. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 64 ANALYTICAL METHODS IN OCEANOGRAPHY 0 4 03. 1000° 1500° 2000° ATOMIZING TEMPERATURE CO 2500° Figure 5. Effect of atomization temperature on the absorbance of 5 /xl. of a 10-ppb spike of cadmium in seawater causing overlap and interference. The optimum gas flow rate is, there- fore, about 70 ml/min. It is possible that the limiting factor in resolution of the cadmium and matrix signals is the relatively slow response time of conventional atomic
. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 64 ANALYTICAL METHODS IN OCEANOGRAPHY 0 4 03. 1000° 1500° 2000° ATOMIZING TEMPERATURE CO 2500° Figure 5. Effect of atomization temperature on the absorbance of 5 /xl. of a 10-ppb spike of cadmium in seawater causing overlap and interference. The optimum gas flow rate is, there- fore, about 70 ml/min. It is possible that the limiting factor in resolution of the cadmium and matrix signals is the relatively slow response time of conventional atomic absorption spectrophotometer readout electronics. If this is the case, then use of a faster readout system and lower gas flow should improve sensitivity. Atomization Temperature and Time. The maximum temperature of the heated graphite tube during the atomization step and the rate at which this temperature is achieved determines the rate of volatilization and atomization of the sample and, therefore, the peak atom population and sensitivity. For involatile elements, the peak height sensitivity in- creases with increasing temperature until a plateau is reached. The optimum atomization temperature is then the lowest temperature at which maximum sensitivity is obtained. For some volatile elements, the peak absorbance may reach a maximum with increasing temperature and Table II. Optimum Conditions for Element Cd Cu Fe Mn Ashing Temp. (°C) 400 600 1250 1100 Ashing Time (sec) 10 25 25 25 Atomization Temp. (°C) 1500 2500 2500 2400 Rotameter reading HGA-2100. 676. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Atlantic Oceanographic and Meteorological Laboratories; Pacific Oceanographic Laboratories; United States. Environmental Science Services Administration. Research Laboratories; Environmental Research La
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