multi N/C pharma HT
Function and design
35
oxidizable one. The ratio of the recovery rate of p-benzoquinone to the recovery rate of
sucrose must be within the range of 85 to 115 %. Only then is the selected method suit-
able.
Procedure:
}
Create a reference solution of sucrose and TOC water with a concentration of 500
µg/l. This corresponds to a concentration of 1.19 mg/l sucrose.
}
Prepare a solution of p-benzoquinone and TOC water that also has a concentration
of 500 µg/l to check system suitability. This corresponds to a concentration of
0.75 mg/l p-benzoquinone.
}
Determine the TOC concentrations of the reference solution, the system suitability
solution and the TOC water in the selected mode (direct or differential method).
The effectiveness of the system in percent is calculated using the following formula:
E = (r
ss
– r
W
)/(r
s
– r
W
) x 100
E: System efficiency in %
r
s
: TOC of the reference solution (sucrose)
r
ss
: TOC of the system suitability solution (p-benzoquinone)
r
w
: TOC of the TOC water used (preparation water blank value)
