Development of an Ephedrine In-House Matrix Reference Material and Its Application to Doping Analysis.

Area of Science:

• Analytical Chemistry
• Biomaterials Science

Background:

• Biomatrix-based reference materials (RMs) enhance laboratory test accuracy by mimicking real samples.
• A specific matrix RM for ephedrine (EP), a threshold substance, was previously unavailable, hindering precise analysis.

Purpose of the Study:

• To develop an in-house matrix RM for ephedrine (EP).
• To validate its utility in analytical procedures and quality control.

Main Methods:

• Homogeneity and stability studies were conducted on the developed matrix RM.
• An interlaboratory comparison involving 11 laboratories, including WADA-accredited facilities, was performed.
• Traceability and uncertainty were evaluated for the assigned value.

Main Results:

• The matrix RM demonstrated excellent stability and homogeneity across batches.
• Interlaboratory comparison assigned a traceability value of 9.83 ± 0.57 μg/mL (k = 2).
• The RM proved feasible as a single calibration standard in validation studies.

Conclusions:

• The developed in-house matrix EP RM is reliable and consistent for quality control.
• This study provides a framework for creating similar matrix RMs for other substances.
• Accurate EP quantification is crucial for anti-doping and forensic analysis.