Validation: It helps in validating analytical methods by checking the method's ability to accurately measure the analyte in the presence of complex biological matrices.
Recovery Studies: Spiking is used to determine the
recovery rate of an analyte from a sample matrix.
Quality Control: It ensures that the analytical method remains accurate and reliable over time by monitoring performance through
quality control samples.
How is Spiking Done?
Spiking is typically performed by adding a known concentration of the analyte to a blank sample, which is a sample containing all the components except the analyte of interest. The spiked sample is then processed and analyzed in the same manner as the actual samples. Key steps involved in spiking include:
Preparation of Spiking Solution: A concentrated solution of the analyte is prepared, often in a solvent compatible with the sample matrix.
Addition to Sample: A calculated volume of the spiking solution is added to the blank sample to achieve the desired concentration.
Mixing: The sample is thoroughly mixed to ensure homogeneity.
Applications of Spiking
Spiking has a wide range of applications in bioanalytical sciences, including: Pharmacokinetic Studies: Spiking is used to validate the methods employed in
pharmacokinetic studies to ensure accurate measurement of drug concentrations in biological samples.
Toxicology: In
toxicology, spiking helps in the validation of methods used to detect and quantify toxins in biological specimens.
Clinical Chemistry: Spiking is used to validate and calibrate methods for measuring biomarkers, hormones, and other clinical analytes.
Challenges and Considerations
While spiking is a valuable tool, it comes with its own set of challenges and considerations: Matrix Effects: The presence of other substances in the sample matrix can affect the recovery and measurement of the spiked analyte, a phenomenon known as
matrix effects.
Stability: The stability of the spiked analyte in the sample matrix must be considered, as degradation can affect the accuracy of the results.
Homogeneity: Ensuring that the spiked analyte is evenly distributed throughout the sample is crucial for accurate measurement.
Conclusion
Spiking is a fundamental practice in bioanalytical sciences that plays a critical role in the validation, calibration, and quality control of analytical methods. By understanding and effectively applying spiking techniques, researchers can ensure the accuracy, precision, and reliability of their analytical results, thereby advancing the field of bioanalysis.
