Our expertise, combined with our state-of-the-art instrumentation, allows us to achieve:
- Extremely low LLOQ
- Low sample volume
- Large dynamic ranges
- Analysis of multiple metabolites
- Analysis from various matrices (plasma, serum, CSF, blood, urine, etc.)
- Quick method development for high throughput assays using strict criteria
- Successful method transfer or adaptations
Our expertise enables us to overcome challenges like potential stability issues and matrix effects. We have performed extensive work on the removal of phospholipids from plasma using solid-phase and liquid-liquid extraction. The presence of the phospholipids is one of the frequent causes of matrix effect observed in bioanalysis.
One area of focus is to develop methods that are free of interference from metabolites. All molecules and potentially unstable metabolites such as glucuronides, sulfates and lactones are tested whenever possible using authentic reference standards. With the reference standard, multiple evaluations, including all stability evaluations, are performed to prove the absence of ex-vivo and in-vitro conversion. Also, we have developed multiple approaches to avoid interference from labile metabolites, especially for the mass spectrometer in-source and/or interface conversion of glucuronide metabolites. Techniques such as the utilization of adduct ions for analyte monitoring or use of different ionization modes are employed to avoid such interference.