Lab Med Qual Assur.  2021 Sep;43(3):162-165. 10.15263/jlmqa.2021.43.3.162.

Implementation and Validation of a Gas Chromatography-Mass Spectrometry Method for Pristanic Acid and Phytanic Acid Quantification in Plasma Specimens

• Yi A
• Lee JH
• Yoo G
• Lim HJ
• Park E
• Han J
• Kim GY
• Cho SE
• Lee SG
• Lee EH

• KMID: 2520824
• DOI: http://doi.org/10.15263/jlmqa.2021.43.3.162

Abstract

We validated a gas chromatography-mass spectrometry (GC-MS) method for quantifying pristanic acid (PrA) and phytanic acid (PhA) in plasma specimens. We developed a GC-MS method based on the analysis of 20 µM ² H ₃ -pristanic acid (PrA-IS) and 80 µM ² H ₃ -phytanic acid (PhA-IS) as internal standards. The GC-MS was fitted with a 30 m×0.25 mm×0.25 µm HP-5MS (Agilent, USA) column. The mass spectrometer was operated through the transitions from the precursor to the product ions (m/z [mass-to-charge ratio] 355, 369, 358, and 372 for PrA, PhA, PrA-IS, and PhA-IS, respectively). The retention times of PrA, PhA, PrA-IS, and PhA-IS were 19.33, 20.39, 19.31, and 20.38 minutes in a 26.83-minute analysis, respectively. Linearity, recovery, precision, and carryover were evaluated to validate the method. The GC-MS method yielded a linear response from 0.032 to 9.951 µmol/L for PrA (R ² =0.9999) and from 0.127 to 39.432 µmol/L for PhA (R ²=0.9998). The limits of quantification by the methods were 0.032 µmol/L for PrA and 0.127 µmol/L for PhA. The recovery of PrA and PhA GC-MS method measurements were within ±10% when evaluated with external quality assessment materials. The within-batch and total coefficients of variation were all below 6% for both PrA and PhA test results. Twenty-interday imprecision (%) were all below 5% for both PrA and PhA test results. Carry-over was found to be 0.001% for PrA and –0.008% for PhA. The GC-MS PrA and PhA assay showed adequate recovery, precision, sensitivity, and linearity. Hence, it is suitable for routine clinical work.

Keyword

Pristanic acid; Phytanic acid; Gas chromatography-mass spectro metry; Method validation