Tap water is measured for arsenic andfound to have a mean signal of 0.0061.Next, a small amount of Arsenic is spikedinto the tap water such that the new valueis 0.700 ppb higher than before. The meansignal from this new low-levelconcentration is 0.0447, with a standarddeviation of 0.00560. What is the LowerLimit of Quantitation?(Hint: estimate slope as fraction numeratortriangle Y over denominator triangle X endfraction , where triangle Y is the differencebetween the low level spike and the blanksignals; and triangle X is the concentrationchange between the spiked and unspikedsample)

Concept: Lower limit of quantitation: A signal that is 10 times greater than the noise or the…

Tap water is measured for arsenic and found to have a mean signal of 0.0061. Next, a small amount of Arsenic is spiked into the tap water such that the new value is 0.700 ppb higher than before. The mean signal from this new low-level concentration is 0.0447, with a standard

Tap water is measured for arsenic and found to have a mean signal of 0.0061. Next, a small amount of Arsenic is spiked into the tap water such that the new value is 0.700 ppb higher than before. The mean signal from this new low-level concentration is 0.0447, with a standard

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter4: Least-squares And Calibration Methods

Section: Chapter Questions

Problem 11P

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Question

Tap water is measured for arsenic and
found to have a mean signal of 0.0061.
Next, a small amount of Arsenic is spiked
into the tap water such that the new value
is 0.700 ppb higher than before. The mean
signal from this new low-level
concentration is 0.0447, with a standard
deviation of 0.00560. What is the Lower
Limit of Quantitation?
(Hint: estimate slope as fraction numerator
triangle Y over denominator triangle X end
fraction , where triangle Y is the difference
between the low level spike and the blank
signals; and triangle X is the concentration
change between the spiked and unspiked
sample)

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