Stockdale, Anthony and Davison, William and Zhang, Hao (2010) 2D simultaneous measurement of the oxyanions of P, V, As, Mo, Sb, W and U. Journal of Environmental Monitoring, 12 (4). pp. 981-984. ISSN 1464-0325
Abstract
Previous work used the sampling technique diffusive gradients in thin-films analysed by laser ablation mass spectrometry to measure sulphide, P, V and As at a microniche of reactive organic carbon in a freshwater sediment. Here we present new developments of this technique. The number of analytes has been extended and we demonstrate the technique for depth profiling of analytes in both one and two dimensions. The physical dimensions of the cell in the laser ablation unit restrict the maximum length of gel that can be analysed. We address this problem by proposing a method for obtaining better data continuity when analysing multiple segments of gel from the same probe. 13C is used as the internal standard for each gel segment. For the cross standardisation of different gel segments 58Fe signals are obtained from ablation of a small piece of standard ferrihydrite gel analysed during the same run as the sample gel. As the ferrihydrite gel is a subsection of a much larger gel (i.e. the Fe concentration is consistent for all subsection), then any difference in signal can be attributed to changes in detector sensitivity and gels across different runs and performed on different days can be standardised.