INSTRUMENTAL ANALYSIS ACS
COMPREHENSIVE EXAM 2026 TEST PAPER
QUESTIONS AND SOLUTIONS GRADED A+
● how to calculate calibration sensitivity Answer: y=mx+b (m is the
calibration sensitivity)
graph concentration vs mean analytical signal
● how to find the analytical sensitivity Answer: As (concentation) =
calibration sensitivity/SD [ ]
● how to find the coefficient of variation for the mean of each of the
replicate sets Answer: CV = SD/Average x 100
● how to find the detection limit for method? Answer:
3.3*SD(blank)/calibration sensitivity
● voltage in a series Answer: Vt = Vc + Vb + Va
● Voltage in a parallel circuit Answer: 1/Veff = 1/Va + 1/Vb
,● Capacitance in a series Answer: 1/Ceff = 1/Ca + 1/Cb
● capacitance equals Answer: Q/V
● 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 Answer: a) (S/N)a = sqrt(n) (S/N)b
b) 105
● what type of noise can be reduced by decreasing the temperature of a
measurement Answer: thermal noise
● what type of noise can be reduced by decreasing the frequency used
for the measurement Answer: flicker noise
● what type of noise can be reduced by decreasing the bandwidth of the
measurement Answer: environmental noise
● What would be an appropriate source and detector to determine the
emission lines for lithium from 200 to 780 nm? Answer: flame and
photo multiplier tube (PMT)
, ● 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? Answer: fused silica or quartz
● which of the following changes will result in a decreased effective
bandwidth?
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 Answer: a
● what would be the distance between blazes for a grating where the
first order diffraction line for 600 nm light is reflected at 10 degrees and
the angle of incidence light is 45 degrees?
a) formula
b) answer Answer: a) n(wavelength) = distance*(sin(i)+sin(r))
b) 680 nm
● which of the following would be considered a discontinuous
wavelength selector?
a) quartz prism
b) Czerny-Turner Grating (monochormator)
c)interference filter
COMPREHENSIVE EXAM 2026 TEST PAPER
QUESTIONS AND SOLUTIONS GRADED A+
● how to calculate calibration sensitivity Answer: y=mx+b (m is the
calibration sensitivity)
graph concentration vs mean analytical signal
● how to find the analytical sensitivity Answer: As (concentation) =
calibration sensitivity/SD [ ]
● how to find the coefficient of variation for the mean of each of the
replicate sets Answer: CV = SD/Average x 100
● how to find the detection limit for method? Answer:
3.3*SD(blank)/calibration sensitivity
● voltage in a series Answer: Vt = Vc + Vb + Va
● Voltage in a parallel circuit Answer: 1/Veff = 1/Va + 1/Vb
,● Capacitance in a series Answer: 1/Ceff = 1/Ca + 1/Cb
● capacitance equals Answer: Q/V
● 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 Answer: a) (S/N)a = sqrt(n) (S/N)b
b) 105
● what type of noise can be reduced by decreasing the temperature of a
measurement Answer: thermal noise
● what type of noise can be reduced by decreasing the frequency used
for the measurement Answer: flicker noise
● what type of noise can be reduced by decreasing the bandwidth of the
measurement Answer: environmental noise
● What would be an appropriate source and detector to determine the
emission lines for lithium from 200 to 780 nm? Answer: flame and
photo multiplier tube (PMT)
, ● 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? Answer: fused silica or quartz
● which of the following changes will result in a decreased effective
bandwidth?
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 Answer: a
● what would be the distance between blazes for a grating where the
first order diffraction line for 600 nm light is reflected at 10 degrees and
the angle of incidence light is 45 degrees?
a) formula
b) answer Answer: a) n(wavelength) = distance*(sin(i)+sin(r))
b) 680 nm
● which of the following would be considered a discontinuous
wavelength selector?
a) quartz prism
b) Czerny-Turner Grating (monochormator)
c)interference filter
