Precise and accurate measurements at the regulated levels are an important factor for assuring safe drinking water. U.S. EPA Method 200.91 is the method cited by EPA, Health Canada, and the WHO for the use of graphite furnace atomic absorption spectroscopy (GFAAS). In evaluating a GFAAS system for determination of these elements, it must provide good sensitivity, low noise, limited drift, and accuracy in matrices with high salt content (hard water) that might be found in drinking waters. In this work, the PinAAcle™ 900T, with a unique optical system, is evaluated for the use of EPA Method 200.9 for As, Cd, Pb, Se, and Tl in drinking waters.