Laboratory practice of organic acid analysis based on gas chromatography-mass spectrometry in China

Objectives: The aim of this study is to investigate the status of laboratory practice of organic acid (OA) analysis using gas chromatography-mass spectrometry in China. Methods: A survey, investigating details of laboratory practice of OA analysis, was issued on the website of the National Center for Clinical Laboratories of China. Nationwide external quality assessment participating laboratories of OA assay were informed to participate in this survey. Results: A total of 36 laboratories completed this survey. Most laboratories started OA analysis during 2016-2020. Most (100%) labs reported semi-quantitative results, in which 79.4% of labs adopted the form of the ratio of peak area of OA and quantitative internal standard. Rare labs reported quantitative results. Few labs released reports in three days, most in 5-7 days. The source of control materials varied, 64.5% of labs adapted self-made materials. A total of 43.8% of laboratories directly used reference intervals (RIs) from published literature, 43.8% of laboratories established RIs themselves, but 21.2% of laboratories reported they didn't verify RIs. Conclusions: Appropriate supervision for the organic acid assay is needed in the aspect of the turnaround time of reporting results, the establishment validation and verification of reference ranges, and the quantification of results.