Determination of calcium,magnesium, zinc and manganese in plant tissue using a dilute HCl extraction method1

Abstract

A non digestion method described earlier for K determination was tested for its ability to extract several other elements in plant tissues of sorghum, pearl millet, chickpea, and pigeonpea. The method involves shaking 0.5 g finely ground (<0.4 mm) plant sample with 40 ml of 0.5 N HCl for 5 minutes at room temperature (25°C) followed by measurement of element concentrations in the filtrate. The values of Ca, Mg, Zn, and Mn obtained by this method were in good agreement with those obtained using the triacid digestion technique. However, this was not the case for P, Fe and Cu. The precision obtained in determining Ca, Mg, Zn and Mn by the HCl extraction method was generally comparable to that obtained by the triacid digestion method. These results suggest that the HCl extraction method can be used for routine and rapid analysis of plant tissues for Ca, Mg, Zn and Mn contents as well as for K content.     

Determination of total sulfur in plant materials using an automated sulfur analyzer

Abstract

An automated sulfur analyzer (ASA), which has been developed for sulfur analysis of coal and coke was evaluated for determination of total sulfur in plant materials. Plant materials containing from 0.15% to 0.75% sulfur have been analyzed with precision and accuracy superior to other accepted methods which are more tedious and time‐consuming. The direct reading unit is capable of making approximately one sulfur determination every three minutes.     

Quantitative determination of nitrogen content in plant tissue by a colorimetric method

Abstract

This study was to evaluate the applicability of a colorimetric method in measuring the nitrogen (N) concentration in samples of vegetable origin. In order to do this, the same samples were analyzed with a colorimetric, and macro‐ and microKjeldahl methods. The colorimetric method has been used successfully in the determination of N in nutritional studies with rats and humans. The present procedure has the advantage of eliminating the distillation and titration steps of the Kjeldahl method and it is practical for nutritional studies, since many samples can be run in a single day. The N concentration was measured in leaves of two tropical grasses: Paspalum fasciculatum Willd. ex Flugge and Hyparrhenia rufa (Nees) Stapf, and a Standard Reference Material (SRM 1547 Peach Leaves). In all cases, there were no significant difference (P>0.05) in N concentration in these plant materials using the colorimetric, and micro‐ and macroKjeldahl methods. There was a good agreement between the N concentration of Peach leaves determined by the colorimetric method (2.94%) and the certified N concentration (2.94%). Hyparrhenia rufa, the African grass, and P. fasciculatum, the native species, showed very low N concentration in their leaves, respectively. These results indicate that the colorimetric method, with some light adjustments, is capable of determining the N concentration in plant samples of diverse origin and in very low N levels. The low N concentrations of the grass species suggest the strong limitation imposed by the low soil fertility for the growth and establishment of forage species in tropical savannas.     

The determination of phosphorus in Kjeldahl digests of plant material by automatic analysis

Abstract

A method is proposed for the determination of phosphorus in plant material using a modified Kjeldahl digestion and a Technicon Autoanalyzer. The procedure depends upon the formation of phosphomolybdate and its reduction to molybdenum blue by ferrous ammonium sulphate. The method enables the simultaneous determination of phosphorus and nitrogen on the same plant digest.     

A rapid method for nitrogen determination in plant tissue

Abstract

A method is described for determining the total N content of plant tissue by a modified Kjeldahl digestion employing a Technicon Auto‐Analyzer. It is faster than the manual AOAC Kjeldahl method. Reproducibility is not as good as that for the AOAC method, but coefficients of variability are comparable with those for the analyses of mineral elements in plant tissue by emission spectroscopy.     

A manual colorimetric procedure for measuring ammonium nitrogen in soil and plant Kjeldahl digests

Abstract

The measurement of NH4⁺‐N in soil, and plant digests is one of the greatest needs in laboratories conducting agricultural and environmental research. Many laboratories do not have access to automated equipment for colorimetric analysis of soil and plant digests. The objective of this research was to modify an automated colorimetric analysis procedure for determining NH₄+‐N in soil and plant digests for manual use, and compare the proposed technique with the standard distillation‐titration technique. The modified procedure is based on the color reaction between NH₄ ⁺‐ and a weakly alkaline mixture of Na salicylate and a chlorine source in the presence of Na nitroprusside. Wavelength scans indicated a very well defined peak for determinations at 650 nm. Time scans showed that color development in the manual procedure was rapid, 12 to 40 minutes depending on temperature, and that the color development remained stable for at least 120 minutes. Regression analysis of the results from 18 soil and 20 plant tissue sample determinations by distillation‐titration and the proposed method indicated NH₄ ⁺ ‐N recoveries of 99% or higher. The results obtained using the colorimetric procedure were very similar to the values obtained by distil ling and titrating the digests for both soil and plant samples as indicated by the large coefficients of determination (R² = 0.99).     

Interferences in colorimetric determination of silica in hydrofluoric acid digests

Abstract

Soil and sediment samples were digested in HF and Si was determined by the ammonium molybdate‐oxalic acid procedure. Results were compared with three Standard Reference Materials from the United States Bureau of Standards. It was found that more than 0.05 % HF in the digests significantly suppresses Si color development. The ratio Si/Fe was more important than absolute Fe concentrations, and Si/Fe below 1 intensified Si color development. It is recommended that HF and Si/Fe should be maintained at below 0.05 % and 1, respectively.     

A simple apparatus used for effective fume control during plant tissue digestion using a heating block

Abstract

Rapid digestion of plant tissue using sulfuric acid results in emission of large quantities of SO₃ fumes. These fumes are a serious hazard to personnel and cause corrosion of equipment and exhaust ducts. A simple apparatus was designed for effective fume control during plant tissue digestion with sulfuric acid using a heating block. The apparatus consists of a battery of reflux columns that can be installed as a unit on top of the digestion tubes after they have been placed in the heating block. The apparatus is very economical to construct.     

植物组织培养的环境调节研究进展

传统植物组织培养方式下封闭式小容器内光照弱,CO     

The determination of sugars in tomato fruit: A comparison of volumetric,automated colorimetric and gas chromatographic methods

Abstract

Fifty samples of tomato fruit have been analysed for sugars using a reliable but laborious volumetric method and the results compared with those obtained both by a rapid automated colorimetric procedure employing the Technicon AutoAnalyzer and by a gas Chromatographic (GLC) technique. Using cleared fruit extracts, the overall mean results for the volumetric and automated methods were not significantly different. Automated analysis of uncleared extracts gave only slightly lower results and in view of its speed this method is recommended for the rapid routine analysis of tomato fruit. The GLC procedure gave results some 4% lower than those for cleared extracts by the other methods, but this technique has the advantage that the concentrations of the individual sugars (glucose and fructose) are readily obtained if required.     

全波长扫描式多功能读数仪-靛酚蓝比色法测定水样铵态氮含量

全波长扫描式多功能读数仪(酶标仪)是一种多通道光学系统的分光光度计,将靛酚蓝比色法与酶标仪相结合,建立了酶标仪-靛酚蓝测定水中铵态氮的方法,方法检出限为0.046 mg/L。方法的加标回收率在90.7%~101.8%之间,该方法与连续流动分析仪-水杨酸分光光度法相比,两者测定数据之间回归直线方程为Y(连续流动分析仪-NH_4~+-N)=1.052 4X(酶标仪-NH_4~+-N)-0.009,相关系数R=0.976 1**(n=32,P0.01)。5个水样重复6次测定,测定结果的相对标准偏差均小于3%。全波长扫描式多功能读数仪(酶标仪)结合靛酚蓝比色法测定重现性好,结果准确,快速方便,可用于水样中铵态氮含量测定。     

Rapid perchloric acid digest methods for analysis of major elements in plant tissue

Abstract

The nutrient element composition of tissue from a plant species is not fixed. Composition in the plant varies among different plant parts at the same or different physiological stages of maturity, as soil type changes, from day to day, even hour to hour on the same day due to past and current environmental conditions. These observations seem to undermine the general trend in plant tissue analysis to develop quantitative procedures that are time consuming and, therefore, foster insufficient nutrient status monitoring within and/or between different physiological stages of maturity of like or different plant parts. Therefore, until tissue sampling becomes more definitive, a digest procedure with 90–100% recovery should be more than adequate for major elemental analysis. The HClO₄ digestion procedures described here meet that requirement and take only 15 to 30 min to complete. N recovery was greater than 100% with the H₂O₂‐HClO₄ digestion procedure. However, when HNO₃ was combined with H₂O₂ and HClO₄, N was lost, although even then N volatilization occured only when digestion was extended past clearing.     

Determination of gentian violet, its demethylated metabolites, and leucogentian violet in chicken tissue by liquid chromatography with electrochemical detection

A method is presented for determination of residues of gentian violet (GV), its demethylated metabolites (pentamethyl and tetramethyl), and leucogentian violet (LGV) in chicken tissue. The analytes are extracted from tissue with acetonitrile/buffer and partitioned into methylene chloride. Polar lipids are removed on an alumina column followed by partitioning into methylene chloride from a citrate buffer. The compounds of interest are isolated on a disposable carboxylic acid cation exchange column and then eluted with 0.02% HCl in methanol. GV, its metabolites, and LGV are determined by liquid chromatography using isocratic elution with a buffered mobile phase from a cyano column and amperometric electrochemical detection at +1.000 V. Average recoveries of GV and LGV from commercially purchased chicken liver fortified with 20 ppb of each compound were 92% [standard deviation (SD) = 7, coefficient of variation (CV) = 7.6%] and 86% (SD = 7, CV = 8.1%), respectively. Average recoveries of GV, LGV, the pentamethyl metabolite, and 1 of the tetramethyl metabolites from control chicken liver (provided by the Center for Veterinary Medicine) fortified with 20 ppb of each compound were 80% (SD = 7, CV = 8.8%), 76% (SD = 3, CV = 3.9%), 83% (SD = 6, CV = 7.2%), and 76% (SD = 8, CV = 10.5%), respectively. Mean results from 10 analyses of residue-incurred chicken liver were 31 ppb GV (SD = 3, CV = 9.7%), 34 ppb pentamethyl metabolite (SD = 3, CV = 8.8%), and 40 ppb tetramethyl metabolite(s) (SD = 2, CV = 5.0%), for an average value of 105 ppb total residues (SD = 6, CV = 5.7%); no LGV was found. Data are also presented to show applicability of the method to muscle tissue.     

Determination of optimum nutrient element ratios in plant tissue

A new approach for determining optimum nutrient element ratios in plant tissue is presented. Essential steps in the procedure involve: a) measuring patterns of response to pairs of nutrient elements in factorial fertilizer trials, b) modeling the yield response surface using a bivariate, Mitscherlich‐related response function, c) defining balanced nutrition in terms of the parameters of the response surface, d) identifying combinations of P and S fertilizer resulting in balanced nutrition, and e) determining from plant chemical analysis the ratio of nutrients in plant tissue in nutritionally balanced combinations. The approach is illustrated by data from a phosphorus (P) by sulfur (S) factorial field fertilizer trial on a mown mixed white clover (Trifolium repens cv Grasslands Huia) and ryegrass (Lolium perenne L cv Grasslands Nui) sward. Different parameters of yield [total dry matter production, clover dry matter production, clover nitrogen (N) uptake] required different ratios of S:P in fertilizer and consequently in plant tissue for nutritional balance. Also, plant tissue S:P ratios for balanced nutrition declined as the level of nutrition increased. Economic optimum S:P fertilizer ratios were higher than those ratios required for nutrient element balance due to the lower cost and higher effectiveness per kilogram of fertilizer S compared with fertilizer P. Ratios of S and P to N in clover tissue were useful indicators of the adequacy of S and P for clover which was dependent on N₂ fixation for its N supply. It is suggested that a nutrient element index system showing both relative and absolute nutrient element status might be built around N as an internal standard for legumes dependent on N₂ fixation and possibly also for non‐legumes.     

Comparison of a tissue solubilization and a wet combustion method for determining14C in plant tissue

Abstract

Nine different types of plant material labeled with¹⁴CO₂were used to compare two methods for analyzing¹⁴C in biological material. The methods were total carbon by wet oxidation (TC) and tissue solubilization using hyamine hydroxide (HH). In addition 3 sizes of material were used and 3 variations of the HH method were evaluated. Overall there were no significant differences between the HH and TC methods for¹⁴C activity, provided the samples are finely ground. Significant differences occurred in total counts and counting efficiency when the plant particle size decreased from .84 mm to .25 ram. Differences also were found between quench reducing treatments in the HH method. Differences between methods in terms of total counts, may be plant material specific     

Determination of the bioavailable fraction of triclosan in biosolid-treated soils using a predictive method and wheat plant bioassays

Purpose

Triclosan (TCS, 5-chloro-2-(2,4-dichlorophenoxy) phenol) an antimicrobial compound used in a range of household products, is an emerging hydrophobic organic contaminant, that may be incorporated into soil through the application of biosolids. The present study assessed the bioavailable fraction of TCS in a soil-biosolid system using wheat (Triticum aestivum) plant assays and a predictive extraction method using a solution of hydroxypropyl-β-cyclodextrin (HPCD) to determine if it was a reliable surrogate for this bioassay.

Materials and methods

Three soils were obtained from the central region of Chile (Cuesta Vieja, Polpaico, and Taqueral). Biosolid was obtained from a regional wastewater treatment plant. The soils were amended with biosolids at different rates (30, 60, 90, and 200 Mg ha^-1). The TCS concentration was determined in biosolids, soil, and plant samples via gas chromatography coupled with mass spectrometry (GC-MS).

Results and discussion

The total TCS concentration in the biosolids was 5.45 mg kg^-1. The results of the TCS extraction from the wheat plants (roots and shoots) indicated that TCS was primarily found in the roots. TCS uptake by the plant varied based on soil properties. The predictive capability of the HPCD extraction was assessed using a simple linear correlation test for TCS concentration in wheat plants.

Conclusions

The study yielded a linear relationship, which demonstrated the validity of the chemical method as a biosimulation technique.

     

Determination of water-soluble and total extractable polyphenolics in biomass, necromass and decomposing plant material using near-infrared reflectance spectroscopy (NIRS)

Near infrared reflectance spectroscopy (NIRS) was used to predict the water-soluble and total extractable polyphenolics of plant material. Different life forms (forbs, grasses, shrubs, giant rosettes), organs (leaves, stems, roots) and decomposition stages (biomass, necromass and decomposing plant material) were studied. Prediction was good, with a R² in validation ranging from 0.91 to 0.93 and in prediction from 0.88 to 0.94. Various standard error ratios were used to assess the quality of the models, which are generally very good, being the model for predicting the water-soluble polyphenolics in the decomposing plant material the slightly less good. Because it is a cheap and rapid method, it would allow to perform a large screening for studies concerning (i) polyphenolics control on decomposition process and (ii) phenolics implication in herbivory.     

Digestion of plant tissue for analysis by ICP emission spectroscopy

Abstract

A method of digesting plant tissue samples for multi‐element analysis by inductively‐coupled plasma (ICP) emission spectroscopy was developed which does not require the use of HclO₄. A substitute oxidant, H₂O₂, eliminated the hazards associated with hot, concentrated HClO₄. Optimal conditions for pre‐digestion and digestion were investigated.

The procedure adopted consists of a pre‐digestion in concentrated HNO₃ from room temperature to 60°C in 30 min followed by digestion at 90°C for 90 min with the addition of 30% H₂O₂ Analysis of NBS standard tissue samples by the proposed method gave results in good agreement with analysis following digestion in HNO₃,‐HClO₄ and with certified values, except for Fe.     

An automated colorimetric method for the determination of urease activity in soil and plant material

Abstract

An automated colorimetric method Cor determining urease activity in soils and plant material is described. The method, using ammonium determination by the nitroprusside‐catalysed indophenol reaction, is Caster and more precise than a colorimetric measurement of urea.