CN104655580B - A kind of method of the chemical cellulose content in quick measure dissolving pulp - Google Patents
A kind of method of the chemical cellulose content in quick measure dissolving pulp Download PDFInfo
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- CN104655580B CN104655580B CN201510072051.XA CN201510072051A CN104655580B CN 104655580 B CN104655580 B CN 104655580B CN 201510072051 A CN201510072051 A CN 201510072051A CN 104655580 B CN104655580 B CN 104655580B
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Abstract
The invention discloses a kind of method for determining chemical cellulose content in dissolving pulp, and in particular to a kind of method that utilization ultraviolet visible spectrometry determines chemical cellulose content in dissolving pulp.Its step is：(1) sample pretreatment；(2) standard curve or Mathematical Modeling are set up；(3) sample is detected using ultraviolet/visible spectrophotometer；(4) result is calculated.Organic effect of this method is to employ the above method to determine chemical cellulose content in dissolving pulp, and fast and convenient with operating, testing result only needs can just provide for one hour, and result is objective and accurate.
Description
Technical field
The present invention relates to the alpha fibre in pulping and paper-making and field of textile industry, more particularly to a kind of quick measure dissolving pulp
The method of cellulose content.
Background technology
Dissolving pulp is the high-purity bleached chemical refined stock of a kind of alpha-cellulose high, low hemicellulose and lignin.It is many
The raw material of chemical products are planted, multiple fiber element derivative can be prepared by method chemically or physically, be such as made various
Cellulose ether, cellulose esters etc..With dissolving pulp as raw material prepare cellulose derivative product when, its purity (commonly referred to as α-fibre
Dimension cellulose content) there is highly important influence to the operation of subsequent production cellulose derivative and products thereof quality.Such as, in viscose glue
In fiber production process, the height of its alpha-cellulose content, to the yield of alkali process section, the carbon disulfide consumed to sulfonation section
Amount and obtained viscose rayon quality all play conclusive effect.Therefore, a kind of quick, simple and effective alpha-cellulose contains
Quantity measuring method is the important prerequisite for implementing dissolving pulp product quality supervision.Measure on alpha-cellulose content in dissolving pulp,
Traditional method is mainly the mass ratio of remaining alkali cellulose and primary sample after determining mercerization, or surveys respectively
Determine alkali cellulose and filtrate in acid condition by potassium dichromate oxidation after, the sulfuric acid that it is each consumed using titration measuring
The ratio between milliliter number of ferrous ammonium salt solution come represent slurry in alpha-cellulose content.Both approaches not only take, and operate numerous
It is trivial.Therefore, it is necessary to developing a kind of new detection method carrys out the quick and easy content for determining alpha-cellulose in dissolving pulp.Closely
Nian Lai, someone is established using near-infrared spectrum technique combination chemometrics and directly determine alpha-cellulose in plant fiber material
The method of content.But the method is not only without very clear and definite physical significance, and substantial amounts of primary sample is needed in modeling
And institute's established model has significant limitation.
As shown in formula (1), alpha-cellulose is the ratio that alkali resistance part accounts for total fibre mass.
W in formulaa, --- the quality of alkali resistance cellulose/hemicellulose, g；
ws--- the quality of alkali solubility cellulose/hemicellulose, g；
wi--- the quality of ash content or other impurity, g.
For dissolving pulp, the quality of lignin, ash content or other impurity can be ignored.Therefore,
wα+ws=100% (2)
Therefore, it can be obtained indirectly by determining the alkali-soluble substance being dissolved in filter liquor the amount of alpha-cellulose.Many institutes
Known, alkali solubility cellulose/hemicellulose can be separated out in ethanol-water solution, generate micron particles, so that solution is produced
Turbidity.Therefore, it can using this analysis of ultraviolet visible spectrometry quick (only needing 1~2min), easy to operate (sample is without place
Reason), the measuring technology of favorable reproducibility determines turbidity, then by mathematical computations, realizes to alpha-cellulose content in dissolving pulp
Quick and easy measure.So, the alpha-cellulose content in dissolving pulp is determined using ultraviolet/visible light spectrometry solid
Theoretical foundation, and absorption spectrum has significant physical significance.
The content of the invention
Shortcoming and defect it is an object of the invention to overcome above-mentioned prior art, there is provided in a kind of quick measure dissolving pulp
Alpha-cellulose content method.The drawbacks of overcoming existing for the method for alpha-cellulose content in present analysis paper pulp.The present invention
Alkali-soluble substance is separated out using alcohol, it is produced turbidity in the solution, dissolving pulp is then determined using ultraviolet/visible color spectrometry
The content of middle alpha-cellulose.The method can realize quick measure, and its analysis result accuracy is high and easy to operate.
The present invention is achieved through the following technical solutions：
A kind of method of the alpha-cellulose content in quick measure dissolving pulp, comprises the following steps：
(1) sample pretreatment：
Testing sample is put into beaker, to the sodium hydroxide solution that addition mass fraction in beaker is 18% or 10%,
Beaker is put into water bath with thermostatic control again, with tack glass bar compregnate sample repeatedly；
Then remaining sodium hydroxide solution is added, and is stirred；
Beaker finally is covered with surface plate, starts reaction, and record is tied since first time adds NaOH to reaction
Time during beam, the i.e. time of mercerization process, after question response terminates, beaker is taken out, and with the glass after cleaned and air-dried
Glass filter and bottle,suction are filtered, and collect filtrate with vial with cover；The testing sample is dissolving pulp；
(2) standard curve is set up：After the dissolving pulp of known different alpha-cellulose contents is processed through step (1), to gained
Filtrate carries out ultraviolet visible spectrometry detection, according to the alpha fibre in resulting spectral absorbance signal value and known dissolving pulp
Corresponding relation between cellulose content, obtains a standard curve or a universal model；
(3) sample detection：With pipette pipette 0.2-2mL steps (1) process after filtrate to 10~20mL volumetric flasks in,
Addition absolute ethyl alcohol is 5~10mL, finally uses deionized water constant volume, and shake up mixed liquor；Mixed liquor is poured into cuvette, so
After carry out ultraviolet visible spectrometry detection, record its spectral absorbance signal value；
(4) result is calculated：Standard curve obtained by step (3) gained spectral signal value and step (2) is compared or
Input universal model, obtains alpha-cellulose content in sample.
It is used for the sample absolute dry mass for pre-processing in above-mentioned steps (1) for 2.5 ± 0.05g (claims accurate to 1mg), the compregnate
Time is 2~3min, and the time of the mercerization process is 60min, and the water bath with thermostatic control temperature is 20 DEG C ± 2 DEG C；The burning
Cup volume is 150mL, and glass filter (model 1G2) volume is 30mL, and the bottle,suction volume is 250mL.
Standard sample in above-mentioned steps (2) is the dissolving pulp of the different alpha-cellulose contents that same raw material is prepared
When, what is obtained is standard curve；If step (2) Plays dissolving pulp sample type is unknown, by multidimensional data processing method
Treatment optic spectrum line, obtains a universal model.
The measure wavelength that above-mentioned steps (2) are described when setting up standard curve is 500nm；Set up the suction selected during universal model
It is 400~800nm to receive spectral signature wave band.
When testing sample described in above-mentioned steps (4) is identical with the species for starching sample when setting up standard curve, according to standard
The mathematical formulae of curve can calculate the alpha-cellulose content in sample；When testing sample species is unknown, to original absorbance spectrum
Treatment, including first derivative treatment is carried out to the spectrum of gained, then universal model is input to after doing smoothing processing to curve obtained
In, experimental results after being analyzed through universal model.
It refers to physical significance from absorption spectrum that features described above wave band is extracted, investigate except alpha-cellulose in dissolving pulp and
The factor impacted to absorption spectrum outside hemicellulose, if influence of these factors to absorption spectrum can be by single order
Derivative spectrum treatment is eliminated, then the factor is ignored, if can not eliminate, needs to reject the wave band of influence caused by the factor, is removed
Remaining wave band is the characteristic wave bands to be extracted after going to reject wave band.
The method that above-mentioned steps (2) are described to set up universal model is：Known alpha-cellulose content is obtained from different slurry factories
Dissolving pulp sample；Then the pretreatment filtrates to these samples carry out uv-vis spectra scanning, the spectrum of acquisition are carried out pre-
Treatment, sets up the mapping between alpha-cellulose content in feature spectrogram and slurry, so as to obtain a universal model for refining, and should
Universal model provides alpha-cellulose content in slurry to be measured according to the ultraviolet/visible light spectrum information of input.
The present invention has the following advantages and effect relative to prior art：
It is of the invention compared with traditional detection method (GB/T 744-2004), have the following advantages：
First, when determining the alpha-cellulose content in dissolving pulp using this method, it is not necessary to after pretreatment in step (1)
The alkali for obtaining does not allow the residue to carry out washing (first with pickling, reusable heat distillation be washed to neutrality) repeatedly；
Secondly, it is not required that the alkali insoluble residue constant weight after to cleaning weighs (typically at least needing 6h)；Only need to step
(1) filtrate obtained after pretreatment in carries out ultraviolet-visible analysis of spectrum (＜ 10min), is then brought into spectroscopic data in advance
The alpha-cellulose content in dissolving pulp is obtained by the standard curve or universal model that establish.
Therefore, when carrying out the alpha-cellulose content in dissolving pulp using this method, not only can with streamline operation, and
Greatly shorten the testing time (pretreatment time and spectroscopic assay time and about 1h), allow testing result on the spot to
Go out, and result is objective and accurate (relative deviation is within 0.5%).Be particularly well-suited in laboratory batch samples analysis and
The timely monitoring of sample alpha-cellulose content is starched after being floated in factory floor.
Technical measure is easy, is not only applicable dissolving pulp but also applicable lignin and content of ashes are negligible
Paper pulp.
Brief description of the drawings
Fig. 1 is the ultraviolet/visible light spectrum absorbance signal value-alkali-soluble substance concentration standard curve in example 1.
Fig. 2 is the first derivative spectrum figure of universal model in example 2.
Fig. 3 is the relation between the predicted value that is obtained by universal model and actual value in example 2.
Specific embodiment
The present invention is more specifically described in detail with reference to specific embodiment.
Embodiment 1
Determine the content of alpha-cellulose in Eucalyptus and Chinese red pine dissolving pulp
(1) sample pretreatment：The accurate Eucalyptus for weighing the oven dry weight equivalent to 2.50g (being accurate to 1mg) or masson pine
Dissolving pulp sample in beaker, then to the sodium hydroxide solution that the mass fraction for adding 25mL in beaker is 18%, then by beaker
It is put into water bath with thermostatic control, with tack glass bar 2~3min of compregnate sample repeatedly.Then remaining sodium hydroxide solution is added,
And stir it.Finally beaker is covered with surface plate.Terminate time-consuming 60min to reaction since first time adds NaOH.Treat
After reaction terminates, beaker is taken out, and with the 30-mL 1G2 glass filters and 250-mL bottle,suction mistakes after cleaned and air-dried
Filter, and collect filtrate with vial with cover.The testing sample is dissolving pulp or the negligible paper pulp of lignin content.
(2) standard curve is set up：By the Eucalyptus and Chinese red pine dissolving pulp of known different alpha-cellulose contents through step (1) place
After reason, ultraviolet visible spectrometry detection is carried out to gained filtrate, according in resulting spectral absorbance signal value and dissolving pulp
Alpha-cellulose content between corresponding relation can obtain respective standard curve；
(3) sample detection：The filtrate after 1mL steps (1) are processed is pipetted in 10mL volumetric flasks with pipette, adds 8mL
Absolute ethyl alcohol, finally uses deionized water constant volume, and shake up mixed liquor.Filtrate is poured into cuvette, UV, visible light is then carried out
Spectroscopic methodology detection, records the spectral absorbance signal value of sample；
(4) result is calculated：Step (3) gained spectral signal value is compared with the standard curve obtained by step (2), is obtained
The content of alpha-cellulose in sample.
(5) measurement result：
Standard curve：CAlpha-cellulose(%)=100-Aq/k
For masson pine and eucalyptus dissolving pulp, k, q value are respectively 0.079,0.5 and in respective standard curve
0.092、0.8。
Embodiment 2
Determine the content of the alpha-cellulose in the dissolving pulp of unknown species
(1) sample pretreatment：The accurate Eucalyptus for weighing the oven dry weight equivalent to 2.50g (being accurate to 1mg) or masson pine
Dissolving pulp sample in beaker, then to the sodium hydroxide solution that the mass fraction for adding 25mL in beaker is 18%, then by beaker
It is put into water bath with thermostatic control, with tack glass bar 2~3min of compregnate sample repeatedly.Then remaining sodium hydroxide solution is added,
And stir it.Finally beaker is covered with surface plate.Terminate time-consuming 60min to reaction since first time adds NaOH.Treat
After reaction terminates, beaker is taken out, and with the 30-mL 1G2 glass filters and 250-mL bottle,suction mistakes after cleaned and air-dried
Filter, and collect filtrate with vial with cover.The testing sample is dissolving pulp or the negligible paper pulp of lignin content.
(2) universal model is set up：After the dissolving pulp of the unknown species of known alpha-cellulose content is processed through step (1),
Ultraviolet visible spectrometry detection is carried out to gained filtrate, the ultraviolet-visible spectrogram to obtaining carries out first derivative and smooth place
Reason, recycles chemometrics software to set up the mapping in feature spectrogram and standard dissolution slurry between alpha-cellulose content, so that
Obtain a universal model for refining；
(3) sample detection：The filtrate after 1mL steps (1) are processed is pipetted in 10mL volumetric flasks with pipette, adds 8mL
Absolute ethyl alcohol, finally uses deionized water constant volume, and shake up mixed liquor.Filtrate is poured into cuvette, UV, visible light is then carried out
Spectroscopic methodology detection, records the spectrogram of sample；
(4) result output：The feature spectrogram that spectrogram obtained by step (3) is obtained after first derivative and smoothing processing
It is input in the universal model set up in step (2), automatically derives a predicted value for alpha-cellulose, records numerical value.
(5) measurement result：
Experimental result is shown in accompanying drawing 3.
As described above, the present invention can be better realized.
Embodiment is only used for explaining the present invention, is not intended to limit the present invention.Other are any without departing from Spirit Essence of the invention
With the change, modification, replacement made under principle, combine, simplify, should be equivalent substitute mode, be included in of the invention
Within protection domain.
Claims (5)
1. the method for the alpha-cellulose content in a kind of quick measure dissolving pulp, it is characterised in that comprise the following steps：
(1) sample pretreatment：
Testing sample is put into beaker, to the sodium hydroxide solution that addition mass fraction in beaker is 18% or 10%, then will
Beaker is put into water bath with thermostatic control, with tack glass bar compregnate sample repeatedly；
Then remaining sodium hydroxide solution is added, and is stirred；
Finally with surface plate cover beaker, start reaction, and record from first time add sodium hydroxide solution to reaction at the end of
Time, i.e. the time of mercerization process, after question response terminates, beaker is taken out, and filtered with the glass after cleaned and air-dried
Device and bottle,suction are filtered, and collect filtrate with vial with cover；The testing sample is dissolving pulp；
(2) standard curve is set up：After the dissolving pulp of known different alpha-cellulose contents is processed through step (1), to gained filtrate
Ultraviolet visible spectrometry detection is carried out, is contained according to resulting spectral absorbance signal value and the alpha-cellulose in known dissolving pulp
Corresponding relation between amount, obtains a standard curve or a universal model；
(3) sample detection：With pipette pipette 0.2-2mL steps (1) process after filtrate to 10~20mL volumetric flasks in, add
Absolute ethyl alcohol is 5~10mL, finally uses deionized water constant volume, and shake up mixed liquor；Mixed liquor is poured into cuvette, Ran Houjin
The detection of row ultraviolet visible spectrometry, records its spectral absorbance signal value；
(4) result is calculated：Step (3) gained spectral signal value is compared or be input into the standard curve obtained by step (2)
Universal model, obtains alpha-cellulose content in sample；
The sample absolute dry mass for being used to pre-process in step (1) is 2.5 ± 0.05g, and the compregnate time is 2~3min, described
The time of mercerization process is 60min, and the water bath with thermostatic control temperature is 20 DEG C ± 2 DEG C；The beaker volume is 150mL, glass
Filter volume is 30mL, and the bottle,suction volume is 250mL；
When standard sample in step (2) is the dissolving pulp of the different alpha-cellulose contents that same raw material is prepared, obtain
Be standard curve；If step (2) Plays dissolving pulp sample type is unknown, by multidimensional data disposal methods spectrum
Spectral line, what is obtained is a universal model.
2. method according to claim 1, it is characterised in that：The measure wavelength that step (2) is described when setting up standard curve
It is 500nm；It is 400~800nm to set up the absorption spectrum characteristic wave bands selected during universal model.
3. method according to claim 1, it is characterised in that：The species of testing sample and slurry sample when setting up standard curve
When identical, according to the mathematical formulae of standard curve, the alpha-cellulose content in sample is calculated；
When testing sample species is unknown, to original absorbance spectral manipulation, including first derivative treatment is carried out to the spectrum of gained, then
It is input in universal model after smoothing processing is done to curve obtained, experimental results after being analyzed through universal model.
4. method according to claim 3, it is characterised in that：Characteristic wave bands extraction refers to the physical significance from absorption spectrum
Set out, investigate the factor impacted to absorption spectrum in addition to alpha-cellulose in dissolving pulp and hemicellulose, if these
Influence of the factor to absorption spectrum can be processed by first derivative spectrum and eliminated, then the factor is ignored, if can not eliminate, needs
The wave band of influence caused by the factor is rejected, remaining wave band is the characteristic wave bands to be extracted after removing rejecting wave band.
5. method according to claim 4, it is characterised in that：The foundation of universal model：From different slurry factories obtain known α-
The dissolving pulp sample of content of cellulose；
Then the pretreatment filtrates to these samples carry out uv-vis spectra scanning, and the spectrum of acquisition is pre-processed, and build
Mapping in vertical feature spectrogram and slurry between alpha-cellulose content, so as to obtain a universal model for refining, and the Universal Die
Type provides alpha-cellulose content in slurry to be measured according to the ultraviolet/visible light spectrum information of input.
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Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104849166B (en) * | 2015-05-26 | 2018-02-23 | 宜宾丝丽雅集团有限公司 | Method for detecting content of alpha fibers in alkali fibers |
| CN105300901B (en) * | 2015-10-13 | 2018-09-14 | 华南理工大学 | A kind of method of the reactivity worth of rapid and accurate determination dissolving pulp |
| CN105572260B (en) * | 2016-01-19 | 2018-05-15 | 华南理工大学 | One kind measure dissolving pulp in α-, β-and gamma cellulose content method |
| CN106979929B (en) * | 2016-01-19 | 2020-05-19 | 中国制浆造纸研究院有限公司 | Method for rapidly determining reaction performance of dissolving pulp |
| CN109738389A (en) * | 2019-01-15 | 2019-05-10 | 西派特（北京）科技有限公司 | Alkali fibre component quantifying test method based on near-infrared spectrum technique |
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| WO2001079816A1 (en) * | 2000-04-14 | 2001-10-25 | Stora Enso Aktiebolag | Method in connection with the production of pulp, paper or paperboard |
| CN101105444A (en) * | 2007-04-10 | 2008-01-16 | 新疆农业科学院核技术生物技术研究所 | Detection and analysis method for cotton fiber lignin content |
| CN102192890A (en) * | 2010-03-03 | 2011-09-21 | 中国制浆造纸研究院 | Method for rapidly measuring chemical compositions of wood by utilizing near infrared spectroscopic analysis technique |
| CN102998274A (en) * | 2012-11-30 | 2013-03-27 | 华南理工大学 | Method for rapidly measuring total sulfur content in black pulping liquor |
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|---|---|---|---|---|
| WO2001079816A1 (en) * | 2000-04-14 | 2001-10-25 | Stora Enso Aktiebolag | Method in connection with the production of pulp, paper or paperboard |
| CN101105444A (en) * | 2007-04-10 | 2008-01-16 | 新疆农业科学院核技术生物技术研究所 | Detection and analysis method for cotton fiber lignin content |
| CN102192890A (en) * | 2010-03-03 | 2011-09-21 | 中国制浆造纸研究院 | Method for rapidly measuring chemical compositions of wood by utilizing near infrared spectroscopic analysis technique |
| CN102998274A (en) * | 2012-11-30 | 2013-03-27 | 华南理工大学 | Method for rapidly measuring total sulfur content in black pulping liquor |
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| 醋化级溶解浆制备及其理化性能的分析表征;刘文;《中国博士学位论文全文数据库 工程科技Ⅰ辑》;20141115(第11期);第36-38页 * |
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