On spiked samples blind analysis should fall between?

On spiked samples blind analysis should fall between?

• A. 60-100
• B. 70-100
• C. 80-120
• D. 90-140

Answer: (C)

In spiked samples used for blind analysis, you’re checking how accurately the method can recover a known amount of analyte added to the sample. The standard target is to recover about 100% of that added amount, but allowing for real-world variability, a typical acceptable range is 80–120% of the added spike. This ±20% window accounts for matrix effects, instrument precision, and small procedural differences, ensuring the method is neither systematically under- nor overestimating. The 80–120% range is preferred because it centers on perfect recovery and provides a balanced tolerance for both under- and over-recovery. Other ranges either cap the upper or lower ends too tightly or shift the window away from 100%, which would not reflect the expected symmetry of typical analytical performance.

In spiked samples used for blind analysis, you’re checking how accurately the method can recover a known amount of analyte added to the sample. The standard target is to recover about 100% of that added amount, but allowing for real-world variability, a typical acceptable range is 80–120% of the added spike. This ±20% window accounts for matrix effects, instrument precision, and small procedural differences, ensuring the method is neither systematically under- nor overestimating.

The 80–120% range is preferred because it centers on perfect recovery and provides a balanced tolerance for both under- and over-recovery. Other ranges either cap the upper or lower ends too tightly or shift the window away from 100%, which would not reflect the expected symmetry of typical analytical performance.