Development of new matrix reference materials for quantitative urine analysis in drug tests

Area of Science:

• Clinical Chemistry
• Analytical Chemistry
• Laboratory Medicine

Background:

• Accurate quantitative analyses in laboratories necessitate standardized methods for process control and improvement.
• Urine reference materials (RMs) can enhance urine analysis accuracy and mitigate matrix effects.
• Developing reliable RMs is crucial for consistent laboratory diagnostics.

Purpose of the Study:

• To detail the development of matrix reference materials in urine.
• To assess homogeneity, stability, and uncertainty of the developed urine RMs.
• To validate the utility of freeze-dried urine RMs for quality control.

Main Methods:

• A freeze-drying process was established for human and pig urine samples.
• Homogeneity, stability (at various temperatures and conditions), and uncertainty were evaluated.
• Quantification reliability was assessed by measuring authentic urine samples using the developed RMs.

Main Results:

• Freeze-dried urine samples exhibited homogeneity comparable to liquid samples.
• Freeze-dried RMs demonstrated superior stability over liquid samples under various conditions.
• The human urine matrix RM provided consistent results with spiked samples, indicating high reliability.

Conclusions:

• Freeze-dried urine matrix reference materials are stable and reliable tools for laboratory use.
• These RMs are suitable for daily quality control in urine analysis.
• The developed RMs contribute to improving the accuracy and standardization of laboratory testing.