Laserfiche WebLink
METHOD 7841 <br />THALLIUM (ATOMIC ABSORPTION. F RNACE TECHNIQUE) <br />1.0 SCOPE AND APPLICATION <br />1.1 See Section 1.0 of Method 7000. <br />2.0 SUMMARY OF METHOD <br />2.1 See Section 2.0 of Method 7000. <br />3.0 INTERFERENCES <br />3.1 See Section 3.0 of Method 7000 if interferences are suspected. <br />3.2 Background correction is required. <br />3.3 Hydrochloric acid or excessive chloride will cause volatilization of <br />thallium at low temperatures. Verification that lasses are not occurring, by <br />spiked samples or standard additions, must be made for each sample matrix. <br />3.4 Palladium is a suitable matrix modifier for thallium analysis. <br />4.0 APPARATUS AND MATERIALS <br />4.1 For basic apparatus, see Section 4.0 of Method 7000. <br />4.2 Instrument parameters (general): <br />4.2.1 Drying time and temp: 30 sec at 125°C. <br />4.2.2 Ashing time and temp: 30 sec at 400°C. <br />4.2.3 Atomizing time and temp: 10 sec at 2400°C. <br />4.2.4 Purge gas: Argon or nitrogen. <br />4.2.5 Wavelength: 276.8 nm. <br />4.2.6 Background correction: Required. <br />4.2.7 Other operating parameters should be set as specified by the <br />particular instrument manufacturer. <br />NOTE: The above concentration values and instrument conditions are for a <br />Perkin-Elmer HGA-2100, based on the use of a 20-uL injection, <br />continuous-flow purge gas, and nonpyrolytic graphite. Smaller sizes <br />of furnace devices or those employing faster rates of atomization <br />can be operated using lower atomization temperatures for shorter <br />time periods than the above recommended settings. <br />7841 - 1 <br />CD-ROM Revision 0 <br />Date September 1986 <br />