Studies on reduction of chloride matrix interferences on determination of germanium using zirconium–ruthenium and palladium–magnesium modifiers by electrothermal atomic absorption spectrometry

The performance of the Zr–Ru permanent chemical modifier has been compared with the conventional Pd–Mg modifier for the determination of germanium in chloride matrix. Interferences from different matrices such as NaCl, KCl, MgCl2, CaCl2, FeCl3 and HCl were studied, in a transverse heated graphite atomizer (THGA) with and without end caps. End capped tubes coated with Zr–Ru showed less interference due to chloride matrix compared to Pd–Mg also measured in end capped tube. The linear calibration range is up to 1.6 mg l− 1, nearly three orders of magnitude when the Zr–Ru coated end capped THGA tube is used. The precision of the measurements (RSD, N = 3) was 0.6–3% for 1.6–0.01 mg l− 1 Ge solution and the limit of detection was 0.002 mg l− 1. The characteristic mass was 30 ± 5 pg for Zr–Ru and 90 ± 10 pg for Pd–Mg modifiers. A GBW 07312 stream sediment certified reference material was used to check validity of the method.