In situ determination of the syringyl/guaiacyl ratio of residual lignin in pre-bleached eucalypt kraft pulps by analytical pyrolysis

AbstractQuantitative determination of cellulose content by means of diglyme [bis(2-methoxyethyl) ether] isolation is useful for rapid screening experiments. However, diglyme isolation from softwoods results in a certain amount of residual lignin in the cellulose. In this paper, the lignin content (L) in diglyme cellulose of three pine species (Pinus halepensisMiller,Pinus sylvestrisL. andPinus pinasterAiton) was analysed by ATR-FTIR spectroscopy and analytical pyrolysis (Py). Py allowed lignin quantification. The influence of wood milling on cellulose yield was also analyzed and it was shown that a particle size between 10 and 60 mesh did not noticeably influence the cellulose yield or L; however, ball-milling to powder did cause a cellulose loss of around 37%. The diglyme method is only reproducible if the experimental parameters are standardized and meticulously followed.

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INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

Acta Endocrinologica ◽

10.1530/acta.0.0380545 ◽

1961 ◽

Vol 38 (4) ◽

pp. 545-562 ◽

Cited By ~ 2

Author(s):

L. Kecskés ◽

F. Mutschler ◽

I. Glós ◽

E. Thán ◽

I. Farkas ◽

...

Keyword(s):

Pregnant Women ◽

Granulosa Cell ◽

Iron Content ◽

List Type ◽

Granulosa Cell Tumour ◽

Hydrolysis Of ◽

Phenol Fraction ◽

Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

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In situ determination of toughness indices of fibre reinforced concrete

Materials and Structures ◽

10.1617/14157 ◽

2005 ◽

Author(s):

P. Antonaci

Keyword(s):

Reinforced Concrete ◽

Fibre Reinforced Concrete

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In Situ Determination of the Increase in Saturation Solubility of Nanocrystals of Poorly Soluble Drugs

10.26226/morressier.57d6b2bdd462b8028d88d9ab ◽

2016 ◽

Author(s):

Roland Bodmeier

Keyword(s):

Poorly Soluble Drugs ◽

Saturation Solubility ◽

Poorly Soluble

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Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

10.26434/chemrxiv.11345063.v2 ◽

2020 ◽

Author(s):

Keishiro Yamashita ◽

Kazuki Komatsu ◽

Hiroyuki Kagi

Keyword(s):

Crystal Structure ◽

High Pressure ◽

Crystal Growth ◽

Single Crystal ◽

Room Temperature ◽

Growth Technique ◽

Salt Hydrate ◽

X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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