Quantification of plasma myo-inositol using gas chromatography–mass spectrometry

• We report GC–MS method to detect myo-inositol (MI) in plasma.
• The method is accurate, fast, convenient, and trace amount of sample needed.
• The method might be used for daily clinical sample detection in MI related disease.

BackgroundMyo-inositol (MI) deficiency is associated with an increased risk for neural tube defects (NTDs), mental disorders and metabolic diseases. We developed a gas chromatography–mass spectrometry (GC–MS) method to detect MI in human plasma, which was accurate, relatively efficient and convenient for clinical application.MethodsAn external standard method was used for determination of plasma MI. Samples were analyzed by GC–MS after derivatization. The stable-isotope labeled internal standard approach was used to validate the method's accuracy. Alpha fetal protein (AFP) was detected by chemiluminescence immunoassay.ResultsThe method was validated by determining the linearity, sensitivity and recovery rate. There was a good agreement between the internal standard approach and the present method. The NTD-affected pregnancies showed lower plasma MI (P = 0.024) and higher AFP levels (P = 0.001) than control. Maternal MI level showed a better discrimination in spina bifida subgroup, while AFP level showed a better discrimination in anencephaly subgroup after stratification analysis.ConclusionsWe developed a sensitive and reliable method for the detection of clinical plasma MI, which might be a marker for NTDs screening, and established fundamental knowledge for clinical diagnosis and prevention for the diseases related to disturbed MI metabolism.