Determination of boron in cell suspensions using electrothermal atomic absorption spectrometry

Abstract

A simple and sensitive method for the determination of boron in cell suspensions has been developed. Following incubation of cultured B16F1-mouse melanoma cells with various concentrations of boronophenylalanine (BPA), the cells were washed and removed mechanically from their solid matrix or were trypsinized. All the samples were analysed by electrothermal atomic absorption spectrometry employing a modified autosampling system. A limit of detection of 0.05 mg of boron per litre of suspension could be achieved, which is within the range of that of direct current plasma atomic emission spectrometry (0.10 mg l^–1) and inductively coupled plasma atomic emission spectrometry (0.05 mg l^–1). The precision of the boron determination in cell suspensions is 100 ± 5.7%. The method which is introduced here is an improvement over existing techniques because it eliminates a time-consuming sample digestion, normally involving loss of boron. Modern digestion procedures involving microwave-induced heating can compensate for the loss of boron. Furthermore, the boron concentration determined in cell suspensions varies with the method of cell detachment. In any case, high boron accumulation in cells, using BPA, of up to 159 micrograms of boron per gram of melanoma cells was registered.