EXPRESS: ICP-MS Analysis of Pipe Tobacco Using Calibration by Proxy.

Calibration by Proxy (CbPx) is applied to the inductively coupled plasma mass spectrometry analysis of seven commercial pipe tobacco samples. Five proxy elements are employed to construct a single calibration curve that applies to every analyte in the sample. Both the preparation of the calibration curve and the multielement analysis of each sample is performed from the analysis of just two solutions. The analysis of a standard reference material (tomato leaves) demonstrates excellent recoveries for 12 test elements, ranging from 77% (Ni) to 104% (Cu), with relative standard deviations averaging 6.6%. Detection limits are in the ppb range (µg analyte per kg leaf). Pipe tobacco samples containing between 0.04 and 700 mg analyte per kg leaf are analyzed for Al, As, Ba, Cd, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn.