Analyte stability during the total testing process: studies of vitamins A, D and E by LC-MS/MS

Area of Science:

• Clinical Chemistry
• Analytical Chemistry
• Biochemistry

Background:

• Limited evidence exists on the stability of fat-soluble vitamins (FSV) in blood samples.
• Understanding FSV stability is crucial for accurate diagnostic testing.

Purpose of the Study:

• To investigate the impact of light, temperature, and time on vitamins A, D, and E stability.
• To determine optimal pre-analytical and analytical conditions for FSV testing.

Main Methods:

• Four experiments assessed stability in whole blood, serum, and extracted samples.
• Variables included light exposure, temperature, and time.
• Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for analysis.
• Allowable clinical percentage changes were calculated based on biological variation.

Main Results:

• Vitamins D and E remained stable (<4% change) under tested conditions.
• Vitamin A showed photosensitivity after 48 hours (>48 h) in blood and serum (-6.8% and -6.5% change).
• Extracted vitamin A degraded significantly (-18.4% change) after 48 hours of light exposure.
• Vitamin A in serum and extracts was stable for one month at -20°C.

Conclusions:

• Vitamins D and E analyses are robust under standard laboratory conditions.
• Vitamin A analysis requires protection from light within 48 hours.
• Long-term storage of serum and vitamin A extracts necessitates -20°C conditions.