Tables, and 27 References A C C E P T E D M A N U S C R I P T
ACCEPTED MANUSCRIPTABSTRACT Background: Histamine (HA) is a small amine playing an important role in anaphylactic reactions. In order to identify and quantify HA in plasma matrix, different methods have been developed but present several disadvantages. Here, we developed an alternative method using liquid chromatography coupled with an ultra-high resolution and accurate mass instrument, Q Exactive TM (Thermofisher) (LCHRMS).
Methods:The method includes a protein precipitation of plasma samples spiked with HA-d4as internal standard (IS). LC separation was performed on a C18 Accucore column (100*2.1 mm, 2.6 μm) using a mobile phase containing nonafluoropentanoic acid (3 nM) and acetonitrile with 0.1% (v/v) formic acid on gradient mode. Separation of analytes was obtained within 10 min. Analysis was performed from full scan mode and targeted MS2 mode using a 5 ppm mass window. Ion transition monitored for targeted MS2 mode were 112.0869>95.0607m/z for HA and 116.1120>99.0855m/z for HAd4. Calibration curves were obtained by adding standard calibration dilution at 1 to 180 nM in TrisBSA.Results: Elution of HA and IS occurred at 4.1 min. The method was validated over a range of concentrations from 1 nM to 100 nM. The intra-and inter-run precisions were <15% for quality controls. Human plasma samples from 30 patients were analysed by LCHRMS, and the results were highly correlated with those obtained using the gold standard Radioimmunoassay (RIA) method.
Conclusion:Overall, we demonstrate here that LCHRMS is a sensitive method for histamine quantification in biological human plasmas, suitable for routinely use in medical laboratories. In addition, LCHRMS is less time-consuming than RIA, avoid the use of radioactivity, and could then be considered as an alternative quantitative method.