Scanning electron microscopy with energy-dispersive electron probe X-ray analysis investigation of a sequential extraction scheme for copper, chromium, iron and aluminium speciation in marine suspended particulate matter

In a wider context of solid speciation studies and with a view to future application to real marine suspended particulate matter, a sequential chemical extraction procedure was tested on a plankton reference standard and checked with scanning electron microscopy with energy-dispersive electron probe X-ray analysis, and with atomic absorption and emission spectroscopic techniques. The results indicate that the procedure has a limited efficiency and needs further improvement. To increase the accuracy of the entire procedure, some steps, such as separation of the particulate matter from the filter and weighing of the particulate, have been optimized.