Universal calibration for analysis of organic solutions of medium and low volatility by inductively coupled plasma-atomic emission spectrometry

A novel chemometric technique is described to facilitate the use of a singl e organic solvent matrix standard to calibrate inductively coupled plasma a tomic emission spectrometry (ICP-AES) for the accurate determination of tra ce elements in another organic solvent or complex mixture of several organi c solvents. Analysis errors arising from the difference in solvent matrix v apor loading and chemical composition between standard and sample are corre cted. The technique is intended for organic solvent mixtures for which the plasma vapor loading is tolerable with conventional sample introduction tec hniques (ic., conventional nebulizer-spray chamber arrangement without a so lvent desolvator). Simultaneous measurement of atomic and ionic spectral li nes of the same analyte is required. A correction factor is estimated from its linear correlation with the line intensity ratio. For elements without a sensitive atom line, the correction is estimated from the correlation bet ween their ionic line intensities and the ratio of ionic-to-atomic line int ensities of another analyte in the same sample. Experimental tests with sev en trace elements (Al, Be, Ca, Cu, Fe, Mg, and Mn) in different organic sol vent mixtures (xylene, dichloromethane, hexane, carbon disulfide, acetone a nd 1,2,3,4-tetrahydronaphthalene) demonstrate the effectiveness of universa l calibration.