multi EA 4000
Measuring methods
43
4.3.2
Direct method for the TOC analysis
With the automatic TIC solids module the TIC and TOC can also be determined directly.
After purging the TIC in the reactor with
hydrochloric acid
and the determination of
the TIC content the sample boat is transferred into the combustion tube. As with the
TC/TS analysis, the sample is digested and oxidized in the oxygen flow at high temper-
ature.
For the determination of the TOC with the automatic TIC solids module hydrochloric
acid must be added to the sample. For the TOC analysis the differential method is
therefore preferred.
For the determination of the TOC without using the automatic TIC solids module hy-
drochloric acid is added to the solids sample in the combustion boat to remove the in-
organically bound carbon. The CO
2
developing from the carbonates in the reaction
evaporates. The wet sample with added acid is dried in the drying cabinet at < 40 °C
for min. 3 hours where the excess hydrochloric acid evaporates. The sample prepared
in this way can then be examined in the multi EA 4000 for organically bound carbon
as for the TC/TS analysis.
Because the acid only releases CO
2
from carbonates and hydrocarbonates, elementary
carbon or the carbon from carbides, cyanides, isocyanates and thiocyanates is also de-
tected as TOC.
4.4
Determination of carbon after pyrolysis: TC-EC (optional)
The determination of the carbon content of a sample takes four steps in the optional
pyrolysis mode.
The original sample is weighed in in two boats–
boat 1 and boat 2
.
1.
The sample in
boat 1
is first pyrolized in the argon flow. In the process the volatile
parts of the carbon compounds contained escape at the selected temperature. Ide-
ally and / or after appropriate pretreatment the elementary carbon (EC) remains
on the boat.
2.
The share of the remaining carbon (EC) in the already pyrolized sample is deter-
mined through combustion in the oxygen flow.
3.
The sample in
boat 2
is moved into the oxygen flow for the determination of the
total carbon content (TC).
4.
From the difference of the two measurements obtained (TC and EC) the volume of
degradable or active carbon can be derived.
4.5
Data analysis in the C/S mode
4.5.1
Calibration techniques
Every parameter (procedure) of a method can be calibrated. The parameters of a
method to be calibrated can be individually defined. Not all parameters need neces-
sarily be calibrated.
Содержание Analytik Jena multi EA 4000
Страница 1: ...Operating Manual multi EA 4000 Elementary analyzer C S and Cl solids analysis...
Страница 50: ...Commissioning multi EA 4000 50 Figure 32 multi EA 4000 C S Hose diagram...
Страница 52: ...Commissioning multi EA 4000 52 Figure 33 multi EA 4000 Cl Hose diagram...
Страница 54: ...Commissioning multi EA 4000 54 Figure 34 multi EA C S Cl for C S measurements Hose diagrams...
Страница 55: ...multi EA 4000 Commissioning 55 Figure 35 multi EA 4000 C S Cl for Cl measurements...
Страница 57: ...multi EA 4000 Commissioning 57 Figure 36 Automatic TIC solids module Hose diagrams...
Страница 58: ...Commissioning multi EA 4000 58 Figure 37 multi EA 4000 C S with automatic TIC solids module...
Страница 60: ...Commissioning multi EA 4000 60 Figure 38 multi EA 4000 with man TIC solids module Hose diagrams...
Страница 61: ...multi EA 4000 Commissioning 61 Figure 39 multi EA 4000 C S Cl with man TIC solids module...
