Identification of a frit-related sample carryover in newborn screening by tandem mass spectrometry

•Sample carryover in newborn screening test can increase false positive results.•The risk of carryover is increased with newer generations of mass spectrometers.•Column-related carryover due to a stainless-steel frit inline filter was detected.•Compound-dependent factor of stainless-steel frit-related carryover is suggested.•Routine backpressure monitoring and timely replacement of frit rings are mandatory.