Abstract
In this study, capillary electrophoresis (CE) was used for separation of
inorganic and organic ions from waters of paper and paperboard machines
at mills. The instrument was constructed for on-line measurements by
building a batch-type sample feeding unit. Chloride, thiosulphate,
sulphate, oxalate, sulphite, hydrogen sulphide, formate, carbonate,
phosphate and acetate in the process water samples were separated using
an ion-specific separation system in CE with dicarboxylic acid buffer
(pH 8.2), with pyridinium-2,3-dicarboxylic acid modified with commercial
NICE-Pak OFM-OH solution (pH 12.0) or with a cetyltrimethylammonium
bromide solution modified with chromate (pH 10.6). In addition, Analis
CEofix Anions 8 electrolyte solution was tested in on-line studies at
mills. It allowed 5 min separation time for the anions. Aluminium was determined at pH 3.6 in 10 min
by using a laboratory-made imidazole buffer modified with 18-crown
6-ether. The developed CE systems were used to monitor the
concentrations of sulphur species in dithionite degradation, to estimate
corrosion degree in the water tanks, to monitor formaldehyde as the
biocide chemical in wire washing and, in general, to observe process
disturbances resulting from chemical feedings and their sites. The CE
combination was on-line coupled to eight different process machines for
continuous monitoring of concentrations for periods between two weeks
and one month at paper and pulp mills in Finland.
Original language | English |
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Pages (from-to) | 243-252 |
Journal | Journal of Chromatography A |
Volume | 1032 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 2004 |
MoE publication type | A1 Journal article-refereed |
Keywords
- process monitoring
- water analysis
- paper
- inorganic anions
- organic acids