Miniaturization and Automation Protocol of a Urinary Organic Acid Liquid-Liquid Extraction Method on GC-MS

Area of Science:

• Clinical Chemistry
• Analytical Chemistry
• Biochemistry

Background:

• Manual extraction of urinary organic acids is time-consuming and prone to result variability.
• Current methods lack efficiency and standardization, impacting diagnostic accuracy.

Purpose of the Study:

• To miniaturize and automate the in-house extraction method for urinary organic acids.
• To enhance efficiency, reduce errors, and improve the reliability of organic acid analysis.

Main Methods:

• Reassessed and miniaturized an existing in-house extraction protocol, reducing steps and volumes.
• Automated the miniaturized method using a Hamilton MicroLab Star liquid handler.
• Validated the automated method with samples from the ERNDIM External Quality Assurance program.

Main Results:

• Successful miniaturization and automation of urinary organic acid extraction.
• Established linear ranges (0-300 mg/L) and high correlation coefficients (r >0.99) for 13 analytes.
• Demonstrated acceptable precision with coefficients of variation (CVs) below 20% for most organic acids.

Conclusions:

• The automated extraction method is comparable or superior to the manual in-house method.
• Automation reduces solvent consumption, increases sample throughput, and minimizes errors in diagnostics.
• This method holds significant potential for routine clinical laboratory applications.