Serum methionine: its rapid determination by continuous-flow colorimetry

Area of Science:

• Clinical Chemistry
• Analytical Chemistry

Background:

• Accurate serum methionine measurement is crucial for diagnosing various diseases.
• Existing methods may be time-consuming or less precise.

Purpose of the Study:

• To develop and validate a rapid, automated method for serum methionine determination.
• To establish reference ranges and assess the method's precision and accuracy.

Main Methods:

• Utilized the Technicon AutoAnalyzer system for automation.
• Employed a reaction based on the decolorization of halide platinates by organic sulfides, including methionine.

Main Results:

• Established a reference range of 20–60 mumol/l (mean 35 mumol/l) from 249 patient sera.
• Demonstrated high precision with a standard deviation of 2.2 mumol/l for duplicate samples.
• Achieved excellent recovery rates between 101% and 105%.

Conclusions:

• The developed automated method provides a reliable and efficient means for serum methionine quantification.
• This assay supports the clinical evaluation of liver disease (especially acute liver failure), kidney disease, and diabetes mellitus.