title: Bioanalytical aspects on method validation.
abstract: The validation of methods for neurotransmitter amines and metabolites depends on various sample related factors such as interferences, complexity of matrix composition, analyte stability or variations in concentration due to changing physiological responses. Also, the ultimate precision and accuracy of a method in whole would be related to the complexity of the sample work up procedure, the efficiency and reproducibility of the separation system, the use of a suitable internal standard to correct for volumetric errors and the sensitivity, linearity and selectivity of the detection system. A critical factor in the validation of those methods based in the chromatographic separation of the analyte is the confirmation of peak homogeneity through procedures such as changes on retention time, collection of analyte and reinjection into another system, correlation of recoveries in both systems, pharmacological manipulations prior to the assay or collection and derivatization followed by rechromatography. Isotope dilution GC-MS is widely accepted as a definitive reference method for its accuracy and precision although, as it is not always available, crossvalidation between different non-mass spectrometric methods is often given as proof of analytical reliability.
mesh_terms: D000818:Animals; D001679:Biogenic Amines / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005069:Evaluation Studies as Topic; D006801:Humans; D008722:Methods; D018377:Neurotransmitter Agents / Q000032:analysis*
chemical_list: D001679:Biogenic Amines; D018377:Neurotransmitter Agents