A METHOD FOR THE DETERMINATION OF THE LIGNIN CONTENT OF FRESH PLANT TISSUE WITHOUT PRELIMINARY DRYING

1948 ◽  
Vol 26b (6) ◽  
pp. 468-471 ◽  
Author(s):  
W. A. DeLong ◽  
D. MacDougall
Keyword(s):  
Plant Tissue ◽  
Lignin Content ◽  
Standard Procedure ◽  
Growth Stages ◽  
Fresh Tissue ◽  
Modified Method ◽  
Saturated Water ◽  
Fresh Plant ◽  
Oat Straw

A method of determining the lignin content of fresh plant tissue without preliminary drying has been devised. Prior to the final lignin determination with 72% sulphuric acid, the tissue is cut up, extracted with ether saturated water in a Waring Blendor, refluxed with 1% hydrochloric acid, and finally extracted with ethanol–benzene. For comparison, determinations were carried out by the above method and the standard A.O.A.C. procedure on material that had been air-dried at room temperature. Both greenhouse and field grown oat plants cut at various growth stages were used in this study. The modified method gave lower lignin values than the standard procedure with young succulent tissue. This difference decreased as the age of the tissue increased, and the results by all methods were very similar with oat straw. That the modified procedure on fresh tissue removes more interfering nitrogenous material than the other methods used is indicated by the lower nitrogen content of the lignin isolated. The absolute methoxyl contents of the residues isolated from dried tissue were greater than of those isolated from fresh material (from the same source). This may have been due to the inclusion of more methoxyl-containing carbohydrates in the former residues.

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.

Determination of Hyoscyamine and Scopolamine in Datura innoxia Plants by High Performance Liquid Chromatography

1986 ◽  
Vol 41 (4) ◽  
pp. 391-395 ◽  
Author(s):  
Karin-Heide Plank ◽  
Karl G. Wagner
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Plant Tissue ◽  
High Performance ◽  
Datura Innoxia ◽  
Aerial Parts ◽  
Fresh Plant ◽  
Hyoscyamine And Scopolamine

For the determination of the hyoscyamine-scopolamine content in small quantities of fresh plant tissue an HP LC assay was developed; with a sensitivity of about 20 ng alkaloid per run. Analysis of the different organs of Datura innoxia plants are in accord with the concept that hyoscyamine is synthesized in the roots, whereas transformation to scopolamine starts in these organs and proceeds in the aerial parts of the plant.

Adaptation of the AOAC Fluorine Method for Determining Fluoride in Fish Protein Concentrate

1970 ◽  
Vol 53 (1) ◽  
pp. 3-6
Author(s):  
R. Bruce Klemm ◽  
Mary E. Ambrose Klemm
Keyword(s):  
Steam Distillation ◽  
Silica Sand ◽  
Official Method ◽  
Protein Concentrate ◽  
Fish Protein ◽  
Direct Titration ◽  
Modified Method ◽  
Aoac Official ◽  
Aoac Official Method

Abstract The AOAC official method, 24.029–24.035, for the determination of fluorine in foods was modified slightly to o btain quantitative recoveries of fluorine from samples of fish protein concentrate (FPC). The most important alterations include the use of steam distillation, the addition of finely ground silica sand in the distillation, a decrease in the distillation temperature, and the utilization of direct titration. Recoveries of fluoride added to FPC before ashing, using this modified method, averaged 96.0 ± 3.0%. Our results are in agreement with those of several other analysts who used a variety of methods.

Improved Method for the Determination of Ethylenebisdithiocarbamate Residues in Plants, Fruits, and Vegetables

1967 ◽  
Vol 50 (5) ◽  
pp. 1102-1108
Author(s):  
Charles F Gordon ◽  
Richard J Schuckert ◽  
William E Bornak
Keyword(s):  
Sulfuric Acid ◽  
Fruits And Vegetables ◽  
Analytical Procedure ◽  
Improved Method ◽  
Modified Method ◽  
Fungicide Residues ◽  
Crop Types ◽  
Large Representative

Abstract A modified method for the determination of dithiocarbamate fungicide residues on crops is presented. A large representative subsample of the frozen crop is blended in ice-cold deaerated water and an aliquot of the homogenate is added to the analytical apparatus containing hot 5 0% sulfuric acid. Dithiocarbamates are decomposed to evolve CS2 which is removed by a continuous gentle air-sweep from the digestion flask. Variations in technique allow the analysis of dithiocarbamate fungicide residues in several ranges, 1-10, 10-200, and 200-1000 /ig maneb. Recoveries from a wide variety of crops averaged 70 to 103%. Certain crop types present low recoveries and/or high apparent control values, but modifications in the analytical procedure are successful in solving these problems.

A Reliability-Based Approach to Assess Fatigue Behaviour Based on Small Incomplete Data Sets

2008 ◽  
Vol 44-46 ◽  
pp. 871-878 ◽  
Author(s):  
Chu Yang Luo ◽  
Jun Jiang Xiong ◽  
R.A. Shenoi
Keyword(s):  
Incomplete Data ◽  
Standard Procedure ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Small Sample ◽  
Data Sets ◽  
Safe Life ◽  
A New Technique ◽  
And Performance

This paper outlines a new technique to address the paucity of data in determining fatigue life and performance based on reliability concepts. Two new randomized models are presented for estimating the safe life and pS-N curve, by using the standard procedure for statistical analysis and dealing with small sample numbers of incomplete data. The confidence level formulations for the safe and p-S-N curve are also given. The concepts are then applied for the determination of the safe life and p-S-N curve. Two sets of fatigue tests for the safe life and p-S-N curve are conducted to validate the presented method, demonstrating the practical use of the proposed technique.

Rapid, Microscale, Acetyl Bromide-Based Method for High-Throughput Determination of Lignin Content in Arabidopsis thaliana

2008 ◽  
Vol 56 (16) ◽  
pp. 6825-6834 ◽  
Author(s):  
Xue Feng Chang ◽  
Richard Chandra ◽  
Thomas Berleth ◽  
Rodger P. Beatson
Keyword(s):  
Arabidopsis Thaliana ◽  
High Throughput ◽  
Lignin Content ◽  
Acetyl Bromide

scholarly journals Constitutive Model of Rock Uniaxial Damage Based on Rock Strength Statistics

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ming Ji ◽  
Kai Chen ◽  
Hong Jun Guo
Keyword(s):  
Constitutive Model ◽  
Rock Strength ◽  
Strength Criterion ◽  
Uniaxial Stress ◽  
Evolution Process ◽  
Growth Stages ◽  
Numerical Fitting ◽  
Damage Constitutive Model ◽  
Log Normal

Based on the assumption that rock strength follows the log normal distribution statistically, this paper establishes a damage constitutive model of rock under uniaxial stress conditions in combination with the Mohr–Coulomb strength criterion and damage mechanical theory. Experiments were carried out to investigate the damage evolution process of rock material, which can be categorized into nondamaging, accelerated growth, constant-speed, similar growth, and speed-reducing growth stages. The evolution process had a good corresponding relationship with the rock stress-strain curves. Based on the statistical damage constitutive model proposed in this paper, a numerical fitting analysis was conducted on the uniaxial compression testing data of laboratory sand rock and on experimental data from other literature, in order to validate the rationality of the constitutive equation and the determination of its parameters and to analyze the effect of internal friction variables on damage variables and compression strength. The research outcomes presented in this paper can provide useful reference for the theory of rock mechanics and for rock engineering.

Sign in / Sign up

Export Citation Format

Share Document