Page 36 - 5_TOC in daily practice

Sum parameter – Total Organic Carbon

Detection and determination limit of TN

method with TOC-L CXN

SCA-130-520

■ Calculation of detection and

determination limit according to DIN 32645
(based on linear regression)

■ Measurement parameters
System: TOC-L CPN
Catalyst: Standard catalyst
(Al-balls covered with Pt)
Method: TN (with TNM-L)
Injection vol.: 140µl

■ Calibration with automatic dilution
function
A 10 point calibration curve is carried out by Characteristics
using the automatic dilution of a 2mg/L TN Slope a: 30,531
(based on NO3) stock solution. Intercept b: -1,847
Correlation coefficient r: 0,9998
Result uncertainty: 33,3%
Probability of error (a): 5,00%
Number of measurements n: 3
Standard error of estimate Sy: 0,426
Standard error of procedure Sx: 0,014
Sum of squared deviations: 3,3
Quantile (one-sided): 1,860
Quantile (two-sided): 2,306

Limit of detection: 0,023mg/L
Limit of quantification: 0,084mg/L

Note: The results depend on the selected
injection volume, the purity of the
vessels, water, chemicals and gases
used.