INSTRUMENTAL ANALYSIS ACS
EXAMINATION TEST 2026 VERIFIED
QUESTIONS AND COMPLETE ANSWERS
GRADED A+
⩥ types of instrumental noise Answer: thermal, shot, flicker,
environmental
⩥ thermal noise cause and how to minimize Answer: - random
movement
- lower temperature
⩥ shot noise cause and how to minimize Answer: - over any period of
time, variation in instrument detection
- have lots of sample to minimize noise, only a problem with low signal
⩥ flicker noise cause and how to minmize Answer: - low frequency
flicker/slight change in signal (lightbulb turning on)
- run blank everytime
,⩥ environmental noise cause and how to minimize Answer: - physical
noise like walking vibrations, breathing, temperature and frequency
events
- you can not really minimize this
⩥ when is atomic spectroscopy used and what for? Answer: most often
used to detect trace amounts of metals in things
⩥ flame source pros and cons Answer: pros: cheaper than ICP, good for
absorbance because not as hot
cons: possible contaminats from flame, oxidation of analyte, sample
waste, flickering and soot can cause problems
⩥ flame source how it works - atomic spec Answer: temp depends on
fuel source, hottest part is the middle of the flame
⩥ graphite furnace souce pros and cons - atomic spec Answer: pros:
samplecan be solid, good for absorbance and small sample sizes, good
sensitivity (more than flame), consistent temperature
cons: can only do one analyte at a time, analyte cant have carbon, hard
to build curve, non reproducible introduction
, ⩥ graphite furnace source how does it work - atomic spec Answer:
grpahite tube with a gas that flows through and wire wrapped around
gets really hot
⩥ ICP torch source - pros and cons - atomic spec Answer: pros: no
matrix effect, ionizes everything, extremely hot, everything can be
excited
cons: not good for absorbance, expensive, destroys sample
⩥ ICP torch how does it work - atomic spec Answer: glass tube with
metal wrapped around it, argon flows through and is sparked ot create
ions and electrons. these flow thorough the tube
⩥ ARC lamp pros and cons - atomic spec Answer: pros: easy sample
prep
cons: not reproducible
⩥ laser ablation source pros and cons - atomic spec Answer: pros: can
map things
cons: small signals, hard to quantify and make calibration curve
⩥ direct source (throwing in flame) for atomic spec pros and cons
Answer: pros: easy
EXAMINATION TEST 2026 VERIFIED
QUESTIONS AND COMPLETE ANSWERS
GRADED A+
⩥ types of instrumental noise Answer: thermal, shot, flicker,
environmental
⩥ thermal noise cause and how to minimize Answer: - random
movement
- lower temperature
⩥ shot noise cause and how to minimize Answer: - over any period of
time, variation in instrument detection
- have lots of sample to minimize noise, only a problem with low signal
⩥ flicker noise cause and how to minmize Answer: - low frequency
flicker/slight change in signal (lightbulb turning on)
- run blank everytime
,⩥ environmental noise cause and how to minimize Answer: - physical
noise like walking vibrations, breathing, temperature and frequency
events
- you can not really minimize this
⩥ when is atomic spectroscopy used and what for? Answer: most often
used to detect trace amounts of metals in things
⩥ flame source pros and cons Answer: pros: cheaper than ICP, good for
absorbance because not as hot
cons: possible contaminats from flame, oxidation of analyte, sample
waste, flickering and soot can cause problems
⩥ flame source how it works - atomic spec Answer: temp depends on
fuel source, hottest part is the middle of the flame
⩥ graphite furnace souce pros and cons - atomic spec Answer: pros:
samplecan be solid, good for absorbance and small sample sizes, good
sensitivity (more than flame), consistent temperature
cons: can only do one analyte at a time, analyte cant have carbon, hard
to build curve, non reproducible introduction
, ⩥ graphite furnace source how does it work - atomic spec Answer:
grpahite tube with a gas that flows through and wire wrapped around
gets really hot
⩥ ICP torch source - pros and cons - atomic spec Answer: pros: no
matrix effect, ionizes everything, extremely hot, everything can be
excited
cons: not good for absorbance, expensive, destroys sample
⩥ ICP torch how does it work - atomic spec Answer: glass tube with
metal wrapped around it, argon flows through and is sparked ot create
ions and electrons. these flow thorough the tube
⩥ ARC lamp pros and cons - atomic spec Answer: pros: easy sample
prep
cons: not reproducible
⩥ laser ablation source pros and cons - atomic spec Answer: pros: can
map things
cons: small signals, hard to quantify and make calibration curve
⩥ direct source (throwing in flame) for atomic spec pros and cons
Answer: pros: easy
