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

作者:Albahrani Ali A; Rotarou Victor; Roche Peter J; Greaves Ronda F
来源:Clinical Chemistry and Laboratory Medicine, 2016, 54(10): 1609-1618.
DOI:10.1515/cclm-2015-1034

摘要

Background: There are limited evidence based studies demonstrating the stability of fat-soluble vitamins (FSV) measured in blood. This study aimed to examine the effects of light, temperature and time on vitamins A, D and E throughout the total testing process. Methods: Four experiments were conducted. Three investigated the sample matrix, of whole blood, serum and the extracted sample, against the variables of temperature and light; and the fourth experiment investigated the sample during the extraction process against the variable of light. All samples were analysed via our simultaneous FSV method using liquid chromatography-tandem mass spectrometry technology. The allowable clinical percentage change was calculated based on biological variation and desirable method imprecision for each analyte. The total change limit was +/-7.3% for 25-OH-vitamin D3, +/-11.8% for retinol and +/-10.8% for alpha-tocopherol. Results: Vitamins D and E were stable in the investigated conditions (concentration changes <4%) in the pre-analytical and analytical stages. Vitamin A showed photosensitivity in times >48 h with concentration changes of -6.8% (blood) and -6.5% (serum), both are within the allowable clinical percentage change. By contrast, the extracted retinol sample demonstrated a concentration change of -18.4% after 48 h of light exposure. However, vitamin A in the serum and extracted solution was stable for one month when stored at -20 degrees C. Conclusions: Blood samples for vitamins D and E analyses can be processed in normal laboratory conditions of lighting and temperature. The required conditions for vitamin A analysis are similar when performed within 48 h. For longer-term storage, serum and vitamin A extracts should be stored at -20 degrees C.

  • 出版日期2016-10