Determination Of Major Components Research Articles

Determination of major components from Radix Achyranthes bidentate using ultra high performance liquid chromatography with triple quadrupole tandem mass spectrometry and an evaluation of their anti-osteoporosis effect in vitro.

Ecdysterone and saponins are the most characteristic components of Radix Achyranthes bidentate, which acts on the human body to promote collagen synthesis and stimulates cell growth. However, the relationship between these components and the differentiation of MC3T3-E1 osteoblastic cells is unknown. We developed a rapid ultra high performance liquid chromatography with triple quadrupole tandem mass spectrometry method for direct determination of one ecdysterone and four saponins in crude and salt-processed Radix Achyranthes bidentate. The method was interrogated in terms of linearity, intra- and inter-day precision, repeatability, stability and recovery. The method was linear within the concentration ranges of 0.003-336 μg/mL for β-ecdysterone, 0.0035-130 μg/mL for 25S-inokosterone, 0.004-423 μg/mL for ginsenoside Ro, 0.0036-66 μg/mL for chikusetsusaponin IV and 0.0044-111 μg/mL for chikusetsusaponin IVa. The intra- and inter-day precisions were all within 2.7%. The standard addition method determined recovery rates for each component (98.7-102.5%). The method was successfully applied to simultaneously quantify five components in ten batches of crude and salt-processed Radix Achyranthes bidentate. Subsequently, the examination of these extracts on the differentiation of MC3T3-E1 osteoblastic cells were carried out. Finally, the relationships between the contents of five components and their anti-osteoporosis effect were investigated by using canonical correlation analysis.

MLD Method for the Determination of Major Components in MgO-Cr Refractory Products

In this paper a novel approach is presented for determination of the main components in MgO-Cr refractory material. With the approach, the intensity conversion of fused sample at different dilution ratios can be obtained by establishing the correlation between elements’ intensity and dilution ratio. MgO-Cr refractory material is fused hardly and the dilution ratio requires more than 20 in XRF analysis. Nevertheless, high dilution can reduce the detection sensitivity of low content elements. Using the technology of intensity conversion at different dilution ratio in this paper, a calibration curve was obtained with different dilution ratios. In this method, we obtained a calibration curve successfully and got the satisfactory results for MgO-Cr refractory which was fused well. The new method suggests consistent accuracy and precision with standard method, and it can also simplify the preparation process of samples. The approach shows high sensitivity, good accuracy and precision, meanwhile, it reduces the technical difficulty and labor intensity greatly in analysis method.

Direct determination of major components in human diets and baby foods.

A fast method has been developed for the determination of fat, proteins, carbohydrates, and energy value in baby food, infant fast food, and canteen menus, using near-infrared (NIR) and mid-infrared (MIR) spectroscopy measurements and multivariate calibration methods based on partial least square regression. Reference standard methods were employed to build and validate the infrared methods for direct determination of nutrients. Coefficients of determination obtained between predicted values and reference ones for total fat, proteins, carbohydrates, and energy value were 96.7, 98.1, 98.9, and 96.5 for NIR and 91.0, 93.0, 92.0, and 84.1 for MIR, respectively, with relative root mean square error of prediction (RRMSEP) below or equal to 9% for NIR and 16% for MIR. Results obtained indicate that both NIR and MIR techniques have good predictive capabilities, with the NIR method being the most accurate and simple.

Determination of carbohydrate- and lignin-derived components in complex effluents from cellulose processing by capillary electrophoresis with electrospray ionization-mass spectrometric detection

Degradation products from lignocellulosic materials receive increasing attention due to the continuously growing interest in their utilization. The inherent structural variance of lignocellulosics combined with the intricacy of lignocellulosic processing (e.g. pulping of wood and bleaching of cellulosic pulps) and the complexity of degradation processes occurring therein result in rather complex mixtures in the process streams and effluents that contain a large quantity of structurally different degradation products. This is true for most processing steps, but also for degradation reactions occurring during aging of lignocellulosic materials, such as paper, cellulosic tissue or textiles. In order to render such mixtures better analytically accessible than hitherto possible a CE-ESI-MS method was established for the simultaneous determination of aliphatic carboxylic acids from the degradation of (hemi)celluloses and aromatic compounds from lignin degradation. CE and ESI-MS parameters have been optimized towards sensitivity and good reproducibility. The method was tested in two real-world scenarios: the determination of major components in effluents from bleaching stages in the pulp and paper industry, and the analysis of degradation products in extracts of naturally aged papers. The advantages and drawbacks of this approach are critically discussed.

Application of near-infrared reflectance spectroscopy in the determination of major components in taramosalata

This work evaluates the feasibility of near-infrared (NIR) for determining moisture, protein and fat content of the famous Greek dish taramosalata. Furthermore, it is investigated the relative performance of the calibration model in the context of varying calibration data size and number of used wavelengths. Various calibration data sizes ( n=40,50,…,80) and number of wavelengths (1, 2,…,6) were considered. Calibration samples were analyzed employing traditional chemical methods and scanned using an Instalab 600-Dickey-John NIR apparatus. Calibrations were achieved with the use of multilinear regression between chemical and spectral data from each calibration data set. The optimal prediction errors (root mean square error of prediction, RMSEP), obtained with models based on six wavelengths and a calibration data size of 80, were 0.115% for moisture, 0.023% for protein and 0.088% for fat. The prediction errors decrease with an increase in calibration size and in number of wavelengths but seem to become stabilized around calibration data size 60 and number of wavelengths 3. Since a calibration set may be expensive to acquire and calibrations using many wavelengths tend to over-fit the data, the accurate calibrations based on three wavelengths and a calibration data size of 60 might be preferred. The RMSEP values obtained with these models were 0.271% for moisture, 0.115% for protein and 0.222% for fat. NIR measurement as performed by the Dickey John Analyzer was proved a rapid and accurate method for analysis of taramosalata and may be used as a replacement for conventional expensive and time-consuming wet chemistry methods.

Simultaneous ICP atomic emission spectrometry for accurate stoichiometric determination: application to a YNi2B2C superconducting material system

For characterisation of the exact stoichiometry of semiconductor or superconductor compounds, the determination of major components with high precision and accuracy is necessary. In order to assess ICP-AES for this task, sophisticated procedures for sample preparation, measurement optimisation and data correction and evaluation, such as multi-line measurements for each analyte element, optimum calibration and recalibration, and internal standardisation, have been developed for simultaneous Echelle spectrometers with CID or CCD detectors. Procedures and results are demonstrated for superconducting materials of the YNi2B2C type. For the analyte elements Y, Ni and B, as well as for the internal standard element In, three optimum spectral lines were used. Calibration and external standardisation were carried out using different mixtures of mono-elemental standard solutions. The confidence intervals for the determination of Y, Ni and B were lowered to 0.17, 0.11 and 0.13% (w/w), respectively. Thus, the stoichiometric coefficients were determined with an error smaller than 0.002, 0.002 and 0.003 for Y, Ni and B, respectively. Using the F-test, the sample homogeneity was tested and, in this way, the presence of trace amounts of secondary phases were detected.

The precise determination of principal components for characterizing stoichiometry in micro-amounts of special materials

Problems of accuracy and precision are discussed in terms of chemical methods, INAA and FAAS for the determination of major components in special materials. The relative standard deviation has been reduced to 0.1% by paying attention to certain analytical rules. Experimental improvements have been introduced into INAA and FAAS, giving an RSD≤1%. Such physical techniques are then suitable for characterizing stoichiometry in small specimens.

Determination of major components and trace elements in ancient silver by thermal neutron activation analysis

Thermal neutron activation of minute samples of ancient silver objects has provided useful information concerning their silver, copper and gold content. The results of such analysis of eighteen Sasanian silver objects are discussed together with consideration of the sampling problems involved. In order to extend these measurements to include other elements, an isotopic exchange system has been developed to separate other activities present in irradiated silver specimens quantitatively from the silver, copper and gold activities. Following exchange with cuprous and silver iodides it has been possible to count quantitatively the activity of fourteen additional elements: As, Br, Co, Cr, Fe, Hg, Ir, K, Mn, Na, Sb, Sc, Se and Zn.

The determination of major components in oxides and oxide mixtures by precision automatic spectrophotometry

A highly accurate spectrophotometric determination of major components in oxides and oxide mixtures with a Unicam SP3000 automatic ultraviolet spectrophotometer is described. Coefficients of variation of 0·2 per cent. have been achieved and under ideal conditions, for a simple system, coefficients of variation of 0·03 per cent. are possible. Details of procedures evolved for the analysis of pre-fired ferrites are included.