Microwave-assisted derivatization for methylmalonic acid analysis in human serum by gas chromatography-mass spectrometry

Abstract

Methylmalonic acid (MMA) in human serum is an important biomarker of methylmalonic acidemias. In this work, a simple and fast method based on microwave-assisted derivatization (MAD) followed by gas chromatography-mass spectrometry (GC-MS) was developed for the determination of methylmalonic acid in serum. In the proposed method, the MMA was extracted from serum and rapidly derivatized with bis(trimethylsilyl)trifluoroacetamide under microwave irradiation, finally the derivative was analyzed by GC-MS. The experimental parameters were investigated and the method validations were studied. The optimal conditions were obtained: 50 μL of bis(trimethylsilyl)trifluoroacetamide plus 1% trimethylchlorosilane (BSTFA-TMCS (99 : 1)) as derivatization regent, microwave power of 400 W and irradiation time of 2 min. The proposed method provided satisfactory precision (RSD 2.3–4.5%), wide linear range (0.021–5 mM), good linearity (R² >0.999), and good recovery (96–101.3%). The proposed method was successfully applied to the analysis of MMA in serum samples. The experimental results showed that the proposed method was a simple, rapid, and efficient technique for the quantitative determination of MMA in serum.