Agilent Technologies 7500 ICP-MS

A-14
Agilent 7500 ICP-MS ChemStation Operator’s Manual
Appendix
Internal Standard
When an internal standard is selected, the count of each data point in the calibration
curve is divided by the ratio of the count per concentration of the internal standard
of the same level.
where
This value is used as the measured value of y in the following sections.
Correlation Coefficient
This value is calculated using the following formula.
where
: average of
: average of
: measured value of
: measured value of
This is available only for linear regressions.
()
y
y
yx y
y
x
ii
i
===
σσ
// ( if ) 0
x
y
y
i
i
:
:
:
concentration of internal standard
count of internal standard
count of sample data
σ
τ
x
i
x–()y
i
y–(){}
i
∑
x
i
x–()
2
i
∑
y
i
y–()
2
i
∑
⎩⎭
⎨⎬
⎧⎫
12⁄
--------------------------------------------------------------------------------
=
x x
i
y y
i
x
i
x
y
i
y