Quantification of bromide ion in biological samples using headspace gas chromatography-mass spectrometry

In this study, we aimed to establish a method for quantifying bromide ions (Br^- ) in blood and urine using gas chromatograph-mass spectrometer (GC-MS) equipped with a headspace sampler, for biological monitoring of workers exposed to methyl bromide.

Samples were mixed with dimethyl sulfate, and Br^- ions were detected using GC-MS with a headspace sampler. The validity of the proposed method was evaluated based on most of the US FDA guidance. The values obtained were compared with reference values by analysis using Seronorm^TM Trace Elements Whole Blood L-1 RUO.

The calibration curve showed good linearity in the Br^- concentration range of 0.1-20.0 mg/L, and the coefficient of determination R² value was >.999. Intraday and interday accuracy values were 99.3%-103.1% and 97.4%-101.8%, respectively. The measured and reference values of Seronorm were concordant. Herein, eight urine and serum samples of workers were analyzed; the samples' Br^- concentrations were known. The correlation coefficients of urine and serum samples were 0.97 and 0.96, respectively, and results were consistent.

This study established a simple and rapid method for the determination of Br^- concentration in biological samples using GC-MS with a headspace sampler. Moreover, it can be used for biological monitoring of occupational exposure to methyl bromide and for the determination of Br^- concentration in a wide range of biological samples.