ACS INSTRUMENTAL ANALYSIS FINAL
PREP Questions and Answers
1.what are the difference between calibration sensitivity and
analytical sensi- tivity
ANS calibration sensitivity is the slope of a calibration curve at the
concentration of interest while analytical sensitivity is a response to the
noise ratio
2.how to calculate calibration sensitivity
ANS y=mx+b (m is the calibration sensitivity)
graph concentration vs mean analytical signal
3.how to find the analytical sensitivity
ANS As (concentation) = calibration sensitivity/SD [ ]
4.how to find the coefficient of variation for the mean of each of
the replicate sets
ANS CV = SD/Average x 100
5.how to find the detection limit for method?
ANS 3.3*SD(blank)/calibration sensitivity
6.voltage in a series
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, ANS Vt = Vc + Vb + Va
7.Voltage in a parallel circuit
ANS 1/Veff = 1/Va + 1/Vb
8.Capacitance in a series
ANS 1/Ceff = 1/Ca + 1/Cb
9.capacitance equals
ANS Q/V
10.if a spectrum is the result of a single scan while another is
the result of multiple scans, how man individual spectra were
summed to increase S/N from 4.2 to 43?
a) formula?
b) answer
ANS a) (S/N)a = sqrt(n) (S/N)b
b) 105
11.what type of noise can be reduced by decreasing the
temperature of a measurement
ANS thermal noise
12.what type of noise can be reduced by decreasing the
frequency used for the measurement
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, ANS flicker noise
13.what type of noise can be reduced by decreasing the
bandwidth of the measurement
ANS environmental noise
14.What would be an appropriate source and detector to
determine the emis- sion lines for lithium from 200 to 780 nm?
ANS flame and photo multiplier tube (PMT)
15.you've been asked to measure the UV absorbance of a
sample containing poly cyclic aromatic hydrocarbons, a
byproduct of the incomplete combustion of organic matter.
What would be an appropriate material for the sample
container?
ANS fused silica or quartz
16.which of the following changes will result in a decreased
effective band- width?
a) increasing the number of blazes in the monochromatic grating
b) switching from a short-pass filter to a long-pass filter
c) increasing sample concentration
d) decreasing the amount of stray light
ANS a
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21
PREP Questions and Answers
1.what are the difference between calibration sensitivity and
analytical sensi- tivity
ANS calibration sensitivity is the slope of a calibration curve at the
concentration of interest while analytical sensitivity is a response to the
noise ratio
2.how to calculate calibration sensitivity
ANS y=mx+b (m is the calibration sensitivity)
graph concentration vs mean analytical signal
3.how to find the analytical sensitivity
ANS As (concentation) = calibration sensitivity/SD [ ]
4.how to find the coefficient of variation for the mean of each of
the replicate sets
ANS CV = SD/Average x 100
5.how to find the detection limit for method?
ANS 3.3*SD(blank)/calibration sensitivity
6.voltage in a series
1/
21
, ANS Vt = Vc + Vb + Va
7.Voltage in a parallel circuit
ANS 1/Veff = 1/Va + 1/Vb
8.Capacitance in a series
ANS 1/Ceff = 1/Ca + 1/Cb
9.capacitance equals
ANS Q/V
10.if a spectrum is the result of a single scan while another is
the result of multiple scans, how man individual spectra were
summed to increase S/N from 4.2 to 43?
a) formula?
b) answer
ANS a) (S/N)a = sqrt(n) (S/N)b
b) 105
11.what type of noise can be reduced by decreasing the
temperature of a measurement
ANS thermal noise
12.what type of noise can be reduced by decreasing the
frequency used for the measurement
2/
21
, ANS flicker noise
13.what type of noise can be reduced by decreasing the
bandwidth of the measurement
ANS environmental noise
14.What would be an appropriate source and detector to
determine the emis- sion lines for lithium from 200 to 780 nm?
ANS flame and photo multiplier tube (PMT)
15.you've been asked to measure the UV absorbance of a
sample containing poly cyclic aromatic hydrocarbons, a
byproduct of the incomplete combustion of organic matter.
What would be an appropriate material for the sample
container?
ANS fused silica or quartz
16.which of the following changes will result in a decreased
effective band- width?
a) increasing the number of blazes in the monochromatic grating
b) switching from a short-pass filter to a long-pass filter
c) increasing sample concentration
d) decreasing the amount of stray light
ANS a
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21
