Signal correction using molecular species to improve biodiesel analysis by microwave-induced plasma optical emission spectrometry

Microwave-Sustained Inductively Coupled Atmospheric-Pressure Plasma (MICAP) for the Elemental Analysis of Complex Matrix Samples

“…in atomic spectrometry. To date, different IS have been successfully proposed for elemental analysis with MIPs, covering either plasma molecular species (the N 2 + and OH molecular emission band) [47] or elements externally added to both samples and standards (i.e., Te, Co, Be, Ga, In, Sc, Y, etc.) [48,49].…”

Is MIP-OES a suitable alternative to ICP-OES for trace element analysis?

“…34,40,43 Considering MIP-OES 0 limitations, 11,13 matrix effects from some samples may prove too severe for any IS-based signal correction. A less conventional approach to IS has recently been described by Lowery et al 74 Similar to the use of the N 2 + /OH signal ratio, it is based on the premise that signal variation responsible for poor accuracy may be monitored via species such as N 2 , N 2 + , OH and CN, which occur naturally in a N 2 -MIP. As a sample is introduced into the plasma and perturbs it, emission signals from these species change accordingly.…”

“…Taking advantage of MIP's high tolerance for organic solvents, this IS-based calibration strategy was successfully employed in a dilute-and-shoot method to determine Ca, K, Mg and Na in biodiesel. 74 The same method was used for the determination of P from phospholipids in meat, and Al, Ba, Mn, Sr and Zn in matrices containing high concentrations of C, Ca, Na or inorganic acids. 16,43 It is important to note that, similar to traditional IS, the plasma naturally occurring signal correction strategy may not be adequate for analyses involving severe matrix effects, and a method based on matrix matching (e.g.…”

Matrix effects in simultaneous microwave induced plasma optical emission spectrometry: new perspectives on an old problem

“…This correction can be either multiplicative in the form A × X ( A : analyte; X : N 2 + or OH) or as a divisor A / X for the analyte emission signal. 17…”