The application of chemical modification in electrothermal vaporization-inductively coupled plasma atomic emission spectrometry

In this paper, several fluoride chemical modifiers have been tested for electrothermal vaporization-inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES) determination of different volatile elements, such as refractory element Ti, medium volatile element Ni and easy volatile element Pb. Reagents tested include polytetrafluoroethylene (PTFE), NH(4)F, NaF and CuF(2).2H(2)O. The best overall results are obtained using 6% PTFE added to sample. Under the compromise operating conditions, the detection limits of analytes are in the range of 0.8-59 ng ml(-1) and the calibration curves are linear for over three orders of magnitude. The direct determination of Ti, Ni and Pb in GBW 08505 tea leaves reference sample is shown as an example of PTFE chemical modification.