Advantages and Disadvantages of ICP-MS

15

Advantages of ICP-MS

• Detection limits are 10-100 time

s superior to those of ICP-

AES.

• Ability to provide element

al isotopic ratio information.

• Roughly 25 elements can be analyzed in duplicate and

with good precision in 1-2 minutes.

• Large linear dynamic working range.

• The effective combination of

differing types of ICP-MS

instruments coupled with the m

any varied types of sample

introduction allow for customiz

ation of techniques for a

specific sample type or form of analyte.

Disadvantages of ICP-MS

• The lower-cost ICP-MS system

s utilize single-quadrupole

mass analyzer systems, which are inherently sequential

systems, and have relatively low mass resolution.

• Higher cost than ICP-AES, with a much lower body of

knowledge and understanding av

ailable than the other

technique.

• Elements such as Ca and Fe are difficult to determine by

conventional Ar ICP-MS bec

ause of mass spectral

interferences by argides.

• If Ni cones are used, can have as much as 5 ppt of nickel

being detected as orifice ions

. This can be alleviated by

switching to more expensive Pt cones.

• Generally requires a clean r

oom environment for ultra-low

detection limits.

16

Disadvantages of ICP-MS

•An outstanding ICP-AES instrum

ent offers a long-term RSD

of less than 1% compared to le

ss than 4% for most ICP-MS

systems.

•The presence of oxides and

doubly-charged ions in the

plasma deteriorates the quantitat

ive capability of ICP-MS in

ultratrace analysis.

•ICP-MS instruments are more su

sceptible to instability than

ICP-AES intruments when running samples with higher

levels of total dissolved solids.

•The relatively cooler sampler and skimmer cones provide

direct contact points for sample

deposition from

the plasma,

and can become clogged over time when difficult matrices

are analyzed.

Needed Improvements in ICP-MS

• Speciation approaches must

be devised or refined.

• Matrix interferences must be

better understood and controlled.

• Less expensive instruments for the elimination of spectral

interferences must be developed.

• Alternative sources and mass spectrometers should be

considered and evaluated.

• Sample-introduction effici

ency must be improved.

• Sample-utilization efficien

cy ought to be raised.

• Precision must be increased.

• Instrumentation should be reduced

in price and made simpler

to use.