L1 /
3
CH3041
INTERNAL STANDARDS
• 2) Internal
Standard
A known amount of a standard compound different from the analyte
(the internal standard)
is added to the
sample.
A known amount of a standard compound different from the analyte
(the internal standard)
is added to the
sample.
ui = unknown containing analyte i
uj = unknown containing known conc. of
internal standard j
uj = unknown containing known conc. of
internal standard j
refi = reference known conc. of analyte i
refj = reference known conc. of standard j
refj = reference known conc. of standard j
Iu(i) = signal of
analyte in unknown
Iu(j) = signal of internal standard in unknown
Iu(j) = signal of internal standard in unknown
• Used in GC-MS.
