Meaning
Analytical chemistry procedures use standards that replicate the chemical environment of the sample to improve the accuracy of measurement. The matrix matched calibration is a method where the calibration curve is built using standards prepared in a medium that closely resembles the composition of the unknown sample.
Interference Suppression
Components within a polymer resin like pigments, fillers, flame retardants, or glass fibres can alter the signal of the target analyte. Utilizing matrix matched calibration helps correct for these effects by ensuring the background signal in the standard matches the background of the plastic extract. This approach is common in trace element analysis for heavy metals or restricted phthalates where high precision is mandatory.
Standard Preparation
Laboratories often use a blank version of the specific polymer grade, such as virgin polystyrene, to create the calibration series. By adding known concentrations of the substance to the blank resin extract, the matrix matched calibration accounts for any suppression or enhancement caused by the dissolved polymer chains. This eliminates the systematic bias that occurs when using pure solvent standards for complex plastic matrices.
Detection Limit
Precise quantification of additives at parts per billion levels relies on the suppression of background noise through this technique.
