Meaning
Analytical procedures in mass spectrometry introduce a constant stream of a standard solution into the column effluent before it enters the ionization source. Using post column infusion allows analytical chemists to monitor and correct for matrix effects that suppress or enhance the signal of polymer additives. This technique provides a continuous baseline of signal response, ensuring that co-eluting polymer compounds do not compromise the accuracy of quantitative analyses.
It establishes a dynamic baseline of ionization efficiency across each sample injection.
Infusion Method
Syringe pumps deliver a steady flow of a reference compound into the mobile phase after it has passed through the chromatographic column. When a sample component elutes, it can interfere with the ionization of this reference compound, causing a temporary dip or spike in the signal. Analyzing this signal variation allows chemists to pinpoint exactly where in the chromatogram matrix suppression is occurring.
Matrix Assessment
Polymer extracts often contain complex mixtures of oligomers that elute at similar times to the additives of interest. These co-eluting substances can suppress the ionization of stabilizers or flame retardants, leading to underreported additive concentrations. Incorporating this infusion method ensures that these suppression zones are detected and accounted for during the quantitative assessment of the resin.
Instrument Control
Mass spectrometry software tracks the intensity of the infused standard to ensure that the ion source remains clean and stable throughout the run. If the signal decays over time, it indicates that polymer residue is accumulating on the ionization cone, signaling that maintenance is required. This preventative monitoring helps laboratory managers maintain the reliability and reproducibility of their analytical instruments.
