Direct method for the determination of phenolic hydroxyl groups in pulp

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8 Citations (Scopus)

Abstract

AbstractFor evaluation of changes in phenolic lignin units during kraft pulping and bleaching, a direct method based on UV reflectance measurements of pulp handsheets was tested. Similar trends in total phenolic hydroxyl-group contents were evident when UV reflectance results for isolated lignins and pulp sheets were compared. This direct method gave reliable results after alkaline cooking, oxygen delignification, and bleaching stages followed by alkaline extraction (DE, ZE). However, the phenolic content obtained after peroxide bleaching (QP) was over-estimated. This may be due to alkali-induced reactions during pH adjustment of the sheets for measurement concomitant with ionisation of the phenolic hydroxyl groups. Otherwise, this direct method based on UV reflectance measurements is a promising new approach for determining the total content of phenolic lignin units in pulp sheets without isolating the lignin.
Original languageEnglish
Pages (from-to)623-627
JournalHolzforschung
Volume61
Issue number6
DOIs
Publication statusPublished - 2007
MoE publication typeA1 Journal article-refereed

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Lignin
Hydroxyl Radical
Pulp
Bleaching
Reflectometers
Kraft process
Delignification
Cooking
Peroxides
Alkalies
Ionization
Oxygen

Cite this

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title = "Direct method for the determination of phenolic hydroxyl groups in pulp",
abstract = "AbstractFor evaluation of changes in phenolic lignin units during kraft pulping and bleaching, a direct method based on UV reflectance measurements of pulp handsheets was tested. Similar trends in total phenolic hydroxyl-group contents were evident when UV reflectance results for isolated lignins and pulp sheets were compared. This direct method gave reliable results after alkaline cooking, oxygen delignification, and bleaching stages followed by alkaline extraction (DE, ZE). However, the phenolic content obtained after peroxide bleaching (QP) was over-estimated. This may be due to alkali-induced reactions during pH adjustment of the sheets for measurement concomitant with ionisation of the phenolic hydroxyl groups. Otherwise, this direct method based on UV reflectance measurements is a promising new approach for determining the total content of phenolic lignin units in pulp sheets without isolating the lignin.",
author = "Tiina Liiti{\"a} and Tarja Tamminen",
year = "2007",
doi = "10.1515/HF.2007.101",
language = "English",
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pages = "623--627",
journal = "Holzforschung",
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Direct method for the determination of phenolic hydroxyl groups in pulp. / Liitiä, Tiina; Tamminen, Tarja.

In: Holzforschung, Vol. 61, No. 6, 2007, p. 623-627.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Direct method for the determination of phenolic hydroxyl groups in pulp

AU - Liitiä, Tiina

AU - Tamminen, Tarja

PY - 2007

Y1 - 2007

N2 - AbstractFor evaluation of changes in phenolic lignin units during kraft pulping and bleaching, a direct method based on UV reflectance measurements of pulp handsheets was tested. Similar trends in total phenolic hydroxyl-group contents were evident when UV reflectance results for isolated lignins and pulp sheets were compared. This direct method gave reliable results after alkaline cooking, oxygen delignification, and bleaching stages followed by alkaline extraction (DE, ZE). However, the phenolic content obtained after peroxide bleaching (QP) was over-estimated. This may be due to alkali-induced reactions during pH adjustment of the sheets for measurement concomitant with ionisation of the phenolic hydroxyl groups. Otherwise, this direct method based on UV reflectance measurements is a promising new approach for determining the total content of phenolic lignin units in pulp sheets without isolating the lignin.

AB - AbstractFor evaluation of changes in phenolic lignin units during kraft pulping and bleaching, a direct method based on UV reflectance measurements of pulp handsheets was tested. Similar trends in total phenolic hydroxyl-group contents were evident when UV reflectance results for isolated lignins and pulp sheets were compared. This direct method gave reliable results after alkaline cooking, oxygen delignification, and bleaching stages followed by alkaline extraction (DE, ZE). However, the phenolic content obtained after peroxide bleaching (QP) was over-estimated. This may be due to alkali-induced reactions during pH adjustment of the sheets for measurement concomitant with ionisation of the phenolic hydroxyl groups. Otherwise, this direct method based on UV reflectance measurements is a promising new approach for determining the total content of phenolic lignin units in pulp sheets without isolating the lignin.

U2 - 10.1515/HF.2007.101

DO - 10.1515/HF.2007.101

M3 - Article

VL - 61

SP - 623

EP - 627

JO - Holzforschung

JF - Holzforschung

SN - 0018-3830

IS - 6

ER -