Metrohm IC Net 2.0 User Manual

Page 128

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7 Methods

IC Net 2.0

120

7.5.2

Notations

R

Stands for response value, either area or height,

depending on setting selected in the

Calibration

graphs

window.

V

Sample

Volume

injected.

D

Dilution

coefficient, shows number of times to

which the initial solution is dissolved before in-

jection.

V' = V / D

Adjusted volume

of injected sample. A correction

is made for the dilution coefficient.

C

Concentration of the component in the initial so-

lution (before dilution).

Q = C

V'

Quantity

of component, used for calibration curve

construction.

t

Retention time

. Time needed by the mobile phase

to flow through the separation system.

t

0

Void time

. Dead time needed by the mobile

phase to flow through the separation system.

t' = t – t

0

Corrected retention time

, called also net retention

time.

L

Column length.

v = L / t

0

Linear

Flow rate

.

W(R) = k

2

R

2

+ k

1

R + k

0

Calibration function (component quantity W vs.

detector response R). In the case of the most

common linear calibration curve Q = W(R) = k

1

R

it comes through the origin. The concentration of

the component in the analyzed mixture is calcu-

lated by the formula C = W(R) / V'.

RSD(Q, R)

Procedure, used for computation of regression

coefficients (k

0

, k

1

and k

2

) of the calibration

function W(R) using RSD (Residual Standard

Deviation). The procedure gets input as a set of

calibration points (quantity Q vs. response R)

and outputs the calibration function W(R) used

for prediction of the component quantity Q

i

=

W(R

i

)

.

Subscript values used:

j

Stands for j-th calibration level run.

s

Stands for standard component.

i

Stands for component number.

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