ETAAS chemical interferences

Since the work of Baxter et al. [75,76] around 1990, we have not found many more recent applications and it was not until 2003 that Felipe-Sotelo et al. [77] presented another application. They considered a problem where a major element (Fe) caused spectral and chemical interferences on a minor element (Cr), which had to be quantified in natural waters. They demonstrated that linear PLS handled (eventual) nonlinearities since polynomial PLS and locally weighted regression (nonlinear models) did not outperform its results. Further, it was found that linear PLS was able to model three typical effects which currently occur in ETAAS peak shift, peak enhancement (depletion) and random noise. 

Ag, At, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn ETAAS Metals are measured by ETAAS using the manufacturer s recommended conditions and an injection volume of 20 pL Applicable to surface, ground, tap, and waste water. A high CE concentration interferes. To minimize the matrix effect, the chemical modification, standard addition method, and background correction systems may be used. 105... 

Direct measurements of several trace metals by electrothermal atomic absorption spectrometry (ETAAS) have been reported. In general, sensitivities are inadequate for open-ocean waters, though in more metal-enriched environments (e.g., coastal waters and sediment pore waters) such analysis is possible careful corrections for the large and complex salt effects are necessary. The interferences can be minimized by the use of appropriate chemical modifiers, platforms in the graphite tubes, and sophisticated background correction schemes such as Zeeman. 

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