User Manual of CIC-D100 Ion Chromatograph
39
4.5 Preparation of samples
4.5.1 Selection and preservation of samples
Samples are collected in polytetrafluoroethylene bottles cleaned with ultra-pure water. Do
not wash the container with strong acid or washing liquid to prevent a large amount of anions
from remaining on the container and affecting the accuracy of analysis results.
If the sample cannot be analyzed and used on the day of sampling, it should be immediately
filtered with 0.22μm filter membrane, otherwise the bacteria in the sample may change the
concentration of the sample with time. Even if the sample is stored at 4
℃
, the growth of bacteria
can only be inhibited and cannot be eliminated.
Analyze NO
2-
and SO
32-
samples as soon as possible. They will be oxidized to NO
3-
and
SO
42-
ions respectively. Samples that do not contain NO
2-
and SO
32-
ions can be stored in
refrigerator without significant changes in anion concentration within one week.
4.5.2 Sample Pretreatment
Cleaner samples such as acid rain, drinking water and filter liquor of atmospheric smoke
can be directly injected for analysis. However, samples containing more other impurities, such as
wastewater and surface water, need to be pretreated according to requirements before injection
analysis. For samples with high concentration of impurities, the impurities should be filtered out
through the pretreatment column in advance. We provide a variety of SPE cartridges for
selection as required.
Before pretreatment, samples should be separately connected to pretreatment columns
(multiple pretreatment columns can be connected at the same time). Hold the pretreatment
column with one hand and push the injector with another hand. If the push-in resistance of the
sample is found to be too large, inspection should be carried out to avoid violent injection.
：
The experimental operators should conduct the experiment strictly in accordance
with the laboratory operation specifications. Protective equipment such as goggles and
Caution
