Meaning
The influence of co-extracted polymer compounds on the ionization and detection of a target analyte during mass spectrometry is represented by a quantitative comparison of standard responses. This analytical coefficient, known as the matrix effect factor, identifies whether the polymer matrix suppresses or enhances the signal of the compound being measured. It is calculated by comparing the analyte signal in a clean solvent to the signal in a blank polymer extract.
A factor of one indicates no matrix influence, while values measurably above or below one reveal analytical distortion.
Analytical Integrity
Compounding additives like slip agents or oligomers can co-elute with the target analyte during chromatography. These interfering substances alter the ion source conditions, causing erratic quantification. A high matrix effect factor necessitates additional clean-up steps during sample preparation.
Analysts use solid-phase extraction to separate the target additive from the interfering polymer fragments.
Calibration Protocol
Quantifying additives in recycled plastics requires calibration curves that account for varying matrix influences. The use of matrix-matched standards helps correct for the matrix effect factor across different resin batches. These standards are prepared by adding known quantities of the analyte to an extract of the virgin polymer.
This methodology ensures that the reported concentrations of restricted substances are accurate.
Instrument Adjustment
Modifying the chromatographic separation can minimize matrix interference. Optimizing the mobile phase gradient shifts analyte retention times. This separates them from the matrix.
Signal suppression is thereby reduced.
