Liquid Chromatography Tandem Mass Spectrometry Works
Separation of structurally similar compounds based on subtle differences in chemical properties.
- HPLC columns separate target substances based on subtle differences in chemical properties
- Each substance travels through the column at a reproducible rate allowing a unique retention time to be established
- In order for a substance to be confirmed to be present, it's retention time must match with the established value
- The InSource Diagnostics laboratory has carefully validated each of our testing methods to ensure that all structurally similar compounds have unique retention times
A unique chemical fingerprint is established for each target substance based on the chemical structure.
- Molecules are ionized using heat and high voltage energy
- The Q1 zone of the mass spectrometer filters the ionized targe substance based on their mass to charge ratio (m/z)
- The Q2 zone then fragments the ionized substance further by bombarding it with high energy gas
- The molecules break apart in a reproducible fashion into new fragments with a unique mass (product ions)
- The Q3 zone of the mass spectrometer then isolates the appropriate productions
- Based on the ratio of the ions isolated in the Q1 and Q3 zones, the identity of a target substance can be determined
The exact concentration of the drug is determined.
- The amount of ions produced by a target substance is related to it's concentration
- A calibration curve is generated that describes the signal response for a known concentration of the targeted substance
- By comparing the signal response of the substance in a patient sample to the calibration curve, a concentration of the substance can be determined