Page 20 - 5_TOC in daily practice

Sum parameter – Total Organic Carbon

Detection and determination limit of

NPOC method with standard catalyst
SCA-130-510

■ Calculation of detection and
determination limit according to DIN 32645

■ Measurement parameters
System: TOC-L CPN
Catalyst: Standard catalyst
(Al-balls covered with Pt)
Method: NPOC (removing of IC by
acidification and sparging)
Acidification: 1,5%
Sparge time: 2 min
Injection vol.: 150µl Characteristics
Slope a: 7,226
■ Calibration with automatic dilution Intercept b: 0,544
function Correlation coefficient r: 0,9997
A 10 point calibration curve is carried out by Result uncertainty: 33,3%
using the automatic dilution of a 2mg/L C Probability of error (a): 5,00%
stock solution. Number of measurements n: 3
Standard error of estimate Sy: 0,108
Standard error of procedure Sx: 0,015
Sum of squared deviations: 3,3
Quantile (one-sided): 1,860
Quantile (two-sided): 2,306

Limit of detection: 0,025mg/L
Limit of quantification: 0,089mg/L

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