Simultaneous analysis of seven 2-hydroxy fatty acids as tert-butyldimethylsilyl derivatives in plasma by gas chromatography-mass spectrometry

Abstract

An efficient method for the simultaneous analysis of seven 2-hydroxy fatty acids (2-HFAs) as tert-butyldimethylsilyl (TBDMS) derivative was developed by gas chromatography-mass spectrometry in selected ion monitoring mode. New mass spectral data on 2-hydroxycapric, 2-hydroxypalmitic, 2-hydroxystearic and 2-hydroxybehenic acids as di-TBDMS derivatives for hydroxyl and carboxyl groups were built. Under the optimal conditions, the present method showed a good correlation coefficient (r ≥ 0.999) in the range of 0.01-0.5 µg. The precision showed low relative standard deviation of <10%, and the accuracy (percentage relative error) varied from -5.2 to 0.3 for the seven 2-HFAs studied. Recovery rates of all 2-HFAs were ≥ 93.2% with good precision. When applied to normal human plasma, seven 2-HFAs were positively identified. Therefore, the present efficient method will be useful for simultaneous analysis of 2-HFAs in plasma.

Keywords: 2-hydroxy fatty acid; gas chromatography-mass spectrometry; plasma; tert-butyldimethylsilylation.