High-performance Anion Chromatography Research Articles

A systematic high-throughput phenotyping assay for sugarcane stalk quality characterization by near-infrared spectroscopy

BackgroundSugarcane (Saccharum officinarum L.) is an economically important crop with stalks as the harvest organs. Improvement in stalk quality is deemed a promising strategy for enhancing sugarcane production. However, the lack of efficient approaches for systematic evaluation of sugarcane germplasm largely limits improvements in stalk quality. This study is designed to develop a systematic near-infrared spectroscopy (NIRS) assay for high-throughput phenotyping of sugarcane stalk quality, thereby providing a feasible solution for precise evaluation of sugarcane germplasm.ResultsA total of 628 sugarcane accessions harvested at different growth stages before and after maturity were employed to take a high-throughput assay to determine sugarcane stalk quality. Based on high-performance anion chromatography (HPAEC-PAD), large variations in sugarcane stalk quality were detected in terms of biomass composition and the corresponding fundamental ratios. Online and offline NIRS modeling strategies were applied for multiple purpose calibration with partial least square (PLS) regression analysis. Consequently, 25 equations were generated with excellent determination coefficients (R2) and ratio performance deviation (RPD) values. Notably, for some observations, RPD values as high as 6.3 were observed, which indicated their exceptional performance and predictive capability.ConclusionsThis study provides a feasible method for consistent and high-throughput assessment of stalk quality in terms of moisture, soluble sugar, insoluble residue and the corresponding fundamental ratios. The proposed method permits large-scale screening of optimal sugarcane germplasm for sugarcane stalk quality breeding and beyond.

Changes in Mannitol Content, Regulation of Genes Involved in Mannitol Metabolism, and the Protective Effect of Mannitol on Volvariella volvacea at Low Temperature.

The mechanism of autolysis of Volvariella volvacea (V. volvacea) at low temperature has not been fully explained. As mannitol is among the most important osmotic adjustment substances in fungal resistance, this study sampled mycelia of strains V23 and VH3 treated at 0°C for 0, 2, 4, 8, and 10 h to analyze changes in intracellular mannitol content by high-performance anion chromatography with pulsed amperometric detection (HAPEC-PAD). Reverse transcription quantitative PCR (RT-qPCR) analysis was applied to assess differences in the transcript levels of genes associated with mannitol metabolism under low-temperature stress. A mannitol solution was added to cultures of V. volvacea fruiting bodies, and effects on the hypothermic resistance of these organs were explored by evaluating variations in sensory properties during cryogenic storage after harvest. The results suggested that in the initial stage of low-temperature treatment, intracellular mannitol was largely catabolized as an energy storage material and the expression of genes encoding enzymes involved in synthetic reactions was inhibited. However, low-temperature resistance was induced with further treatment, with activation of mannitol synthesis and inhibition of degradation; the cells accumulated mannitol, leading to osmoregulation. No significant elongation of V. volvacea fruiting bodies during storage at 4°C was observed, and these organs tended to shrink and collapse. The sensory quality of mannitol-treated fruiting bodies was much better than that of control fruiting bodies. Application of a mannitol solution at the cultivation stage of V. volvacea somewhat improved the low-temperature resistance of the fruiting bodies, verifying the correlation between mannitol and resistance to this stress in V. volvacea. The results of this study lay a foundation for a deeper understanding of the autolysis mechanism of V. volvacea, providing technical support for increasing the cryopreservation time of this species and extending the postharvest shelf life of its fruiting bodies. In addition, the mechanism underlying the low-temperature tolerance of the VH3 strain should be further explained at the molecular level.

High Performance Anion Chromatography of Gadolinium Chelates.

High performance anion chromatography (HPIC) method to separate ionic Gd chelates, [Formula: see text], [Formula: see text], [Formula: see text] and free matrix anions was developed. At alkaline pHs, polydentate complexing agents such as ethylene-diamine-tetraacetate, diethylene-triamine pentaacetate and trans-1,2-diamine-cyclohexane-tetraacetate tend to form stable Gd chelate anions and can be separated by anion exchange. Separations were studied in the simple isocratic chromatographic run over the wide range of pH and concentration of carbonate eluent using suppressed conductivity detection. The ion exchange and complex forming equilibria were quantitatively described and demonstrated in order to understand major factors in the control of selectivity of Gd chelates. Parameters of optimized resolution between concurrent ions were presented on a 3D resolution surface. The applicability of the developed method is represented by the simultaneous analysis of Gd chelates and organic/inorganic anions. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis was used for confirmation of HPIC results for Gd. Collection protocols for the heart-cutting procedure of chromatograms were applied. SPE procedures were also developed not only to extract traces of free gadolinium ions from samples, but also to remove the high level of interfering anions of the complex matrices. The limit of detection, the recoverability and the linearity of the method were also presented.

Co/Al layered double hydroxide coated electrode for in flow amperometric detection of sugars

This work reports the development and application of a device for the amperometric detection of sugars in flow systems, based on the electrochemical deposition of a Co/Al layered double hydroxide (LDH) on a Pt electrode. A good adhesion of the LDH film on the metal surface was proved with a bending test which did not display areas in which peeling had taken place. The response of the sensor is based on the analytes oxidation catalysed by the Co(IV) centres of the LDH layers. The efficiency of the catalytic Co centres was studied in solutions with different pHs from 10 to 12.8. The highest sensitivity and the lowest LOD for the investigated sugars were obtained when the most basic solution was employed. The most important mono- and di-saccharides were analysed by flow injection analysis and a mixture was submitted to high performance anion chromatography with amperometric detection, using the developed device as the working electrode. To assess the applicability of the device glucose, fructose, and sucrose content in real samples of cereals and tea drink was successfully determined.

Dissolving Behavior of Carbohydrate Ingredients During Pre-Extraction Process of Alkaline Hydrogen Peroxide of Bamboos

Abstract In this work, alkaline peroxide mechanical pulp (APMP), with pre-extracted bamboo by alkaline hydrogen peroxide, is prepared and the effects of pre-extraction on APMP in beating, bleaching, and physical properties are discussed. The results show that after pre-extracting, the energy consumption of beating has a significant reduction, the brightness of unbleached and bleached pulp are increased 5.0 % ISO (International Organization for Standardization) and 6.94 % ISO, respectively, the post-color PC number is reduced more than double, and the yield of bleaching pulp is maintained well. However, the tensile index and the folding strength is decreased, the burst index is kept, and the tear index is increased slightly. Furthermore, with the change of maximum temperature and holding time, in extraction liquid the extraction rate of the main sugars (glucose, xylose, arabinose, galactose) are detected with high-performance anion chromatography, and the contents of solids and the pH variation also are investigated. It is found that with the extension and increase of holding time and temperature, the pH decreases constantly, the contents of solids and the dissolution rate of sugar increase continuously to the maximum when the holding time is 1 h, and the temperature is from 80°C to 90°C. The dissolution rate of xylose is less than 1 %, and the highest dissolution rates of arabinose and galactose are 7 % and 12 %, respectively.

Determination of neomycin in water samples by high performance anion chromatography with pulsed amperometric detection

A simple, fast and reliable method, using high performance anion chromatography with pulsed amperometric detection, had been developed for the analysis of neomycin in water samples. The elution and separation were carried out with an isocratic mobile phase, containing 10 mmol/L NaOH. The influence of the concentration and pH of the mobile phase on the separation and detection was investigated. A quadruple-potential waveform used for the detection was optimized. The detection limit of neomycin was down to 0.027 μg/mL. The linearity of neomycin calibration curve ranged from 0.050 to 0.505 μg/mL with correlation coefficient of 0.9997. R.S.D. ( n = 11) was 4.0%.

The Identification and Behaviour of Branched Dextrins in the Production of Scotch Whisky

Application of high performance anion chromatography (HPAEC) to distillers worts was able to resolve a series of individual fractions (A, B, C, D, E and F) which eluted between α(1-4) linear dextrins (DP4-7) and which were ubiquitous in worts. Their positions in the chromatogram and their behaviour suggested that they might be α(1-6) branched dextrins. Two of these fractions (C and D) were purified and shown to be α(1-6) branched dextrins by treatment with an α(1-6) debranching enzyme (pullulanase). Further characterisation by HPAEC and Matrix Assisted Desorption Ionisation/Time of Flight (MALDI-TOF) mass spectrometry revealed that the unknown fractions, C and D, were α(1-6) branched dextrins consisting of 6 and 7 glucose units respectively. Possible structures were suggested for these two fractions and it was shown that they were comprised of maltosyl and maltotriosyl branches attached by α(1-6) links to maltotriose, maltotetraose and maltopentaose. The behaviour of these dextrins was studied in the context of the Scotch whisky process under both laboratory and production conditions and they were found to be important substrates for the debranching enzyme, limit dextrinase, during fermentation. The study of these dextrins provided a useful tool for monitoring the effects of enzymes (α-, β-amylase and limit dextrinase) in the Scotch malt whisky production process.

Fractionation at pilot-plant scale of an haemoglobin hydrolysate by strong anionic exchange chromatography: application to the preparation of an amphiphilic peptide

The development and the scale-up of high performance anion chromatography to obtain 1 milligram to 1 gram yields of a peptide fraction from a complex peptic haemoglobin hydrolysate is described here. The chromatographic conditions were developed using a 1 cm3 Mono Q analytical column and progressively scaled-up to a 6 dm3 Q Sepharose Fast Flow column. For easy recovery of peptide and easy adjustment of conditions for final purification, a volatile buffer, ethanolamine/HCl buffer 20 mmol dm−3, pH 10·5, was employed; desalting was carried out by a pilot-plant scale electrodialysis which permitted the elimination of 99% NaCl without important loss of peptide (less than 15%). A combination of these techniques with reverse phase HPLC proved a useful strategy for fractionation of a complex peptide mixture and enabled pure peptides to be obtained in sufficient quantities for further analyses and biological tests. The example of preparation and purification of an amphiphilic peptide is described. Its ability to solubilize an insoluble photosensitizer, protoporphyrin IX, was determined in order to study its utilization as a carrier for photochemotherapy. © 1998 SCI.

Mineralization of Selenium‐Containing Amino Acids in Two California Soils

AbstractOrganic forms of Se as the selenoamino acids, selenomethionine (SeMet) and selenocystine (SeCys), are detected in plants grown on seleniferous soil, yet little is known about the speciation and distribution of Se upon decomposition of SeMet and SeCys in soil. To determine the mineralization rate of selenoamino acids in soil, three concentrations of SeMet, SeCys, methionine (Met), or cystine (Cys) were added to samples of a Panoche (fine‐loamy, mixed [calcareous], thermic Typic Torriorthent) or a Panhill (fine‐silty, mixed, thermic Typic Haplargid) soil and aerobically incubated at 22°C for up to 168 h. The amino acid concentrations were analyzed by high performance anion chromatography. Methionine additions closely followed first‐order reaction kinetics and SeMet additions followed pseudo‐first‐order kinetics, with order dependent on SeMet concentration. The time required for 50% mineralization of SeMet additions in the Panhill and Panoche soils was 23.5 and 3.2 h (5 mg Se kg‐1), 41.6 and 15.5 h (25 mg Se kg‐1), and 47.1 and 36.0 h (50 mg Se kg‐1), respectively. The majority of the SeMet and Met additions were recovered as volatile species (50–80%). In contrast to SeMet, SeCys was rapidly nonextractable (<6 h) from both soils, with little to no volatile Se detected and was initially recovered as phosphate‐soluble selenite and selenide after 6 h of incubation. These results suggest that Se present in seleniferous plant tissue as SeMet will not accumulate in soil due to extensive volatilization. In contrast, additions of seleniferous plant residues rich in SeCys will result in organic Se mineralization to inorganic Se forms in soil.

Determination of glycuronic acids by high-performance anion chromatography with pulsed amperometric detection

Acid hydrolysis (0.25M H2SO4) coupled with enzyme catalysis (pectolyase and β-D-glucuronidase) were employed to extract galacturonic and glucuronic acids from microbial polysaccharides, plant residues, animal wastes, sewage sludge and soil. The glycuronic acids were separated by high-performance anion chromatography (HPAC) on a strong anion-exchange column using 0.1M sodium hydroxide with 0.25M sodium acetate as the mobile phase and determined by pulsed amperometric detection (PAD). HPAC-PAD was found to be superior to high-performance liquid chromatography with ultra-violet (UV) detection in terms of resolution and sensitivity of glycuronic acids. HPAC-PAD was not subject to interferences present with low UV detection (210 nm) and was highly selective for glycuronic acids. Enzymatic hydrolysis after treatment with mild acid (0.25M H2SO4) released galacturonic acids from organge peel and pectin, while glucuronic acid was released from Acacia powder. Large amounts of glycuronic acids were also extracted from plant materials. Low levels of uronic acids were detected in poultry manure, sewage sludge and organic-amended soils.

Determination of glycuronic acids by high-performance anion chromatography with pulsed amperometric detection

Determination of glycuronic acids by high-performance anion chromatography with pulsed amperometric detection