ANALYSIS OF SUSPENDED MATTER FROM SAN JORGE GULF

ERICA GIARRATANO; MÓNICA GIL

2016-05-13/2016-07-20

1-11

Química

Rec.Hidr.-Otros

Ten filters were analyzed containing suspended material from 10 stations in San Jorge gulf (Fig. 1). Samples were obtained according to the following procedure (MARES FINAL REPORT): filters (25 mm glass fiber filters Whatman GF/F, pre-weighted and numbered for total suspended matter-TSM) were placed on the holders of the filtration ramp; tulips were attached and rinsed with 100 ml MilliQ water and filtration was performed under low pressure. The filtered volume varied between 0.5 and 1.5 L depending on the particle load. The filters were kept frozen at -20ºC until dried at 100ºC for at least 3 h. Then, they were weighted for the determination of TSM, combusted at 550°C for 1 h and reweighted to obtain the particulate inorganic matter (PIM) and particulate organic matter (POM).The calcined filters were mineralogically and chemically characterized in the ISMER using x-ray fluorescence (XRF) (PANALYTICAL Epsilon 3X-High-performance benchtop spectrometer), alternating gradient force magnetometer (AGM) (Princeton Corp. model MicroMag 2900 AGM) and scanning electron microscopy/energy-dispersive x-ray spectroscopy (SEM/EDS). Elemental composition analysis was made using an INCA X-sight -Oxford Instruments- energy dispersive X-ray spectrometer coupled to a JEOL 6460LV scanning electron microscope. X-ray spectra were acquired from 15 randomly chosen particles. Each spectrum was acquired for 60 seconds of live time at an accelerating voltage of 20 kV. Elements were automatically identified and quantified by the INCA software and results were normalized to 100%. System quantitative optimization was made using copper as standard.