Analytical Recovery

Analytical recovery is the measured amount attributable to a known spike divided by the amount added. The relation is useful for Evaluate sample-preparation losses, matrix effects and analytical accuracy.. A sample receives a 2.00 mg spike and yields a blank-corrected increment of 1.86 mg. Recovery=1.86/2.00·100%=93.0%. Check: numerator and denominator refer to the same spike. The final check tests a balance, direction or magnitude relevant to this formula. First map each quantity to the actual experiment, then substitute values. The result describes the modelled relationship; it does not automatically establish every mechanism in the real sample.

The symbols mean: m_gefunden: analyte amount measured by the method (mg or mol); m_zugesetzt: known amount added as spike (mg or mol). Follow Recovery in % · measured and added mass or amount in the same unit. Concentrations, activities, volumes and times must use compatible scales. A logarithm needs a dimensionless argument, and a balance must include all contributing species. State temperature and standard state whenever they are part of the definition; otherwise the result may refer to a different chemical condition. An amount is not a mass without molar mass, and activity is not an unnormalised concentration. Say whether inputs were measured or taken from a reference.

State whether the numerator is the total measured analyte or the blank-corrected increment. Use matrix-matched spikes, replicates and a defined range. Recovery evaluates method accuracy under stated conditions; it is not a universal correction factor for every sample. Check this assumption for the actual sample, temperature and phase. Nonideality, mass transport or side reactions can make a precise calculation systematically wrong. Compare the balanced reaction and the activity or concentration scale with the model, then state the assumption that most affects the result. Near model boundaries, check activities and phase state rather than extending a dilute-solution approximation. Different conditions require a fresh model check.

Recalculate the example: A sample receives a 2.00 mg spike and yields a blank-corrected increment of 1.86 mg. Recovery=1.86/2.00·100%=93.0%. Check: numerator and denominator refer to the same spike. Check Recovery in % · measured and added mass or amount in the same unit and substitute the value back into the relation. Also ask whether its sign, balance or magnitude is chemically plausible. If a check fails, inspect units, coefficients and reference values before blaming rounding. Substitution checks the algebra; comparing assumptions with the experiment checks whether the model is appropriate.

Analytical Recovery is related to Linear Calibration Line, Standard Addition in Analytical Chemistry, Limit of Detection and Limit of Quantification, Chromatographic Resolution, E-Factor in Green Chemistry, Internal Standard and Relative Response Factor, but answers a distinct question: Evaluate sample-preparation losses, matrix effects and analytical accuracy.. Do not confuse it with a relation for a neighboring quantity or a different standard state. Name the target quantity and sample conditions first, then choose the equation containing that quantity. Similar-looking equations may use different stoichiometric bases or validity ranges. The linked entries may supply inputs for another step, but they do not replace this distinction. This keeps the interpretation auditable.