Determination of ruthenium in photographic materials using solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry

Ru was determined in photographic emulsions and films using electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) after minimal sample pre-treatment (no separation or preconcentration required). The emulsion samples were either (i) converted into a colloidal solution by dissolution in warm water or dilute HNO3 (liquid sampling) or (ii) dried at 105 degrees C (solid sampling) prior to analysis. For the analysis of photographic films, only solid sampling, requiring no sample pre-treatment, was used. By optimization of the ETV heating programme, on-line separation of Ru (analyte) and Ir (internal standard) from the Ag matrix was accomplished: approximate to 90% of the AE present was removed prior to the vaporization of Ru and Ir. Quantification of Ru was accomplished by single standard addition, whereby Ir was used as an internal standard. The absolute limit of detection was found to be approximate to 1 pg. The results obtained showed a good agreement with those obtained by pneumatic nebulization ICP-MS and/or electrothermal atomic absorption spectrometry after sample dissolution.