DETERMINATION OF LIGNIN IN CEREAL STRAWS

1949 ◽  
Vol 27b (12) ◽  
pp. 915-923 ◽  
Author(s):  
G. A. Adams ◽  
A. E. Castagne
Keyword(s):  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Lignin Content ◽  
Maximum Amount ◽  
Dilute Acid ◽  
Rye Straw ◽  
Total Lignin ◽  
Minimum Yield

Determination of lignin in wheat, oat, barley, and rye straw with 64%, 68%, 72%, 76%, and 80% (wt.) sulphuric acid showed that a minimum yield of lignin containing a maximum amount of methoxyl was obtained with the 72% sulphuric acid. In this respect, cereal straws differ from deciduous woods for which 72% sulphuric acid lignin determinations are unsuitable. Comparison of lignin determinations made with 72% sulphuric acid and with 42% fuming hydrochloric acid, on the same straws, after pretreatment with 1.0% hydrochloric acid, showed that the former method preserves a larger proportion of the methoxyl groups. Both methods recovered more total lignin methoxyl from untreated than from treated straws, with the sulphuric acid retaining the larger amount. It is concluded that lignin determination with 72% sulphuric acid on straws untreated with dilute acid yields a residue most representative of the 'true' lignin content, based on the criterion of maximum methoxyl recovery.

scholarly journals HIDROLISIS RUMPUT LAUT (Glacilaria sp.) MENGGUNAKAN KATALIS ENZIM DAN ASAM UNTUK PEMBUATAN BIOETANOL

Jurnal Kimia ◽  
2016 ◽  
Author(s):  
Yohanes Armawan Sandi ◽  
Wiwik Susanah Rita ◽  
Yenni Ciawi
Keyword(s):  
Gas Chromatography ◽  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Ethanol Concentration ◽  
Reducing Sugar ◽  
Optimum Concentration ◽  
Raw Material ◽  
Optimum Length ◽  
Hydrolysis Of

The aim of this research is to determine the effect of enzyme and acids concentration on the yield of glucose produced in the hydrolysis of Glacilaria sp. in the production of bioethanol. The concentrations of cellulase used were 200 units/mL, 400 units/mL, 600 units/mL, 800 units/mL and the concentration of sulphuric acid (H2SO4) and hydrochloric acid (HCl) used were 1%, 3%, 5%, 7% (w/v). The concentration of reduction sugar was determined using Anthrone and analyzed using UV-Vis spectrophotometry and the determination of ethanol concentration was carried out by using gas chromatography. The results showed that the contents of reducing sugar produced by sulphuric acid (H2SO4) hydrolysis were 26,19%; 36,69%; 41,40%; 45,0% (v/v), by hydrochloric acid (HCl) were 12,12%; 14,03%; 15,17%; 16,50% (v/v), and by cellulase enzyme were 46,15%; 46,73%; 47,68%; 48,25% (v/v). Optimum concentration of reducing sugar produced by hydrolysis using 800 units/mL cellulase was 48,25% (v/v). The optimum length of fermentation to produce bioethanol using Glacilaria sp. as raw material was 5 days. In the fermentation, inoculum with a concentrations of 5% and 10% (w/v) produced 0,85% and 1,51% (v/v) ethanol.

THE DETERMINATION OF ZIRCONIUM WITH BENZOYLPHENYLHYDROXYLAMINE

1960 ◽  
Vol 38 (12) ◽  
pp. 2488-2492 ◽  
Author(s):  
D. E. Ryan
Keyword(s):  
Hydrochloric Acid ◽  
Quantitative Determination ◽  
Sulphuric Acid ◽  
Rare Earths ◽  
Acid Solutions ◽  
Constant Composition ◽  
Hydrochloric Acid Solutions

Zirconium is completely precipitated by benzoylphenylhydroxylamine from 0.5 N acid solutions. The complex formed in sulphuric acid solutions has a constant composition, Zr(C13H10O2N)4, and is used for the direct weighing of zirconium; the factor is 0.0970. The product precipitated from hydrochloric acid solutions must be ignited to the oxide. The reaction is sensitive, 1 p.p.m. of zirconium being detectable, and quantitative determination of 0.2 mg is possible. Thorium and the rare earths do not interfere.

Vibration-spectral studies of compounds formed by the combination of methylformamide and dimethylformamide with some strong acids

1966 ◽  
Vol 19 (11) ◽  
pp. 2091 ◽  
Author(s):  
E Spinner
Keyword(s):  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Infrared Spectra ◽  
Spectral Studies ◽  
Ionic Form ◽  
Reaction Products ◽  
Unknown Structure ◽  
Acid Reaction ◽  
Strong Acids

A determination of the infrared spectra of the solid hydrochlorides of methylformamide and dimethylformamide and of the Raman spectra of their aqueous solutions showed that certain spectral features change with the medium used. The infrared spectra of the two amides in concentrated and in aqueous sulphuric acid, and in concentrated hydrochloric acid (HCl and DCl), are consistent with the existence of two amide/acid reaction products for each amide: one (certainly ionic) form predominates in sulphuric acid solutions; a second form, of unknown structure, is present in the solid hydrochlorides, and in hydrochloric acid the two forms coexist in equilibrium.

scholarly journals Iron as a disturbing factor in the determination of phosphate by the molybdenum blue method

1954 ◽  
Vol 26 (1) ◽  
pp. 159-168
Author(s):  
Armi Kaila
Keyword(s):  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Ferrous Iron ◽  
Ferric Iron ◽  
Stannous Chloride ◽  
Phosphorus Concentration ◽  
Colour Intensity ◽  
Molybdenum Blue ◽  
Fading Effect

The interference of ferric and ferrous iron in the determination of phosphate by the molybdenum blue method has been studied. It was found that the presence of ferric iron in the solutions could cause either an increase or a decrease in the colour intensity depending on the amount of stannous chloride applied and on the acid and molybdate concentrations in the reagent. Also the phosphorus concentration exerted its effect upon the course of the errors. If the original modification of Truog and Meyer was employed, generally, the most convenient way for the elimination of the interference of ferric iron was to dilute the solution. An increase in the amount of stannous chloride largely helped to prevent the fading effect of ferric iron, provided the phosphorus concentration was not lower than 0.25 ppm. When the effect of ferric iron upon the development of molybdenum blue at various concentrations of sulphuric acid and ammonium molybdate was studied, the observation was made that at each acidity there could be found a concentration of molybdate in which the effect of even fairly high amounts of ferric iron was almost negligible. In lower molybdate concentrations the presence of ferric iron caused an increase in the colour intensity, in higher molybdate concentrations the fading effect of ferric iron was marked. This most suitable level of the molybdate concentration depended to a certain degree on the phosphorus concentration of the solution and on the amount of stannous chloride applied. Fairly good results could be obtained, if the ratio of molybdate (expressed as mg/ml) to acid (expressed as normality) in the solution to be reduced was five times as high as the acidity of the solution to be reduced (expressed as its normality), e.g. 4 in 0.8 N acid, 3.5 in 0.7 N acid, 3 in 0.6 N acid etc. Although it seemed to be fairly possible to avoid the interference of ferric iron by a proper choice of the concentrations of acid and molybdate and of the amount of stannous chloride applied, the fading effect of ferrous iron could not be prevented, if only sulphuric acid was used in the reagents. But the substitution of sulphuric acid by hydrochloric acid totally prevented the fading effect of ferrous iron. On the contrary, a slight increase in the colour intensity was demonstrated. This was true also when only one half of the acid present was hydrochloric acid. It was found that this mixture of sulphuric acid and hydrochloric acid in the molybdate reagent offers an available way for the elimination of the disturbing effect of iron.

VIII. On the gas voltaic battery. —Experiments made with a view of ascertaining the rationale of its action and its application to eudiometry

1843 ◽  
Vol 133 ◽  
pp. 91-112 ◽  
Keyword(s):  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Lower Extremities ◽  
Hydrogen Gas ◽  
The Other ◽  
Dilute Acid ◽  
Platinum Foil ◽  
Philosophical Magazine ◽  
Gold Leaf ◽  
Chemical Theory

In the Philosophical Magazine for December 1842, I have published an account of a voltaic battery in which the active ingredients were gases, and by which the decom­position of water was effected by means of its composition. The battery described in that paper consisted of a series of tubes containing strips of platinum foil covered with a pulverulent deposit of the same metal; the platinum passed through the upper parts of the tubes, which were closed with cement, the lower extremities were open; they were arranged in pairs in separate vessels of dilute sulphuric acid, and of each pair one tube was charged with oxygen, the other with hydrogen gas, in quantities such as would allow the platinum to touch the dilute acid; the platinum in the oxygen of one pair was metallically connected with the platinum in the hydrogen of the next, and a voltaic series of fifty pairs was thus formed. With this battery the following effects were produced:— 1st. A shock was given which could be felt by five persons joining hands. 2nd. The needle of a moderately sensitive galvanometer was whirled round and remained permanently deflected 60°. 3rd. A gold-leaf electroscope was notably affected. 4th. A brilliant spark visible in broad day-light was given between charcoal points. 5th. Iodide of potassium, hydrochloric acid, and water acidulated with sulphuric acid were severally decomposed; the gas from the decomposed water was collected and detonated. The gases were evolved in the direction which the chemical theory would indicate, the hydrogen travelling in one direction throughout the circuit, and the oxygen in the reverse.

A STUDY OF METHODS FOR THE EXTRACTION OF NITROGENOUS MATERIAL FROM PLANTS WITH PARTICULAR REFERENCE TO SUBSEQUENT DETERMINATION OF THE LIGNIN CONTENT

1948 ◽  
Vol 26b (6) ◽  
pp. 457-463 ◽  
Author(s):  
W. A. DeLong ◽  
D. MacDougall
Keyword(s):  
Hydrochloric Acid ◽  
Extraction Method ◽  
Lignin Content ◽  
Mineral Acid ◽  
Plant Tissues ◽  
Acid Extraction ◽  
Continuous Extraction ◽  
Saturated Water ◽  
Subsequent Determination

A study has been made of methods for the removal of nitrogenous constituents from plant tissues prior to determination of their lignin contents. It was found that substitution of a continuous extraction method for the usual treatment with hot 1% hydrochloric acid had little effect on the amount of lignin isolated but apparently lowered its methoxyl content. Continuous extraction thus appears to cause some demethoxylation of lignin. Treatment with cold 5% acetic acid apparently can be substituted for the hot 1% hydrochloric acid extraction with very young but not with older, undried tissue. Ether saturated water was found to be the most satisfactory nonacid extractant for removal of nitrogen-containing material from young undried tissues. Upwards of 90% of the original nitrogen can be removed from such material by three extractions with this solvent. With older tissues or with material that has been dried, this proportion of the nitrogen cannot be removed except by extraction with hot dilute mineral acid.

Simplified determination of total lignin content in kraft lignin samples and black liquors

Holzforschung ◽  
2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Fredrik Aldaeus ◽  
Hannah Schweinebarth ◽  
Per Törngren ◽  
Anna Jacobs
Keyword(s):  
Acid Hydrolysis ◽  
Standard Method ◽  
Lignin Content ◽  
Kraft Lignin ◽  
Black Liquors ◽  
Total Lignin ◽  
Total Lignin Content

Abstract Determination of total lignin content in lignin samples and black liquors using methods with reduced or omitted acid hydrolysis has been compared to the standard method, and results show that the simplified methods yield equivalent results.

scholarly journals The determination of lignin

1967 ◽  
Vol 21 (2) ◽  
pp. 325-332 ◽  
Author(s):  
J. W. Czerkawski
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sulphuric Acid ◽  
Proteolytic Enzymes ◽  
Maximum Amount ◽  
Common Origin ◽  
Amino Acid Compositions ◽  
Routine Work

1. The methods for estimating lignin based on 72% sulphuric acid are lengthy and usually require large corrections for the residual nitrogenous impurities. The steps used in the initial purification of lignin, and particularly those concerned with the removal of nitrogenous impurities using proteolytic enzymes, have been investigated.2. The conditions that remove the maximum amount of nitrogen were investigated. The nitrogenous material remaining in the lignin isolated by the adopted procedure was partly characterized, and it was shown that about half of the resistant N could be obtained in the form of amino acids which were presumably present in the lignin in the form of protein. The amino acid compositions of the resistant nitrogenous material in lignin derived from grass, and in lignin derived from faeces of sheep, when the same grass was given, were compared. They were found to be sufficiently similar to suggest a common origin.3. A modified procedure is proposed and described in detail; it is suitable for routine work.4. Comparisons were made between the results obtained by determining lignin in forage and faeces samples by the method now presented and those obtained by the method used previously.

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