Page 35 - 5_TOC in daily practice

Sum parameter – Total Organic Carbon

Determination of limit of detection and quantification

for the NPOC method (10mg/l range) using the High
Salt Catalyst

SCA-130-519

■ Calculation of limit of detection and

quantification according to DIN 32645

■ Measurement parameters
System: TOC-L CPH or CPN
Catalyst: High Salt Catalyst
(Pt-coated balls of various size)
Method: NPOC (IC-removal)
Acidification: 1,5%
Sparge time: 1,5 min
Injection vol.: 50µl
Characteristics
■ Calibration with automatic dilution Slope a: 4,555
Intercept b:
0,498
function Correlation coefficient r: 0,9998
A 10-point calibration curve is carried out by Result uncertainty: 33,3%
using the automatic dilution of a 20mg/L C Probability of error (a): 5,00%
stock solution. Number of injections: 3
Standard error of estimate Sy: 0,211
Standard error of procedure Sx: 0,046
© DINTEST

Limit of detection: 0,077mg/L
Limit of quantification: 0,281mg/L

Note: The result depends on the chosen injection
volume and the purity of used gases, reagents and
ultra-pure water.