Meaning
Chemical interactions between the analyte of interest and the other components in a polymer sample can distort the results of a laboratory test. This matrix interference occurs when the plastic resin, fillers or additives affect the signal produced by the target compound. It can lead to an overestimation or underestimation of the actual concentration if not properly managed.
Chemical Coexistence
Complex polymers often contain many different substances that can overlap with the target signal during analysis. For example, a flame retardant might produce a peak that hides a residual monomer in a gas chromatograph. Matrix interference is particularly common in recycled materials where the exact composition is unknown.
Accuracy Reduction
When the background of the sample changes the response of the detector, the calibration curve becomes unreliable. This loss of accuracy can cause a batch of resin to be wrongly accepted or rejected. Technicians must identify these effects early in the method development phase to ensure the data is defensible.
Compensation Strategy
Diluting the sample or using the standard addition method can help to minimize the impact of these interferences. By adding a known amount of the analyte directly to the sample, the chemist can measure the actual response in the presence of the matrix. These strategies are essential for achieving high precision in resin characterization.
