scholarly journals Selection of Method of Chemical Analysis in Measuring the Salinity of Mineral Materials

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 559
Author(s):  
Teresa Stryszewska ◽  
Marta Dudek

The article deals with the issue of salt content in brick buildings, which plays an important role in the assessment of the technical condition, in particular of historic buildings. A question has been asked about the selection of the best research method to determine the salinity of mineral materials. To obtain the answer, the authors conducted some tests on ceramic bricks salted with seven types of salt solutions. Research methods such as: spectrophotometry (UV), ion chromatography (High Performance Liquid Chromatography (HPLC)), X-Ray Fluorescence Spectrometry (XRF) and Energy-Dispersive X-Ray Spectroscopy (EDS) were compared. The above methods belong to two groups: the first is based on aqueous extracts and allows the determination of water-soluble salts, and the second concerns testing directly on the sample so that insoluble salts can also be determined. The results tests indicate that the methods based on solid phases (XRF and EDS) give higher salinity values than those based on aqueous extracts (HPLC and UV). The results were also analysed with regard to the type of salt. Larger differences are observed for sulphate salts while chloride salts are characterised by smaller differences. On this basis, it is concluded that the salt content of the material is best assessed using tests that make it possible to recognise the salt in question and its quantity.

1986 ◽  
Vol 235 (3) ◽  
pp. 755-761 ◽  
Author(s):  
K Miyazaki ◽  
N Okamura ◽  
Y Kishimoto ◽  
Y C Lee

A specific, sensitive and easily performed method for the determination of gangliosides in tissue was developed. After removal of water-soluble compounds, total lipids were extracted from tissue and then treated with 2,4-dinitrophenylhydrazine hydrochloride and dicyclohexylcarbodi-imide in dimethylformamide at 0 degrees C to form ganglioside hydrazides. After removal of excess reagents by column chromatography on silicic acid, the ganglioside 2,4-dinitrophenylhydrazides were eluted from the column and analysed by h.p.l.c. with the use of a silica-gel normal-phase column eluted with an isocratic chloroform/methanol/water/acetic acid system. The addition of CaCl2 improved the separation of GM3 ganglioside containing N-acetylneuraminic acid from that containing N-glycollylneuraminic acid. 2,4-Dinitrophenylhydrazide peaks were measured by the absorbance at 342 nm. Quantification of GM3, GM2, GM1, GD1a, GD1b, GT1b and LM1 gangliosides was linear in a range 0.02-1.6 nmol. GM4, GD3, GT1a and GQ1b gangliosides also yielded distinct peaks, although the range of linearity was not examined. This method was applied to the analysis of the total lipids of rat brain and hepatocytes.


2016 ◽  
Vol 13 (2) ◽  
pp. 447-457 ◽  
Author(s):  
Baghdad Science Journal

High-performance liquid chromatographic methods are used for the determination of water-soluble vitamins with UV-Vis. Detector. A reversed-phase high-performance liquid chromatographic has been developed for determination of water-soluble vitamins. Identification of compounds was achieved by comparing their retention times and UV spectra with those of standards solution. Separation was performed on a C18 column, using an isocratic 30% (v/v) acetonitril in dionozed water as mobile phase at pH 3.5 and flow rate 1.0m/min. The method provides low detection and quantification limits, good linearity in a large concentration interval and good precision. The detection limits ranged from 0.01 to 0.025µg/ml. The accuracy of the method was tested by measuring average recovery values ranged between 94% - 101 %. For standerd solution, and 93%-99% of honey bee samples.


2019 ◽  
Vol 58 (2) ◽  
pp. 178-186 ◽  
Author(s):  
Yaser Pashaei ◽  
Bahram Daraei ◽  
Maryam Shekarchi

Abstract In the present study, a facile modified impregnation method was employed to synthesize superparamagnetic graphene oxide–Fe3O4 (GO–Fe3O4) nanocomposites. Based on the GO–Fe3O4 as adsorbent, a simple and fast magnetic-dispersive solid phase extraction followed by high performance liquid chromatography with fluorescence detection (M-dSPE–HPLC–FL) method was established and validated for the preconcentration and determination of terazosin hydrochloride (TRZ) in human plasma samples. The obtained nanomaterials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and vibrating sample magnetometry. Different parameters affecting the extraction efficiency, such as sample pH, amount of sorbent, extraction time, elution solvent and its volume and desorption time, were evaluated and optimized. The linearity of the proposed method was excellent over the range 0.3–50.0 ng mL−1 with an acceptable coefficient of determination (R2 = 0.9989). The limit of quantification and limit of detection were found to be 0.3 and 0.09 ng mL−1, respectively, and the preconcentration factor of 10 was achieved. Intra- and inter-day precision expressed as relative standard deviation (RSD %, n = 6) were between 2.2–3.8% and 4.7–6.4%, respectively. Accuracy, estimated by recovery assays, was 97.7–106.6% with RSD ≤ 5.2%. Ultimately, the applicability of the method was successfully confirmed by the extraction and determination of TRZ in human plasma samples.


2020 ◽  
Vol 103 (5) ◽  
pp. 1406-1411
Author(s):  
Chu Chu ◽  
Jing Li ◽  
Shan Wang ◽  
Lvnan Weng ◽  
Luyi Jiang ◽  
...  

Abstract Background Honokiol and magnolol were considered as markers for the analysis of Cortex Magnoliae Officinalis, its related Chinese Patent Medicines and their metabolites. However, the determination of these two analytes in a water-soluble sample is difficult and therefore requires a more efficient method. Objective To develop a sensitive method for the determination of honokiol and magnolol in a water-soluble sample for better quality control of Cortex Magnoliae Officinalis and its related Chinese Patent Medicines. Method In this work, a combination of dispersive micro-solid-phase extraction (DMSPE) and high-performance liquid chromatography (HPLC) has been developed for simultaneous preconcentration and determination of honokiol and magnolol in complex bio-samples. Several experimental factors affecting the extraction efficiency were optimized by single factor test. Results Under the optimized extraction conditions, the proposed method exhibited good linearity of not less than 0.9998, satisfactory precision with relative standard deviation of less than 1.3%, and acceptable mean recoveries of 97.3% and 101.5% for honokiol and magnolol, respectively. Furthermore, the method exhibits extremely high sensitivity with detection limits of 0.0097 and 0.0231 ng/mL, which is even more sensitive than those methods developed by MS. Conclusions The method established in this study is fast, economic, accurate, easy to operate, and importantly well suited to the extraction and analysis of honokiol and magnolol in a real complex sample matrix.


1997 ◽  
Vol 778 (1-2) ◽  
pp. 247-253 ◽  
Author(s):  
Soledad Albala´-Hurtado ◽  
M. Teresa Veciana-Nogue´s ◽  
Mari´a Izquierdo-Pulido ◽  
Abel Marine´-Font

2000 ◽  
Vol 636 ◽  
Author(s):  
A. Eichhöfer ◽  
C.V. Hänisch ◽  
M. Jacobsohn ◽  
U. Banin

AbstractHigh performance dynamic light scattering (DLS) has been used to determine the hydrodynamic diameters of CdSe-nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm. The method enables the determination of the particle sizes including the ligand shells directly in solution. Consistent with the blue shift of the absorption onset by reducing the particle sizes the values for the hydrodynamic radii decrease. For the CdSe nanoparticles the measured sizes were compared with the diameters determined by TEM experiments; the sizes of the cluster molecules were on the other hand estimated from the space filling models of the single crystal X-ray structure determination. Regarding both types of compounds, DLS yield comparable values for the radii, indicating that it provides a potentially important tool in addition to other size determining techniques like TEM, which operates at more drastic conditions, and powder X-ray diffraction being difficult to interpret below 5 nm.


1994 ◽  
Vol 48 (2) ◽  
pp. 236-240 ◽  
Author(s):  
Régina Zamojska ◽  
Jeff Sharman ◽  
Yvon Cote ◽  
Carmel Jolicoeur

Energy-dispersive x-ray spectrometric methods have been developed for the determination of chlorine in asbestos (chrysotile) fibers. Chlorine, which is a minor constituent, is determined by a standard addition method from the ground fiber and by a standardless method in six different fibers. The lower limit of detection for a qualitative analysis and the lower limit of determination for a quantitative analysis of chlorine in the asbestos matrix are 40 ppm and 120 ppm, respectively. The water-soluble and acid-soluble chlorine have also been determined by ion-exchange chromatography and by a colorimetric method. The agreement of the three different methods is very good in all cases.


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