Expressing self-absorption in the analytical function of inductively coupled plasma atomic emission spectrometry

• Peak height and peak area of Cd and Mg atomic and ionic resonance lines were measured.
• Constant matrix concentration of 10,000 mg/L Ca was ensured in nebulized solutions.
• Equation with exponential term is valid up to 2000 mg/L analyte concentration.

The self-absorption of spectral lines was studied with up to date multi-element inductively coupled plasma atomic emission spectrometry (ICP–AES) instrumentation using radial and axial viewing of the plasma, as well, performing line peak height and line peak area measurements. Two resonance atomic and ionic lines of Cd and Mg were studied, the concentration range was extended up to 2000 mg/L. At the varying analyte concentration, constant matrix concentration of 10,000 mg/L Ca was ensured in the pneumatically nebulized solutions. The physical and the phenomenological formulation of the emission analytical function is overviewed and as the continuity of the earlier results the following equation is offered:I=ac.exp(−ßc+kc2)I=ac.exp−ßc+kc2where I is net line intensity, c is concentration and a, β and k are constants. The constant k has significance only above 100 mg/L concentration. Comparison was made also with the polynomial fitting of the calibration curve.