In isotopic dilution, what outcome is achieved?

In isotopic dilution, what outcome is achieved?

• A. Compensate for matrix effects and instrument variability.
• B. Increase the analyte's concentration by dilution.
• C. Eliminate the need for calibration.
• D. Change the analyte's identity.

Answer: (A)

Isotopic dilution achieves accurate quantitation by adding a stable-isotope–labeled version of the target analyte as an internal standard to the sample. Because the labeled and native molecules behave identically through extraction, chromatography, and ionization, any matrix effects or instrument fluctuations affect both forms equally. By comparing the signal ratio of the native analyte to the labeled standard, those variations cancel out, yielding reliable measurements of the analyte concentration. This approach also helps account for losses during sample preparation since both forms are recovered together. It does not increase the analyte’s concentration, eliminate the need for calibration altogether, or change the analyte’s identity.

Isotopic dilution achieves accurate quantitation by adding a stable-isotope–labeled version of the target analyte as an internal standard to the sample. Because the labeled and native molecules behave identically through extraction, chromatography, and ionization, any matrix effects or instrument fluctuations affect both forms equally. By comparing the signal ratio of the native analyte to the labeled standard, those variations cancel out, yielding reliable measurements of the analyte concentration. This approach also helps account for losses during sample preparation since both forms are recovered together. It does not increase the analyte’s concentration, eliminate the need for calibration altogether, or change the analyte’s identity.