MassChrom® Phosphatidylethanol (PEth)
Quantification of Phosphatidylethanol as alcohol consumption marker
Introduction
Material & Methods
LC-MS/MS
Injection volume of 1–20 µl is used. Chromatographic separation is performed on an Analytical Column (order no. 63100) at a column temperature of 40 °C. The analytes are separated under isocratic conditions at a flow rate of 0.4 ml/min using Mobile Phase (order no. 63001).
Electrospray ionization in negative ion mode is used. The multiple reaction monitoring (MRM) transitions used for quantification are listed in Table 1.
Quantification
A full calibration of the analysis system for each series of measurements is performed with 6PLUS1® calibrator (order no. 63039). Calibration curves are constructed by calculating the analyte to internal standard (ISTD) peak area ratio on the y axis against calibrator concentrations on the x axis. Then a calibration curve is plotted for both PEth homolouges using linear regression and 1/x weighting.


Table 1
Results
The run time is 3.5 min (see chromatogram in fig. 1). The calibration range of 10-1000 ng/mL covers the forensic and clinical relevant concentrations (table 2).


Table 2
Conclusion
This application note describes a protocol for the determination of PEth 16:0/18:1 and PEth 16:0/18:2 in whole blood using Chromsystems components.


Fig. 1
Ordering Information (To order the products or for a quote, please contact us here)
MassTox® Series A
| Order No. | Products |
| 92001/RUO |
Mobile Phase 1 |
| 92002/RUO |
Mobile Phase 2 |
| 92009/RUO |
Rinsing Solution |
| 92110 |
MassTox® TDM Master Column Series A |
| 92007/RUO |
Dilution Buffer 1 |
RUO: For research use only and not for diagnostic purposes
MassTox® Immunosuppressants
| Order No. | Products |
| 29039/XL |
6PLUS1® Multilevel Whole Blood Calibrator Set |
| 0081-0085, 0089 |
MassCheck® Immunosuppressants Whole Blood Controls Level I-IV, Blank |
| 93946/RUO |
Internal Standard Set |
| 93003/RUO |
Precipitation Reagent |
| 93005/RUO |
Extraction Buffer |
| 33006 |
Reaction vials, transparent |
| 93915/RUO |
Tuning Mix |
Last Update March 2026
