Use of on‐line supercritical fluid extraction‐supercritical fluid chromatography/tandem mass spectrometry to analyze disease biomarkers in dried serum spots compared with serum analysis using liquid chromatography/tandem mass spectrometry

Rationale The analytical stability and throughput of biomarker assays based on dried serum spots (DSS) are strongly dependent on the extraction process and determination method. In the present study, an on‐line system based on supercritical fluid extraction‐supercritical fluid chromatography coupled with tandem mass spectrometry (SFE‐SFC/MS/MS) was established for analyzing the levels of disease biomarkers in DSS. Methods The chromatographic conditions were investigated using the ODS‐EP, diol, and SIL‐100A columns. Then, we optimized the SFE‐SFC/MS/MS method using the diol column, focusing on candidate biomarkers of oral, colorectal, and pancreatic cancer that were identified using liquid chromatography (LC)/MS/MS. Results By using this system, four hydrophilic metabolites and 17 hydrophobic metabolites were simultaneously detected within 15 min. In an experiment involving clinical samples, PC 16:0‐18:2/16:1‐18:1 exhibited 93.8% sensitivity and 64.3% specificity, whereas PC 17:1‐18:1/17:0‐18:2 showed 81.3% sensitivity and 92.9% specificity for detecting oral cancer. In addition, assessments of the creatine levels demonstrated 92.3% sensitivity and 78.6% specificity for detecting colorectal cancer. Conclusions The results of this study indicate that our method has great potential for clinical diagnosis and would be suitable for large‐scale screening. Copyright © 2017 John Wiley & Sons, Ltd.