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Metrohm 792 Basic IC User Manual

Page 104

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4.4 Methods

792 Basic IC

95

Notations

R

Stands for response value, either

area or height, de-

pending 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 injection.

V' = V / D

Adjusted volume

of injected sample. A correction is

made for the dilution coefficient.

C

Concentration of the component in the initial solution

(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. de-

tector 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 compo-

nent in the analyzed mixture is calculated by the for-

mula C = W(R) / V'.

RSD(Q, R)

Procedure, used for computation of regression coef-

ficients (k

0

, k

1

and k

2

) of the calibration function W(R)

using RSD (Residual Standard Deviation). The proce-

dure gets input as a set of calibration points (quantity
Q

vs. response R) and outputs the calibration func-

tion 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.