Signal Interference
Reductions in the efficiency of ion formation within a mass spectrometer occur when co-eluting compounds from the sample compete for the available charge. Matrix ion suppression leads to a lower detected signal for a target chemical than its actual concentration in the textile would warrant. It hides the presence of hazardous substances by preventing them from being correctly identified by the detector.
Physical Mechanism
Droplets in the electrospray ionization source become crowded with non-volatile components that hinder the evaporation process. Because the target molecules cannot reach the gas phase, they never enter the analyzer. High concentrations of salt or finishing oils are the primary drivers of matrix ion suppression in industrial laboratory settings.
Mitigation Method
Increasing the dilution of the sample extract often reduces the density of these interfering molecules enough to restore the signal. Another approach involves improving the chromatographic separation to ensure the analyte exits the column at a different time than the suppressing agents. More rigorous cleaning of the fabric sample before extraction also minimizes the risk.
Impact Assessment
Monitoring the response of a known internal standard across every injection reveals the extent of the problem. If the recovery falls below a certain percentage, the test result is considered invalid and must be repeated with better sample preparation.
