Simultaneous determination of Co, Mn, P and Ti in PET samples by solid sampling electrothermal vaporization ICP-MS

The coupling of a graphite furnace to an ICP mass spectrometer results in a method that combines the suitability of the graphite furnace for handling solid samples with the detection power of ICP mass spectrometry (ICP-MS). Surprisingly, the majority of previous work devoted to solid sampling electrothermal vaporization (ETV) ICP-MS has only dealt with the determination of a single element, thereby wasting the pronounced multi-element capabilities of the detection method. In this work, solid sampling ETV-ICP-MS was used for the simultaneous determination of Co, Mn, P and Ti in two PET (polyethyleneterephthalate) materials, showing the suitability of the approach used for this kind of analysis. For this determination, the problems caused by the different furnace chemistry of the elements had to be tackled. In order to enable the determination of P, a combination of Pd and ascorbic acid was used as a chemical modifier. Different calibration methods-external calibration using either an aqueous standard solution or a solid standard and single standard addition-were studied and the results obtained were compared with those obtained by (i) ICP atomic emission spectrometry after sample dissolution and (ii) X-ray fluorescence. External calibration using a solid external standard and single standard addition were proved to be equally successful, but the latter is more practicable as only an aqueous standard solution is required.