/MS coupled with DFT calculations

Simultaneous enantioseparation of methcathinone and two isomeric methylmethcathinones using capillary electrophoresis assisted by 2‐hydroxyethyl‐β‐cyclodextrin

Separation of positional isomers of nine 2‐phenethylamine‐derived designer drugs by liquid chromatography–tandem mass spectrometry

Contact Info

Product

Resources

About