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INSTRUMENTAL ANALYSIS ACS EXAM
2026- WELL REVISED ASSESSMENT EXAM
WITH VERIFIED ANSWERS
How to calculate signal to noise - correct-answer -S/N = mean/STDEV
-inverse of RSD
-STDEV: 5 (#STDEV gaussian curve)
-STDEV: peak-to-peak noise/5
S/N relationships - correct-answer --increase S/N, increase run time
-decrease noise, increase S/N
Beer's Law - correct-answer -
Beer's Law Calculations - correct-answer -
, 2
Hard ionization vs soft ionization - correct-answer --hard: no M+ peak (or small)
-soft: M+ peak is visible
MS: hard ionization sources - correct-answer --impart high quantities of residual
energy in the subject molecule invoking large degrees of fragmentation
MS: hard ionization sources examples - correct-answer --electron impact
Electron Impact (EI) - correct-answer --Uses electron impact to ionize a molecule
-gas phase
-energetic electrons
-possibility of over fragmentation
-hard
-most common
EI advantages - correct-answer --good stability
-universal ionization
-reproducible spectra
INSTRUMENTAL ANALYSIS ACS EXAM
2026- WELL REVISED ASSESSMENT EXAM
WITH VERIFIED ANSWERS
How to calculate signal to noise - correct-answer -S/N = mean/STDEV
-inverse of RSD
-STDEV: 5 (#STDEV gaussian curve)
-STDEV: peak-to-peak noise/5
S/N relationships - correct-answer --increase S/N, increase run time
-decrease noise, increase S/N
Beer's Law - correct-answer -
Beer's Law Calculations - correct-answer -
, 2
Hard ionization vs soft ionization - correct-answer --hard: no M+ peak (or small)
-soft: M+ peak is visible
MS: hard ionization sources - correct-answer --impart high quantities of residual
energy in the subject molecule invoking large degrees of fragmentation
MS: hard ionization sources examples - correct-answer --electron impact
Electron Impact (EI) - correct-answer --Uses electron impact to ionize a molecule
-gas phase
-energetic electrons
-possibility of over fragmentation
-hard
-most common
EI advantages - correct-answer --good stability
-universal ionization
-reproducible spectra
