Determining nonesterified and total docosahexaenoic acid and eicosapenaenoic acid concentrations by LC-MS/MS in the plasma of patients with schizophrenia.

Background: Nonesterified, total docosahexaenoic acid (DHA) and eicosapenaenoic acid (EPA) plasma levels were evaluated in patients with schizophrenia on different medications compared with healthy individuals using validated LC-MS/MS methods. Methods: Samples for nonesterified DHA and EPA assay were extracted in n-hexane-dichloromethane-isopropyl alcohol (2:1:0.1, V/V/V) and hydrolyzed at 90°C for 2 h before total DHA and EPA determination. Methods were validated in surrogate matrix and plasma. Results: These methods generated similar recovery for plasma (>89%) and surrogate matrix (>87%) and negligible matrix effects. Linearity, lower limit of quantification, accuracy, precision and stability were also validated. Conclusions: This study successfully determined DHA and EPA plasma levels in patients with schizophrenia and healthy individuals using validated LC-MS/MS methods. Therefore, nonesterified DHA and total EPA levels could be used as schizophrenia biomarkers.