Warning indicators for the presence of plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry

Several readily measured parameters were evaluated for their ability to flag the presence of plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry. Of six plasma-species or analyte-emission-based candidates, two showed positive responses to plasma-related matrix effects. These two, the emission intensity from argon neutral-atomic lines and the spatially resolved vertical pattern of analyte emission, change considerably when matrix effects are present. In addition, the coupling of radiofrequency energy to a probe coil placed inside the ICP torch box correlated strongly with matrix effects. All three parameters show promise as alternatives to commonly used ion/atom emission intensity ratios for indicating the presence of plasma-related matrix effects.