Analytical performance of the Conical torch in inductively coupled plasma optical emission spectroscopy operating methanol and 1-propanol solutions

This work explores, for the first time, the strengths and weaknesses of the Conical torch in ICP-OES operating methanol and 1-propanol solutions ranging from 30% to 100% w w −1 . To this end, Conical torch performance has been evaluated considering: (i) plasma fundamental properties; (ii) plasma robustness; (iii) carbon-based background emission; and (iv) analytical figures of merit. For the sake of comparison, a Fassel torch has been employed as a reference. Results show that the discharge for the Conical torch is highly robust and plasma characteristics ( i.e. , excitation temperature and electron number density) are mostly unaffected by the introduction of pure and hydroalcoholic solutions of methanol and 1-propanol. In contrast, the discharge for the Fassel torch is severely affected by organics introduction and it is not feasible to operate methanol solutions above 30% w w −1 . Because torch geometry and improved gas flow patterns, the Conical torch affords higher emission signal (2-fold) than the Fassel torch. Nevertheless, the detection limits for both torches are comparable, which is due to the increase in both (carbon-based) background emission and signal noise for the Conical torch. From these results and considering that the Conical torch requires less r.f. power (35%) and argon consumption (55%) than the Fassel one, it is beyond doubt that the former torch is more advantageous for those applications requiring the analysis of alcohol solutions ( i.e. extraction procedures and chromatographic separations). Conical torch allows direct analysis of pure and hydro-alcoholic solutions of methanol and 1-propanol in ICPOES.