|= Emerging. More than 5 years before clinical availability.|
|= Expected to be clinically available in 1 to 4 years.|
|= Clinically available now.|
Authors: Tania Grobler, Marli Dercksen, Barend Christiaan Vorster, Peet Janse van Rensburg, Mari van Reenen, Yolanda Kruger
INTRODUCTION: The current method of choice for the clinical investigation of analytes in biological matrices is LC coupled to tandem mass spectrometer via electrospray ionization based on the high selectivity and sensitivity it offers. One of the major obstacles with this analytical method is matrix effects, where the ionization of the compounds of interest are altered by co-extracting and co-eluting matrix components. Many mitigation strategies exist on overcoming matrix effects. One of these strategies is the use matrix-matching calibrators, where the matrix of the biological sample and that of the calibration range are the same or similar. Compensation occurs assuming that the calibrator and sample are influenced by matrix components in the same manner. For the analysis of a complex matrix such as urine, where the dilution range is extensive and matrix components are sample specific, finding a matching matrix is challenging.
METHODS: Our recent investigation in the quantitative LC-MS/MS assessment of urinary GAGs (glycosaminoglycans) again emphasized the challenge in choosing a stable matrix. Three calibrator matrix substitutes containing three commercially obtained GAGs, were selected and compared.
RESULTS: Synthetic urine, saline and water’s suitability is being assessed with the analysis of external quality control material and recovery experiments. An additional mitigation strategy for overcoming matrix effects is the use of isotopically labeled internal standards. The lack of the commercial availability of such internal standards prompted the in-house preparation of them.
CONCLUSION: Combating matrix effect by use of a stable calibrator matrix and isotopically labeled internal standards remains under investigation for this study.
References & Acknowledgements:
IP Royalty: no
|Planning to mention or discuss specific products or technology of the company(ies) listed above:||