This paper demonstrates that the use of a HRMS instrument in a regulated environment is a viable technique for quantification of large molecules. The latter was able to allow flexibility and selectivity to adapt the specificity of each assay with sensitivity comparable to the triple quadrupole instrument.

Due to the presence of endogenous components in biofluids, ionization suppression or enhancement may occur for bioanalytical assays using LC-MS or LC-MS/MS technologies. The matrix effect may affect the precision and accuracy of a bioanalytical method and, therefore, compromise the quality of the results. Protein precipitation sample preparation along with LC-MS/MS is a high-throughput method most commonly used in bioanalysis and is largely affected by the matrix effect. In order to eliminate the matrix effect during the method development, some considerations may be used: cleaner sample preparations, more sensitive instruments, which allow less material to be injected, different chromatographic separations and much more must be investigated. More than giving tools to adequately assess the matrix effect during the method development, this review gives scientists numerous ways to eliminate or reduce the matrix effect based on novel sample-preparation techniques, new chromatographic optimization methods and new technologies.

Combinations of specific eluents and reversed-phase solid-phase extraction cartridges were found to prevent matrix effect due to phospholipids.

Analytical chemists should carefully choose the right combination of sample preparation and chromatographic conditions when working under HILIC conditions to avoid variable results.

A strong correlation between PK data obtained by the DBS and conventional plasma method was observed, which makes DBS a valuable technique for further naproxen bioavailability and PK investigations and studies.